全文获取类型
收费全文 | 16684篇 |
免费 | 2554篇 |
国内免费 | 1569篇 |
专业分类
化学 | 12038篇 |
晶体学 | 250篇 |
力学 | 965篇 |
综合类 | 79篇 |
数学 | 1905篇 |
物理学 | 5570篇 |
出版年
2024年 | 61篇 |
2023年 | 409篇 |
2022年 | 695篇 |
2021年 | 758篇 |
2020年 | 835篇 |
2019年 | 714篇 |
2018年 | 630篇 |
2017年 | 559篇 |
2016年 | 815篇 |
2015年 | 899篇 |
2014年 | 936篇 |
2013年 | 1275篇 |
2012年 | 1445篇 |
2011年 | 1437篇 |
2010年 | 900篇 |
2009年 | 929篇 |
2008年 | 1053篇 |
2007年 | 894篇 |
2006年 | 801篇 |
2005年 | 743篇 |
2004年 | 533篇 |
2003年 | 430篇 |
2002年 | 419篇 |
2001年 | 326篇 |
2000年 | 298篇 |
1999年 | 298篇 |
1998年 | 197篇 |
1997年 | 157篇 |
1996年 | 202篇 |
1995年 | 166篇 |
1994年 | 140篇 |
1993年 | 125篇 |
1992年 | 105篇 |
1991年 | 88篇 |
1990年 | 94篇 |
1989年 | 68篇 |
1988年 | 63篇 |
1987年 | 50篇 |
1986年 | 40篇 |
1985年 | 43篇 |
1984年 | 37篇 |
1983年 | 17篇 |
1982年 | 16篇 |
1981年 | 20篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1976年 | 10篇 |
1975年 | 11篇 |
1971年 | 7篇 |
1969年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 22 毫秒
991.
In this article, we propose a tailored finite point method (TFPM) for the numerical solution of a type of fourth‐order singular perturbation problem in two dimensions based on the equation decomposition technique. Our finite point method has been tailored based on the local exponential basis functions. Furthermore, our TFPM satisfies the discrete maximum principle automatically. Our numerical examples show that our method has second order convergence rate in energy norm as $\varepsilon\to0$ . © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2011 相似文献
992.
Hong‐Lin Liao Zhi‐Zhong Sun Han‐Sheng Shi Ting‐Chun Wang 《Numerical Methods for Partial Differential Equations》2012,28(5):1598-1619
A compact ADI scheme of second‐order in time and fourth‐order in space is proposed for solving linear Schrödinger equations with periodic boundary conditions. By using the recently suggested discrete energy method, it is shown that the stable compact ADI method is unconditionally convergent in the maximum norm. Numerical experiments, including the comparisons with the second‐order ADI scheme and the time‐splitting Fourier pseudospectral method, are presented to support the theoretical results and show the effectiveness of our method. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2012 相似文献
993.
Renji Han Dept.of Basic Courses Huishang Vocational College Hefei Wei Jiang 《Annals of Differential Equations》2012,(1):38-47
In this paper,the asymptotic stability of singular nonlinear differential systems with unbounded delays is considered.The stability criteria are derived based on a kind of Lyapunov-functional and some technique of matrix inequalities.The criteria are described as matrix equation and matrix inequalities,which are computationally flexible and efficient.Two examples are given to illustrate the results. 相似文献
994.
设K是一个代数闭域,A是域K上一个有限维代数.我们利用箭图方法给出了(*)-serial incidence代数的分类. 相似文献
995.
若(X,Y)服从二元Block-Basu型指数分布,则X,Y相互独立与不相关是等价的.还给出了X,Y的相关系数和尾部相关系数. 相似文献
996.
In this paper we derive some irrationality and linear independence results for series of the form where is either a non-negative integer sequence with υn = o(log n/log log n) or a non-decreasing integer sequence with . 相似文献
997.
In this paper, we discuss the classical ill-posed problem of numerical differentiation, assuming that the smoothness of the function to be differentiated is unknown. Using recent results on adaptive regularization of general ill-posed problems, we propose new rules for the choice of the stepsize in the finite-difference methods, and for the regularization parameter choice in numerical differentiation regularized by the iterated Tikhonov method. These methods are shown to be effective for the differentiation of noisy functions, and the order-optimal convergence results for them are proved.
998.
Jong Yeoul Park Jae Ug Jeong Yong Han Kang 《Nonlinear Analysis: Theory, Methods & Applications》2009,71(12):e329
In this paper, an optimal control problem for parabolic variational inequalities with delays and state constraint is investigated and the necessary conditions for optimal controls are derived. 相似文献
999.
Bin Han 《Advances in Computational Mathematics》2006,24(1-4):375-403
In this paper, we present a necessary and sufficient condition for the existence of solutions in a Sobolev space Wpk(ℝs) (1≤p≤∞) to a vector refinement equation with a general dilation matrix. The criterion is constructive and can be implemented.
Rate of convergence of vector cascade algorithms in a Sobolev space Wpk(ℝs) will be investigated. When the dilation matrix is isotropic, a characterization will be given for the Lp (1≤p≤∞) critical smoothness exponent of a refinable function vector without the assumption of stability on the refinable function
vector. As a consequence, we show that if a compactly supported function vector φ∈Lp(ℝs) (φ∈C(ℝs) when p=∞) satisfies a refinement equation with a finitely supported matrix mask, then all the components of φ must belong to a Lipschitz
space Lip(ν,Lp(ℝs)) for some ν>0. This paper generalizes the results in R.Q. Jia, K.S. Lau and D.X. Zhou (J. Fourier Anal. Appl. 7 (2001) 143–167)
in the univariate setting to the multivariate setting.
Dedicated to Professor Charles A. Micchelli on the occasion of his 60th birthday
Mathematics subject classifications (2000) 42C20, 41A25, 39B12.
Research was supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC Canada) under Grant
G121210654. 相似文献
1000.
引入两个与GA-凸函数有关的函数,研究了它们的凸性、单调性及相互关系,获得了已有文献关于GA-凸函数的Hadamard型不等式的加细,也得到一些新的不等式. 相似文献