全文获取类型
收费全文 | 7209篇 |
免费 | 189篇 |
国内免费 | 264篇 |
专业分类
化学 | 849篇 |
晶体学 | 29篇 |
力学 | 34篇 |
综合类 | 9篇 |
数学 | 6166篇 |
物理学 | 575篇 |
出版年
2023年 | 12篇 |
2022年 | 20篇 |
2021年 | 14篇 |
2020年 | 20篇 |
2019年 | 211篇 |
2018年 | 235篇 |
2017年 | 96篇 |
2016年 | 50篇 |
2015年 | 72篇 |
2014年 | 240篇 |
2013年 | 592篇 |
2012年 | 277篇 |
2011年 | 490篇 |
2010年 | 386篇 |
2009年 | 472篇 |
2008年 | 508篇 |
2007年 | 460篇 |
2006年 | 392篇 |
2005年 | 255篇 |
2004年 | 203篇 |
2003年 | 202篇 |
2002年 | 150篇 |
2001年 | 162篇 |
2000年 | 159篇 |
1999年 | 197篇 |
1998年 | 185篇 |
1997年 | 154篇 |
1996年 | 199篇 |
1995年 | 192篇 |
1994年 | 184篇 |
1993年 | 169篇 |
1992年 | 98篇 |
1991年 | 32篇 |
1990年 | 19篇 |
1989年 | 18篇 |
1988年 | 22篇 |
1987年 | 23篇 |
1986年 | 16篇 |
1985年 | 51篇 |
1984年 | 64篇 |
1983年 | 47篇 |
1982年 | 51篇 |
1981年 | 54篇 |
1980年 | 38篇 |
1979年 | 37篇 |
1978年 | 38篇 |
1977年 | 29篇 |
1976年 | 20篇 |
1975年 | 17篇 |
1973年 | 12篇 |
排序方式: 共有7662条查询结果,搜索用时 421 毫秒
11.
富勒烯 (C60 /C70 )与N ,N ,N′ ,N′ 四 (对甲苯基 ) 4,4′ 二胺 1,1′ 二苯硒醚 (TPDASe)间在激光光诱导条件下 ,发生了分子间的电子转移过程 .在可见 -近红外区 ( 60 0~ 12 0 0nm) ,观测到了TPDASe阳离子自由基、富勒烯 (C60 /C70 )激发三线态和阴离子自由基 ,在苯腈溶液中 ,观测瞬态谱测定了电子从TPDASe转移到富勒烯 (C60 /C70 )激发三线态的量子转化产率(ΦTet)和电子转移常数 (Ket) . 相似文献
12.
M Gubinelli 《Journal of Functional Analysis》2004,216(1):86-140
We formulate indefinite integration with respect to an irregular function as an algebraic problem which has a unique solution under some analytic constraints. This allows us to define a good notion of integral with respect to irregular paths with Hölder exponent greater than 1/3 (e.g. samples of Brownian motion) and study the problem of the existence, uniqueness and continuity of solution of differential equations driven by such paths. We recover Young's theory of integration and the main results of Lyons’ theory of rough paths in Hölder topology. 相似文献
13.
Marco Biroli Silvia Mataloni Michele Matzeu 《NoDEA : Nonlinear Differential Equations and Applications》2005,12(3):295-321
Some stability results for Mountain Pass and Linking type solutions of semilinear problems involving a very general class
of Dirichlet forms are stated. The non linear terms are supposed to have a suitable superlinear growth and the family of Dirichlet
forms is required to be dominated from below and from above by a fixed diffusion type form. Some concrete examples are also
given. 相似文献
14.
Michael T. Anderson 《Advances in Mathematics》2003,179(2):205-249
This paper studies several aspects of asymptotically hyperbolic (AH) Einstein metrics, mostly on 4-manifolds. We prove boundary regularity (at infinity) for such metrics and establish uniqueness under natural conditions on the boundary data. By examination of explicit black hole metrics, it is shown that neither uniqueness nor finiteness holds in general for AH Einstein metrics with a prescribed conformal infinity. We then describe natural conditions which are sufficient to ensure finiteness. 相似文献
15.
We prove the existence of solutions to nonlinear free boundary problem with singularities at given points. 相似文献
16.
On a Definitizable Analog of the Trigonometric Moment Problem Generating an Indefinite Toeplitz Form
We prove the existence of an integro-polynomial representation for a sequence of numbers such that there exists a difference operator mapping this sequence to a sequence that generates the solvable trigonometric moment problem. A similar result related to the power moment problem was given in [12]. 相似文献
17.
In this paper, we consider Girsanov transforms of pure jump type for discontinuous Markov processes. We show that, under some quite natural conditions, the Green functions of the Girsanov transformed process are comparable to those of the original process. As an application of the general results, the drift transform of symmetric stable processes is studied in detail. In particular, we show that the relativistic α-stable process in a bounded C1,1-smooth open set D can be obtained from symmetric α-stable process in D through a combination of a pure jump Girsanov transform and a Feynman-Kac transform. From this, we deduce that the Green functions for these two processes in D are comparable. 相似文献
18.
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
19.
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
20.
Sans résumé
相似文献
相似文献