全文获取类型
收费全文 | 404篇 |
免费 | 33篇 |
国内免费 | 40篇 |
专业分类
化学 | 66篇 |
力学 | 13篇 |
综合类 | 11篇 |
数学 | 309篇 |
物理学 | 78篇 |
出版年
2023年 | 5篇 |
2022年 | 8篇 |
2021年 | 10篇 |
2020年 | 12篇 |
2019年 | 11篇 |
2018年 | 16篇 |
2017年 | 8篇 |
2016年 | 15篇 |
2015年 | 7篇 |
2014年 | 11篇 |
2013年 | 44篇 |
2012年 | 17篇 |
2011年 | 16篇 |
2010年 | 12篇 |
2009年 | 22篇 |
2008年 | 24篇 |
2007年 | 30篇 |
2006年 | 21篇 |
2005年 | 29篇 |
2004年 | 11篇 |
2003年 | 22篇 |
2002年 | 20篇 |
2001年 | 20篇 |
2000年 | 20篇 |
1999年 | 15篇 |
1998年 | 8篇 |
1997年 | 12篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 7篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有477条查询结果,搜索用时 15 毫秒
1.
Mathematical Notes - 相似文献
2.
3.
A horizontal translation of a function is the focus of this study. We examine the explanations provided by secondary school students and secondary school teachers to a translation of a function, focusing on the example of the parabola y=(x−3)2 and its relationship to y=x2. The participants’ explanations focused on attending to patterns, locating the zero of the function, and the point-wise calculation of function values. The results confirm that the horizontal shift of the parabola is, at least initially, inconsistent with expectations and counterintuitive to most participants. We articulate possible sources of this perceived inconsistency and describe a pedagogical approach aimed at resolving it. 相似文献
4.
Andrea Vietri 《Graphs and Combinatorics》2007,23(1):111-121
We analyse 3-subset difference families of Z2d+1⊕Z2d+1 arising as reductions (mod 2d+1) of particular families of 3-subsets of Z⊕Z. The latter structures, namely perfect d-families, can be viewed as 2-dimensional analogues of difference triangle sets having the least scope. Indeed, every perfect d-family is a set of base blocks which, under the natural action of the translation group Z⊕Z, cover all edges {(x,y),(x′,y′)} such that |x−x′|, |y−y′|≤d. In particular, such a family realises a translation invariant (G,K3)-design, where V(G)=Z⊕Z and the edges satisfy the above constraint. For that reason, we regard perfect families as part of the hereby defined translation designs, which comprise and slightly generalise many structures already existing in the literature. The geometric context allows
some suggestive additional definitions. The main result of the paper is the construction of two infinite classes of d-families. Furthermore, we provide two sporadic examples and show that a d-family may exist only if d≡0,3,8,11 (mod 12). 相似文献
5.
Considering a plane hyperbolic system with time-periodic coefficients, we construct a version of the direct Lyapunov method with the condition on the derivative of the Lyapunov functional along the trajectories of the system which is weakened by use of periodicity of the coefficients. We exhibit an illustrative example. 相似文献
6.
Alistair Savage 《Algebras and Representation Theory》2006,9(2):161-199
For irreducible integrable highest weight modules of the finite and affine Lie algebras of type A and D, we define an isomorphism between the geometric realization of the crystal graphs in terms of irreducible components of Nakajima
quiver varieties and the combinatorial realizations in terms of Young tableaux and Young walls. For type An(1), we extend the Young wall construction to arbitrary level, describing a combinatorial realization of the crystals in terms
of new objects which we call Young pyramids.
Presented by P. Littleman
Mathematics Subject Classifications (2000) Primary 16G10, 17B37.
Alistair Savage: This research was supported in part by the Natural Sciences and Engineering Research Council (NSERC) of Canada
and was partially conducted by the author for the Clay Mathematics Institute. 相似文献
7.
Translation planes of order q
2 containing non-Desarguesian Baer subplanes are used to construct transversal-free translation nets with very small deficiencies. Also, a generalization of the ideas of Bruen shows that any non-Desarguesian spread in PG(3, q) produces a transversal-free net of small deficiency. 相似文献
8.
In the present paper, we prove that the Bernstein-Kantorovič operators have the ability of preserving translation property
in both C and Lp norms.
Supported (in part) by the NSFC(10471130,10371024) of PRC and the Natural Science Foundation (Y604003) of Zhejiang Province. 相似文献
9.
In this paper, a model of translation gateway is proposed. The communications between IPv4 network and IPv6 network are realized by using the Microsoft intermediate driver technology in environment of Windows 2000. 相似文献
10.