全文获取类型
收费全文 | 5620篇 |
免费 | 965篇 |
国内免费 | 377篇 |
专业分类
化学 | 3558篇 |
晶体学 | 30篇 |
力学 | 715篇 |
综合类 | 52篇 |
数学 | 1131篇 |
物理学 | 1476篇 |
出版年
2024年 | 3篇 |
2023年 | 52篇 |
2022年 | 69篇 |
2021年 | 104篇 |
2020年 | 197篇 |
2019年 | 154篇 |
2018年 | 137篇 |
2017年 | 117篇 |
2016年 | 246篇 |
2015年 | 237篇 |
2014年 | 305篇 |
2013年 | 476篇 |
2012年 | 362篇 |
2011年 | 403篇 |
2010年 | 345篇 |
2009年 | 417篇 |
2008年 | 430篇 |
2007年 | 358篇 |
2006年 | 378篇 |
2005年 | 310篇 |
2004年 | 316篇 |
2003年 | 272篇 |
2002年 | 202篇 |
2001年 | 128篇 |
2000年 | 126篇 |
1999年 | 107篇 |
1998年 | 109篇 |
1997年 | 135篇 |
1996年 | 74篇 |
1995年 | 68篇 |
1994年 | 53篇 |
1993年 | 37篇 |
1992年 | 41篇 |
1991年 | 35篇 |
1990年 | 32篇 |
1989年 | 22篇 |
1988年 | 19篇 |
1987年 | 14篇 |
1986年 | 14篇 |
1985年 | 13篇 |
1984年 | 10篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1973年 | 3篇 |
1969年 | 1篇 |
排序方式: 共有6962条查询结果,搜索用时 15 毫秒
41.
XU Yichao CHEN Minru & MA Songya Academy of Mathematics Systems Science Chinese Academy of Sciences Beijing China College of Mathematics Information Sciences Henan University Kaifeng China 《中国科学A辑(英文版)》2006,49(10):1392-1404
We known that the maximal connected holomorphic automorphism group Aut (D)(0) is a semi-direct product of the triangle group T(D) and the maximal connected isotropic subgroup Iso(D)(0) of a fixed point in the complex homogeneous bounded domain D and any complex homogeneous bounded domain is holomorphic isomorphic to a normal Siegel domain D(VN,F). In this paper, we give the explicit formula of any holomorphic automorphism in T(D(VN, F)) and Iso(D(VN,F))(0), where G(0) is the unit connected component of the Lie group G. 相似文献
42.
HarmonicAnalysisontheCompactHomogeneousSpaces──aboutFourierMultiplierofH~P(M)Space¥DongDaozhen;ZhengXuean(HenanUniversity,Kai?.. 相似文献
43.
44.
The problem treated in this paper concerns calculating the evolution of the pressure in a single-phase, slightly compressible fluid in a porous medium consisting of communicating layers. The fluid is produced through a point sink located on the side of an otherwise sealed cylindrical wellbore. This location of the sink causes the flow around the wellbore to be azimuthally asymmetric.The problem is solved through successive application of Laplace, finite Fourier and finite Hankel transforms. Although apparently straightforward, this approach leads to serious numerical difficulties. The published form of the inversion formula for the finite Hankel transform leads to inaccurate computation for the higher azimuthal modes even with 128 bit arithmetic. An alternative form is developed which enables accurate evaluation of the solution with the more practical 64 bit arithmetic. The technique for two-layer solution presented here can be directly extended to a problem with a larger number of communicating layers. This is the first instance of successful application of the finite Hankel transform to an azimuthally asymmetric diffusion problem. 相似文献
45.
46.
Backlund transformation and variable separation solutions for the generalized Nozhnik—Novikov—Veselov equation
下载免费PDF全文
![点击此处可从《中国物理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Using the extended homogeneous balance method, the B?cklund transformation for a (2+1)-dimensional integrable model, the generalized Nizhnik-Novikov-Veselov (GNNV) equation, is first obtained. Also, making use of the B?cklund transformation, the GNNV equation is changed into three equations: linear, bilinear and trilinear form equations. Starting from these three equations, a rather general variable separation solution of the model is constructed. The abundant localized coherent structures of the model can be induced by the entrance of two variable-separated arbitrary functions. 相似文献
47.
V. D. Lakiza 《International Applied Mechanics》2005,41(1):85-89
The results from an experimental study into the dynamic behavior of a gas-liquid medium and solid particles in a compound shell (sphere-truncated cone) are reported on. The following processes are studied: formation of gas bubbles and their clusters, strong macroflows, and intensive chaotic motion of the medium in the truncated cone as a nonlinear vibrating liquid-gas system__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 1, pp. 112–118, January 2005. 相似文献
48.
复合广义齐次Poisson过程的多险种破产概率 总被引:11,自引:0,他引:11
于文广 《应用数学与计算数学学报》2003,17(2):63-69
本文推广了经典的复合泊松风险模型,建立了两类复合广义齐次poisson过程的多险种破产模型.对于新模型,我们得到了初始资本为u的破产概率φ(u)的精确表达式以及特殊情况下φ(0)的表达式,并且导出了调节系数方程和调节系数R的上下界. 相似文献
49.
The enthalpies and free energies of proton affinity (PA) were calculated by the PM3 method for 27 thiophenoxide anions. For thiophenols, linear correlation has been found between the PAs and the values of pK
a
measured by different authors in aqueous acetone, aqueous ethanol, and methanol media. The dependences found permit one to predict a priori the protolytic properties of thiophenols. The differential effects of aqueous ethanol media with different ethanol contents on thiophenol acidity were evaluated based on quantum-chemical data.Original Russian Text Copyright © 2004 by A. N. Pankratov and A. V. Shalabai__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 5, pp. 800–806, September–October, 2004. 相似文献
50.
杨大春 《中国科学A辑(英文版)》2003,46(5)
This paper introduces the fractional Sobolev spaces on spaces of homogeneous type,includingmetric spaces and fractals. These Sobolev spaces include the well-known Hajfasz-Sobolev spaces as specialmodels.The author establishes varions chaaracterizations of(sharp)maximal functions for these spaces.Asapplications,the author identifies the fractional Sobolev spaces with some Lipscitz-type spaces.Moreover;some embedding theorems are also given. 相似文献