全文获取类型
收费全文 | 15295篇 |
免费 | 1033篇 |
国内免费 | 859篇 |
专业分类
化学 | 301篇 |
晶体学 | 2篇 |
力学 | 1549篇 |
综合类 | 179篇 |
数学 | 13914篇 |
物理学 | 1242篇 |
出版年
2024年 | 30篇 |
2023年 | 148篇 |
2022年 | 165篇 |
2021年 | 214篇 |
2020年 | 334篇 |
2019年 | 344篇 |
2018年 | 394篇 |
2017年 | 406篇 |
2016年 | 391篇 |
2015年 | 298篇 |
2014年 | 630篇 |
2013年 | 1214篇 |
2012年 | 690篇 |
2011年 | 805篇 |
2010年 | 719篇 |
2009年 | 980篇 |
2008年 | 1034篇 |
2007年 | 1054篇 |
2006年 | 950篇 |
2005年 | 738篇 |
2004年 | 651篇 |
2003年 | 711篇 |
2002年 | 614篇 |
2001年 | 460篇 |
2000年 | 478篇 |
1999年 | 412篇 |
1998年 | 386篇 |
1997年 | 350篇 |
1996年 | 255篇 |
1995年 | 225篇 |
1994年 | 155篇 |
1993年 | 125篇 |
1992年 | 138篇 |
1991年 | 111篇 |
1990年 | 89篇 |
1989年 | 45篇 |
1988年 | 45篇 |
1987年 | 44篇 |
1986年 | 49篇 |
1985年 | 61篇 |
1984年 | 55篇 |
1983年 | 28篇 |
1982年 | 32篇 |
1981年 | 28篇 |
1980年 | 21篇 |
1979年 | 24篇 |
1978年 | 15篇 |
1977年 | 15篇 |
1976年 | 11篇 |
1936年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 38 毫秒
61.
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
62.
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
63.
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
64.
65.
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
66.
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
67.
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
68.
A new approach to the robust handling of non‐linear constraints for GAs (genetic algorithms) optimization is proposed. A specific feature of the approach consists of the change in the conventional search strategy by employing search paths which pass through both feasible and infeasible points (contrary to the traditional approach where only feasible points may be included in a path). The method (driven by full Navier–Stokes computations) was applied to the problem of multiobjective optimization of aerodynamic shapes subject to various geometrical and aerodynamic constraints. The results demonstrated that the method retains high robustness of conventional GAs while keeping CFD computational volume to an acceptable level, which allowed the algorithm to be used in a demanding engineering environment. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
69.
在等离子体增强化学气相淀积系统中,采用aSi:H层淀积和原位等离子体氧化相结合的逐层生长技术制备了aSi:H/SiO_2多层膜.在激光诱导限制结晶原理基础上,使用KrF准分子脉冲激光为辐照源,对aSi:H/SiO_2多层膜进行辐照,使纳米级厚度的aSi:H子层晶化.Raman散射谱和电子衍射谱的结果表明,经过激光辐照后纳米Si颗粒在原始的aSi:H子层内形成,晶粒尺寸可以根据aSi:H层的厚度精确控制.还研究了样品的光致发光(PL)特性以及激光辐照能量密度对PL性质的影响.
关键词:
脉冲激光
多层膜
限制结晶 相似文献
70.
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