全文获取类型
收费全文 | 725篇 |
免费 | 15篇 |
专业分类
化学 | 519篇 |
晶体学 | 15篇 |
力学 | 25篇 |
数学 | 14篇 |
物理学 | 167篇 |
出版年
2022年 | 7篇 |
2021年 | 6篇 |
2020年 | 10篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 13篇 |
2015年 | 14篇 |
2014年 | 14篇 |
2013年 | 32篇 |
2012年 | 24篇 |
2011年 | 47篇 |
2010年 | 16篇 |
2009年 | 20篇 |
2008年 | 32篇 |
2007年 | 36篇 |
2006年 | 36篇 |
2005年 | 47篇 |
2004年 | 34篇 |
2003年 | 35篇 |
2002年 | 23篇 |
2001年 | 13篇 |
2000年 | 15篇 |
1998年 | 6篇 |
1997年 | 8篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 15篇 |
1993年 | 15篇 |
1992年 | 6篇 |
1991年 | 15篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 9篇 |
1987年 | 13篇 |
1986年 | 13篇 |
1985年 | 10篇 |
1984年 | 16篇 |
1983年 | 3篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1968年 | 3篇 |
1965年 | 4篇 |
1963年 | 5篇 |
排序方式: 共有740条查询结果,搜索用时 15 毫秒
31.
32.
33.
Yohji Nakatsuji Toshinori Inoue Masato Wada Mitsuo Okahara 《Journal of inclusion phenomena and macrocyclic chemistry》1991,10(3):379-386
A new type of 18-crown-6 derivative having two carboxylic acids on the side arms transported calcium and potassium ions in opposite directions across a dichloromethane membrane by pH control. Calcium and potassium ions were concentrated in the acidic and the basic phases, respectively. The presence of picrate ion in the acidic phase plays an important role in the transport of potassium ion from the acidic to the basic phase. 相似文献
34.
35.
Y. Ohashi Y. Kurita T. Suzuki M. Tokuda 《Journal of the mechanics and physics of solids》1981,29(1):51-67
Ilyushin's general plasticity theory expressed in a vector space corresponding to the deviatoric tensor space is available in formulating precise stress-strain relations of inelastic deformations by incorporating the deformation history of metals under complex loadings. In this case, the hypothesis of local determinability proposed by Lensky (1960) is useful for determining the explicit form of the stress-strain relation. In the present paper, the hypothesis is discussed by using not only data obtained by an experiment in which the history effect on the succeeding deformation is clearly estimated, but also data described in previous work. As the result, the hypothesis of local determinability has been confirmed to hold with high accuracy in every case. 相似文献
36.
37.
An apparatus and the procedure for cellulose acetate isoelectric focusing were refined and optimized for routine use in clinical laboratories. The space in the electrophoretic chamber was minimized to maintain high humidity during the run. The water content of the thin cellulose acetate membranes in the chamber was well controlled during isoelectric focusing and the effect of atmospheric carbon dioxide was also excluded. The temperature of the membranes was kept below 2 degrees C, even under conditions of high electric field strength for faster isoelectric focusing of high-molecular-weight proteins. No special training was required for technicians in clinical laboratories to obtain reproducible isoelectric profiles of human serum proteins. 相似文献
38.
39.
The effect of pressure on the lattice parameters of R Ni 2 B 2 C ( R = Y, Ho, Er, Tm, Lu) has been measured in order to investigate the relation of T C to axial ratio c/a in the tetragonal lattice or the cohesive properties of these materials. The large anisotropies are observed in the lattice compression curves especially for R =Ho and Tm; the c -axis is more compressible than the a -axis. On the other hand, the anisotropy in the lattice compression is found to be relatively small for R =Y and Lu. The close relation between T C and c/a is pointed out particularly for R =Ho. 相似文献
40.
Energy distributions of π+ produced from 12C by electrons of total energy 195 MeV were measured at various angles. The results show large contributions from transitions leaving the residual nucleus in the ground (1+), first (2+) excited state and states at around 4.5 MeV. The angular distributions of 12C(γ, π+)12B leading to these residual states are deduced from the energy distributions by the unfolding method with the virtual photon theory. Theoretical results with the Helm model and the shell model are compared with the experimental results. Their relative shapes are in good agreement. A better agreement in the absolute value is found for the theoretical results which include the final-state interaction estimated with a pion optical potential. The surface production model shows better agreement with the experimental (γ, π+) cross sections than the volume production model. 相似文献