全文获取类型
收费全文 | 8531篇 |
免费 | 197篇 |
国内免费 | 4篇 |
专业分类
化学 | 5106篇 |
晶体学 | 173篇 |
力学 | 155篇 |
数学 | 1219篇 |
物理学 | 2079篇 |
出版年
2022年 | 199篇 |
2021年 | 252篇 |
2020年 | 132篇 |
2019年 | 163篇 |
2018年 | 159篇 |
2017年 | 159篇 |
2016年 | 282篇 |
2015年 | 218篇 |
2014年 | 299篇 |
2013年 | 700篇 |
2012年 | 455篇 |
2011年 | 493篇 |
2010年 | 396篇 |
2009年 | 347篇 |
2008年 | 400篇 |
2007年 | 379篇 |
2006年 | 348篇 |
2005年 | 290篇 |
2004年 | 250篇 |
2003年 | 248篇 |
2002年 | 184篇 |
2001年 | 156篇 |
2000年 | 132篇 |
1999年 | 94篇 |
1998年 | 103篇 |
1997年 | 73篇 |
1996年 | 78篇 |
1995年 | 101篇 |
1994年 | 59篇 |
1993年 | 43篇 |
1992年 | 73篇 |
1991年 | 48篇 |
1990年 | 69篇 |
1989年 | 58篇 |
1988年 | 74篇 |
1987年 | 55篇 |
1986年 | 65篇 |
1985年 | 97篇 |
1984年 | 107篇 |
1983年 | 68篇 |
1982年 | 64篇 |
1981年 | 68篇 |
1980年 | 83篇 |
1979年 | 57篇 |
1978年 | 63篇 |
1977年 | 67篇 |
1976年 | 66篇 |
1975年 | 51篇 |
1974年 | 47篇 |
1973年 | 44篇 |
排序方式: 共有8732条查询结果,搜索用时 15 毫秒
1.
Gürbüzbalaban Mert Ruszczyński Andrzej Zhu Landi 《Journal of Optimization Theory and Applications》2022,194(3):1014-1041
Journal of Optimization Theory and Applications - We consider a distributionally robust formulation of stochastic optimization problems arising in statistical learning, where robustness is with... 相似文献
2.
3.
4.
Russian Chemical Bulletin - The discovery and studies of chemistry of dichlorocarbene and other electron deficient carbenes are discussed. 相似文献
5.
Karolina Kula Agnieszka Kcka-Zych Agnieszka apczuk-Krygier Zbigniew Wzorek Anna K. Nowak Radomir Jasiski 《Molecules (Basel, Switzerland)》2021,26(5)
The present paper is a continuation of comprehensive study regarding to synthesis and properties of pyrazoles and their derivatives. In its framework an experimental and theoretical studies of thermal decomposition of the 3,3-diphenyl-4-(trichloromethyl)-5-nitropyrazoline were performed. It was found, that the decompositions of the mentioned pyrazoline system in the solution and at the melted state proceed via completely different molecular mechanisms. These mechanisms have been explained in the framework of the Molecular Electron Density Theory (MEDT) with the computational level of B3LYP/6-31G(d). A Bonding Evolution Theory (BET) examination of dehydrochlorination of the 3,3-diphenyl-4-(trichloromethyl)-5-nitropyrazoline permits elucidation of the molecular mechanism. It was found, that on the contrary for most known HCl extrusion processes in solution, this reaction is realised via single-step mechanism. 相似文献
6.
Summary Carbon deposits on the surface ofRu/Fe2O3 catalysts used in the water-gas shift reaction have been investigated by Auger Electron Spectrometry. A correlation has been
found between the thickness of the carbon deposit and the catalytic activity in WGSR. The carbon deposit covers the metallic
active centers and blocks their contact with reagents. The dotting of the iron oxide support with sodium has been found to
reduce the amount of carbon deposit. . 相似文献
7.
Space-time directional Lyapunov exponents are introduced. They describe the maximal velocity of propagation to the right or to the left of fronts of perturbations in a frame moving with a given velocity. The continuity of these exponents as function of the velocity and an inequality relating them to the directional entropy is proved. 相似文献
8.
Agnieszka Kaamajska 《Mathematical Methods in the Applied Sciences》2006,29(11):1307-1325
The weak limits of sequences {f(uν)}ν∈? where uν's are vector‐valued µ‐measurable functions defined on a compact set Ω and f is (possibly) discontinuous are investigated. As shown by the author (J. Conv. Anal. (to appear)), they are described in terms of integral formulae involving parametrized measures independent of f, similarly as in the classical theorem by Young and its generalization due to DiPerna and Majda. In the present paper we describe the supports of the involved parametrized measures. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
9.
10.
Teresa Regińska 《BIT Numerical Mathematics》2004,44(1):119-133
The paper concerns conditioning aspects of finite-dimensional problems arising when the Tikhonov regularization is applied
to discrete ill-posed problems. A relation between the regularization parameter and the sensitivity of the regularized solution
is investigated. The main conclusion is that the condition number can be decreased only to the square root of that for the
nonregularized problem. The convergence of solutions of regularized discrete problems to the exact generalized solution is
analyzed just in the case when the regularization corresponds to the minimal condition number. The convergence theorem is
proved under the assumption of the suitable relation between the discretization level and the data error. As an example the
method of truncated singular value decomposition with regularization is considered.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献