全文获取类型
收费全文 | 1754篇 |
免费 | 50篇 |
国内免费 | 7篇 |
专业分类
化学 | 1245篇 |
晶体学 | 21篇 |
力学 | 70篇 |
数学 | 109篇 |
物理学 | 366篇 |
出版年
2024年 | 10篇 |
2023年 | 20篇 |
2022年 | 31篇 |
2021年 | 39篇 |
2020年 | 35篇 |
2019年 | 62篇 |
2018年 | 37篇 |
2017年 | 35篇 |
2016年 | 62篇 |
2015年 | 31篇 |
2014年 | 49篇 |
2013年 | 141篇 |
2012年 | 78篇 |
2011年 | 149篇 |
2010年 | 75篇 |
2009年 | 48篇 |
2008年 | 65篇 |
2007年 | 68篇 |
2006年 | 63篇 |
2005年 | 46篇 |
2004年 | 51篇 |
2003年 | 39篇 |
2002年 | 47篇 |
2001年 | 26篇 |
2000年 | 24篇 |
1999年 | 11篇 |
1997年 | 11篇 |
1996年 | 16篇 |
1995年 | 10篇 |
1994年 | 13篇 |
1993年 | 15篇 |
1992年 | 16篇 |
1988年 | 17篇 |
1987年 | 19篇 |
1986年 | 13篇 |
1985年 | 19篇 |
1984年 | 11篇 |
1983年 | 14篇 |
1980年 | 20篇 |
1979年 | 11篇 |
1978年 | 15篇 |
1976年 | 9篇 |
1975年 | 10篇 |
1966年 | 25篇 |
1965年 | 18篇 |
1964年 | 14篇 |
1963年 | 16篇 |
1962年 | 43篇 |
1961年 | 11篇 |
1960年 | 12篇 |
排序方式: 共有1811条查询结果,搜索用时 15 毫秒
101.
We provide experimental evidence for stretching and collapse of neutral polymer layers, already adsorbed at an oil-in-water interface, due to its interaction with surfactants. Upon stretching, the first interaction length (2L(0)) follows a power law dependence on surfactant concentration ( proportional, variant C(x)(s), where x approximately 0.5 for cationic surfactants) and collapses in the presence of salt, as a relatively weak power law (C(-y)(s), where y=0.17), in good agreement with brush length decay for polyelectrolyte brushes. 相似文献
102.
The electronic structure of substitutional non-magnetic impurities Cu, Ag, Cd, Mg, Zn, Ga, In, Ge, Si and Sn in Al is studied
using density functional theory. A simple physical model is proposed to calculate the effective charges on impurities in trivalent
metal Al. A linear relation is found between the effective charges on impurities and impurity vacancy capture radii. The spherical
solid model (SSM) is used to account for discrete nature of the host. The impurity-induced change in charge density, scattering
phase shifts, host-impurity potential, residual resistivity and impurity self-energy are calculated. Higher order scattering
phase shifts are found significant and the host-impurity potential is found proportional to effective charge on impurity in
its vicinity. The self-consistently calculated potential is used to calculate the electric field gradients (EFGs) at the first
and second nearest neighbours (1NNs, 2NNs) of impurity. The calculated values are in agreement with the experimental results. 相似文献
103.
V. K. Gupta S. K. Badval I. K. Daftari G. L. Kaul L. K. Mangotra N. K. Rao S. K. Sharma Gian Singh Y. Prakash 《Zeitschrift fur Physik C Particles and Fields》1981,10(1):29-36
The shower particle multiplicity (〈n s 〉) in thep-nucleus interactions for different targets, in the incident energy range of ~6–500 GeV has been studied. The variation of multiplicity parameters with target mass (A) or with number of interactions that the incident hadron suffers inside the nucleus (v A ) and with the changed particle multiplicity inp-p interactions (〈n ch〉) has been examined in the light of the various models of multiparticle production. The present analysis favours the hydrodynamical model though some other models can not be conclusively ruled out. 相似文献
104.
S. Prakash 《Fresenius' Journal of Analytical Chemistry》1962,192(3):425
Ohne Zusammenfassung 相似文献
105.
Steady propagation of a single pulse in an inhomogeneously broadened resonant medium is studied. 2π-pulse solutions which are slightly different from those given in the literature are reported and it is shown that π-pulse solutions do not exist. 相似文献
106.
B.G. Prakash 《Journal of sound and vibration》1980,70(2):303-305
107.
S. S. Rattan A. V. R. Reddy V. S. Mallapurkar R. J. Singh Satya Prakash 《Journal of Radioanalytical and Nuclear Chemistry》1981,67(1):95-99
A simple method is reported in this paper to estimate229Th in the presence of228Th. The total activity of229Th and228Th was determined by following the alpha activity growth (using a liquid scintillation counter and proportional counter) of
purified thorium samples. The activity ratio of229Th/228Th was determined by alpha spectrometry. From the initial total activity and ratio, disintegration rates of229Th and228Th were calculated. The values obtained for the activities have a precision better than ±2%. 相似文献
108.
109.
110.
Let A be an infinite subset of natural numbers, and X a positive real number. Let r(n) denotes the number of solution of the equation n=a1+a2 where a1?a2 and a1, a2∈A. Also let |A(X)| denotes the number of natural numbers which are less than or equal to X and belong to A. For those A which satisfy the condition that for all sufficiently large natural numbers n we have r(n)≠1, we improve the lower bound of |A(X)| given by Nicolas et. al. [NRS98]. The bound which we obtain is essentially best possible. 相似文献