全文获取类型
收费全文 | 7464篇 |
免费 | 485篇 |
国内免费 | 725篇 |
专业分类
化学 | 422篇 |
晶体学 | 4篇 |
力学 | 351篇 |
综合类 | 160篇 |
数学 | 7306篇 |
物理学 | 431篇 |
出版年
2024年 | 6篇 |
2023年 | 70篇 |
2022年 | 78篇 |
2021年 | 126篇 |
2020年 | 133篇 |
2019年 | 158篇 |
2018年 | 171篇 |
2017年 | 191篇 |
2016年 | 196篇 |
2015年 | 157篇 |
2014年 | 285篇 |
2013年 | 467篇 |
2012年 | 344篇 |
2011年 | 369篇 |
2010年 | 339篇 |
2009年 | 480篇 |
2008年 | 466篇 |
2007年 | 469篇 |
2006年 | 473篇 |
2005年 | 393篇 |
2004年 | 343篇 |
2003年 | 372篇 |
2002年 | 330篇 |
2001年 | 291篇 |
2000年 | 295篇 |
1999年 | 256篇 |
1998年 | 264篇 |
1997年 | 241篇 |
1996年 | 140篇 |
1995年 | 112篇 |
1994年 | 96篇 |
1993年 | 84篇 |
1992年 | 65篇 |
1991年 | 50篇 |
1990年 | 40篇 |
1989年 | 22篇 |
1988年 | 28篇 |
1987年 | 22篇 |
1986年 | 16篇 |
1985年 | 38篇 |
1984年 | 34篇 |
1983年 | 15篇 |
1982年 | 31篇 |
1981年 | 29篇 |
1980年 | 25篇 |
1979年 | 15篇 |
1978年 | 15篇 |
1977年 | 11篇 |
1976年 | 6篇 |
1974年 | 8篇 |
排序方式: 共有8674条查询结果,搜索用时 343 毫秒
81.
戴滨林 《数学物理学报(A辑)》2007,27(5):935-940
该文对高维非初等Mò'bius变换群进行了研究,得到了一些重要性质,给出了几个关于离散准则和代数收敛性的定理. 相似文献
82.
本文给出递归集的Hausdorff维数的下界估计,并由此确定了一类递归集的维数,所获结果包含并推广了Bedford,Dekking及文志英、钟红柳等人的有关结果。 相似文献
83.
几何凸函数与琴生型不等式 总被引:20,自引:3,他引:17
吴善和 《数学的实践与认识》2004,34(2):155-163
给出几何凸函数的定义以及判定几何凸函数的方法 ,建立关于几何凸函数的琴生型不等式 ,最后给出它的应用 ,包括改进一些已知不等式和建立一些新不等式 . 相似文献
84.
Joe Warren Scott Schaefer Anil N. Hirani Mathieu Desbrun 《Advances in Computational Mathematics》2007,27(3):319-338
In this paper we provide an extension of barycentric coordinates from simplices to arbitrary convex sets. Barycentric coordinates
over convex 2D polygons have found numerous applications in various fields as they allow smooth interpolation of data located
on vertices. However, no explicit formulation valid for arbitrary convex polytopes has been proposed to extend this interpolation
in higher dimensions. Moreover, there has been no attempt to extend these functions into the continuous domain, where barycentric
coordinates are related to Green’s functions and construct functions that satisfy a boundary value problem. First, we review
the properties and construction of barycentric coordinates in the discrete domain for convex polytopes. Next, we show how
these concepts extend into the continuous domain to yield barycentric coordinates for continuous functions. We then provide
a proof that our functions satisfy all the desirable properties of barycentric coordinates in arbitrary dimensions. Finally,
we provide an example of constructing such barycentric functions over regions bounded by parametric curves and show how they
can be used to perform freeform deformations.
相似文献
85.
On a question of Gross 总被引:1,自引:0,他引:1
Abhijit Banerjee 《Journal of Mathematical Analysis and Applications》2007,327(2):1273-1283
Using the notion of weighted sharing of sets we prove two uniqueness theorems which improve the results proved by Fang and Qiu [H. Qiu, M. Fang, A unicity theorem for meromorphic functions, Bull. Malaysian Math. Sci. Soc. 25 (2002) 31-38], Lahiri and Banerjee [I. Lahiri, A. Banerjee, Uniqueness of meromorphic functions with deficient poles, Kyungpook Math. J. 44 (2004) 575-584] and Yi and Lin [H.X. Yi, W.C. Lin, Uniqueness theorems concerning a question of Gross, Proc. Japan Acad. Ser. A 80 (2004) 136-140] and thus provide an answer to the question of Gross [F. Gross, Factorization of meromorphic functions and some open problems, in: Proc. Conf. Univ. Kentucky, Lexington, KY, 1976, in: Lecture Notes in Math., vol. 599, Springer, Berlin, 1977, pp. 51-69], under a weaker hypothesis. 相似文献
86.
P. C. Chen 《中国化学会会志》1995,42(5):755-760
Three ab initio calculations (HF/6-3IG, HF/6-3IG*, and HF/6-3IG**) on 2,4,6-trinitrotoluene were made, The results compare well with xray data, except dihedral angles of NO2 relative to the plane of the benzene ring. The deviations are attributed to packing forces and steric effects in the crystal. The most stable structure was a torsional angle 10° of the methyl top with the benzene ring, unlike toluene. The rotational barriers of the methyl top and the 4-nitro group are small. Hydrogen bonding, dipole moments and total atomic charges arc calculated. 相似文献
87.
THENBELCANDNWELCCLASSESOFLIFEDISTRIBUTIONS¥CAOJINHUA;WANGYUEDONG(InstituteofAppliedMathematics,ChineseAcademyofScience,Beijin... 相似文献
88.
We address in this paper the problem of finding an optimal strategy for dealing with bottleneck machines and bottleneck parts in the cell formation process in group technology. Three types of economic decisions are considered: subcontracting, machine duplication and intercell moves. The problem is formulated as a minimum weighted node covering problem in a hypergraph, and we show that it can be solved in polynomial time by finding a maximum weighted stable set in a bipartite graph. We extend this result to cellular manufacturing systems in which the sequence of operations of each part is known in advance. 相似文献
89.
Jaroslav Neetil 《Journal of Graph Theory》2002,39(2):108-110
A graph G is called rigid if the identical mapping V(G)→V(G) is the only homomorphism G→G. In this note we give a simple construction of a rigid oriented graph on every set. © 2002 John Wiley & Sons, Inc. J Graph Theory 39: 108–110, 2002 相似文献
90.
A BRANCH BOUND METHOD FOR SUBSET SUM PROBLEM 总被引:1,自引:0,他引:1
吴士泉 《应用数学学报(英文版)》1994,10(3):302-314
ABRANCHBOUNDMETHODFORSUBSETSUMPROBLEMWUSHIQUAN(吴士泉)(InstituteofAppliedMathematics,theChineseAcademyofSciences,Beijing100080,C... 相似文献