全文获取类型
收费全文 | 549篇 |
免费 | 11篇 |
国内免费 | 1篇 |
专业分类
化学 | 336篇 |
晶体学 | 11篇 |
力学 | 11篇 |
数学 | 30篇 |
物理学 | 173篇 |
出版年
2023年 | 7篇 |
2022年 | 12篇 |
2021年 | 8篇 |
2020年 | 14篇 |
2019年 | 20篇 |
2018年 | 20篇 |
2017年 | 14篇 |
2016年 | 19篇 |
2015年 | 14篇 |
2014年 | 12篇 |
2013年 | 30篇 |
2012年 | 36篇 |
2011年 | 31篇 |
2010年 | 22篇 |
2009年 | 14篇 |
2008年 | 23篇 |
2007年 | 28篇 |
2006年 | 23篇 |
2005年 | 19篇 |
2004年 | 14篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 13篇 |
1983年 | 6篇 |
1981年 | 12篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1971年 | 5篇 |
1955年 | 2篇 |
1954年 | 2篇 |
排序方式: 共有561条查询结果,搜索用时 15 毫秒
491.
James O. Thomas Jakub K. Sowa Bart Limburg Xinya Bian Charalambos Evangeli Jacob L. Swett Sumit Tewari Jonathan Baugh George C. Schatz G. Andrew D. Briggs Harry L. Anderson Jan A. Mol 《Chemical science》2021,12(33):11121
Electron–electron interactions are at the heart of chemistry and understanding how to control them is crucial for the development of molecular-scale electronic devices. Here, we investigate single-electron tunneling through a redox-active edge-fused porphyrin trimer and demonstrate that its transport behavior is well described by the Hubbard dimer model, providing insights into the role of electron–electron interactions in charge transport. In particular, we empirically determine the molecule''s on-site and inter-site electron–electron repulsion energies, which are in good agreement with density functional calculations, and establish the molecular electronic structure within various oxidation states. The gate-dependent rectification behavior confirms the selection rules and state degeneracies deduced from the Hubbard model. We demonstrate that current flow through the molecule is governed by a non-trivial set of vibrationally coupled electronic transitions between various many-body ground and excited states, and experimentally confirm the importance of electron–electron interactions in single-molecule devices.Experimental studies of electron transport through an edge-fused porphyrin oligomer in a graphene junction are interpreted within a Hubbard dimer framework. 相似文献
492.
Bhatia Sumit Kaur 《Nonlinear Analysis: Theory, Methods & Applications》2010,73(8):2368-2382
Let Ω be a bounded domain in RN,N≥2, with C2 boundary. In this work, we study the existence of multiple positive solutions of the following problem:
493.
494.
495.
496.
We construct and study the twisted reduced SU(N)×SU(N) chiral model in two dimensions. The equivalence of the reduced model to the field theory is established by examining the Dyson-Schwinger equations and weak coupling perturbation expansion. We evaluate the internal energy and two-point correlation function by extensive Monte Carlo simulations for N=12, 24 and 36. We find a non-analyticity near the weak coupling edge of the crossover region in which the system flips back and forth between the “normal” state and one characterised by a strongly disordered correlation function. 相似文献
497.
The three dominant mechanisms giving major contributions to vibrational relaxation in molecular systems are (a) pure dephasing,
(b) depopulation (or energy relaxation), and (c) resonant transfer. Here (c) is not considered but the effects due to thesimultaneous occurrence of (a) and (b) are treated within a stochastic model. In dealing with (a), the vibrational frequency is assumed
to undergo random uncorrelated ‘jump’, due to fluctuations in the environment of the active molecule between a continuous
set of values. The ensuing results are somewhat different from those of the commonly used Kubo model of vibrational dephasing,
especially at long times and appear to be better suited in interpreting certain experimental data. The model is next extended
to include the simultaneous occurrence of (b). The calculation leads to two important conclusions: (i) the lineshape is not
just the convolution of those due to (a) and (b), and (ii) the lineshape is asymmetric, if the intermolecular interactions
are not isotropic. 相似文献
498.
We discuss the possibility of equilibrium (and thermalization) in heavy-ion collisions at intermediate energies within a transport model. This was achieved by dividing the nuclear matter into different collision zones. We find that those nucleons which experience at least ten collisions are close to complete equilibrium whereas others never achieve any equilibrium. 相似文献
499.
500.
TheL shell x-ray intensity ratios have been measured for the elements Ta and W by photoionization ofL shell electrons in the photon energy region 14⩽E⩽44 keV. The experimental results are compared with those calculated at the photon energies used in the present measurements.
The measured values show fairly good agreement with the calculated values within the experimental uncertainties. 相似文献