全文获取类型
收费全文 | 2595篇 |
免费 | 55篇 |
国内免费 | 8篇 |
专业分类
化学 | 1586篇 |
晶体学 | 16篇 |
力学 | 107篇 |
数学 | 492篇 |
物理学 | 457篇 |
出版年
2022年 | 27篇 |
2021年 | 49篇 |
2020年 | 47篇 |
2019年 | 28篇 |
2018年 | 29篇 |
2017年 | 24篇 |
2016年 | 73篇 |
2015年 | 40篇 |
2014年 | 50篇 |
2013年 | 129篇 |
2012年 | 132篇 |
2011年 | 142篇 |
2010年 | 86篇 |
2009年 | 81篇 |
2008年 | 142篇 |
2007年 | 143篇 |
2006年 | 131篇 |
2005年 | 125篇 |
2004年 | 104篇 |
2003年 | 98篇 |
2002年 | 81篇 |
2001年 | 42篇 |
2000年 | 33篇 |
1999年 | 31篇 |
1998年 | 27篇 |
1997年 | 37篇 |
1996年 | 57篇 |
1995年 | 28篇 |
1994年 | 38篇 |
1993年 | 28篇 |
1992年 | 35篇 |
1991年 | 28篇 |
1990年 | 22篇 |
1989年 | 28篇 |
1988年 | 19篇 |
1987年 | 21篇 |
1986年 | 23篇 |
1985年 | 22篇 |
1984年 | 25篇 |
1983年 | 26篇 |
1982年 | 29篇 |
1981年 | 16篇 |
1980年 | 24篇 |
1979年 | 19篇 |
1978年 | 16篇 |
1977年 | 17篇 |
1976年 | 13篇 |
1975年 | 12篇 |
1973年 | 15篇 |
1971年 | 10篇 |
排序方式: 共有2658条查询结果,搜索用时 46 毫秒
261.
262.
For a linear anisotropic hyperelastic body subjected to a state of pure strain it is shown that there are at least three directions such that the stress and strain tensors are coaxial. 相似文献
263.
Carlo Cercignani 《Journal of statistical physics》1994,77(5-6):1039-1048
We consider a simple model for the electron Boltzmann equation in a semiconductor and show that specific boundary value problems can be explicitly solved. Cases of both homogeneous and inhomogeneous electric fields are considered. 相似文献
264.
This paper overviews the work made by our group during the past 10–15 years on crystalline systems, semiconductor surfaces,
molecular complexes and on materials of interest for technological applications, such as the defective silicon or the novel
generation thermoelectric materials. Our main aim of extracting chemical insight into the analysis of electron densities and
computed wave functions is illustrated through a number of examples. The recently proposed Source Function analysis is reviewed
and a few of its more interesting applications are summarized. Software package developments, motivated by the need of a direct
comparison with experiment or by the help these packages can provide for interpreting complex experimental outcomes, are described
and future directions outlined. A particular emphasis is given to the TOPOND and TOPXD programs, which enable one to analyze
theoretical and experimental crystalline densities using the rigorous framework of the Quantum Theory of Atoms in Molecules,
due to Bader. 相似文献
265.
266.
Martina Mazzoni Lorenzo Franco Alberta Ferrarini Carlo Corvaja Giovanni Zordan Gianfranco Scorrano Michele Maggini 《Liquid crystals》2002,29(2):203-208
A nitroxide [60]fullerene adduct containing a pyrrolidine-1-oxyl group has been synthesized. Its orientational order in the nematic phase of the liquid crystal solvent 4,4'-azoxyanisole (PAA) has been measured from the variation of the EPR spectral parameters on passing from the isotropic to the nematic phase. Highly resolved EPR lines allow for precise evaluation of the shifts of the g , a N and a H values. Since the g and the hyperfine tensors are known, the order matrix could be obtained. This is compared with the one calculated with a theoretical model based on short range solute-solvent interactions, which predicts a considerable degree of orientation of the molecular axes, despite the almost spherical shape of the molecule. The agreement with experimental findings is quite good and it is further improved if a bent structure of the pyrrolidine ring is taken into account. 相似文献
267.
Giovanni Candiano Gian Marco Ghiggeri Gerolamo Delfino Carlo Queirolo Fabrizio Ginevri 《Analytica chimica acta》1986
A typical product (glycosyl lysine) formed by reaction of lysine with glyceraldehyde is measured at 490 nm after coupling with diazotized sulfanilic acid. Reaction with 4-dimethylaminobenzaldehyde was less satisfactory. 相似文献
268.
269.
Comparison results of Talenti type for elliptic problems with Dirichlet boundary conditions have been widely investigated in recent decades. In this paper, we deal with Robin boundary conditions. Surprisingly, contrary to the Dirichlet case, Robin boundary conditions make the comparison sensitive to the dimension, and while the planar case seems to be completely settled, in higher dimensions some open problems are yet unsolved. © 2023 The Authors. Communications on Pure and Applied Mathematics published by Wiley Periodicals LLC. 相似文献
270.