全文获取类型
收费全文 | 780篇 |
免费 | 19篇 |
国内免费 | 6篇 |
专业分类
化学 | 552篇 |
晶体学 | 2篇 |
力学 | 17篇 |
数学 | 145篇 |
物理学 | 89篇 |
出版年
2020年 | 8篇 |
2019年 | 13篇 |
2018年 | 4篇 |
2016年 | 12篇 |
2015年 | 18篇 |
2014年 | 16篇 |
2013年 | 28篇 |
2012年 | 30篇 |
2011年 | 43篇 |
2010年 | 32篇 |
2009年 | 22篇 |
2008年 | 39篇 |
2007年 | 31篇 |
2006年 | 39篇 |
2005年 | 25篇 |
2004年 | 26篇 |
2003年 | 27篇 |
2002年 | 21篇 |
2001年 | 20篇 |
2000年 | 19篇 |
1999年 | 10篇 |
1998年 | 16篇 |
1997年 | 15篇 |
1996年 | 7篇 |
1995年 | 11篇 |
1994年 | 15篇 |
1993年 | 11篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1987年 | 12篇 |
1985年 | 13篇 |
1984年 | 14篇 |
1983年 | 11篇 |
1982年 | 8篇 |
1981年 | 12篇 |
1980年 | 13篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 13篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1973年 | 4篇 |
1972年 | 8篇 |
1970年 | 5篇 |
1968年 | 5篇 |
1967年 | 5篇 |
1926年 | 7篇 |
排序方式: 共有805条查询结果,搜索用时 15 毫秒
101.
102.
103.
Reiner Horst 《The Journal of the Operational Research Society》1984,35(4):327-335
The relationships between multiple optimal dual solutions of a convex programming problem and the corresponding primal optimal value function are established by straightforward arguments on known results in duality theory. The subsequent discussion includes a demonstration that one-sided shadow prices can be found by solving a linear programming problem, conditions for the uniqueness and validity of the classical shadow price interpretation and a specialization of the results to the linear programming case. 相似文献
104.
Diethyl-2,2′-bipyridyl-palladium(II) is synthesized and its decomposition reactions in absence and presence of methyl acrylate are compared with those of the corresponding nickel and platinum complexes. Depending on the reaction conditions either CC-coupling or disproportionation can be induced. 相似文献
105.
Helmut Poleschner Reiner Radeglia Hinrich Meyer 《Magnetic resonance in chemistry : MRC》1984,22(8):480-485
This paper reports the 77Se NMR chemical shifts of 1,3-dithiole-, 1,3-thiaselenole- and 1,3-diselenole-2-ones, -thiones and -selones, of the corresponding saturated compounds 1,3-diselenolane-2-one, -thione and -selone, and the 1,3-thiaselenolium tetrafluoroborates, either unsubstituted or substituted by morpholino, ethylthio or ethylseleno groups in the 2-position. The 77Se chemical shift values of the ring selenium and the C?Se groups are compared with the 13C chemical shift values of neighbouring carbon atoms. The relationships between the 77Se chemical shifts of the C?Se groups and the wavelengths of their n→* absorption in the UV-visible spectrum are discussed with respect to the significance of the δE term in the contribution of the paramagnetic screening and the electron density distribution. 相似文献
106.
The 13C NMR signals of some mono- and disubstituted aryl compounds were assigned by means of empirical additive substituent parameters and information taken from fully coupled spectra. This assignment was compared with that obtained with the help of the method of automatic assignment of the signals based on the linear relationship between 13C chemical shift and charge density. The results show that in the cases of XR substituents (X = O, NH and R = H, CH3, CH2CH2OH) a good correlation is observed and the automatic assignment is correct. In contrast, in the cases of ? CH2CH2Y substituents (Y = OH, NH2, Cl) a worsening of the correlation is observed and the automatic assignment is not correct. It is suggested that for compounds with a preliminarily known assignment, the automatic assignment can serve as an additional criterion for the reliability of the linear relationship between 13C chemical shift and charge density. 相似文献
107.
Dr. Reiner Kümmel 《Zeitschrift für Physik A Hadrons and Nuclei》1969,218(5):472-494
The time-dependent Bogoliubov Equations — which are derived in a slightly generalized form — are applied to the problem of quasiparticle reflection from the phaseboundary between a normal and a superconducting region. The momentum balance of current flow through the boundary is discussed. The supercurrent induced by a quasiparticle with excitation energy less than the maximum value of the pair-potential is calculated. 相似文献
108.
109.
Reiner Fritzsche 《Mathematische Annalen》1966,164(1):54-57
Ohne Zusammenfassung 相似文献
110.