全文获取类型
收费全文 | 17798篇 |
免费 | 405篇 |
国内免费 | 241篇 |
专业分类
化学 | 949篇 |
晶体学 | 23篇 |
力学 | 207篇 |
综合类 | 26篇 |
数学 | 16126篇 |
物理学 | 1113篇 |
出版年
2023年 | 28篇 |
2022年 | 57篇 |
2021年 | 47篇 |
2020年 | 66篇 |
2019年 | 393篇 |
2018年 | 475篇 |
2017年 | 247篇 |
2016年 | 166篇 |
2015年 | 193篇 |
2014年 | 473篇 |
2013年 | 1019篇 |
2012年 | 585篇 |
2011年 | 1007篇 |
2010年 | 970篇 |
2009年 | 1307篇 |
2008年 | 1376篇 |
2007年 | 1255篇 |
2006年 | 917篇 |
2005年 | 581篇 |
2004年 | 460篇 |
2003年 | 449篇 |
2002年 | 410篇 |
2001年 | 391篇 |
2000年 | 391篇 |
1999年 | 463篇 |
1998年 | 448篇 |
1997年 | 366篇 |
1996年 | 361篇 |
1995年 | 373篇 |
1994年 | 397篇 |
1993年 | 310篇 |
1992年 | 279篇 |
1991年 | 228篇 |
1990年 | 216篇 |
1989年 | 234篇 |
1988年 | 152篇 |
1987年 | 133篇 |
1986年 | 159篇 |
1985年 | 153篇 |
1984年 | 162篇 |
1983年 | 76篇 |
1982年 | 147篇 |
1981年 | 110篇 |
1980年 | 123篇 |
1979年 | 84篇 |
1978年 | 88篇 |
1977年 | 45篇 |
1976年 | 32篇 |
1974年 | 15篇 |
1973年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Victor Bondarenko 《Bulletin des Sciences Mathématiques》2003,127(3):191-206
In present paper the parabolic equation solution is built. The construction is reduced to iterative procedure. And convergence of the latter is proven. 相似文献
22.
We investigate several versions of a cardinal characteristic defined by Frankiewicz. Vojtáš showed , and Blass showed . We show that all the versions coincide and that is greater than or equal to the splitting number. We prove the consistency of and of .
Received: 2 October 1996 / Revised version: 22 May 1997 相似文献
23.
Modifying complex plane rotations, we derive a new Jacobi-type algorithm for the Hermitian eigendecomposition, which uses only real arithmetic. When the fast-scaled rotations are incorporated, the new algorithm brings a substantial reduction in computational costs. The new method has the same convergence properties and parallelism as the symmetric Jacobi algorithm. Computational test results show that it produces accurate eigenvalues and eigenvectors and achieves great reduction in computational time.The work of this author was supported in part by the National Science Foundation grant CCR-8813493 and by the University of Minnesota Army High Performance Computing Research Center contract DAAL 03-89-C-0038.The work of this author was supported in part by the University of Minnesota Army High Performance Computing Research Center contract DAAL 03-89-C-0038. 相似文献
24.
Summary. We study a diffusion model of an interacting particles system with general drift and diffusion coefficients, and electrostatic
inter-particles repulsion. More precisely, the finite particle system is shown to be well defined thanks to recent results
on multivalued stochastic differential equations (see [2]), and then we consider the behaviour of this system when the number
of particles goes to infinity (through the empirical measure process). In the particular case of affine drift and constant diffusion coefficient,
we prove that a limiting measure-valued process exists and is the unique solution of a deterministic PDE. Our treatment of
the convergence problem (as ) is partly similar to that of T. Chan [3] and L.C.G. Rogers - Z. Shi [5], except we consider here a more general case allowing
collisions between particles, which leads to a second-order limiting PDE.
Received: 5 August 1996 / In revised form: 17 October 1996 相似文献
25.
J. Schropp 《Numerische Mathematik》1997,78(1):87-101
Summary. We use the qualitative properties of the solution flow of the gradient equation to compute a local minimum of a real-valued function . Under the regularity assumption of all equilibria we show a convergence result for bounded trajectories of a consistent,
strictly stable linear multistep method applied to the gradient equation. Moreover, we compare the asymptotic features of
the numerical and the exact solutions as done by Humphries, Stuart (1994) and Schropp (1995) for one-step methods. In the
case of -stable formulae this leads to an efficient solver for stiff minimization problems.
Received July 10, 1995 / Revised version received June 27, 1996 相似文献
26.
27.
A. Sánchez-Lavega A. Salazar A. Ocariz L. Pottier E. Gomez L.M. Villar E. Macho 《Applied Physics A: Materials Science & Processing》1997,65(1):15-22
Received: 16 September 1996/Accepted: 6 January 1997 相似文献
28.
Summary. We present a simple proof, based on modified logarithmic Sobolev inequalities, of Talagrand’s concentration inequality for
the exponential distribution. We actually observe that every measure satisfying a Poincaré inequality shares the same concentration
phenomenon. We also discuss exponential integrability under Poincaré inequalities and its consequence to sharp diameter upper
bounds on spectral gaps.
Received: 10 June 1996 / In revised form: 9 August 1996 相似文献
29.
Robert L. Jerrard Halil Mete Soner 《Calculus of Variations and Partial Differential Equations》2002,14(2):151-191
We study the Ginzburg-Landau functional
for , where U is a bounded, open subset of . We show that if a sequence of functions satisfies , then their Jacobians are precompact in the dual of for every . Moreover, any limiting measure is a sum of point masses. We also characterize the -limit of the functionals , in terms of the function space B2V introduced by the authors in [16,17]: we show that I(u) is finite if and only if , and for is equal to the total variation of the Jacobian measure Ju. When the domain U has dimension greater than two, we prove if then the Jacobians are again precompact in for all , and moreover we show that any limiting measure must be integer multiplicity rectifiable. We also show that the total variation
of the Jacobian measure is a lower bound for the limit of the Ginzburg-Landau functional.
Received: 15 December 2000 / Accepted: 23 January 2001 / Published online: 25 June 2001 相似文献
30.
Summary In this paper, we develop a framework suitable for performing a multiresolution analysis using univariate spline spaces of arbitrary degree and with non-uniform knot-sequences. To this end, we show, among other things, the existence of compactly supported prewavelets and of prewavelets that are globally supported, but decay exponentially. In each case we obtain a decomposition of a fine spline space as a sum of a coarse spline space plus a spline space spanned by prewavelets. 相似文献