全文获取类型
收费全文 | 5436篇 |
免费 | 695篇 |
国内免费 | 484篇 |
专业分类
化学 | 416篇 |
晶体学 | 21篇 |
力学 | 548篇 |
综合类 | 107篇 |
数学 | 4571篇 |
物理学 | 952篇 |
出版年
2024年 | 14篇 |
2023年 | 75篇 |
2022年 | 97篇 |
2021年 | 123篇 |
2020年 | 174篇 |
2019年 | 156篇 |
2018年 | 193篇 |
2017年 | 221篇 |
2016年 | 185篇 |
2015年 | 145篇 |
2014年 | 237篇 |
2013年 | 531篇 |
2012年 | 227篇 |
2011年 | 242篇 |
2010年 | 236篇 |
2009年 | 303篇 |
2008年 | 299篇 |
2007年 | 360篇 |
2006年 | 306篇 |
2005年 | 320篇 |
2004年 | 231篇 |
2003年 | 234篇 |
2002年 | 253篇 |
2001年 | 200篇 |
2000年 | 187篇 |
1999年 | 153篇 |
1998年 | 150篇 |
1997年 | 140篇 |
1996年 | 104篇 |
1995年 | 73篇 |
1994年 | 63篇 |
1993年 | 35篇 |
1992年 | 41篇 |
1991年 | 37篇 |
1990年 | 21篇 |
1989年 | 15篇 |
1988年 | 18篇 |
1987年 | 18篇 |
1986年 | 20篇 |
1985年 | 25篇 |
1984年 | 27篇 |
1983年 | 15篇 |
1982年 | 16篇 |
1981年 | 12篇 |
1980年 | 21篇 |
1979年 | 12篇 |
1978年 | 16篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1971年 | 4篇 |
排序方式: 共有6615条查询结果,搜索用时 0 毫秒
1.
Jinchao Xu 《应用数学学报(英文版)》2002,18(2):185-200
Abstract Some new local and parallel finite element algorithms are proposed and analyzed in this paper foreigenvalue problems.With these algorithms, the solution of an eigenvalue problem on a fine grid is reduced tothe solution of an eigenvalue problem on a relatively coarse grid together with solutions of some linear algebraicsystems on fine grid by using some local and parallel procedure.A theoretical tool for analyzing these algorithmsis some local error estimate that is also obtained in this paper for finite element approximations of eigenvectorson general shape-regular grids. 相似文献
2.
Michael R. Caputo 《Natural Resource Modeling》1989,3(2):241-259
This paper analyzes the extent to which standard dynamic renewable resource models possess refutable implications. Both the steady state comparative static and local comparative dynamic properties of the standard model are studied. A unified framework is developed which enables one to analyze the qualitative properties of any standard renewable resource model. This is achieved by explicitly linking the local stability, steady state comparative static, and local comparative dynamic properties of the model. 相似文献
3.
Kasper K. Berthelsen Jesper Møller 《Bulletin of the Brazilian Mathematical Society》2002,33(3):351-367
This primer provides a self-contained exposition of the case where spatial birth-and-death processes are used for perfect
simulation of locally stable point processes. Particularly, a simple dominating coupling from the past (CFTP) algorithm and
the CFTP algorithms introduced in [13], [14], and [5] are studied. Some empirical results for the algorithms are discussed.
Received: 30 June 2002 相似文献
4.
5.
Fillmore在[1]中得到一个定理:设A,T是Banach空间X上的线性变换,A有界,若Lat(A) Lat(T)且AT=TA,则T是A的多项式.在本文里,以此作为引理,讨论了Banach空间上可逆线性变换A在什么情况下,A-1可表示为A的多项式.本文最主要的结论是定理3.4:设X是Banach空间,A是X上的有界线性变换,且可逆,则A-1是A的多项式当且仅当A-1是A的局部多项式. 相似文献
6.
We treat here of the question of absorbing boundary conditionsfor nonlinear diffusion equations. We use the conditions designedfor the linear equation, we prove them to be well posed forthe nonlinear problem, and through numerical experiments thatthey are well suited for reactiondiffusion equations. 相似文献
7.
For vector quasivariational inequalities involving multifunctions in topological vector spaces, an existence result is obtained without a monotonicity assumption and with a convergence assumption weaker than semicontinuity. A new type of quasivariational inequality is proposed. Applications to quasicomplementarity problems and traffic network equilibria are considered. In particular, definitions of weak and strong Wardrop equilibria are introduced for the case of multivalued cost functions. 相似文献
8.
Norikazu Yamaguchi 《Mathematical Methods in the Applied Sciences》2005,28(13):1507-1526
In this paper we are concerned with the initial boundary value problem of the micropolar fluid system in a three dimensional bounded domain. We study the resolvent problem of the linearized equations and prove the generation of analytic semigroup and its time decay estimates. In particular, Lp–Lq type estimates are obtained. By use of the Lp–Lq estimates for the semigroup, we prove the existence theorem of global in time solution to the original nonlinear problem for small initial data. Furthermore, we study the magneto‐micropolar fluid system in the final section. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
9.
Song Jiang 《Mathematische Nachrichten》1998,190(1):169-183
We consider initial boundary value problems for the equations of the one-dimensional motion of a viscous, heat-conducting gas with density-dependent viscosity that decreases (to zero) with decreasing density. We prove that if the viscosity does not decrease to zero too rapidly, then smooth solutions exist globally in time. 相似文献
10.
Hidetoshi Shimodaira 《Annals of the Institute of Statistical Mathematics》1997,49(3):395-410
The asymptotic error probability of Linhart's model selection test isevaluated, and compared with the nominal significance level. We examine thecase where the expected discrepancies of the candidate models from the truemodel are asymptotically equal. The local alternatives method is employed inthe limiting operation of the asymptotic evaluation. Although the errorprobability under the null hypothesis is actually shown to be equal to orless than the level for most situations, intolerable violations of the errorcontrol are observed for nested models: It is often erroneously concludedthat the smaller model is significantly better than the larger model. Toprevent this violation, a modification of Linhart's test statistic isproposed. The effectiveness of the proposed test is confirmed throughtheoretical analysis and numerical simulations. 相似文献