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“Determination of selenium in blood components by X-ray emission spectrometry”. Robberecht H, Deelstra H, Van Grieken R, Biological trace element research 25, 149 (1990). http://doi.org/10.1007/BF02990412
Abstract: Sampling, storing, sample pretreatment, and experimental conditions for selenium (Se) determination in human serum, plasma, and whole blood by X-ray emission spectrometric (XRS) methods are described. Concentration levels in these biological fluids, found by this technique, are discussed and compared to values found by other techniques for the same healthy population group in the same area. XRS analysis of blood from patients with various pathological conditions is reviewed, with special attention to the relation of Se with the concentration level of other essential or nonessential trace elements.
Keywords: A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02990412
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“Aerosol characteristics and sources for the Amazon Basin during the wet season”. Artaxo P, Maenhaut W, Storms H, Van Grieken R, Journal of geophysical research 95, 16971 (1990). http://doi.org/10.1029/JD095ID10P16971
Abstract: As a part of the NASA Global Tropospheric Experiment (GTE), aerosols were sampled in the tropical rain forest of the Amazon Basin during the Amazon Boundary Layer Experiment (ABLE 2B) in April and May 1987, in the wet season, when no forest burning occurs. Fine (dp < 2.0 μm) and coarse (2.0 < dp < 15 μm) aerosol fractions were collected using stacked filter units, at three sites under the forest canopy and at three levels of a tower inside the jungle. Particle-induced X ray emission (PIXE) was used to measure concentrations of 22 elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Zr, and Pb). Morphological and trace element measurements of individual particles were carried out by automated electron probe X ray microanalysis. Gravimetric analysis was performed to obtain the fine and coarse aerosol mass concentration. Absolute factor analysis was used to interpret the large data set of the trace element concentrations and to obtain elemental source profiles. Hierarchical cluster analysis was used to derive groups of individual particles. The concentrations of soil dust related elements (Al, Si, Ti, Fe, Mn) were 5 times larger in the wet season compared to the 1985 ABLE 2A dry season experiment. Biogenic aerosol related elements in the fine fraction showed lower concentrations in the wet season. Fine aerosol mass concentration averaged only 2.1±0.7 μg m−3, while the average coarse mass concentration was 6.1±1.8 μg m −3. Sulphur concentrations averaged 76±14 ng m −3 in the fine fraction and 37±9 ng m −3 in the coarse fraction. Biogenic aerosol-related elements were dominant under the forest canopy, while soil dust dominated at the top of the forest canopy. Only two factors explained about 90% of the data variability for the fine and coarse aerosol fractions. These were soil dust (represented mainly by Al, Si, Ti, Mn, and Fe) and biogenic aerosol (represented by K, P, Cl, S, Zn, and the aerosol mass concentration). Source profiles showed a homogeneous aerosol distribution with similar elemental compositions at the different sampling sites. Enrichment factor calculations revealed a soil dust elemental profile similar to the average bulk soil composition, and a biogenic component similar to the plant bulk elemental composition. Total aerosol mass source apportionment showed that biogenic particles account for 5595% of the airborne concentrations. The analysis of individual aerosol particles showed that the biogenic particles consist of leaf fragments, pollen grains, fungi, algae, and other types of particles. Several groups of particles with K, Cl, P, S, and Ca as minor elements could easily be identified as biogenic particles on the basis of their morphology. Considering the vast area of tropical rain forests and the concentrations measured in this work, it is possible that biogenic particles can play an important role in the global aerosol budget and in the global biogeochemical cycles of various elements.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1029/JD095ID10P16971
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“Conductivity and electron density of undoped model compounds of poly(phenylene vinylene)”. Yang Z, Geise HJ, Mehbod M, Debrue G, Visser JW, Sonneveld EJ, Van 't dack L, Gijbels R, Synthetic metals 39, 137 (1990). http://doi.org/10.1016/0379-6779(90)90179-O
Abstract: Fourteen derivatives of trans,trans-1,4-bis[2-phenylethenyl]benzene were synthesized by Wittig reactions as model compounds of poly(paraphenylene vinylene). Structure, configurational homogeneity and absence of ionic impurities were controlled by mass spectrometry, infrared and neutron activation analysis, respectively. Crystallographic unit cell parameters were obtained from X-ray powder patterns and measurements of electrical conductivities were performed on undoped samples. The data of four more compounds containing one or more thiophene rings instead of phenyl rings were added from the 3iterature. If NO2 and Cl groups are excluded from the electron count a good linear correlation is found between the logarithm of the conductivity and the non-σ electron density (View the MathML source). The position of the substituents, on the central or on the terminal ring, also plays a role in as much as it affects the molecular volume of the compound but not the non-σ electron density. The correlation between the logarithm of the conductivity and the absorption coefficient of the longest wavelength of UV absorption identifies the π electrons in the chromophore as the principal charge carriers.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.252
Times cited: 25
DOI: 10.1016/0379-6779(90)90179-O
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“Micro-analysis of individual environmental particles”. Van Grieken R, Artaxo P, Bernard P, Leysen L, Otten P, Storms H, Van Put A, Wouters L, Xhoffer C, Chemia analityczna 35, 75 (1990)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“A critical comparison of MINDO/3, MNDO, AM1 and PM3 for a model problem: carbon clusters C2-C10. An ad hoc reparametrization of MNDO well suited for the accurate prediction of their spectroscopic constants”. Martin JML, François JP, Gijbels R, Journal of computational chemistry 12, 52 (1991)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.589
Times cited: 76
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“Sulfur species and associated trace elements in south-west Bulgarian thermal waters”. Veldeman E, Van 't dack L, Gijbels R, Pentcheva E, Applied geochemistry 6, 49 (1991)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.268
Times cited: 7
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“Electron microscopy and diffraction study of the composition dependency of the 3R microtwinned martensite in Ni-Al”. Schryvers D, de Saegher B, van Landuyt J, Materials research bulletin 26, 57 (1991)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.288
Times cited: 11
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“Defects in high-dose oxygen implanted silicon : a TEM study”. Deveirman A, van Landuyt J, Vanhellemont J, Maes HE, Yallup K, Vacuum: the international journal and abstracting service for vacuum science and technology
T2 –, 1ST SIOMX WORKSHOP ( SEPARATION BY IMPLANTATION OF OXYGEN ) ( SWI-88 ), NOV 07-08, 1988, UNIV SURREY, GUILDFORD, ENGLAND 42, 367 (1991). http://doi.org/10.1016/0042-207X(91)90055-N
Abstract: Results are discussed of a transmission electron microscopy study of high-dose oxygen implanted silicon. In addition to the general high temperature (> 1200-degrees-C) annealing treatments also annealings at 'low' temperatures (1000-1100-degrees-C) were performed in order to slow down the precipitate and defect reactions. The observed dissolution of the oxide precipitates during prolonged high temperature annealing is explained by critical radius considerations. Threading dislocations are the remaining lattice defects in the silicon overlayer and cannot be removed by further annealing. Low temperature annealing results in the formation and subsequent unfaulting of extrinsic stacking fault loops below the buried oxide layer.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.858
Times cited: 4
DOI: 10.1016/0042-207X(91)90055-N
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“Expansion of laser-generated plumes near the plasma ignition threshold”. Balazs L, Gijbels R, Vertes A, Analytical chemistry 63, 314 (1991)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 5.636
Times cited: 71
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“Dynamics of a quadrupolar glass”. Bostoen C, Michel KH, Physical review : B : condensed matter and materials physics 43, 4415 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 33
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“The observation and theory of optically detected magnetophonon resonance”. Barnes DJ, Nicholas RJ, Peeters FM, Wu XG, Devreese JT, Singleton J, Langerak CJGM, Harris JJ, Foxon CT, Physical review letters 66, 794 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 7.512
Times cited: 38
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“Exact and approximate results for the polaron in one dimension”. Peeters FM, Smondyrev MA, Physical review : B : condensed matter and materials physics 43, 4920 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 16
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“Binding energy of the barbell exciton”. Peeters FM, Golub JE, Physical review : B : condensed matter and materials physics 43, 5159 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 27
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“The study of high Tc-superconducting materials by electron microscopy and electron diffraction”. Amelinckx S, Van Tendeloo G, van Landuyt J, Superconductor science and technology
T2 –, SATELLITE CONF TO THE 19TH INTERNATIONAL CONF ON LOW TEMPERATURE PHYSICS : HIGH TEMPERATURE SUPERCONDUCTIVITY, AUG 13-15, 1990, QUEENS COLL, CAMBRIDGE, ENGLAND 4, S19 (1991). http://doi.org/10.1088/0953-2048/4/1S/003
Abstract: A survey is given of the application of different electron microscopic techniques to the study of structural features of high T(c)-superconducting materials. Emphasis is laid in this contribution on those structural aspects for the study of which electron microscopy has been essential or has contributed to a significant extent.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.325
Times cited: 2
DOI: 10.1088/0953-2048/4/1S/003
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“Ab initio study of the structure, infrared spectra and heat of formation of C4”. Martin JML, François JP, Gijbels R, The journal of chemical physics 94, 3753 (1991)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.952
Times cited: 62
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“Large bipolarons in three and two dimensions”. Verbist G, Peeters FM, Devreese JT, Physical review : B : condensed matter and materials physics 43, 2712 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.736
Times cited: 155
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“Characterization of crystal defects in mixed tabular silver halide grains by conventional transmission electron microscopy and X-ray diffractometry”. Goessens C, Schryvers D, van Landuyt J, Amelinckx S, Verbeeck A, de Keyzer R, Journal of crystal growth 110, 930 (1991)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.698
Times cited: 40
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“Far-infrared spectroscopy of minibands and confined donors in GaAs/AlxGa1-xAs superlattices”. Helm M, Peeters FM, DeRosa F, Colas E, Harbison JP, Florez LT, Physical review : B : condensed matter and materials physics 43, 13983 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 77
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“Diffusion-to-streaming transition in a two-dimensional electron system in a polar semiconductor”. Xu W, Peeters FM, Devreese JT, Physical review : B : condensed matter and materials physics 43, 14134 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.736
Times cited: 24
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“Ab initio spectroscopy and thermochemistry of the BN molecule”. Martin JML, François JP, Gijbels R, Zeitschrift für Physik : D : atoms, molecules and clusters 21, 47 (1991)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Times cited: 17
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“Restricted energy transfer in laser desorption of high molecular weight biomolecules”. Vertes A, Gijbels R, Scanning microscopy 5, 317 (1991)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Times cited: 11
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“The primary energy dependence of backscattered electron images up to 100 keV”. Geuens I, Nys B, Naudts J, Gijbels R, Jacob W, van Espen P, Scanning microscopy 5, 339 (1991)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Chemometrics (Mitac 3)
Times cited: 3
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“Donor transition energy in GaAs-superlattices in a magnetic field along the growth axis”. Shi JM, Peeters FM, Hai GQ, Devreese JT, Physical review : B : condensed matter and materials physics 44, 5692 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.736
Times cited: 78
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“Nonlinear transport phenomena in a triangular quantum well”. Kastalsky A, Peeters FM, Chan WK, Florez LT, Harbison JP, Applied physics letters 59, 1708 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.302
Times cited: 11
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“Quantum-wire spectroscopy and epitaxial-growth velocities in InxGa1-xAs-InP heterostructures”. Worlock JM, Peeters FM, Cox HM, Morais PC, Physical review : B : condensed matter and materials physics 44, 8923 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 12
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“Neutron-scattering and electron microscopy studies of premartensitic phenomena in NixAl100-x alloys”. Shapiro SM, Yang BX, Noda Y, Tanner LE, Schryvers D, Physical review : B : condensed matter and materials physics 44, 9301 (1991)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.736
Times cited: 123
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“On the effect of centrifugal stretching on the rotational partition function of an asymmetric top”. Martin JML, François JP, Gijbels R, The journal of chemical physics 95, 8374 (1991)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.952
Times cited: 12
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“Possible (bi) polaron effects in the high-tc superconductors”. Peeters FM, Devreese JT, Verbist G, Physica scripta
T2 –, 11TH General Conf. Of the Condensed Matter Division of the European Physical Society, April 08-11, 1991, Exeter, England T39, 66 (1991). http://doi.org/10.1088/0031-8949/1991/T39/007
Abstract: In the present paper, the theory of the large bipolaron is reviewed and the possibility of bipolaron formation in the high-T(c) superconductors is indicated. Operator and path-integral formulations of the large bipolaron problem are compared. In the strong-coupling limit, the effect of non-optimal upper-bounds to the single-polaron groundstate energy is emphasized. The fact that the interaction with multiple phonon branches enhances the electron-phonon interaction and might result in a larger stability region for bipolaron formation is indicated. Experimental values for the static and high-frequency dielectric constants are used to discuss the relevance of bipolaron formation as a pair-forming mechanism in the high-T(c) superconductors.
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 1.126
Times cited: 29
DOI: 10.1088/0031-8949/1991/T39/007
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“Quantum magnetotransport of a 2-dimensional electron-gas subject to periodic electric or magnetic modulations”. Vasilopoulos, Peeters FM, Physica scripta : supplements
T2 –, 11TH GENERAL CONF OF THE CONDENSED MATTER DIVISION OF THE EUROPEAN, PHYSICAL SOC, APR 08-11, 1991, EXETER, ENGLAND T39, 177 (1991). http://doi.org/10.1088/0031-8949/1991/T39/027
Abstract: Electrical transport properties of the two-dimensional electron gas are studied in the presence of a perpendicular magnetic field B = Bz and of a weak one-dimensional electric (V0 cos (Kx)) or magnetic (B0 = B0 cos (Kx)z) modulation where B0 << B, K = 2-pi/a, and a is the modulation period. In either case the discrete Landau levels broaden into bands whose width: (1) is proportional to the modulation strength, (2) it oscillates with B, and (3) it gives rise to magnetoresistance oscillations, at low B, that are different in period and temperature dependence from the Shubnikov-de Haas (SdH) ones, at higher B. For equal energy modulation strengths, V0 = heB0/m*, the magnetic bandwidth at the Fermi energy is about one order of magnitude larger than the electric one. The same holds for the oscillation amplitude of the electrical magnetoresistivity tensor. For two-dimensional modulations the energy spectrum has the same structure but with different scales. For weak magnetic fields and equal modulation strengths the gaps in the spectrum can be much larger in the magnetic case thus making easier the observability of the spectrum's fine structure.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.126
Times cited: 8
DOI: 10.1088/0031-8949/1991/T39/027
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“Quantum magnetotransport of a two-dimensional electron gas subject to periodic electric and magnetic modulations”. Vasilopoulos P, Peeters FM, Physica scripta T39, 177 (1991)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.126
Times cited: 8
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