全文获取类型
收费全文 | 4410篇 |
免费 | 378篇 |
国内免费 | 459篇 |
专业分类
化学 | 1290篇 |
晶体学 | 12篇 |
力学 | 103篇 |
综合类 | 101篇 |
数学 | 3134篇 |
物理学 | 607篇 |
出版年
2024年 | 10篇 |
2023年 | 51篇 |
2022年 | 123篇 |
2021年 | 132篇 |
2020年 | 123篇 |
2019年 | 143篇 |
2018年 | 146篇 |
2017年 | 152篇 |
2016年 | 165篇 |
2015年 | 100篇 |
2014年 | 251篇 |
2013年 | 429篇 |
2012年 | 189篇 |
2011年 | 249篇 |
2010年 | 201篇 |
2009年 | 254篇 |
2008年 | 275篇 |
2007年 | 302篇 |
2006年 | 254篇 |
2005年 | 228篇 |
2004年 | 208篇 |
2003年 | 188篇 |
2002年 | 166篇 |
2001年 | 123篇 |
2000年 | 124篇 |
1999年 | 109篇 |
1998年 | 115篇 |
1997年 | 72篇 |
1996年 | 74篇 |
1995年 | 45篇 |
1994年 | 39篇 |
1993年 | 27篇 |
1992年 | 21篇 |
1991年 | 18篇 |
1990年 | 12篇 |
1989年 | 18篇 |
1988年 | 11篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 22篇 |
1984年 | 10篇 |
1983年 | 3篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1973年 | 2篇 |
排序方式: 共有5247条查询结果,搜索用时 15 毫秒
91.
汪嘉冈 《应用数学学报(英文版)》1994,10(1):59-68
ALAWOFTHEITERATEDLOGARITHMFORPROCESSESWITHINDEPENDENTINCREMENTSWANGJIAGANG(汪嘉冈)(EastChinaUniversityofScience&Technology,Shang... 相似文献
92.
The maximum number of non-vanishing and independent second order photoelastic coefficients required by the seven pentagonal
and the two icosahedral point groups 5(C5),
(S10),
(C5h
),
m2(D5h
), 52(D5), 5m(C5v
),
2m(D5d
); 235(I), 2/m
(I
h
)—that describe the quasicrystals symmetry groups in two and three dimensions—is obtained. The schemes of non-vanishing and
independent coefficients have been calculated and listed. Finally the results of this group-theoretical study are briefly
discussed. 相似文献
93.
The transport coefficients for the nine point groups
—which represent the symmetry groups of the quasicrystals in two and three dimensions—have been evaluated and tabulated in
this work, employing group-theoretical methods. 相似文献
94.
Bojan Magajna 《Transactions of the American Mathematical Society》1996,348(6):2427-2440
Tensor products of Calgebras over an abelian Walgebra are studied. The minimal Cnorm on is shown to be just the quotient of the minimal Cnorm on if or is exact.
95.
H. D. Junghenn 《Transactions of the American Mathematical Society》1996,348(3):1051-1073
A weakly continuous, equicontinuous representation of a semitopological semigroup on a locally convex topological vector space gives rise to a family of operator semigroup compactifications of , one for each invariant subspace of . We consider those invariant subspaces which are maximal with respect to the associated compactification possessing a given property of semigroup compactifications and show that under suitable hypotheses this maximality is preserved under the formation of projective limits, strict inductive limits and tensor products.
96.
D. H. Fremlin R. A. Johnson E. Wajch 《Proceedings of the American Mathematical Society》1996,124(9):2897-2903
A space Borel multiplies with a space if each Borel set of is a member of the -algebra in generated by Borel rectangles. We show that a regular space Borel multiplies with every regular space if and only if has a countable network. We give an example of a Hausdorff space with a countable network which fails to Borel multiply with any non-separable metric space. In passing, we obtain a characterization of those spaces which Borel multiply with the space of countable ordinals, and an internal necessary and sufficient condition for to Borel multiply with every metric space.
97.
Fang Jie 《数学学报(英文版)》1996,12(3):249-253
In this paper we introduce an algebraic concept of the product of Ockham algebras called the Braided product. We show that ifL
i
MS(i=1, 2, ,n) then the Braided product ofL
i(i=1, 2, ,n) exists if and only ifL
1, ,L
n have isomorphic skeletons. 相似文献
98.
Robert W. Baddeley 《Journal of Algebraic Combinatorics》1993,2(3):215-237
The paper addresses a part of the problem of classifying all 2-arc transitive graphs: namely, that of finding all groups acting 2-arc transitively on finite connected graphs such that there exists a minimal normal subgroup that is nonabelian and regular on vertices. A construction is given for such groups, together with the associated graphs, in terms of the following ingredients: a nonabelian simple group T, a permutation group P acting 2-transitively on a set , and a map F : Tsuch that x = x
–1 for all x
F() and such that Tis generated by F(). Conversely we show that all such groups and graphs arise in this way. Necessary and sufficient conditions are found for the construction to yield groups that are permutation equivalent in their action on the vertices of the associated graphs (which are consequently isomorphic). The different types of groups arising are discussed and various examples given. 相似文献
99.
Rosario De Lisi Mario Goffredi Vincenzo Turco Liveri 《Journal of solution chemistry》1981,10(5):351-356
The conductances of dilute aqueous solutions of KCl, KBr, and KI have been measured over the temperature range 2 to 8°C and have been analyzed by the Fuoss-Hsia equation. The ionic Walden products at infinite dilution have been discussed in terms of local viscosity. The temperature dependence of these products suggest that near the temperature of maximum density of water, the structure-breaking ability of these ions changes in a regular way. 相似文献
100.
S. G. Chung 《Journal of statistical physics》1985,40(1-2):303-328
A fermionic perturbation theory is developed for the statistical mechanics of the nonlinear Schrödinger model. The theory is based on an interacting-fermion picture of the Bethe wave function. The inner product of the Bethe wave function is explicitly evaluated, and a simple graphical representation of it is given. The basic equations obtained for the free energy agree with those of Yang and Yang. In particular, the present theory gives a clear-cut meaning to the function of Yang and Yang: It represents a fermion energy at finite temperatures. 相似文献