全文获取类型
收费全文 | 18788篇 |
免费 | 1787篇 |
国内免费 | 2059篇 |
专业分类
化学 | 1741篇 |
晶体学 | 112篇 |
力学 | 1315篇 |
综合类 | 417篇 |
数学 | 15579篇 |
物理学 | 3470篇 |
出版年
2024年 | 24篇 |
2023年 | 207篇 |
2022年 | 222篇 |
2021年 | 299篇 |
2020年 | 399篇 |
2019年 | 518篇 |
2018年 | 467篇 |
2017年 | 520篇 |
2016年 | 597篇 |
2015年 | 464篇 |
2014年 | 880篇 |
2013年 | 1431篇 |
2012年 | 792篇 |
2011年 | 1098篇 |
2010年 | 967篇 |
2009年 | 1248篇 |
2008年 | 1360篇 |
2007年 | 1379篇 |
2006年 | 1156篇 |
2005年 | 1073篇 |
2004年 | 838篇 |
2003年 | 895篇 |
2002年 | 843篇 |
2001年 | 694篇 |
2000年 | 738篇 |
1999年 | 637篇 |
1998年 | 563篇 |
1997年 | 496篇 |
1996年 | 349篇 |
1995年 | 212篇 |
1994年 | 195篇 |
1993年 | 137篇 |
1992年 | 110篇 |
1991年 | 109篇 |
1990年 | 68篇 |
1989年 | 69篇 |
1988年 | 63篇 |
1987年 | 44篇 |
1986年 | 36篇 |
1985年 | 73篇 |
1984年 | 66篇 |
1983年 | 32篇 |
1982年 | 51篇 |
1981年 | 34篇 |
1980年 | 36篇 |
1979年 | 38篇 |
1978年 | 28篇 |
1977年 | 16篇 |
1976年 | 16篇 |
1975年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
91.
92.
Two Convergence Problems for Monotone Sequences 总被引:1,自引:0,他引:1
Eight measures of rate of convergence of monotone sequences of real numbers have been proposed and discussed in a paper by Beyer, Ebanks, and Qualls (Acta Appl. Math. 20 (1990), 267–284). These rates arose in discussions of dynamical systems. In the comparisons of these rates, two problems remained. A complete answer is given to one of the problems and a partial answer is given to the other problem. 相似文献
93.
Gunther Jäger 《Fuzzy Sets and Systems》1997,90(3):737-348
Lowen and Lowen [Applications of category theory to fuzzy subsets (Kluwer, 1992) p. 153] and Lowen et al. [Fuzzy Sets and Systems 40 (1991) 347] recently introduced the category FCS of fuzzy convergence spaces, a topological quasitopos which is a supercategory of FTS, the category of fuzzy topological spaces. In this paper, compactness in FCS is examined. Doing so we found that to define compactness as an absolute property we had to generalize the definition of fuzzy convergence space to fuzzy subsets. All basic theorems are proved including the Tychonoff product theorem. Based on the theory developed here, in a following publication, a Richardson compactification for fuzzy convergence spaces will be given. 相似文献
94.
95.
具有奇异值分解性质的代数 总被引:4,自引:0,他引:4
设F为一个域,R为一个带有对合的F-代数,如果R上每一个矩阵都有奇异值分解(简称SVD),则称R为一个有SVD性质的F-代数.本文指出:R为一个有SVD性质的F-代数的充要条件是:R同构于R~+,或R~+上二次扩域,或R~+上四元数体((-1,-1)/R~+),其中R~+为R的对称元集合,并且R~+为一个Galois序闭域. 相似文献
96.
A complete study of the spectrum of a finite-dimensional Bose operator is carried out in the paper. The cases in which the
spectrum is discrete or continuous are studied.
Translated fromMatematicheskie Zametki, Vol. 61, No. 6, pp. 835–854, June, 1997.
Translated by A. M. Chebotarev 相似文献
97.
Recently, Fishbum and Lavalle (1995) and Lefèvre and Utev (1996) have considered some stochastic order relations specific for arithmetic random variables. The present work is concerned with these orderings, together with two other classes of stochastic order relations closely related. First, attention is paid to characterizations and various properties of all these orderings. Then, sufficient conditions of crossing-type for the two new classes of orderings are derived and extrema among discrete random variables are deduced. This is applied in actuarial sciences to obtain new bounds for the classical single life premiums as well as for the probability of ruin in the compound binomial risk model. 相似文献
98.
Alexander P. Schuster 《Proceedings of the American Mathematical Society》1997,125(6):1717-1725
Properties of the unions of sampling and interpolation sets for Bergman spaces are discussed in conjunction with the examples given by Seip (1993). Their relationship to the classical interpolation sequences is explored. In addition, the role played by canonical divisors in the study of these sets is examined and an example of a sampling set is constructed in the disk.
99.
Alexander Afriat 《Foundations of Physics Letters》1995,8(5):467-480
We consider the question of factorizability in tensor product spaces, and argue that the correlations associated with entangled states are even more problematic in the general case involving any tensor product of Hilbert spaces, than in the Einstein, Podolsky, and Rosen case with only two [1]. 相似文献
100.
透镜空间L~1(p)上向量丛的示性类 总被引:1,自引:1,他引:0
本文讨论了透镜空间 L1( p)的上同调环中生成元的运算性质 ,进而利用 L1( p)的 KO -结构得到了L1( p)上任一向量丛的全 Stiefel-Whitney类 相似文献