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Author |
Shanenko, A.A.; Croitoru, M.D.; Vagov, A.V.; Axt, V.M.; Perali, A.; Peeters, F.M. |
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Title |
Atypical BCS-BEC crossover induced by quantum-size effects |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
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Volume |
86 |
Issue |
3 |
Pages |
033612 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Quantum-size oscillations of the basic physical characteristics of a confined fermionic condensate are a well-known phenomenon. Its conventional understanding is based on the single-particle physics, whereby the oscillations follow variations in the single-particle density of states driven by the size quantization. Here we present a study of a cigar-shaped ultracold superfluid Fermi gas, which demonstrates an important many-body aspect of the quantum-size coherent effects, overlooked previously. The many-body physics is revealed here in the atypical crossover from the Bardeen-Cooper-Schrieffer (BCS) superfluid to the Bose-Einstein condensate (BEC) induced by the size quantization of the particle motion. The single-particle energy spectrum for the transverse dimensions is tightly bound, whereas for the longitudinal direction it resembles a quasi-free dispersion. This results in the formation of a series of single-particle subbands (shells) so that the aggregate fermionic condensate becomes a coherent mixture of subband condensates. Each time when the lower edge of a subband crosses the chemical potential, the BCS-BEC crossover is approached in this subband, and the aggregate condensate contains both BCS and BEC-like components. |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000308639500004 |
Publication Date |
2012-09-15 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1050-2947;1094-1622; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.925 |
Times cited |
34 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). The authors thank C. Salomon and C. Vale for their valuable explications of the experimental situation and interest to our work. We are grateful to G. C. Strinati, D. Neilson, and P. Pieri for useful discussions. M. D. C. acknowledges support of the EU Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR). A. P. gratefully acknowledges financial support of the European Science Foundation, POLATOM Research Networking Programme, Ref. No. 4844 for his visit to the University of Antwerp. A. A. S. acknowledges financial support of the European Science Foundation, POLATOM Research Networking Programme, Ref. No. 5200 for his visit to the University of Camerino. ; |
Approved |
Most recent IF: 2.925; 2012 IF: 3.042 |
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Call Number |
UA @ lucian @ c:irua:101844 |
Serial |
203 |
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Permanent link to this record |
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Author |
Corthals, S.; van Noyen, J.; Geboers, J.; Vosch, T.; Liang, D.; Ke, X.; Hofkens, J.; Van Tendeloo, G.; Jacobs, P.; Sels, B. |
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Title |
The beneficial effect of CO2 in the low temperature synthesis of high quality carbon nanofibers and thin multiwalled carbon nanotubes from CH_{4} over Ni catalysts |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
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Volume |
50 |
Issue |
2 |
Pages |
372-384 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A low temperature chemical vapor deposition method is described for converting CH4 into high-quality carbon nanofibers (CNFs) using a Ni catalyst supported on either spinel or perovskite oxides in the presence of CO2. The addition of CO2 has a significant influence on CNF purity and stability, while the CNF diameter distribution is significantly narrowed. Ultimately, the addition of CO2 changes the CNF structure from fishbone fibers to thin multiwalled carbon nanotubes. A new in situ cooling principle taking into account dry reforming chemistry and thermodynamics is introduced to account for the structural effects of CO2. |
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Place of Publication |
Oxford |
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Wos |
000297397700004 |
Publication Date |
2011-09-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0008-6223; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.337 |
Times cited |
26 |
Open Access |
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Notes |
Iwt; Iap |
Approved |
Most recent IF: 6.337; 2012 IF: 5.868 |
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Call Number |
UA @ lucian @ c:irua:93626 |
Serial |
228 |
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Permanent link to this record |
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Author |
Rønnow, T.F.; Pedersen, T.G.; Partoens, B. |
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Title |
Biexciton binding energy in fractional dimensional semiconductors |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
85 |
Issue |
4 |
Pages |
045412-045412,7 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Biexcitons in fractional dimensional spaces are studied using variational quantum Monte Carlo. We investigate the biexciton binding energy as a function of the electron-hole mass fraction sigma as well as study the dimensional dependence of biexcitons for sigma = 0 and sigma = 1. As our first application of this model we treat the H(2) molecule in two and three dimensions. Next we investigate biexcitons in carbon nanotubes within the fractional dimensional model. To this end we find a relation between the nanotube radius and the effective dimension. The results of both applications are compared with results obtained using different models and we find a reasonable agreement. Within the fractional dimensional model we find that the biexciton binding energy in carbon nanotubes accurately scales as E(B)(r,epsilon) = 1280 meV angstrom/(r epsilon), as a function of radius r and the dielectric screening epsilon. |
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Place of Publication |
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Wos |
000298922200008 |
Publication Date |
2012-01-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
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Call Number |
UA @ lucian @ c:irua:96234 |
Serial |
231 |
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Permanent link to this record |
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Author |
Ramos, I.R.O.; Ferreira, W.P.; Munarin, F.F.; Farias, G.A.; Peeters, F.M. |
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Title |
Bilayer crystals of charged magnetic dipoles : structure and phonon spectrum |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
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Volume |
85 |
Issue |
5:1 |
Pages |
051404-051404,12 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We study the structure and phonon spectrum of a two-dimensional bilayer system of classical charged dipoles oriented perpendicular to the plane of the layers for equal density in each layer. This system can be tuned through six different crystalline phases by changing the interlayer separation or the charge and/or dipole moment of the particle. The presence of the charge on the dipole particles is responsible for the nucleation of five staggered phases and a disordered phase which are not found in the magnetic dipole bilayer system. These extra phases are a consequence of the competition between the repulsive Coulomb and the attractive dipole interlayer interaction. We present the phase diagram and determine the order of the phase transitions. The phonon spectrum of the system was calculated within the harmonic approximation, and a nonmonotonic behavior of the phonon spectrum is found as a function of the effective strength of the interparticle interaction. The stability of the different phases is determined. |
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Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
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Language |
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Wos |
000304403400002 |
Publication Date |
2012-05-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1539-3755;1550-2376; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.366 |
Times cited |
8 |
Open Access |
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Notes |
; This work was supported by the Brazilian agencies CNPq, CAPES, and FUNCAP (PRONEX grant), the Flemish Science Foundation (FWO-Vl), the bilateral program between Flanders and Brazil, and the CNPq-FWO collaborating project. The authors are grateful to Prof. G. Goldoni for some technical clarifications concerning Ref. [18]. ; |
Approved |
Most recent IF: 2.366; 2012 IF: 2.313 |
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Call Number |
UA @ lucian @ c:irua:98940 |
Serial |
233 |
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Permanent link to this record |
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Author |
Vinchurkar, S.; De Backer, L.; Vos, W.; Van Holsbeke, C.; de Backer, J.; de Backer, W. |
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Title |
A case series on lung deposition analysis of inhaled medication using functional imaging based computational fluid dynamics in asthmatic patients : effect of upper airway morphology and comparison with in vivo data |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Inhalation Toxicology |
Abbreviated Journal |
Inhal Toxicol |
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Volume |
24 |
Issue |
2 |
Pages |
81-88 |
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Keywords |
A1 Journal article; Pharmacology. Therapy; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP) |
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Abstract |
Context: Asthma affects 20 million Americans resulting in an economic burden of approximately $18 billion in the US alone (Allergies and Asthma Foundation 2000; National Center for Environmental Health (NCEH) 1999). Research studies based on differences in patient-specific airway morphology for asthma and the associated effect on deposition of inhaled aerosols are currently not available in the literature. Therefore, the role of morphological variations such as upper airway (extrathoracic) occlusion is not well documented. Objective: Functional imaging based computational fluid dynamics (CFD) of the respiratory airways for five asthmatic subjects is performed in this study using computed tomography (CT) based patient-specific airway models and boundary conditions. Methods: CT scans for 5 asthma patients were used to reconstruct 3D lung models using segmentation software. An averaged inhalation profile and patient-specific lobar flow distribution were used to perform the simulation. The simulations were used to obtain deposition for BDP/Formoterol (R) HFA pMDI in the patient-specific airway models. Results: The lung deposition obtained using CFD was in excellent agreement with available in vivo data using the same product. Specifically, CFD resulted in 30% lung deposition, whereas in vivo lung deposition was reported to be approximately 31%. Conclusion: It was concluded that a combination of patient-specific airway models and lobar boundary conditions can be used to obtain accurate lung deposition estimates. Lower lung deposition can be expected for patients with higher extrathoracic resistance. Novel respiratory drug delivery devices need to accommodate population subgroups based on these morphological and anatomical differences in addition to subject age. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000299744800001 |
Publication Date |
2012-01-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0895-8378;1091-7691; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.751 |
Times cited |
36 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 1.751; 2012 IF: 1.894 |
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Call Number |
UA @ lucian @ c:irua:96238 |
Serial |
286 |
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Permanent link to this record |
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Author |
Marikutsa, A.; Krivetskiy, V.; Yashina, L.; Rumyantseva, M.; Konstantinova, E.; Ponzoni, A.; Comini, E.; Abakumov, A.; Gaskov, A. |
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Title |
Catalytic impact of RuOx clusters to high ammonia sensitivity of tin dioxide |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Sensors and actuators : B : chemical
T2 – 25th Eurosensors Conference, SEP 04-07, 2011, Athens, GREECE |
Abbreviated Journal |
Sensor Actuat B-Chem |
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Volume |
175 |
Issue |
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Pages |
186-193 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A comparative study of NH3-sensing performance of blank and modified nanocrystal line SnO2 was performed. Tin dioxide modified by ruthenium displayed the highest ammonia sensitivity with a maximum signal at 200 degrees C. The modifier was shown by XPS and EPR to occur in a mixed valence state of oxidized ruthenium distributed between the surface and bulk of tin dioxide nanocrystals. RuOx clustering on SnO2 surface was detected by means of electron microscopy assisted EDX-mapping. The effect of RuOx on tin dioxide interaction with ammonia was studied by temperature-programmed NH3 desorption, simultaneous Kelvin probe and DC-resistance measurements, EPR spectroscopy and analyses of the gas-solid interaction products. The modifier was shown to promote the materials reactivity to NH3 due to the catalytic activity of RuOx. The interaction with ammonia resulted in dipoles formation on the oxide surface along with reducing the grains net surface charge, established from the electron affinity increase and resistance decrease during NH3 exposure. The RuOx-catalyzed gas-solid interaction was deduced to proceed deeper than in the case of non-modified SnO2 and to yield nitrogen oxides (e.g. NO2), as was suggested by the oxidative character of gaseous products of NH3 interaction with RuOx-modified tin dioxide at 200 degrees C. (C) 2012 Elsevier B.V. All rights reserved. |
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Place of Publication |
Lausanne |
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Wos |
000312358700033 |
Publication Date |
2012-06-19 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0925-4005; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.401 |
Times cited |
20 |
Open Access |
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Notes |
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Approved |
Most recent IF: 5.401; 2012 IF: 3.535 |
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Call Number |
UA @ lucian @ c:irua:105985 |
Serial |
293 |
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Permanent link to this record |
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Author |
Kirilenko, D. |
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Title |
Characterization of graphene by electron diffraction |
Type |
Doctoral thesis |
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Year |
2012 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
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Keywords |
Doctoral thesis; Electron microscopy for materials research (EMAT) |
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Abstract |
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Publisher |
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Place of Publication |
Antwerpen |
Editor |
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Language |
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Wos |
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Publication Date |
0000-00-00 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:98834 |
Serial |
323 |
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Permanent link to this record |
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Author |
Leroux, F. |
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Title |
Characterization of soft-hard matter composite materials by advanced transmission electron microscopy |
Type |
Doctoral thesis |
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Year |
2012 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
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Keywords |
Doctoral thesis; Electron microscopy for materials research (EMAT) |
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Abstract |
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Corporate Author |
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Publisher |
Universiteit Antwerpen, EMAT |
Place of Publication |
Antwerpen |
Editor |
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Language |
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Wos |
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Publication Date |
0000-00-00 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:99023 |
Serial |
333 |
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Permanent link to this record |
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Author |
Sels, D.; Brosens, F.; Magnus, W. |
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Title |
Classical trajectories : a powerful tool for solving tunneling problems |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physica: A : theoretical and statistical physics |
Abbreviated Journal |
Physica A |
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Volume |
391 |
Issue |
1/2 |
Pages |
78-81 |
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Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
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Abstract |
In the realm of Ehrenfests theorem, classical trajectories obeying Newtons laws have been proven useful to construct explicit solutions to the time-dependent WignerLiouville equation. Whereas previous works have particularly focused on the initial distribution function as a vehicle found to carry the signatures of quantum statistics into the time-dependent solution, the present paper shows that the LagrangeCharpit method based on classical trajectories can be successfully invoked as well to tackle quantum mechanical features with no classical counterpart, such as tunneling. |
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Corporate Author |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000297230700010 |
Publication Date |
2011-08-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0378-4371; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.243 |
Times cited |
7 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.243; 2012 IF: 1.676 |
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Call Number |
UA @ lucian @ c:irua:92359 |
Serial |
370 |
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Permanent link to this record |
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Author |
Carrillo Nuñez, H. |
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Title |
Combining the modified local density approach with variational calculus : a flexible tandem for studying electron transport in nano-devices |
Type |
Doctoral thesis |
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Year |
2012 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
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Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
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Abstract |
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Corporate Author |
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Publisher |
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Place of Publication |
Antwerpen |
Editor |
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Wos |
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Publication Date |
0000-00-00 |
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Series Editor |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:109447 |
Serial |
405 |
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Permanent link to this record |
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Author |
Van Duppen, B.; Peeters, F.M. |
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Title |
Comment on “Chiral tunneling in trilayer graphene” [Appl. Phys. Lett. 100, 163102 (2012)] |
Type |
Editorial |
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Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
101 |
Issue |
22 |
Pages |
226101-1 |
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Keywords |
Editorial; Condensed Matter Theory (CMT) |
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Abstract |
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Address |
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Publisher |
Amer inst physics |
Place of Publication |
Melville |
Editor |
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Language |
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Wos |
000311967000107 |
Publication Date |
2012-11-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
7 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
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Call Number |
UA @ lucian @ c:irua:105999 |
Serial |
408 |
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Permanent link to this record |
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Author |
Adamson, P.; Hadermann, J.; Smura, C.F.; Rutt, O.J.; Hyett, G.; Free, D.G.; Clarke, S.J. |
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Title |
Competing magnetic structures and the evolution of copper ion/vacancy ordering with composition in the manganite oxide chalcogenides Sr2MnO2Cu1.5(S1-xSex)2 |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
24 |
Issue |
14 |
Pages |
2802-2816 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The series Sr2MnO2Cu1.5(S1-xSex)(2) (0 <= x <= 1) contains mixed-valent Mn ions (Mn2+/Mn3+) in MnO2 sheets which are separated by copper-deficient antifluorite-type Cu(2-delta)Ch(2) layers with delta similar to 0.5. The compounds crystallize in the structure type first described for Sr2Mn3Sb2O2 and are described in the I4/mmm space group at ambient temperatures. Below about 250 K, ordering between Cu+ ions and tetrahedral vacancies occurs which is long-range and close to complete in the sulfide-containing end member of the series Sr2MnO2Cu1.5S2 but which occurs over shorter length scales as the selenide content increases. The superstructure is an orthorhombic 2 root 2a x root 2a x c expansion in Ibam of the room temperature cell. For x > 0.3 there are no superstructure reflections evident in the X-ray or neutron diffraction patterns, and the I4/mmm description is valid for the average structure at all temperatures. However, in the pure selenide end member, Sr2MnO2Cu1.5Se2, diffuse scattering in electron diffractograms and modulation in high resolution lattice image profiles may arise from short-range Cu/vacancy order. All members of the series exhibit long-range magnetic order. In the sulfide-rich end member and in compounds with x < 0.1 in the formula Sr2MnO2Cu1.5(S1-xSex)(2), which show well developed superstructures due to long-range Cu/vacancy order, the magnetic structure has a (1/4 1/4 0) propagation vector in which ferromagnetic zigzag chains of Mn moments in the MnO2 sheets are coupled antiferromagnetically in an arrangement described as the CE-type magnetic structure and found in many mixed-valent perovskite and Ruddlesden-Popper type oxide manganites. In these cases the magnetic cell is an a x 2b x c expansion of the low temperature Ibam structural cell. For x >= 0.2 in the formula Sr2MnO2Cu1.5(S1-xSex)(2) the magnetic structure has a (0 0 0) propagation vector and is similar to the A-type structure, also commonly adopted by some perovskite-related manganites, in which the Mn moments in the MnO2 sheets are coupled ferromagnetically and long-range antiferromagnetic order results from antiferromagnetic coupling between planes. In the region of the transition between the two different structural and magnetic long-range ordering schemes (0.1 < x < 0.2) the two magnetic structures coexist in the same sample. The evolution of the competition between magnetic ordering schemes and the length scale of the structural order with composition in Sr2MnO2Cu1.5(S1-xSex)(2) suggest that the changes in magnetic and structural order are related consequences of the introduction of chemical disorder. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000306674200024 |
Publication Date |
2012-06-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
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|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
9.466 |
Times cited |
11 |
Open Access |
|
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|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 9.466; 2012 IF: 8.238 |
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Call Number |
UA @ lucian @ c:irua:100839 |
Serial |
435 |
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Permanent link to this record |
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Author |
de Oliveira, E.L.; Albuquerque, E.L.; de Sousa, J.S.; Farias, G.A.; Peeters, F.M. |
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Title |
Configuration-interaction excitonic absorption in small Si/Ge and Ge/Si core/shell nanocrystals |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
116 |
Issue |
7 |
Pages |
4399-4407 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The excitonic properties of Si(core)/Ge(shell) and Ge(core)/Si(shell) nanocrystals (NC's) with diameters of similar to 1.9 nm are investigated using a combination density functional ab initio method to obtain the single particle wave functions and a configuration interaction method to compute the exciton fine structure and absorption coefficient. These core/shell structures exhibit type II confinement, which is more pronounced for the Si/Ge NC as a consequence of strain. The absorption coefficients of these NC's exhibit a single dominant peak, which has a much larger oscillator strength than the multipeaks found for pure Si and Ge NC's. The exciton lifetime in Si, Ge, and Ge/Si shows a small i:emperature dependence in the range 10-300 K, whereas in Si/Ge, the exciton lifetime decreases more than an order of magnitude in the same temperature range. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000301156500007 |
Publication Date |
2012-01-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447;1932-7455; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
44 |
Open Access |
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Notes |
; The authors acknowledge financial support from CNPq and the bilateral program between Flanders and Brazil and the Belgian Science Foundation (IAP). ; |
Approved |
Most recent IF: 4.536; 2012 IF: 4.814 |
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Call Number |
UA @ lucian @ c:irua:113045 |
Serial |
482 |
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Permanent link to this record |
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Author |
Grimaldi, G.; Leo, A.; Nigro, A.; Silhanek, A.V.; Verellen, N.; Moshchalkov, V.V.; Milošević, M.V.; Casaburi, A.; Cristiano, R.; Pace, S. |
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Title |
Controlling flux flow dissipation by changing flux pinning in superconducting films |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
100 |
Issue |
20 |
Pages |
202601-202601,4 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We study the flux flow state in superconducting materials characterized by rather strong intrinsic pinning, such as Nb, NbN, and nanostructured Al thin films, in which we drag the superconducting dissipative state into the normal state by current biasing. We modify the vortex pinning strength either by ion irradiation, by tuning the measuring temperature or by including artificial pinning centers. We measure critical flux flow voltages for all materials and the same effect is observed: switching to low flux flow dissipations at low fields for an intermediate pinning regime. This mechanism offers a way to additionally promote the stability of the superconducting state. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4718309] |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000304265000051 |
Publication Date |
2012-05-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
33 |
Open Access |
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|
Notes |
; ; |
Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
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Call Number |
UA @ lucian @ c:irua:98946 |
Serial |
504 |
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Permanent link to this record |
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Author |
Frabboni, S.; Grillo, V.; Gazzadi, G.C.; Balboni, R.; Trotta, R.; Polimeni, A.; Capizzi, M.; Martelli, F.; Rubini, S.; Guzzinati, G.; Glas, F.; |
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Title |
Convergent beam electron-diffraction investigation of lattice mismatch and static disorder in GaAs/GaAs1-xNx intercalated GaAs/GaAs1-xNx:H heterostructures |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
101 |
Issue |
11 |
Pages |
111912-111914 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Hydrogen incorporation in diluted nitride semiconductors dramatically modifies the electronic and structural properties of the crystal through the creation of nitrogen-hydrogen complexes. We report a convergent beam electron-diffraction characterization of diluted nitride semiconductor-heterostructures patterned at a sub-micron scale and selectively exposed to hydrogen. We present a method to determine separately perpendicular mismatch and static disorder in pristine and hydrogenated heterostructures. The roles of chemical composition and strain on static disorder have been separately assessed. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4752464] |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000309329300033 |
Publication Date |
2012-09-15 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
1 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
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Call Number |
UA @ lucian @ c:irua:102203 |
Serial |
511 |
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Permanent link to this record |
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Author |
Wee, L.H.; Wiktor, C.; Turner, S.; Vanderlinden, W.; Janssens, N.; Bajpe, S.R.; Houthoofd, K.; Van Tendeloo, G.; De Feyter, S.; Kirschhock, C.E.A.; Martens, J.A.; |
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Title |
Copper benzene tricarboxylate metal-organic framework with wide permanent mesopores stabilized by keggin polyoxometallate ions |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
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Volume |
134 |
Issue |
26 |
Pages |
10911-10919 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Porous solids with organized multiple porosity are of scientific and technological importance for broadening the application range from traditional areas of catalysis and adsorption/separation to drug release and biomedical imaging. Synthesis of crystalline porous materials offering a network of uniform micro- and mesopores remains a major scientific challenge. One strategy is based on variation of synthesis parameters of microporous networks, such as, for example, zeolites or metal organic frameworks (MOFs). Here, we show the rational development of an hierarchical variant of the microporous cubic Cu-3(BTC)(2) (BTC = 1,3,5-benzenetricarboxylate) HKUST-1 MOF having strictly repetitive S inn wide mesopores separated by uniform microporous walls in a single crystal structure. This new material coined COK-15 (COK = Centrum voor Oppervlaktechemie en Katalyse) was synthesized via a dual-templating approach. Stability was enhanced by Keggin type phosphotungstate (HPW) systematically occluded in the cavities constituting the walls between the mesopores. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000305863900037 |
Publication Date |
2012-06-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.858 |
Times cited |
83 |
Open Access |
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Notes |
Iap; Fwo |
Approved |
Most recent IF: 13.858; 2012 IF: 10.677 |
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Call Number |
UA @ lucian @ c:irua:100330 |
Serial |
514 |
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Permanent link to this record |
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Author |
Nagy, N.V.; Van Doorslaer, S.; Szabó-Plánka, T.; Van Rompaey, S.; Hamza, A.; Fülöp, F.; Tóth, G.K.; Rockenbauer, A. |
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Title |
Copper(II)-binding ability of stereoisomeric cis- and trans-2-aminocyclohexanecarboxylic acidl-phenylalanine dipeptides : a combined CW/pulsed EPR and DFT study |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
51 |
Issue |
3 |
Pages |
1386-1399 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
With the aim of an improved understanding of the metal-complexation properties of alicyclic β-amino acid stereoisomers, and their peptides, the complex equilibria and modes of coordination with copper(II) of l-phenylalanine (F) derivatives of cis/trans-2-aminocyclohexanecarboxylic acid (c/tACHC), i.e. the dipeptides F-c/tACHC and c/tACHC-F, were investigated by a combination of CW and pulsed EPR methods. For the interpretation of the experimental data, DFT quantum-chemical calculations were carried out. Simulation of a pH-dependent series of room-temperature CW-EPR spectra revealed the presence of EPR-active complexes ([Cu(aqua)]2+, [CuL]+, [CuLH1], [CuLH2]−, and [CuL2H1]−), and an EPR-inactive species ([Cu2L2H3]−) in aqueous solutions for all studied cases. [CuLH]2+ was included in the equilibrium model for the c/tACHC-Fcopper(II) systems, and [CuL2], together with two coordination isomers of [CuL2H1]−, were also identified in the F-tACHCcopper(II) system. Comparison of the complexation properties of the diastereomeric ligand pair F-(1S,2R)-ACHC and F-(1R,2S)-ACHC did not reveal significant differences. Considerably lower formation constants were obtained for the trans than for the cis isomers for both the F-c/tACHC and the c/tACHC-F pairs in the case of [CuLH1] involving tridentate coordination by the amino, the deprotonated peptide, and the carboxylate groups. A detailed structural analysis by pulsed EPR methods and DFT calculations indicated that there was no significant destabilization for the complexes of the trans isomers. The lower stability of their complexes was explained by the limitation that only the conformer with donor groups in equatorialequatorial ring positions can bind to copper(II), whereas both equatorial-axial conformers of the cis isomers are capable of binding. From a consideration of the proton couplings obtained with X-band 1H HYSCORE, 2H exchange experiments, and DFT, the thermodynamically most stable cyclohexane ring conformer was assigned for all four [CuLH1] complexes. For the F-cACHC case, the conformer did not match the most stable conformer of the free ligand. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000300474700029 |
Publication Date |
2012-01-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
18 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
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Call Number |
UA @ lucian @ c:irua:96729 |
Serial |
515 |
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Permanent link to this record |
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Author |
Hadermann, J.; Abakumov, A.; Van Rompaey, S.; Perkisas, T.; Filinchuk, Y.; Van Tendeloo, G. |
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Title |
Crystal structure of a lightweight borohydride from submicrometer crystallites by precession electron diffraction |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
24 |
Issue |
17 |
Pages |
3401-3405 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We demonstrate that precession electron diffraction at low-dose conditions can be successfully applied for structure analysis of extremely electron-beam-sensitive materials. Using LiBH4 as a test material, complete structural information, including the location of the H atoms, was obtained from submicrometer-sized crystallites. This demonstrates for the first time that, where conventional transmission electron microscopy techniques fail, quantitative precession electron diffraction can provide structural information from submicrometer particles of such extremely electron-beam-sensitive materials as complex lightweight hydrides. We expect the precession electron diffraction technique to be a useful tool for nanoscale investigations of thermally unstable lightweight hydrogen-storage materials. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000308833400012 |
Publication Date |
2012-08-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
17 |
Open Access |
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Notes |
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Approved |
Most recent IF: 9.466; 2012 IF: 8.238 |
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Call Number |
UA @ lucian @ c:irua:101845 |
Serial |
567 |
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Permanent link to this record |
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Author |
Sena, S.H.R.; Pereira, J.M.; Farias, G.A.; Peeters, F.M. |
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Title |
Cyclotron resonance of trilayer graphene |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
86 |
Issue |
8 |
Pages |
085412 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The cyclotron resonance energies, the corresponding oscillator strengths, and the cyclotron absorption spectrum for trilayer graphene are calculated for both ABA and ABC stacking. A gate potential across the stacked layers leads to (1) a reduction of the transition energies, (2) a lifting of the degeneracy of the zero Landau level, and (3) the removal of the electron-hole symmetry. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000307273100009 |
Publication Date |
2012-08-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
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Notes |
; This work was supported by the National Council for the Improvement of Higher education (CAPES), the Brazilian Council for Research (CNPq), the Flemish Science Foundation (FWO-V1), the bilateral projects between Flanders and Brazil and the CNPq and FWO-V1, and the ESF-Eurographene project CONGRAN. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
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Call Number |
UA @ lucian @ c:irua:100815 |
Serial |
604 |
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Permanent link to this record |
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Author |
Ray, S.; Kolen'ko, Y.V.; Kovnir, K.A.; Lebedev, O.I.; Turner, S.; Chakraborty, T.; Erni, R.; Watanabe, T.; Van Tendeloo, G.; Yoshimura, M.; Itoh, M. |
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Title |
Defect controlled room temperature ferromagnetism in Co-doped barium titanate nanocrystals |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
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Volume |
23 |
Issue |
2 |
Pages |
025702,1-025702,10 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Defect mediated high temperature ferromagnetism in oxide nanocrystallites is the central feature of this work. Here, we report the development of room temperature ferromagnetism in nanosized Co-doped barium titanate particles with a size of around 14 nm, synthesized by a solvothermal drying method. A combination of x-ray diffraction with state-of-the-art electron microscopy techniques confirms the intrinsic doping of Co into BaTiO3. The development of the room temperature ferromagnetism was tracked down to the different donor defects, namely hydroxyl groups at the oxygen site (\mathrm {OH}\mathrm {(O)} |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000298409000011 |
Publication Date |
2011-12-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
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ISSN |
0957-4484;1361-6528; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
3.44 |
Times cited |
19 |
Open Access |
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Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 3.44; 2012 IF: 3.842 |
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Call Number |
UA @ lucian @ c:irua:93636 |
Serial |
614 |
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Permanent link to this record |
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Author |
Tirumalasetty, G.K.; van Huis, M.A.; Kwakernaak, C.; Sietsma, J.; Sloof, W.G.; Zandbergen, H.W. |
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Title |
Deformation-induced austenite grain rotation and transformation in TRIP-assisted steel |
Type |
A1 Journal article |
|
Year |
2012 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
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Volume |
60 |
Issue |
3 |
Pages |
1311-1321 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Uniaxial straining experiments were performed on a rolled and annealed Si-alloyed TRIP (transformation-induced plasticity) steel sheet in order to assess the role of its microstructure on the mechanical stability of austenite grains with respect to martensitic transformation. The transformation behavior of individual metastable austenite grains was studied both at the surface and inside the bulk of the material using electron back-scattered diffraction (EBSD) and X-ray diffraction (XRD) by deforming the samples to different strain levels up to about 20%. A comparison of the XRD and EBSD results revealed that the retained austenite grains at the surface have a stronger tendency to transform than the austenite grains in the bulk of the material. The deformation-induced changes of individual austenite grains before and after straining were monitored with EBSD. Three different types of austenite grains can be distinguished that have different transformation behaviors: austenite grains at the grain boundaries between ferrite grains, twinned austenite grains, and embedded austenite grains that are completely surrounded by a single ferrite grain. It was found that twinned austenite grains and the austenite grains present at the grain boundaries between larger ferrite grains typically transform first, i.e. are less stable, in contrast to austenite grains that are completely embedded in a larger ferrite grain. In the latter case, straining leads to rotations of the harder austenite grain within the softer ferrite matrix before the austenite transforms into martensite. The analysis suggests that austenite grain rotation behavior is also a significant factor contributing to enhancement of the ductility. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000301157900054 |
Publication Date |
2011-12-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
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ISSN |
1359-6454; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.301 |
Times cited |
80 |
Open Access |
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|
Notes |
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Approved |
Most recent IF: 5.301; 2012 IF: 3.941 |
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Call Number |
UA @ lucian @ c:irua:97210 |
Serial |
630 |
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Permanent link to this record |
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Author |
Lin, N.S.; Misko, V.R.; Heitmann, T.W.; Yu, K.; Plourde, B.L.T. |
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Title |
Density dependence of the rectification of vortex motion in a circular asymmetric channel |
Type |
A1 Journal article |
|
Year |
2012 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
|
|
Volume |
479 |
Issue |
|
Pages |
137-139 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We study the rectification of vortex motion in an asymmetric ring channel in a Corbino setup. With an applied ac current, the motion of vortices in the channel is rectified by the asymmetric potential and induces a dc net flow. The net flow in such a system strongly depends on vortex density, and we distinguish “single-vortex'' rectification regime (for low density, when each vortex is rectified individually) determined by the potential-energy landscape inside each cell of the channel and ”multi-vortex'', or "collective'', rectification (high density case) when the interaction between vortices becomes important. (C) 2012 Elsevier B.V. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000308580600032 |
Publication Date |
2012-01-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0921-4534; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
1.404 |
Times cited |
|
Open Access |
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|
Notes |
; This work was supported by the "Odysseus'' Program of the Flemish Government and the Flemish Science Foundation (FWO-Vl), the Interuniversity Attraction Poles (IAP) Programme – Belgian State – Belgian Science Policy, and the FWO-Vl (Belgium). ; |
Approved |
Most recent IF: 1.404; 2012 IF: 0.718 |
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Call Number |
UA @ lucian @ c:irua:101873 |
Serial |
635 |
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Permanent link to this record |
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Author |
Verheyen, E.; Joos, L.; Van Havenbergh, K.; Breynaert, E.; Kasian, N.; Gobechiya, E.; Houthoofd, K.; Martineau, C.; Hinterstein, M.; Taulelle, F.; Van Speybroeck, V.; Waroquier, M.; Bals, S.; Van Tendeloo, G.; Kirschhock, C.E.A.; Martens, J.A.; |
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Title |
Design of zeolite by inverse sigma transformation |
Type |
A1 Journal article |
|
Year |
2012 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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|
Volume |
11 |
Issue |
12 |
Pages |
1059-1064 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Although the search for new zeolites has traditionally been based on trial and error, more rational methods are now available. The theoretical concept of inverse transformation of a zeolite framework to generate a new structure by removal of a layer of framework atoms and contraction has for the first time been achieved experimentally. The reactivity of framework germanium atoms in strong mineral acid was exploited to selectively remove germanium-containing four-ring units from an UTL type germanosilicate zeolite. Annealing of the leached framework through calcination led to the new all-silica COK-14 zeolite with intersecting 12- and 10-membered ring channel systems. An intermediate stage of this inverse transformation with dislodged germanate four-rings still residing in the pores could be demonstrated. Inverse transformation involving elimination of germanium-containing structural units opens perspectives for the synthesis of many more zeolites. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000311432600025 |
Publication Date |
2012-10-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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ISSN |
1476-1122;1476-4660; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
39.737 |
Times cited |
140 |
Open Access |
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|
|
Notes |
Fwo |
Approved |
Most recent IF: 39.737; 2012 IF: 35.749 |
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Call Number |
UA @ lucian @ c:irua:101783 |
Serial |
661 |
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Permanent link to this record |
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Author |
Carvalho, J.C.N.; Nelissen, K.; Ferreira, W.P.; Farias, G.A.; Peeters, F.M. |
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Title |
Diffusion in a quasi-one-dimensional system on a periodic substrate |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
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Volume |
85 |
Issue |
2:1 |
Pages |
021136-021136,8 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The diffusion of charged particles interacting through a repulsive Yukawa potential, exp(-r/lambda)/r, confined by a parabolic potential in the y direction and subjected to a periodic substrate potential in the x direction is investigated. Langevin dynamic simulations are used to investigate the effect of the particle density, the amplitude of the periodic substrate, and the range of the interparticle interaction potential on the diffusive behavior of the particles. We found that in general the diffusion is suppressed with increasing the amplitude of the periodic potential, but for specific values of the strength of the substrate potential a remarkable increase of the diffusion is found with increasing the periodic potential amplitude. In addition, we found a strong dependence of the diffusion on the specific arrangement of the particles, e. g., single-chain versus multichain configuration. For certain particle configurations, a reentrant behavior of the diffusion is found as a function of the substrate strength due to structural transitions in the ordering of the particles. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
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Language |
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Wos |
000300671500007 |
Publication Date |
2012-02-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
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ISSN |
1539-3755;1550-2376; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.366 |
Times cited |
9 |
Open Access |
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Notes |
; This work was supported by the Brazilian agencies CNPq and FUNCAP (PRONEX-Grant), the Flemish Science Foundation (FWO-Vl), and the bilateral projects between Flanders and Brazil and the Flemish Science Foundation (FWO-VI) and CNPq. ; |
Approved |
Most recent IF: 2.366; 2012 IF: 2.313 |
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Call Number |
UA @ lucian @ c:irua:97203 |
Serial |
698 |
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Permanent link to this record |
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Author |
Kao, K.-H.; Verhulst, A.S.; Vandenberghe, W.G.; Sorée, B.; Groeseneken, G.; De Meyer, K. |
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Title |
Direct and indirect band-to-band tunneling in germanium-based TFETs |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
IEEE transactions on electron devices |
Abbreviated Journal |
Ieee T Electron Dev |
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Volume |
59 |
Issue |
2 |
Pages |
292-301 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Germanium is a widely used material for tunnel FETs because of its small band gap and compatibility with silicon. Typically, only the indirect band gap of Ge at 0.66 eV is considered. However, direct band-to-band tunneling (BTBT) in Ge should be included in tunnel FET modeling and simulations since the energy difference between the Ge conduction band edges at the L and G valleys is only 0.14 eV at room temperature. In this paper, we theoretically calculate the parameters A and B of Kane's direct and indirect BTBT models at different tunneling directions ([100], [110], and [111]) for Si, Ge and unstrained Si1-xGex. We highlight how the direct BTBT component becomes more important as the Ge mole fraction increases. The calculation of the band-to-band generation rate in the uniform electric field limit reveals that direct tunneling always dominates over indirect tunneling in Ge. The impact of the direct transition in Ge on the performance of two realistic tunnel field-effect transistor configurations is illustrated with TCAD simulations. The influence of field-induced quantum confinement is included in the analysis based on a back-of-the-envelope calculation. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000299430200005 |
Publication Date |
2011-12-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0018-9383;1557-9646; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.605 |
Times cited |
212 |
Open Access |
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Notes |
; Manuscript received August 5, 2011; revised October 5, 2011 and October 28, 2011; accepted October 30, 2011. Date of publication December 7, 2011; date of current version January 25, 2012. This work was supported by the Interuniversity Microelectronics Center's (IMEC) Industrial Affiliation Program. The work of W. G. Vandenberghe was supported by a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). The review of this paper was arranged by Editor A. Schenk. ; |
Approved |
Most recent IF: 2.605; 2012 IF: 2.062 |
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Call Number |
UA @ lucian @ c:irua:97215 |
Serial |
708 |
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Permanent link to this record |
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Author |
Bertoni, G.; Grillo, V.; Brescia, R.; Ke, X.; Bals, S.; Catellani, A.; Li, H.; Manna, L. |
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Title |
Direct determination of polarity, faceting, and core location in colloidal core/shell wurtzite semiconductor nanocrystals |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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Volume |
6 |
Issue |
7 |
Pages |
6453-6461 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The ability to determine the atomic arrangement and termination of various facets of surfactant-coated nanocrystals is of great importance for understanding their growth mechanism and their surface properties and represents a critical piece of information that can be coupled to other experimental techniques and to calculations. This is especially appealing in the study of nanocrystals that can be grown in strongly anisotropic shapes, for which the relative growth rates of various facets can be influenced under varying reaction conditions. Here we show that in two representative cases of rod-shaped nanocrystals in the wurtzite phase (CdSe(core)/CdS(shell) and ZnSe(core)/ZnS(shell) nanorods) the terminations of the polar facets can be resolved unambiguously by combining advanced electron microscopy techniques, such as aberration-corrected HRTEM with exit wave reconstruction or aberration-corrected HAADF-STEM. The [0001] and [000-1] polar directions of these rods, which grow preferentially along their c-axis, are revealed clearly, with one side consisting of the Cd (or Zn)-terminated (0001) facet and the other side with a pronounced faceting due to Cd (or Zn)-terminated {10-1-1} facets. The lateral faceting of the rods is instead dominated by three nonpolar {10-10} facets. The core buried in the nanostructure can be localized in both the exit wave phase and HAADF-STEM images. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000306673800079 |
Publication Date |
2012-06-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1936-0851;1936-086X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
63 |
Open Access |
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Notes |
The authors gratefully acknowledge funding from the European Research Council under grant number 240111 (NANO-ARCH) and the financial support from the Flemish Hercules 3 Programme for large infrastructures. G.B. and V.G. thank E. Rotunno for his help with STEM_CELL and IWFR. |
Approved |
Most recent IF: 13.942; 2012 IF: 12.062 |
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Call Number |
UA @ lucian @ c:irua:101138 |
Serial |
710 |
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Permanent link to this record |
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Author |
He, Z.; Ke, X.; Bals, S.; Van Tendeloo, G. |
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Title |
Direct evidence for the existence of multi-walled carbon nanotubes with hexagonal cross-sections |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
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Volume |
50 |
Issue |
7 |
Pages |
2524-2529 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Carbon nanotubes (CNTs) with a polygonal cross-section have been paid increasing attention since their three-dimensional structure is related to specific physical properties, which are found to be different in comparison to CNTs with a circular cross-section. Here, we report the existence of novel multi-walled CNTs yielding walls with a rounded-hexagonal configuration. This structure was directly confirmed for the first time by both cross-sectional transmission electron microscopy and electron tomography. The morphology of the Fe catalytic particle also exhibits hexagonal characteristics, and is proposed as the origin of the formation of the rounded-hexagonal walls of the CNT. This observation is of great importance with respect to the design of polygonal (such as pentagonal or hexagonal) cross-sectional CNTs. By controlling the morphology of the catalytic nanoparticles it will be possible to grow CNTs with desired electronic and mechanical properties. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000303038400015 |
Publication Date |
2012-02-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0008-6223; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.337 |
Times cited |
8 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 6.337; 2012 IF: 5.868 |
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Call Number |
UA @ lucian @ c:irua:96956 |
Serial |
711 |
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Permanent link to this record |
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Author |
Van Aert, S.; Turner, S.; Delville, R.; Schryvers, D.; Van Tendeloo, G.; Salje, E.K.H. |
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Title |
Direct observation of ferrielectricity at ferroelastic domain boundaries in CaTiO3 by electron microscopy |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
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Volume |
24 |
Issue |
4 |
Pages |
523-527 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
High-resolution aberration-corrected transmission electron microscopy aided by statistical parameter estimation theory is used to quantify localized displacements at a (110) twin boundary in orthorhombic CaTiO3. The displacements are 36 pm for the Ti atoms and confined to a thin layer. This is the first direct observation of the generation of ferroelectricity by interfaces inside this material which opens the door for domain boundary engineering. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Weinheim |
Editor |
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Language |
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Wos |
000299156400011 |
Publication Date |
2011-12-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0935-9648; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
19.791 |
Times cited |
150 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 19.791; 2012 IF: 14.829 |
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Call Number |
UA @ lucian @ c:irua:94110 |
Serial |
717 |
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Permanent link to this record |
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Author |
Wang, A.; Chen, F.R.; Van Aert, S.; van Dyck, D. |
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Title |
Direct structure inversion from exit waves : part 2 : a practical example |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
116 |
Issue |
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Pages |
77-85 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab |
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Abstract |
This paper is the second part of a two-part paper on direct structure inversion from exit waves. In the first part, a method has been proposed to quantitatively determine structure parameters with atomic resolution such as atom column positions, surface profile and the number of atoms in the atom columns. In this part, the theory will be demonstrated by means of a Au[110] exit wave reconstructed from a set of focal-series images. The procedures to analyze the experimentally reconstructed exit wave in terms of quantitative structure information are described in detail. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000304473700011 |
Publication Date |
2012-03-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
|
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ISSN |
0304-3991; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.843 |
Times cited |
8 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 2.843; 2012 IF: 2.470 |
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Call Number |
UA @ lucian @ c:irua:96660 |
Serial |
724 |
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Permanent link to this record |
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Author |
Berdiyorov, G.R.; de Romaguera, A.R.C.; Milošević, M.V.; Doria, M.M.; Covaci, L.; Peeters, F.M. |
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Title |
Dynamic and static phases of vortices under an applied drive in a superconducting stripe with an array of weak links |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
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Volume |
85 |
Issue |
4 |
Pages |
130-130,8 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Static and dynamic properties of superconducting vortices in a superconducting stripe with a periodic array of weakly-superconducting (or normal metal) regions are studied in the presence of external magnetic and electric fields. The time-dependent Ginzburg-Landau theory is used to describe the electronic transport, where the anisotropy is included through the spatially-dependent critical temperature T-c. Superconducting vortices penetrating into the weak-superconducting region with smaller T-c are more mobile than the ones in the strong superconducting regions. We observe periodic entrance and exit of vortices which reside in the weak link for some short interval. The mobility of the weakly-pinned vortices can be reduced by increasing the uniform applied magnetic field leading to distinct features in the voltage vs. magnetic field response of the system. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Berlin |
Editor |
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Language |
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Wos |
000303545400013 |
Publication Date |
2012-04-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-6028;1434-6036; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
1.461 |
Times cited |
32 |
Open Access |
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|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the bilateral programme between Flanders and Brazil. G.R.B. and L.C. acknowledge individual support from FWO-Vl. A.R.de C.R. acknowledges CNPq and FACEPE for financial support. ; |
Approved |
Most recent IF: 1.461; 2012 IF: 1.282 |
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Call Number |
UA @ lucian @ c:irua:98267 |
Serial |
761 |
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Permanent link to this record |