全文获取类型
收费全文 | 7062篇 |
免费 | 402篇 |
国内免费 | 419篇 |
专业分类
化学 | 2206篇 |
晶体学 | 58篇 |
力学 | 162篇 |
综合类 | 145篇 |
数学 | 4360篇 |
物理学 | 952篇 |
出版年
2023年 | 35篇 |
2022年 | 157篇 |
2021年 | 166篇 |
2020年 | 145篇 |
2019年 | 183篇 |
2018年 | 205篇 |
2017年 | 163篇 |
2016年 | 163篇 |
2015年 | 168篇 |
2014年 | 222篇 |
2013年 | 545篇 |
2012年 | 279篇 |
2011年 | 370篇 |
2010年 | 352篇 |
2009年 | 433篇 |
2008年 | 462篇 |
2007年 | 456篇 |
2006年 | 411篇 |
2005年 | 323篇 |
2004年 | 317篇 |
2003年 | 253篇 |
2002年 | 218篇 |
2001年 | 181篇 |
2000年 | 210篇 |
1999年 | 199篇 |
1998年 | 151篇 |
1997年 | 145篇 |
1996年 | 99篇 |
1995年 | 95篇 |
1994年 | 92篇 |
1993年 | 96篇 |
1992年 | 76篇 |
1991年 | 61篇 |
1990年 | 55篇 |
1989年 | 48篇 |
1988年 | 43篇 |
1987年 | 41篇 |
1986年 | 36篇 |
1985年 | 27篇 |
1984年 | 33篇 |
1983年 | 15篇 |
1982年 | 27篇 |
1981年 | 20篇 |
1980年 | 23篇 |
1979年 | 29篇 |
1978年 | 25篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1975年 | 4篇 |
1974年 | 3篇 |
排序方式: 共有7883条查询结果,搜索用时 46 毫秒
91.
An analogy between social and hydrodynamic processes is developed. The relation of the state system to the passionarity theory suggested by L. N. Gumilev is discussed. 相似文献
92.
在误差序列为Lqmixingale情形下,给出了半参数回归模型中β和g(t)估计,研究了估计量的q阶平均相合性在较一般的条件下,得到了理想的结果 相似文献
93.
Anatol Odzijewicz 《Journal of Functional Analysis》2004,217(1):103-125
The extension of Banach Lie-Poisson spaces is studied and linked to the extension of a special class of Banach Lie algebras. The case of W∗-algebras is given particular attention. Semidirect products and the extension of the restricted Banach Lie-Poisson space by the Banach Lie-Poisson space of compact operators are given as examples. 相似文献
94.
The fracture mechanisms of Hg0.8Cd0.2Te induced by pulsed TEA-CO2 laser have been investigated theoretically and experimentally in this paper. The Hg0.8Cd0.2Te target was irradiated by a TEA-CO2 laser with wavelength of 10.6 μm and spike width of 240 ns in an ambient atmosphere. The evident cracks can be found on the surface of the target from the scanning electron microscopy (SEM) photos, indicating that the severe breaks happened during the experiment. Theoretical analysis has also been carried out and the results show that the fracture of Hg0.8Cd0.2Te is mainly induced by thermal stresses, although there are three forces (thermal stress, evaporation wave and laser-supported detonation (LSD) wave) exerted on the target surface during the process. 相似文献
95.
Chau O. Shillor M. Sofonea M. 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2004,55(1):32-47
A model for the dynamic, adhesive, frictionless contact
between a viscoelastic body and a deformable foundation is
described. The adhesion process is modeled by a bonding field on
the contact surface. The contact is described by a modified normal
compliance condition. The tangential shear due to the bonding
field is included. The problem is formulated as a coupled system
of a variational equality for the displacements and a differential
equation for the bonding field. The existence of a unique weak
solution for the problem is established, together with a partial
regularity result. The existence proof proceeds by construction of
an appropriate mapping which is shown to be a contraction on a
Hilbert space. 相似文献
96.
We provide a proof of Connes’ formula for a representative of the Hochschild class of the Chern character for (p,∞)-summable spectral triples. Our proof is valid for all semifinite von Neumann algebras, and all integral p?1. We employ the minimum possible hypotheses on the spectral triples. 相似文献
97.
Andrzej Skowronski Kunio Yamagata 《Proceedings of the American Mathematical Society》2004,132(3):659-667
We prove that a large class of self-injective algebras of tilted type is invariant under stable equivalences of module categories.
98.
When trains of impulse controls are present on the right-hand side of a system of ordinary differential equations, the solution
is no longer smooth and contains jumps which can accumulate at several points in the time interval. In technological and physical
systems the sum of the absolute value of all the impulses is finite and hence the total variation of the solution is finite.
So the solution at best belongs to the space BV of vector functions with bounded variation. Unless variable node methods are
used, the loss of smoothness of the solution would a priori make higher-order methods over a fixed mesh inactractive. Indeed
in general the order of -convergence is and the nodal rate is . However in the linear case -convergence rate remains but the nodal rate can go up to by using one-step or multistep scheme with a nodal rate up to when the solution belongs to . Proofs are given of error estimates and several numerical experiments confirm the optimality of the estimates.
Received March 15, 1996 / Revised version received January 3, 1997 相似文献
99.
Geetha Ramaswami 《BIT Numerical Mathematics》1997,37(2):465-471
In this paper, we derive a one-parameter family of symplectic Runge-Kutta-Nyström methods of order 2s-1 and a two-parameter family of symplectic Runge-Kutta methods of order 2s-2. 相似文献
100.