全文获取类型
收费全文 | 12870篇 |
免费 | 303篇 |
国内免费 | 181篇 |
专业分类
化学 | 912篇 |
晶体学 | 88篇 |
力学 | 139篇 |
综合类 | 25篇 |
数学 | 10723篇 |
物理学 | 1467篇 |
出版年
2023年 | 26篇 |
2022年 | 64篇 |
2021年 | 91篇 |
2020年 | 60篇 |
2019年 | 290篇 |
2018年 | 314篇 |
2017年 | 195篇 |
2016年 | 115篇 |
2015年 | 139篇 |
2014年 | 325篇 |
2013年 | 622篇 |
2012年 | 459篇 |
2011年 | 720篇 |
2010年 | 573篇 |
2009年 | 839篇 |
2008年 | 913篇 |
2007年 | 947篇 |
2006年 | 799篇 |
2005年 | 606篇 |
2004年 | 475篇 |
2003年 | 340篇 |
2002年 | 341篇 |
2001年 | 311篇 |
2000年 | 314篇 |
1999年 | 346篇 |
1998年 | 281篇 |
1997年 | 243篇 |
1996年 | 298篇 |
1995年 | 281篇 |
1994年 | 289篇 |
1993年 | 202篇 |
1992年 | 180篇 |
1991年 | 126篇 |
1990年 | 120篇 |
1989年 | 135篇 |
1988年 | 88篇 |
1987年 | 94篇 |
1986年 | 74篇 |
1985年 | 103篇 |
1984年 | 90篇 |
1983年 | 54篇 |
1982年 | 83篇 |
1981年 | 69篇 |
1980年 | 77篇 |
1979年 | 43篇 |
1978年 | 56篇 |
1977年 | 48篇 |
1976年 | 43篇 |
1975年 | 14篇 |
1973年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
51.
Pascal Cherrier 《Bulletin des Sciences Mathématiques》2007,131(4):375-396
We study a parabolic version of a system of Von Karman type on a compact Kähler manifold of arbitrary dimension. We provide local in time regular solutions, which can be extended to global bounded ones if the data of the problem are small. 相似文献
52.
Daisuke Kishimoto 《Topology and its Applications》2007,154(7):1465-1469
By calculating certain generalized cohomology theory, lower bounds for the L-S category of quaternionic Stiefel manifolds are given. 相似文献
53.
Lévy processes in matrix Lie groups are studied. Subordination (random time change) is used to show that quasi-invariance of the Brownian motion in a Lie group induces absolute continuity of the laws of the corresponding pure jump processes. These results are applied to several examples which are discussed in detail. 相似文献
54.
We propose a new scheme for the long time approximation of a diffusion when the drift vector field is not globally Lipschitz. Under this assumption, a regular explicit Euler scheme–with constant or decreasing step–may explode and implicit Euler schemes are CPU-time expensive. The algorithm we introduce is explicit and we prove that any weak limit of the weighted empirical measures of this scheme is a stationary distribution of the stochastic differential equation. Several examples are presented including gradient dissipative systems and Hamiltonian dissipative systems. 相似文献
55.
In this paper, we present a numerical scheme for solving the coupled system of compressible miscible displacement problem in porous media. The flow equation is solved by the mixed finite element method, and the transport equation is approximated by a discontinuous Galerkin method. The scheme is continuous in time and a priori hp error estimates is presented. 相似文献
56.
M. Frigon 《Journal of Fixed Point Theory and Applications》2007,1(2):189-194
We present results on the global existence of analytic solutions to the Cauchy problem in starshaped or convex complex domains.
No growth conditions are imposed. Our results rely on a notion of solution-tube that we introduce.
à la mémoire de Jean Leray 相似文献
57.
58.
Marilyn Breen 《Journal of Geometry》1989,36(1-2):8-16
LetS be a compact, simply connected set inR
2. If every boundary point ofS is clearly visible viaS from at least one of the three pointsa, b, c, thenS is a union of three starshaped sets whose kernels containa, b, c, respectively. The result fails when the number three is replaced by four.As a partial converse, ifS is a union of three starshaped sets whose kernels containa, b, c, respectively, then the set of points in the boundary ofS clearly visible from at least one ofa, b, orc is dense in the boundary ofS.Supported in part by NSF grant DMS-8705336. 相似文献
59.
Jan Annaert Griselda Deelstra Michèle Vanmaele 《Insurance: Mathematics and Economics》2007,41(3):299-316
In this paper, we elaborate a formula for determining the optimal strike price for a bond put option, used to hedge a position in a bond. This strike price is optimal in the sense that it minimizes, for a given budget, either Value-at-Risk or Tail Value-at-Risk. Formulas are derived for both zero-coupon and coupon bonds, which can also be understood as a portfolio of bonds. These formulas are valid for any short rate model that implies an affine term structure model and in particular that implies a lognormal distribution of future zero-coupon bond prices. As an application, we focus on the Hull-White one-factor model, which is calibrated to a set of cap prices. We illustrate our procedure by hedging a Belgian government bond, and take into account the possibility of divergence between theoretical option prices and real option prices. This paper can be seen as an extension of the work of Ahn and co-workers [Ahn, D., Boudoukh, J., Richardson, M., Whitelaw, R., 1999. Optimal risk management using options. J. Financ. 54, 359-375], who consider the same problem for an investment in a share. 相似文献
60.
Martin Loebl 《Advances in Mathematics》2007,211(2):546-565
We define a q-chromatic function and q-dichromate on graphs and compare it with existing graph functions. Then we study in more detail the class of general chordal graphs. This is partly motivated by the graph isomorphism problem. Finally we relate the q-chromatic function to the colored Jones function of knots. This leads to a curious expression of the colored Jones function of a knot diagram K as a chromatic operator applied to a power series whose coefficients are linear combinations of long chord diagrams. Chromatic operators are directly related to weight systems by the work of Chmutov, Duzhin, Lando and Noble, Welsh. 相似文献