全文获取类型
收费全文 | 870篇 |
免费 | 60篇 |
国内免费 | 96篇 |
专业分类
化学 | 9篇 |
力学 | 46篇 |
综合类 | 32篇 |
数学 | 906篇 |
物理学 | 33篇 |
出版年
2023年 | 12篇 |
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 16篇 |
2019年 | 18篇 |
2018年 | 23篇 |
2017年 | 19篇 |
2016年 | 17篇 |
2015年 | 16篇 |
2014年 | 32篇 |
2013年 | 61篇 |
2012年 | 31篇 |
2011年 | 53篇 |
2010年 | 36篇 |
2009年 | 55篇 |
2008年 | 70篇 |
2007年 | 57篇 |
2006年 | 51篇 |
2005年 | 46篇 |
2004年 | 31篇 |
2003年 | 45篇 |
2002年 | 46篇 |
2001年 | 31篇 |
2000年 | 38篇 |
1999年 | 32篇 |
1998年 | 28篇 |
1997年 | 23篇 |
1996年 | 29篇 |
1995年 | 10篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有1026条查询结果,搜索用时 15 毫秒
51.
G. Filippone N. Tz. Dintcheva F. P. La Mantia D. Acierno 《Journal of Polymer Science.Polymer Physics》2010,48(5):600-609
A study was made on the effect of small amounts of organically modified clay on the morphology and mechanical properties of blends of low‐density polyethylene and polyamide 11 at different compositions. The influence of the filler on the blend morphology was investigated using wide angle X‐ray diffractometry, scanning and transmission electron microscopy and selective extraction experiments. The filler was found to locate predominantly in the more hydrophilic polyamide phase. Although such uneven distribution does not have a significant effect on the onset of phase co‐continuity of the polymer components, it brings about a drastic refinement of the microstructure for the blends both with droplets/matrix and co‐continuous morphologies. In addition to the expected reinforcing action of the filler, the resulting fine microstructure plays an important role in enhancing the mechanical properties of the blends. This is essentially because of a good quality of stress transfer across the interface between the constituents, which also seems to benefit for a good interfacial adhesion promoted by the filler. Our results provide the experimental evidence for the capabilities of nanoparticles added to multiphase polymer systems to act selectively as a reinforcing agent for specific domains of the material and as a medium able to assist the refinement of the polymer phases during mixing. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 600–609, 2010 相似文献
52.
Daniel Lenz Norbert Peyerimhoff Olaf Post Ivan Veselić 《Japanese Journal of Mathematics》2008,3(1):121-161
We first analyze the integrated density of states (IDS) of periodic Schrödinger operators on an amenable covering manifold. A criterion for the continuity of the IDS at a prescribed energy is given along with examples of operators with both continuous and discontinuous IDS. Subsequently, alloy-type perturbations of the periodic operator are considered. The randomness may enter both via the potential and the metric. A Wegner estimate is proven which implies the continuity of the corresponding IDS. This gives an example of a discontinuous “periodic” IDS which is regularized by a random perturbation. 相似文献
53.
In this paper, general conditions of state classification for the total weighted occupation times of a class of infinitely
divisible superprocesses on a bounded domain D in ℝ
d
are given. As an application, some sufficient and necessary conditions are found for the total weighted occupation times
of some special superprocesses on D to be absolutely continuous or singular with respect to the Lebesgue measure on D.
The research of Yan-Xia Ren is supported by NNSF of China (Grant No. 10471003) and Foundation for Authors Awarded Excellent
Ph.D. Dissertation. 相似文献
54.
Saïd Hilout 《Journal of Mathematical Analysis and Applications》2008,339(2):753-761
A class of Steffensen-type algorithms for solving generalized equations on Banach spaces is proposed. Using well-known fixed point theorem for set-valued maps [A.L. Dontchev, W.W. Hager, An inverse function theorem for set-valued maps, Proc. Amer. Math. Soc. 121 (1994) 481-489] and some conditions on the first-order divided difference, we provide a local convergence analysis. We also study the perturbed problem and we present a new regula-falsi-type method for set-valued mapping. This study follows the works on the Secant-type method presented in [S. Hilout, A uniparametric Secant-type methods for nonsmooth generalized equations, Positivity (2007), submitted for publication; S. Hilout, A. Piétrus, A semilocal convergence of a Secant-type method for solving generalized equations, Positivity 10 (2006) 673-700] and extends the results related to the resolution of nonlinear equations [M.A. Hernández, M.J. Rubio, The Secant method and divided differences Hölder continuous, Appl. Math. Comput. 124 (2001) 139-149; M.A. Hernández, M.J. Rubio, Semilocal convergence of the Secant method under mild convergence conditions of differentiability, Comput. Math. Appl. 44 (2002) 277-285; M.A. Hernández, M.J. Rubio, ω-Conditioned divided differences to solve nonlinear equations, in: Monogr. Semin. Mat. García Galdeano, vol. 27, 2003, pp. 323-330; M.A. Hernández, M.J. Rubio, A modification of Newton's method for nondifferentiable equations, J. Comput. Appl. Math. 164/165 (2004) 323-330]. 相似文献
55.
In this paper we answer to a question raised by Ambrosio and Rigot [L. Ambrosio, S. Rigot, Optimal mass transportation in the Heisenberg group, J. Funct. Anal. 208 (2) (2004) 261-301] proving that any interior point of a Wasserstein geodesic in the Heisenberg group is absolutely continuous if one of the end-points is. Since our proof relies on the validity of the so-called Measure Contraction Property and on the fact that the optimal transport map exists and the Wasserstein geodesic is unique, the absolute continuity of Wasserstein geodesic also holds for Alexandrov spaces with curvature bounded from below. 相似文献
56.
§ 1 Introduction and ResultsLet{W(t) ;t≥ 0 }be a standard Brownian motion.For a positive integer m,define aGaussian processXm(t) =1m!∫t0 (t-s) md W(s) ,(1 .1 )which was firstmentioned by[1 ] .This class of processes arises in several domains of ap-plied mathematics.For instance,the process X1 (· ) ,which has been studied at length,isthe solution of the Langevin's equation under certain physical conditions.Wahba[2 ,3] usedXm(· ) to derive a correspondence between smoothing by splines … 相似文献
57.
Fubao Xi 《Journal of Mathematical Analysis and Applications》2008,341(1):588-600
In this paper we consider the stability for a class of jump-diffusions with Markovian switching. We first construct them successively and show that they can be associated with some appropriate generators and they are non-explosive. We then prove their Feller continuity by the coupling methods. Furthermore, we also prove their strong Feller continuity by making use of the relation between the transition probabilities of jump-diffusions and the corresponding diffusions. Finally, we also investigate their exponential ergodicity. 相似文献
58.
Yu. L. Ershov 《Siberian Mathematical Journal》2008,49(5):852-856
The continuity estimates of Theorem 6 of the first part are improved, using Theorem 2 of the author’s article on the norms of roots and coefficients. 相似文献
59.
60.