| Records |
| Author |
Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V. |
| Title |
Tailoring weak and metallic phases in a strong topological insulator by strain and disorder : conductance fluctuations signatures |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
Physical review B |
Abbreviated Journal |
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| Volume |
109 |
Issue |
4 |
Pages |
045129-7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Transport measurements are readily used to probe different phases in disordered topological insulators (TIs), where determining topological invariants explicitly is challenging. On that note, universal conductance fluctuations (UCF) theory asserts the conductance G for an ensemble has a Gaussian distribution, and that standard deviation 8G depends solely on the symmetries and dimensions of the system. Using a real-space tight -binding Hamiltonian on a system with Anderson disorder, we explore conductance fluctuations in a thin Bi2Se3 film and demonstrate the agreement of their behavior with UCF hypotheses. We further show that magnetic field applied out-of-plane breaks the time -reversal symmetry and transforms the system's Wigner-Dyson class from root symplectic to unitary, increasing 8G by 2. Finally, we reveal that while Bi2Se3 is a strong TI, weak TI and metallic phases can be stabilized in presence of strain and disorder, and detected by monitoring the conductance fluctuations. |
| 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  |
001173938400008 |
Publication Date |
2024-01-16 |
| 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 |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:204765 |
Serial |
9177 |
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| Author |
Wang, J.; Zhao, W.-S.; Hu, Y.; Filho, R.N.C.; Peeters, F.M. |
| Title |
Charged vacancy in graphene : interplay between Landau levels and atomic collapse resonances |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
Physical review B |
Abbreviated Journal |
|
| Volume |
109 |
Issue |
10 |
Pages |
104103-104106 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The interplay between a magnetic field and the Coulomb potential from a charged vacancy on the electron states in graphene is investigated within the tight-binding model. The Coulomb potential removes locally Landau level degeneracy, while the vacancy introduces a satellite level next to the normal Landau level. These satellite levels are found throughout the positive-energy region, but in the negative-energy region, they turn into atomic collapse resonances. Crossings between Landau levels with different angular quantum number m are found. Unlike the point impurity system in which an anticrossing occurs between Landau levels of the same m, in this work anticrossing is found between the normal Landau level and the vacancy-induced level. The atomic collapse resonance hybridizes with the Landau levels. The charge at which the lowest Landau level m = -1, N = 1 crosses E = 0 increases with enhancing magnetic field. A Landau level scaling anomaly occurs when the charge is larger than the critical charge beta 0.6 and this critical charge is independent of the magnetic field. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
001199561900008 |
Publication Date |
2024-03-04 |
| 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 |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:205508 |
Serial |
9137 |
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| Author |
Moura, V.N.; Chaves, A.; Peeters, F.M.; Milošević, M.V. |
| Title |
McMillan-Ginzburg-Landau theory of singularities and discommensurations in charge density wave states of transition metal dichalcogenides |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
Physical review B |
Abbreviated Journal |
|
| Volume |
109 |
Issue |
9 |
Pages |
094507-94511 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The McMillan-Ginzburg-Landau (MGL) model for charge density waves (CDW) is employed in a systematic phenomenological study of the different phases that have been probed in recent experiments involving transition metal dichalcogenides. We implemented an efficient imaginary time evolution method to solve the MGL equations, which enabled us to investigate the role of different coupling parameters on the CDW patterns and to perform calculations with different energy functionals that lead to several experimentally observed singularities in the CDW phase profiles. In particular, by choosing the appropriate energy functionals, we were able to obtain phases that go beyond the well-known periodic phase slips (discommensurations), exhibiting also topological defects (i.e., vortex-antivortex pairs), domain walls where the CDW order parameter is suppressed, and even CDW with broken rotational symmetry. Finally, we briefly discuss the effect of these different CDW phases on the profile and critical temperature of the competing superconducting state. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
001199651500001 |
Publication Date |
2024-03-11 |
| 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 |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:205491 |
Serial |
9158 |
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| Author |
Pascucci, F.; Conti, S.; Perali, A.; Tempère, J.; Neilson, D. |
| Title |
Effects of intralayer correlations on electron-hole double-layer superfluidity |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
Physical review B |
Abbreviated Journal |
|
| Volume |
109 |
Issue |
9 |
Pages |
094512-94515 |
| Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
| Abstract |
We investigate the intralayer correlations acting within the layers in a superfluid system of electron -hole spatially separated layers. In this system, superfluidity is predicted to be almost exclusively confined to the Bose-Einstein condensate (BEC) and crossover regimes where the electron -hole pairs are well localized. In this case, Hartree-Fock is an excellent approximation for the intralayer correlations. We find in the BEC regime that the effect of the intralayer correlations on superfluid properties is negligible but in the BCS-BEC crossover regime the superfluid gap is significantly weakened by the intralayer correlations. This is caused by the intralayer correlations boosting the number of low -energy particle -hole excitations that drive the screening. We further find that the intralayer correlations suppress the predicted phenomenon in which the average pair size passes through a minimum as the crossover regime is traversed. |
| 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 |
001199662600001 |
Publication Date |
2024-03-18 |
| 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 |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ admin @ c:irua:205476 |
Serial |
9145 |
| Permanent link to this record |
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| Author |
Nicholas, R.J.; Sasaki, S.; Miura, N.; Peeters, F.M.; Shi, J.M.; Hai, G.Q.; Devreese, J.T.; Lawless, M.J.; Ashenford, D.E.; Lunn, B. |
| Title |
Interband magnetooptical studies of resonant polaron coupling in CdTe/Cd1-xMnxTe quantum-wells |
Type |
A1 Journal article |
| Year |
1994 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
50 |
Issue |
11 |
Pages |
7596-7601 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
| Abstract |
Magnetoreflectivity measurements of the 1s and 2s exciton energies in a CdTe/Cd1-xMnxTe superlattice have been made in magnetic fields up to 45 T, showing the resonant polaron coupling of electrons to LO phonons. Strong reflectivity features are seen for both the 1s and 2s excitons, which show a strong field-dependent spin splitting due to the dilute magnetic barriers. At B-z=0, the 2s exciton feature is observed lying 18 meV above the Is state, and is shifted upward in energy by the magnetic fields. No resonant behavior occurs when the 2s state passes through the LO-phonon energy of 21 meV, but at higher fields of around 20 T, the resonances for both spin states (sigma(+/-)) of the 2s exciton broaden and show a strong anticrossing behavior. These experiments are shown to be in excellent agreement with a theoretical treatment which includes the resonant polaron coupling of the electrons alone. Both experiment and theory demonstrate an extremely strong resonant splitting of the 2s exciton states of approximately 11 meV, which is over 50% of the LO-phonon energy. The dominance of single-particle polaron coupling is attributed to the relative sizes of the polaron (35 Angstrom A) and the exciton (50 Angstrom A) radius. |
| 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 |
A1994PJ43700045 |
Publication Date |
2002-07-27 |
| 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 |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.736 |
Times cited |
10 |
Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ lucian @ c:irua:99837 |
Serial |
1687 |
| Permanent link to this record |
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| Author |
Lamoen, D.; Ballone, P.; Parrinello, M. |
| Title |
Electronic structure, screening and charging effects at a metal/organic tunneling junction: a first principles study |
Type |
A1 Journal article |
| Year |
1996 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
54 |
Issue |
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Pages |
5097 |
| Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
| Abstract |
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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 |
A1996VE48800102 |
Publication Date |
0000-00-00 |
| 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; 0163-1829 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.736 |
Times cited |
33 |
Open Access |
|
| Notes |
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Approved |
PHYSICS, CONDENSED MATTER 16/67 Q1 # |
| Call Number |
UA @ lucian @ c:irua:15820 |
Serial |
1018 |
| Permanent link to this record |
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| Author |
Shi, J.M.; Koenraad, P.M.; van de Stadt, A.F.W.; Peeters, F.M.; Devreese, J.T.; Wolter, J.H. |
| Title |
Electronic structure of a Si \delta-doped layer in a GaAs/AlxGa1-xAs/GaAs quantum barrier |
Type |
A1 Journal article |
| Year |
1996 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
54 |
Issue |
11 |
Pages |
7996-8004 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
| Abstract |
We present a theoretical study of the electronic structure of a heavily Si delta-doped layer in a GaAs/AlxGa1-xAs/GaAs quantum barrier. In this class of structures the effect of DX centers on the electronic properties can be tuned by changing the AlxGa1-xAs barrier width and/or the Al concentration, which leads to a lowering of the DX level with respect to the Fermi energy without disturbing the wave functions much. A self-consistent approach is developed in which the effective confinement potential and the Fermi energy of the system, the energies, the wave functions, and the electron densities of the discrete subbands have been obtained as a function of both the material parameters of the samples and the experimental conditions. The effect of DX centers on such structures at nonzero temperature and under an external pressure is investigated for three different models: (1) the DX(nc)(0) model with no correlation effects, (2) the d(+)/DX(0) model, and (3) the d(+)/DX(-) model with inclusion of correlation effects. In the actual calculation, influences of the background accepters, the discontinuity of the effective mass of the electrons at the interfaces of the different materials, band nonparabolicity, and the exchange-correlation energy of the electrons have been taken into account. We have found that (1) introducing a quantum barrier into delta-doped GaAs makes it possible to control the energy gaps between different electronic; subbands; (2) the electron wave functions are mon spread out when the repellent effect of the barriers is increased as compared to those in delta-doped GaAs; (3) increasing the quantum-barrier height and/or the application of hydrostatic pressure are helpful to experimentally observe the effect of the DX centers through a decrease of the total free-electron density; and (4) the correlation effects of the charged impurities are important for the systems under study. |
| 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 |
A1996VL14500066 |
Publication Date |
2002-07-27 |
| 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 |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.736 |
Times cited |
11 |
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ lucian @ c:irua:104388 |
Serial |
1012 |
| Permanent link to this record |
