全文获取类型
收费全文 | 337篇 |
免费 | 10篇 |
国内免费 | 13篇 |
专业分类
化学 | 38篇 |
力学 | 14篇 |
数学 | 195篇 |
物理学 | 113篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 5篇 |
2020年 | 9篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 4篇 |
2016年 | 12篇 |
2015年 | 9篇 |
2014年 | 15篇 |
2013年 | 47篇 |
2012年 | 7篇 |
2011年 | 19篇 |
2010年 | 8篇 |
2009年 | 27篇 |
2008年 | 30篇 |
2007年 | 24篇 |
2006年 | 19篇 |
2005年 | 13篇 |
2004年 | 10篇 |
2003年 | 11篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有360条查询结果,搜索用时 250 毫秒
1.
2.
3.
4.
Special education and mathematics education are becoming increasingly intertwined in inclusive classrooms. However, research and practice in these two fields are not always aligned. We discuss, in the context of extant research on pedagogical theory, concepts of access, and the findings of an exploratory study, how these two education sub-fields view teacher expertise. Teacher educators (from math and special education) were asked to rank the importance of different types of expertise for effectively posing purposeful mathematical questions. The groups differed significantly in their rankings of the importance of knowing individual students and general teaching experience. There were also notable differences between the groups’ rankings of the importance of knowing the needs of students with disabilities and mathematical content knowledge. The possible reasons for this are discussed, along with suggestions for improving professional collaboration. 相似文献
5.
6.
This paper is devoted to the stationary problem of third-grade fluids in two and three dimensions. In two dimensions, we show existence of solutions and uniqueness, for a boundary of class C2,1 and small data, by generalizing the method used by J.M. Bernard for the stationary problem of second-grade fluids (we deal with a polynomial of four degrees instead of two degrees). Contrary to the case of two dimensions, the resolution of the problem of third-grade fluids in three dimensions requires the physical condition |α1+α2|<(24νβ)1/2. From this condition, we derive two “pseudo ellipticities” for the operator ν|A(u)|2+(α1+α2)tr(A(u)3)+β|A(u)|4, where A(u) is a 3-order symmetric matrix such that tr(A(u))=0. Thus, with, in addition, a sharp estimate of the scalar product (|A(u)|2A(u)-|A(v)|2A(v),A(u)-A(v)), we are able to prove existence of solutions and uniqueness, for a boundary of class C2,1 and small data, in three dimensions.
Résumé
Cet article est consacré au problème stationnaire des fluides de grade trois en dimension deux et trois. En dimension deux, nous montrons l’existence de solutions et l’unicité, pour une frontière de classe C2,1 et une donnée petite, en généralisant la méthode utilisée par J.M. Bernard pour le problème stationnaire des fluides de grade deux (nous avons affaire à un polynôme de degré quatre au lieu de deux). Contrairement au cas de la dimension deux, la résolution du problème des fluides de grade trois en dimension trois requière la condition physique |α1+α2|<(24νβ)1/2. De cette condition, nous déduisons deux “pseudo matrice” pour l’opérateur ν|A(u)|2+(α1+α2)tr(A(u)3)+β|A(u)|4, où A(u) est une matice symétrique d’ordre 3 à trace nulle. De là, avec, en plus, une fine estimation du produit scalaire (|A(u)|2A(u)-|A(v)|2A(v),A(u)-A(v)), nous sommes capables de prouver l’existence de solutions et l’unicité, pour une frontière de classe C2,1 et une donnée petite, en dimension trois. 相似文献7.
8.
In the paper “The Photon Momentum” [1], Dr. Umul makes the erroneous assumption that a photon can be absorbed by a free electron and then discusses the paradoxical consequences of this assumption. In this comment the correct physics is discussed (i.e. Compton scattering [2]). 相似文献
9.
Rolling isolation systems (RISs) protect fragile building contents from earthquake hazards by decoupling horizontal floor motions from the horizontal responses of the isolated object. The RISs in use today have displacement capacities of about 20 cm. This displacement capacity can be increased by stacking two systems. This paper presents and evaluates a complete non-linear model of the coupled dynamics of double RISs. The model is derived through the fundamental form of Lagrange׳s equation and involves the non-holonomic constraints of spheres rolling between non-parallel surfaces. The derivation requires the use of two translating and rotating reference frames. The proposed model is validated through comparisons between experimentally measured and numerically predicted time histories and peak response quantities—total acceleration and relative displacement. The effects of the initial conditions, the mass of the isolated object, and the amplitude and period of the disturbance on the system׳s performance are assessed. 相似文献
10.