全文获取类型
收费全文 | 182篇 |
免费 | 14篇 |
国内免费 | 17篇 |
专业分类
化学 | 1篇 |
晶体学 | 1篇 |
力学 | 18篇 |
综合类 | 3篇 |
数学 | 166篇 |
物理学 | 24篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 3篇 |
2013年 | 27篇 |
2012年 | 9篇 |
2011年 | 12篇 |
2010年 | 8篇 |
2009年 | 11篇 |
2008年 | 24篇 |
2007年 | 10篇 |
2006年 | 5篇 |
2005年 | 10篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有213条查询结果,搜索用时 31 毫秒
121.
Katica 《Acta Mechanica Sinica》2008,24(3):331-344
The study of energy transfer between coupled subsystems in a hybrid system is very important for applications. This paper presents an analytical analysis of energy transfer between plates of a visco-elastically connected double-plate system in free transversal vibrations. The analytical analysis shows that the visco-elastic connection between plates is responsible for the appearance of two-frequency regime in the time function, which corresponds to one eigen amplitude function of one mode, and also that time functions of different vibration modes are uncoupled, but energy transfer between plates in one eigen mode appears. It was shown for each shape of vibrations. Series of the two Lyapunov exponents corresponding to the one eigen amplitude mode are expressed by using the energy of the corresponding eigen amplitude time component. 相似文献
122.
Weigu Li 《中国科学A辑(英文版)》1999,42(7):699-703
A method of identifying the existence of horseshoe for a two-dimension diffeomorphism is introduced and utilized to generalize
the Birkhoff-Smale Theorem to the saddle-node case.
Project supported by the National Natural Science Foundation of China (Grant No. 19531070). 相似文献
123.
完全单半群及完全正则半群的逆断面 总被引:1,自引:1,他引:0
指出完全单半群S的任何一个F-类是逆断面,且为Q-逆断面,而S的任何一个逆断面必是一个F-类,因而所有逆断面同构。并且给出完全正则半群的逆断面存在的充要条件。 相似文献
124.
A set of vertices in a hypergraph which meets all the edges is called a transversal. The transversal number τ(H) of a hypergraph H is the minimum cardinality of a transversal in H. A classical greedy algorithm for constructing a transversal of small size selects in each step a vertex which has the largest degree in the hypergraph formed by the edges not met yet. The analysis of this algorithm (by Chvátal and McDiarmid (1992) [3]) gave some upper bounds for τ(H) in a uniform hypergraph H with a given number of vertices and edges. We discuss a variation of this greedy algorithm. Analyzing this new algorithm, we obtain upper bounds for τ(H) which improve the bounds by Chvátal and McDiarmid. 相似文献
125.
Xiang Jun Kong 《代数通讯》2013,41(4):1431-1447
Generalized orthodox transversals are introduced in this article, and some characterizations associated with them are obtained. The related results of Chen on quasi-ideal orthodox transversals obtained in 1999 and Zhang and Wang on generalized inverse transversals obtained in 2008 are generalized and amplified. A structure theorem of a regular semigroup with a perfect generalized orthodox transversal is also established. 相似文献
126.
127.
We first consider an ordered regular semigroup S in which every element has a biggest inverse and determine necessary and sufficient conditions for the subset S ○ of biggest inverses to be an inverse transversal of S. Such an inverse transversal is necessarily weakly multiplicative. We then investigate principally ordered regular semigroups S with the property that S ○ is an inverse transversal. In such a semigroup we determine precisely when the set S ☆ of biggest pre-inverses is a subsemigroup and show that in this case S ☆ is itself an inverse transversal of a subsemigroup of S. The ordered regular semigroup of 2 × 2 boolean matrices provides an informative illustrative example. The structure of S, when S ☆ is a group, is also described. 相似文献
128.
The so-called split IC quasi-adequate semigroups are in the class of idempotent-connected quasi-adequate semigroups. It is
proved that an IC quasi-adequate semigroup is split if and only if it has an adequate transversal. The structure of such semigroup
whose band of idempotents is regular will be particularly investigated. Our obtained results enrich those results given by
McAlister and Blyth on split orthodox semigroups. 相似文献
129.
We will discuss the following result: for a topological space X with the property that for and every open subset U of X, a finite family of open sets in X has nonempty intersection if for any subfamily of size j, , the ()-dimensional reduced homology group of its intersection is zero. We also use this theorem to discuss new results concerning transversal affine planes to families of convex sets. 相似文献
130.
An idempotent Latin square of order v is called resolvable and denoted by RILS(v) if the off‐diagonal cells can be resolved into disjoint transversals. A large set of resolvable idempotent Latin squares of order v, briefly LRILS(v), is a collection of RILS(v)s pairwise agreeing on only the main diagonal. In this paper, it is established that there exists an LRILS(v) for any positive integer , except for , and except possibly for . 相似文献