全文获取类型
收费全文 | 150篇 |
免费 | 9篇 |
专业分类
化学 | 86篇 |
晶体学 | 9篇 |
力学 | 1篇 |
数学 | 23篇 |
物理学 | 40篇 |
出版年
2023年 | 2篇 |
2022年 | 12篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 9篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 5篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 3篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有159条查询结果,搜索用时 15 毫秒
81.
A linearized variant of relative entropy is used to quantify in a unified scheme the different kinds of correlations in a bipartite quantum system. As illustration, we consider a two-qubit state with parity and exchange symmetries for which we determine the total, classical and quantum correlations. We also give the explicit expressions of its closest product state, closest classical state and the corresponding closest product state. A closed additive relation, involving the various correlations quantified by linear relative entropy, is derived. 相似文献
82.
The lattice dynamics and the elastic properties of the ternary AlAs x Sb1?x alloy have been studied using the density-functional perturbation theory within the local density approximation and employing the virtual-crystal approximation. We study the variation of the optical phonon frequencies (ωTO and ωLO), the high-frequency (?∞) and static (?0) dielectric coefficients, the dynamic effective charge (Z*) and the elastic constants (C 11, C 12, C 44) as a function of the composition (x) and the pressure. We have also predicted the behavior of the optical and acoustical phonons with composition x at the X and L high symmetry points under pressure and determined the Grüneisen parameter. We have found that no mechanical instabilities are associated with the structural transition at high pressures for all compositions. 相似文献
83.
We investigate quantum key distribution where information is carried by a d-level optical quantum system. The sender uses the mutually unbiased bases generated from the phase states of the quantum
system. We consider the effects of several intercept and resend attacks. We derive explicitly the mutual information between
the legitimate parties as well as the mutual information between the sender and the different eavesdroppers in the communication
channel. We discuss the security of the cryptographic scheme and present some numerical analysis. 相似文献
84.
Journal of Nanoparticle Research - Highly sensitive low-cost non-enzymatic glucose sensor of copper oxide (CuO) nanorods (NRs) was successfully fabricated using a two-step anodization method with... 相似文献
85.
86.
Tabti T Chikina J Jacquinot JF Daoud M 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》1999,60(1):645-653
We consider theoretically the possibility of solid state NMR experiments with frozen linear polymer chains at interfaces. Three different cases are studied, namely, when the macromolecules are grafted on the surface, when they are adsorbed, and when they are very strongly adsorbed from a melt that is subsequently washed by a good solvent. The latter case is somewhat intermediate between the two former ones. For each case, we consider the relaxation when paramagnetic centers are located on the surface. We show that the shape of the relaxation curves depends critically on the monomer concentration profile, and exhibits characteristic power-law variations. 相似文献
87.
Salah Daoud Abdelhakim Latreche Abdelhalim Bencheikh 《Crystal Research and Technology》2016,51(1):115-116
In the present work, we have readjusted some empirical parameters obtained by Kumar et al. in their work which contains some numerical errors. 相似文献
88.
A possible model for the formation of interpenetrating polymer networks is suggested. Phase separation is assumed to be faster than gelation. This implies that domains rich in either component grow first until late stages of spinodal decomposition. In these domains, short linear chains are crosslinked, leading to large branched macromolecules. Growth of the domains is slowed down by the presence of crosslinked polymers. It is assumed that it is stopped when the sizes of the domains and of the branched macromolecules are comparable. The resulting domains are significantly larger than the average distance between crosslinks. These results are supported by recent neutron scattering results on a poly(carbonate-urethane)/polyvinyl pyridine interpenetrating network. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1507–1512, 1998 相似文献
89.
Violeta Jevtovi Haneen Hamoud Salma Al-Zahrani Khalaf Alenezi Salman Latif Tahani Alanazi Fahad Abdulaziz Duan Dimi 《Molecules (Basel, Switzerland)》2022,27(15)
New complex Co(III) with ligand Pyridoxal-S-methyl-isothiosemicarbazone, (PLITSC) was synthesized. X-ray analysis showed the bis-ligand octahedral structure of the cobalt complex [Co(PLITSC-H)2]BrNO3·CH3OH (compound 1). The intermolecular interactions governing the crystal structure were described by the Hirsfeld surface analysis. The structure of compound 1 and the corresponding Zn complex (([Zn(PLTSC)(H2O)2]SO4·H2O)) were optimized at the B3LYP/6–31 + G (d,p)/LanL2DZ level of theory, and the applicability was assessed by comparison with the crystallographic structure. The natural bond orbital analysis was used for the discussion on the stability of formed compounds. The antibacterial activity of obtained complexes towards S. aureus and E. coli was determined, along with the effect of compound 1 on the formation of free radical species. Activity of compound 1 towards the removal of methylene blue was also investigated. The voltammograms of these compounds showed the reduction of metal ions, as well as the catalyzed reduction of CO2 in acidic media. 相似文献
90.
Belkadi Ahlem Kenouche Samir Melkemi Nadjib Daoud Ismail Djebaili Rachida 《Structural chemistry》2021,32(6):2235-2249
Structural Chemistry - In this paper, a combined approach based on a k-means algorithm and statistical analysis has been applied successfully to classify 500 cytotoxic agents using 21 molecular... 相似文献