全文获取类型
收费全文 | 3806篇 |
免费 | 238篇 |
国内免费 | 480篇 |
专业分类
化学 | 51篇 |
力学 | 47篇 |
综合类 | 52篇 |
数学 | 3928篇 |
物理学 | 446篇 |
出版年
2023年 | 50篇 |
2022年 | 23篇 |
2021年 | 38篇 |
2020年 | 79篇 |
2019年 | 103篇 |
2018年 | 107篇 |
2017年 | 97篇 |
2016年 | 116篇 |
2015年 | 93篇 |
2014年 | 185篇 |
2013年 | 341篇 |
2012年 | 109篇 |
2011年 | 205篇 |
2010年 | 153篇 |
2009年 | 266篇 |
2008年 | 320篇 |
2007年 | 262篇 |
2006年 | 235篇 |
2005年 | 224篇 |
2004年 | 171篇 |
2003年 | 192篇 |
2002年 | 186篇 |
2001年 | 131篇 |
2000年 | 123篇 |
1999年 | 127篇 |
1998年 | 118篇 |
1997年 | 125篇 |
1996年 | 62篇 |
1995年 | 43篇 |
1994年 | 32篇 |
1993年 | 20篇 |
1992年 | 11篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 13篇 |
1984年 | 9篇 |
1983年 | 3篇 |
1982年 | 18篇 |
1981年 | 17篇 |
1980年 | 14篇 |
1979年 | 16篇 |
1978年 | 13篇 |
1977年 | 10篇 |
1976年 | 5篇 |
1973年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有4524条查询结果,搜索用时 9 毫秒
41.
We study the system of nonlinear differential equations which expresses the constancy of the algebraic invariants of the Jacobian matrix for smooth vector fields in three-dimensional space. This system is equivalent to the equations of gas dynamics which describe the barochronous motions of a gas (the pressure and density depend only on the time). We present the results of computation of the admissible local Lie group and construction of the general solution of the system. We mention a few new problems that arise here. 相似文献
42.
Let G be a group with a set of operators such that Z(G) is -admissible. Central -automorphisms occur in the Krull-Remak-Schmidt Theorem. We discuss the existence of a central -endomorphism of G that is not an automorphism.2000 Mathematics Subject Classification: 20E36 相似文献
43.
Non-compact generalized variational inequalities for quasi-monotone and hemi-continuous operators with applications 总被引:1,自引:0,他引:1
Some results are obtained for non-compact cases in topological vector spaces for the existence problem of solutions for some
set-valued variational inequalities with quasi-monotone and lower hemi-continuous operators, and with quasi-semi-monotone
and upper hemi-continuous operators. Some applications are given in non-reflexive Banach spaces for these existence problems
of solutions and for perturbation problems for these set-valued variational inequalities with quasi-monotone and quasi-semi-monotone
operators.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
44.
A. G. García M. A. Hernndez-Medina 《Journal of Mathematical Analysis and Applications》2003,280(2):221-231
The close relationship between discrete Sturm–Liouville problems belonging to the so-called limit-circle case, the indeterminate Hamburger moment problem and the search of self-adjoint extensions of the associated semi-infinite Jacobi matrix is well known. In this paper, all these important topics are also related with associated sampling expansions involving analytic Lagrange-type interpolation series. 相似文献
45.
朱月萍 《数学物理学报(B辑英文版)》2003,(4)
In this paper, the author gives a characterization of atomic Hardy spaces associated to Schrodinger operators by using area functions, and hence gets the dual spaces of atomic Hardy spaces. 相似文献
46.
47.
摘要:本文在L_[0.1]~p空间给出了 Durrmeyer型修正的shepard算子D_n(f,x),对 f∈L_[0.1]~p,(p≥1),得到了下列的Jackson型估计:││D)n(f)-f││_p≤ C_(pλω)(f,n~(-1))p,λ≥2, Cω(f,n~(-1)logn)p,λ=2, C_(pλω)(f,n~(-1))p,1<λ<2, 相似文献
48.
用A的不变子空间作参数,给出了算子方程AX=XAX的全部解。当A是单射或稠值域时,或者当A是正规算子时,给出了算子方程AX=XA=XAX的全部解。我们还给出正规算子X是算子方程AX=XZ=XAX的解的充分必要条件。 相似文献
49.
Marius Bochniak 《Mathematische Nachrichten》2003,250(1):17-24
The paper is devoted to the study of solutions to linear elliptic boundary value problems in domains depending smoothly on a small perturbation parameter. To this end we transform the boundary value problem onto a fixed reference domain and obtain a problem in a fixed domain but with differential operators depending on the perturbation parameter. Using the Fredholm property of the underlying operator we show the differentiability of the transformed solution under the assumption that the dimension of the kernel does not depend on the perturbation parameter. Furthermore, we obtain an explicit representation for the corresponding derivative. 相似文献
50.
In this paper, we consider a minimax problem of optimal control for a class of strongly nonlinear uncertain evolution equations on a Banach space. We prove the existence of optimal controls. A nontrivial example of a class of systems governed by a nonlinear partial differential equation with uncertain spatial parameters is presented for illustration.This work was supported in part by the National Science and Engineering Research Council of Canada under Grant No. A7109 and The Engineering Faculty Development Fund, University of Ottawa.The authors would like to thank the anonymous reviewers for their valuable comments and suggestions. 相似文献