全文获取类型
收费全文 | 1538篇 |
免费 | 77篇 |
国内免费 | 119篇 |
专业分类
化学 | 142篇 |
力学 | 65篇 |
综合类 | 9篇 |
数学 | 1186篇 |
物理学 | 332篇 |
出版年
2024年 | 4篇 |
2023年 | 24篇 |
2022年 | 28篇 |
2021年 | 25篇 |
2020年 | 43篇 |
2019年 | 50篇 |
2018年 | 35篇 |
2017年 | 41篇 |
2016年 | 38篇 |
2015年 | 43篇 |
2014年 | 102篇 |
2013年 | 138篇 |
2012年 | 55篇 |
2011年 | 103篇 |
2010年 | 79篇 |
2009年 | 106篇 |
2008年 | 130篇 |
2007年 | 95篇 |
2006年 | 90篇 |
2005年 | 47篇 |
2004年 | 49篇 |
2003年 | 47篇 |
2002年 | 45篇 |
2001年 | 46篇 |
2000年 | 30篇 |
1999年 | 42篇 |
1998年 | 28篇 |
1997年 | 32篇 |
1996年 | 20篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 11篇 |
1977年 | 2篇 |
1976年 | 2篇 |
排序方式: 共有1734条查询结果,搜索用时 296 毫秒
991.
The paper is concerned with a hybrid finite element formulation for the geometrically exact dynamics of rods with applications to chaotic motion. The rod theory is developed for in-plane motions using the direct approach where the rod is treated as a one-dimensional Cosserat line. Shear deformation is included in the formulation. Within the elements, a linear distribution of the kinematical fields is combined with a constant distribution of the normal and shear forces. For time integration, the mid-point rule is employed. Various numerical examples of chaotic motion of straight and initially curved rods are presented proving the powerfulness and applicability of the finite element formulation. 相似文献
992.
Fracture mechanics of laminated glass subjected to blast loading 总被引:2,自引:0,他引:2
A failure criterion based on energy balance approach is introduced for the laminated glass panel subjected to blast loading. Based on this failure criterion, a damage factor is developed to assess the failure of the laminated glass panel. If the damage factor is less than one, the plate is safe otherwise unsafe. Trigonometric function is employed to express the transverse deflection and the Airy’s stress function in von Karman’s large deflection equations of a thin plate. The nonlinear ordinary differential equation of motion obtained using the Galerkin method is solved using Runge–Kutta method. The predicted results indicate that the breakages of the laminated glass may be caused by the negative phase of the blast load if the positive phase blast load is not violent enough to cause failure. Also, the size of glass shards the laminated glass plies breaks in to is predicted using the surface energy based failure model. 相似文献
993.
Jae-Kon Lee 《Archive of Applied Mechanics (Ingenieur Archiv)》2007,77(7):453-460
In this study, a new model to predict the thermal conductivity of composites with spherical fillers is proposed. The original
Eshelby model is extended to a finite filler volume fraction by successively embedding small filler volume fraction. The predicted
results by the present model are compared with bounds such as parallel, series, and Hashin–Shtrikman models, results by modified
Eshelby model, generalized self-consistent model, and effective medium theory, and the experimental results from the literature.
It is found that the present model always lies between the bounds and shows better agreement with the experimental results
than the other models for various filler volume fractions and thermal conductivity ratios. 相似文献
994.
Douadi Drihem 《数学研究》2023,56(1):18-92
We introduce Besov spaces with general smoothness. These spaces unify and generalize the classical Besov spaces. We establish the $\varphi $-transform characterization of these spaces in the sense of Frazier and Jawerth and we prove their Sobolev embeddings. We establish the smooth atomic, molecular and wavelet decomposition of these function spaces. A characterization of these function spaces in terms of the difference relations is given. 相似文献
995.
Let M be a d-dimensional compact Riemannian manifold. We prove existence of a unique global strong solution of the stochastic wave equation , where Y is a C1-smooth transformation and W is a spatially homogeneous Wiener process on whose spectral measure has finite moments up to order 2. 相似文献
996.
The sphere S
n+1 contains a simple family of constant mean curvature (CMC) hypersurfaces of the form C
t
: = S
p
(cos t) × S
q
(sin t) for p + q = n and called the generalized Clifford hypersurfaces. This paper demonstrates that new, topologically non-trivial CMC hypersurfaces
resembling a pair of neighbouring generalized Clifford tori connected to each other by small catenoidal bridges at a sufficiently
symmetric configuration of points can be constructed by perturbative PDE methods. That is, one can create an approximate solution
by gluing a rescaled catenoid into the neighbourhood of each point; and then one can show that a perturbation of this approximate
hypersurface exists, which satisfies the CMC condition. The results of this paper generalize those of the authors in [3]. 相似文献
997.
L. Leindler 《Acta Mathematica Hungarica》2007,114(3):227-234
We analyze the relationships of four classical and three recently defined classes of numerical sequences.
This research was partially supported by the Hungarian National Foundation for Scientific Research under Grant # T042462 and
TS44782. 相似文献
998.
999.
Carl de Boor 《Numerical Algorithms》2007,45(1-4):113-125
GC-sets are subsets T of of the appropriate cardinality for which, for each τ ∈ T, there are n hyperplanes whose union contains all of T except for τ, thus making interpolation to arbitrary data on T by polynomials of degree ≤ n uniquely possible. The existing bivariate theory of such sets is extended to the general multivariate case and the concept
of a maximal hyperplane for T is highlighted, in hopes of getting more insight into existing conjectures for the bivariate
case.
相似文献
1000.
Let
, n ≥ 2, be the near 2n-gon on the 2-factors of a complete graph with 2n + 2 vertices. In this paper, we classify the valuations of the near octagon
. We use this classification to study isometric full embeddings of
into DQ(8,2) and DH(7,4). We show that there is up to isomorphism a unique isometric full embedding of
into each of these dual polar spaces. Further applications are expected in the classification of dense near polygons with
lines of size 3. 相似文献