全文获取类型
收费全文 | 3098篇 |
免费 | 376篇 |
国内免费 | 342篇 |
专业分类
化学 | 275篇 |
晶体学 | 1篇 |
力学 | 173篇 |
综合类 | 39篇 |
数学 | 1807篇 |
物理学 | 1521篇 |
出版年
2024年 | 9篇 |
2023年 | 27篇 |
2022年 | 75篇 |
2021年 | 89篇 |
2020年 | 82篇 |
2019年 | 84篇 |
2018年 | 104篇 |
2017年 | 88篇 |
2016年 | 89篇 |
2015年 | 75篇 |
2014年 | 148篇 |
2013年 | 248篇 |
2012年 | 124篇 |
2011年 | 174篇 |
2010年 | 139篇 |
2009年 | 185篇 |
2008年 | 222篇 |
2007年 | 200篇 |
2006年 | 190篇 |
2005年 | 175篇 |
2004年 | 123篇 |
2003年 | 149篇 |
2002年 | 149篇 |
2001年 | 114篇 |
2000年 | 120篇 |
1999年 | 93篇 |
1998年 | 85篇 |
1997年 | 76篇 |
1996年 | 59篇 |
1995年 | 51篇 |
1994年 | 42篇 |
1993年 | 19篇 |
1992年 | 30篇 |
1991年 | 14篇 |
1990年 | 18篇 |
1989年 | 9篇 |
1988年 | 17篇 |
1987年 | 13篇 |
1986年 | 11篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 12篇 |
1981年 | 5篇 |
1980年 | 9篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 5篇 |
排序方式: 共有3816条查询结果,搜索用时 31 毫秒
31.
We construct a multiplicative group structure in the class of integro-differential operators specific for a polydisk which was introduced by I. I. Bavrin. We indicate two applications of these operators to solution of functional equations. 相似文献
32.
WEIERSTRASS REPRESENTATION FORSURFACES WITH PRESCRIBED NORMALGAUSS MAP AND GAUSS CURVATURE IN H~3
下载免费PDF全文
![点击此处可从《数学年刊B辑(英文版)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
SHI Shuguo 《数学年刊B辑(英文版)》2004,25(4):567-586
The author obtains a Weierstrass representation for surfaces with prescribed normal Gauss map and Gauss curvature in H3. A differential equation about the hyperbolic Gauss map is also obtained, which characterizes the relation among the hyperbolic Gauss map, the normal Gauss map and Gauss curvature. The author discusses the harmonicity of the normal Gauss map and the hyperbolic Gauss map from surface with constant Gauss curvature in H3 to S2 with certain altered conformal metric. Finally, the author considers the surface whose normal Gauss map is conformal and derives a completely nonlinear differential equation of second order which graph must satisfy. 相似文献
33.
Two studies investigated how decision makers characterize alternatives in important real-life decisions, which they themselves had made (to leave a partner, to choose an education and to choose a home). First, the participants indicated a very high degree of involvement in the decisions studied and about half of the participants gave maximum involvement ratings for the partner decision. Second, the results showed that concepts that are essential in most decision theories, such as, consequence, probability and value were important characteristics of the decisions. Third, emotion, positive and negative affect were also important characteristics. Fourth, value and emotion were uncorrelated. Fifth, the patterns of characteristics of decisions made in the past did not differ markedly from the characteristics given to future decisions. Principal component analyses were performed on the ratings of applicability of the different characteristics across participants for each decision situation. Three factors were extracted. There was one factor for positive affect/emotions and another factor for negative affect/emotions verified in oblique solutions. Thus, different scales are needed to represent emotion/affect components (and not bipolar scales) in real-life important decisions. The third factor represented the way in which a decision was represented (moving pictures dialogue etc.). An analysis restricted to the participants who rated 100% involvement showed an additional fourth factor with “what others would think”, “similar situations”, “values” and “money” as the most prominent characteristics. This points to the importance of controlling for participant involvement in studies of human decision making to enable generalizations to real-life decisions. 相似文献
34.
35.
尹传存 《数学物理学报(A辑)》1997,17(2):145-151
设中的角域.该文绘出了A上正调和函数的Martin表示,讨论了极小调和函数与条件Brown运动的一个0—1律之间的关系,并给出了A上极小调和函数的表现形式, 相似文献
36.
P.A. Kuzmin 《Journal of Mathematical Analysis and Applications》2007,330(1):744-750
This note is devoted to construction of the domain of the regular representation of Diff+(S1). We consider a subgroup of diffeomorphism group such that the Malliavin-Shavgulidze measure is quasi-invariant with respect to the left action of the subgroup. The measure appears to be quasi-invariant with respect to the left action of diffeomorphisms with discontinuous second derivative. We derive an expression for quasi-invariance density and obtain an additional PSL(2,R) symmetry breaking term. 相似文献
37.
The difference between the classical treatment offlexible body impact and the treatment of impact in flexiblemultibody dynamics is due to several fundamental reasons. Inthe classical impact theory, simple structures such as beamsand plates are used. Infinite dimensional models can bedeveloped for these simple structural elements to study theimpact dynamics and the wave propagation problem. Flexiblemultibody impact problems, on the other hand, involve bodieswith complex geometry that cannot be modeled using infinitenumber of degrees of freedom. Furthermore, the classicalimpact theory has been mainly concerned with the impactbetween a rigid mass that moves without constraints beforeit impacts a simple flexible structure. This is not amultibody simulation scenario in which the impact occursbetween kinematically constrained bodies that are subjectedto impulsive constraint forces in addition to the impactforces. These constraint forces can influence the motion ofthe two bodies immediately after impact, and as aconsequence, the simple classical theory scenario of impactdoes not apply. It is the objective of this paper to discussthe use of the restitution condition in flexible multibodyimpact problems and demonstrate that the use of thisapproach does not exclude the classical formulation.Nonetheless, the impulse momentum balance approach can serveas an effective and efficient procedure for solving theimpact problem in finite dimensional models that do not obeythe classical wave theory. Energy results of simplestructural elements are presented in order to demonstratethe consistency of using the impulse momentum balanceapproach in solving impact problems in finite dimensionalflexible body applications. 相似文献
38.
Won-Sang Chung 《International Journal of Theoretical Physics》2003,42(12):2941-2946
In this paper we use the bosonic realization of ospq(1/2) algebra to obtain its metaplectic representation. The group element for this algebra is shown to be described in terms of the basic hypergeometric function. 相似文献
39.
Let G be a locally compact Abelian group. Following Ruy Exel, we view Fell bundles over the Pontrjagin dual group of G as continuous spectral decompositions of G-actions on C*-algebras. We classify such spectral decompositions using certain dense subspaces related to Marc Rieffel's theory of square-integrability. There is a unique continuous spectral decomposition if the group acts properly on the primitive ideal space of the C*-algebra. But there are also examples of group actions without or with several inequivalent spectral decompositions. 相似文献
40.
Henrik Stetkær 《Journal of Functional Analysis》2007,252(1):1-33
We extend results on square integrable representations of a locally compact group to subrepresentations of a representations induced from a character of a closed subgroup. We do so working in the framework of quotient representations of ∗-algebras. 相似文献