全文获取类型
收费全文 | 364745篇 |
免费 | 3393篇 |
国内免费 | 1567篇 |
专业分类
化学 | 191205篇 |
晶体学 | 5286篇 |
力学 | 17326篇 |
综合类 | 66篇 |
数学 | 43645篇 |
物理学 | 112177篇 |
出版年
2020年 | 3310篇 |
2019年 | 3788篇 |
2018年 | 5290篇 |
2017年 | 5360篇 |
2016年 | 7076篇 |
2015年 | 3914篇 |
2014年 | 6485篇 |
2013年 | 14749篇 |
2012年 | 12177篇 |
2011年 | 14649篇 |
2010年 | 11073篇 |
2009年 | 11004篇 |
2008年 | 13954篇 |
2007年 | 13920篇 |
2006年 | 12831篇 |
2005年 | 11638篇 |
2004年 | 10702篇 |
2003年 | 9480篇 |
2002年 | 9526篇 |
2001年 | 10658篇 |
2000年 | 8002篇 |
1999年 | 5972篇 |
1998年 | 5166篇 |
1997年 | 5022篇 |
1996年 | 4845篇 |
1995年 | 4279篇 |
1994年 | 4343篇 |
1993年 | 4238篇 |
1992年 | 4512篇 |
1991年 | 4847篇 |
1990年 | 4565篇 |
1989年 | 4527篇 |
1988年 | 4378篇 |
1987年 | 4326篇 |
1986年 | 4186篇 |
1985年 | 5439篇 |
1984年 | 5495篇 |
1983年 | 4638篇 |
1982年 | 4913篇 |
1981年 | 4615篇 |
1980年 | 4247篇 |
1979年 | 4666篇 |
1978年 | 4996篇 |
1977年 | 5089篇 |
1976年 | 5245篇 |
1975年 | 4848篇 |
1974年 | 4873篇 |
1973年 | 5012篇 |
1972年 | 3973篇 |
1971年 | 3376篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
122.
I. L. Bataronov A. M. Roshchupkin 《Journal of Applied Mechanics and Technical Physics》1991,32(2):259-265
Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 2, pp. 127–134, March–April, 1991. 相似文献
123.
L. Triolo 《Mathematical Methods in the Applied Sciences》1995,18(7):507-513
A generalized relative entropy functional is associated to the evolution of gas in a container with (generally) non-uniform boundary data. A decomposition for its rate in ‘bulk’ and in ‘boundary’ terms is given; for the linear case both have a definite sign. The relation with the strong L1 stability is pointed out. 相似文献
124.
125.
126.
L. B. Parnovski 《Mathematische Nachrichten》1995,174(1):253-263
We investigate the asymptotic behaviour of the counting function of Dirichlet eigenvalues on some class of noncompact manifolds. We prove that in cases when the volume or the perimeter (the volume of the boundary) of the manifold is infinite, some additional (nonclassical) terms appear in the precise asymptotics. The coefficients at the classical terms in those are regularized in some special way volume (resp. perimeter) of the manifold. 相似文献
127.
The kinetics of hydrogen peroxide decomposition in a guaiacol solution, catalyzed by potassium hexacyanoferrate(II), were studied. The reaction mainly follows the pathway of guaiacol hydroxylation. The reaction order is 1 with respect to H2O2, 0.5 with respect to hexacyanoferrate, and from 0.4 to 0 with respect to guaiacol (the latter parameter decreases with increasing guaiacol concentration). The apparent activation energy is 105 kJ mol-
1. A kinetic scheme of the process was proposed. An expression consistent with the experiment was obtained for the rate of hydrogen peroxide decomposition in the presence of guaiacol, catalyzed by hexacyanoferrate(II). 相似文献
128.
Nikulin S. S. Akatova I. N. Kondrat'eva N. A. 《Russian Journal of Applied Chemistry》2003,76(4):652-655
The influence of the charge of a metal cation and the nature of a coagulant on the recovery of butadiene-styrene rubber and properties of rubber stocks and vulcanizates was examined. 相似文献
129.
130.
Barannikov V. P. Guseinov S. S. V'ugin A. I. 《Russian Journal of Coordination Chemistry》2002,28(3):153-162
A review of the experimental and theoretical studies of the crown ether complexes with polar molecules in their crystals, solutions, and in a gas phase is given. The type of the molecular bonds in the complexes, their stoichiometry, and the change in the macrocycle conformation during complex formation are considered, as well as the effect of the macrocycle structure and the nature of the medium on the efficiency of the molecular bonding. New data are given on the enthalpies of transfer of the crown ethers from tetrachloromethane into solvents capable of forming hydrogen bonds. The enthalpies of specific interactions of macrocycles with the molecules of the solvents in the medium of the same solvents are characterized. The conformations of the crown ethers in the media under study are discussed. 相似文献