全文获取类型
收费全文 | 16803篇 |
免费 | 1298篇 |
国内免费 | 964篇 |
专业分类
化学 | 337篇 |
晶体学 | 5篇 |
力学 | 1945篇 |
综合类 | 206篇 |
数学 | 15023篇 |
物理学 | 1549篇 |
出版年
2024年 | 24篇 |
2023年 | 166篇 |
2022年 | 183篇 |
2021年 | 269篇 |
2020年 | 374篇 |
2019年 | 371篇 |
2018年 | 443篇 |
2017年 | 457篇 |
2016年 | 464篇 |
2015年 | 341篇 |
2014年 | 694篇 |
2013年 | 1338篇 |
2012年 | 767篇 |
2011年 | 880篇 |
2010年 | 801篇 |
2009年 | 1081篇 |
2008年 | 1107篇 |
2007年 | 1158篇 |
2006年 | 1011篇 |
2005年 | 823篇 |
2004年 | 727篇 |
2003年 | 761篇 |
2002年 | 667篇 |
2001年 | 505篇 |
2000年 | 539篇 |
1999年 | 480篇 |
1998年 | 425篇 |
1997年 | 386篇 |
1996年 | 282篇 |
1995年 | 246篇 |
1994年 | 166篇 |
1993年 | 170篇 |
1992年 | 153篇 |
1991年 | 142篇 |
1990年 | 102篇 |
1989年 | 53篇 |
1988年 | 53篇 |
1987年 | 48篇 |
1986年 | 51篇 |
1985年 | 68篇 |
1984年 | 65篇 |
1983年 | 34篇 |
1982年 | 44篇 |
1981年 | 35篇 |
1980年 | 24篇 |
1979年 | 24篇 |
1978年 | 17篇 |
1977年 | 16篇 |
1976年 | 14篇 |
1974年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
71.
一类含有P-Laplacian算子的奇异边值问题解的确切个数 总被引:2,自引:0,他引:2
讨论了一类p-L ap lac ian算子型的奇异边值问题正解的确切个数以及解的性质. 相似文献
72.
广义多目标minmax问题的最优性条件和极大熵方法 总被引:1,自引:0,他引:1
本文讨论了广义多目标minmax问题的最优性条件。利用极大熵逼近函数,研究了广义多目标minmax;问题的逼近问题,在较弱的条件下,证明了由极大熵逼近函数导出的多目标逼近问题的临界点的任一极限点均为原广义多目标minmax问题的临界点。 相似文献
73.
ZhenFengZHANG 《数学学报(英文版)》2005,21(1):155-168
In this paper, we extend a classical result of Hua to arithmetic progressions with large moduli. The result implies the Linnik Theorem on the least prime in an arithmetic progression. 相似文献
74.
75.
Understanding the end state of black hole evaporation, the microscopic origin of black hole entropy, the information loss paradox, and the nature of the singularity arising in gravitational collapse - these are outstanding challenges for any candidate quantum theory of gravity. Recently, a midisuperspace model of quantum gravitational collapse has been solved using a lattice regularization scheme. It is shown that the mass of an eternal black hole follows the Bekenstein spectrum, and a related argument provides a fairly accurate estimate of the entropy. The solution also describes a quantized mass-energy distribution around a central black hole, which in the WKB approximation, is precisely Hawking radiation. The leading quantum gravitational correction makes the spectrum non-thermal, thus providing a plausible resolution of the information loss problem. 相似文献
76.
本文考虑广义C-R组^[1](H)的解f=u iv jw∈C^2的一些性质,提出与之相关的两个边值问题,用积分方程方法和调和函数性质证明了边值问题解的存在唯一性,并写出解的积分表达式. 相似文献
77.
B. Saha S. Bhattacharyya T. K. Mukherjee P. K. Mukherjee 《International journal of quantum chemistry》2003,92(5):413-418
In the framework of nonrelativistic variational formalism a new type of basis set is proposed, to estimate separately the effect of radial and angular correlations on the ground‐state energy for helium isoelectronic sequence H? to Ar16+. Effect of radial correlation is incorporated by using multiexponential functions arising from product basis sets suitably formed out of Slater‐type one‐particle orbitals. The angular correlation can be switched on by incorporating an expansion in terms of basis involving interparticle coordinates. With a set of six‐term Slater‐type one‐particle basis and five‐term interparticle expansion, the ground‐state energy of helium is estimated as ?2.9037236 (a.u.) compared with the multiterm variational estimates ?2.9037244 (a.u.) due to Pekeris and Thakkar and Smith and Drake. Matrix elements of different operators in the ground state have been calculated and found to be in good agreement with available accurate results. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003 相似文献
78.
The goal of the paper is to analyse properties of solutions for linear thermoelastic systems of type III in one space variable. Our approach does not use energy methods, it bases on a special diagonalization procedure which is different in different parts of the phase space. This procedure allows to derive explicit representations of solutions. These representations help to prove results for well‐posedness of the Cauchy problem, LP–Lq decay estimates on the conjugate line and results for propagation of singularities. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
79.
A. J. Zaslavski 《Journal of Optimization Theory and Applications》2004,123(3):695-712
In our previous work, a generic well-posedness result (with respect to variations of the integrand of the integral functional) without the convexity condition was established for a class of optimal control problems satisfying the Cesari growth condition. In this paper, we extend this generic well-posedness result to classes of constrained variational problems in which the values at the endpoints and constraint maps are also subject to variations. 相似文献
80.
In this paper we focus on the problem of identifying the index sets P(x):=i|xi>0, N(x):={i|Fi(x)>0 and C(x):=i|xi=Fi(x)=0} for a solution x of the monotone nonlinear complementarity problem NCP(F). The correct identification of these sets is important from both theoretical and practical points of view. Such an identification enables us to remove complementarity conditions from the NCP and locally reduce the NCP to a system which can be dealt with more easily. We present a new technique that utilizes a sequence generated by the proximal point algorithm (PPA). Using the superlinear convergence property of PPA, we show that the proposed technique can identify the correct index sets without assuming the nondegeneracy and the local uniqueness of the solution.This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture of Japan.Mathematics Subject Classification (2000): 90C33, 65K10 相似文献