全文获取类型
收费全文 | 1404篇 |
免费 | 34篇 |
国内免费 | 192篇 |
专业分类
化学 | 635篇 |
晶体学 | 1篇 |
力学 | 74篇 |
综合类 | 4篇 |
数学 | 474篇 |
物理学 | 442篇 |
出版年
2016年 | 2篇 |
2014年 | 9篇 |
2013年 | 16篇 |
2012年 | 32篇 |
2011年 | 454篇 |
2010年 | 237篇 |
2009年 | 197篇 |
2008年 | 36篇 |
2007年 | 36篇 |
2006年 | 55篇 |
2005年 | 93篇 |
2004年 | 216篇 |
2003年 | 99篇 |
2002年 | 51篇 |
2001年 | 39篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1993年 | 3篇 |
1992年 | 11篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1979年 | 1篇 |
1935年 | 1篇 |
排序方式: 共有1630条查询结果,搜索用时 62 毫秒
991.
Hongyong Xie Luping Zhu Lingling Wang Shengwen Chen D an Yang Lijun Yang Guilan Gao Hao Yuan School of Urban Development Environmental Engineering Shanghai Second Polytechnic University Jinhai Road Pudong Shanghai China 《中国颗粒学报》2011,9(1)
Photodegradation of benzene at ppb levels by mixed-phase TiO 2 nanoparticles, synthesized by the oxidation of TiCl 4 in propane/air turbulent flame chemical vapor deposition (CVD) process, is investigated experimentally by using a tubular photoreactor with thin TiO 2 films coated on the reactor wall by sedimentation. Effects of inlet benzene concentration from 10 to 300 g/m 3 , rutile mass fraction from about 20 to 50% and photoluminescence (PL) intensity of TiO 2 nanoparticles on degradation degree are exa... 相似文献
992.
Wei Liu Hong-xing Rui Hui Guo School of Mathematics Sh ong University Jinan China School of Mathematics Information Ludong University Yantai China School of Mathematics Computational Science China University of Petroleum Dongying China 《应用数学学报(英文版)》2011,(3)
Expanded mixed finite element approximation of nonlinear reaction-diffusion equations is discussed. The equations considered here are used to model the hydrologic and bio-geochemical phenomena. To linearize the mixed-method equations, we use a two-grid method involving a small nonlinear system on a coarse gird of size H and a linear system on a fine grid of size h. Error estimates are derived which demonstrate that the error is O(△t + h k+1 + H 2k+2 d/2 ) (k ≥ 1), where k is the degree of the approximating ... 相似文献
993.
We consider the existence, the growth, poles, zeros, fixed points and the Borel exceptional value of solutions for the following difference equations relating to Gamma function y(z + 1) -y(z) = R(z) and y(z + 1) = P (z)y(z). 相似文献
994.
In this paper, by means of the definition of Borel exceptional value method, another exceptional value of meromorphic function which is a T exceptional value is defined by linking the concept of T direction. And we construct a meromorphic function with zero as Borel exceptional value, but not as T exceptional value; and another meromorphic function with zero as T exceptional value, but not as Borel exceptional value. 相似文献
995.
In this paper, we consider the following integral system: u(x) = R n v q (y) | x y | nα dy, v(x) = R n u p (y) | x y | nμ dy, (0.1) where 0 < α, μ < n; p, q ≥ 1. Using the method of moving planes in an integral form which was recently introduced by Chen, Li, and Ou in [2, 4, 8], we show that all positive solutions of (0.1) are radially symmetric and decreasing with respect to some point under some general conditions of integrability. The results essentially improve and extend previously known results [4, 8]. 相似文献
996.
张剑文 《数学物理学报(B辑英文版)》2011,31(3):882-896
In this paper,the inviscid and non-resistive limit is justified for the local-in-time solutions to the equations of nonhomogeneous incompressible magneto-hydrodynamics (MHD)in R~3.We prove that as the viscosity and resistivity go to zero,the solution of the Cauchy problem for the nonhomogeneous incompressible MHD system converges to the solution of the ideal MHD system.The convergence rate is also obtained simultaneously. 相似文献
997.
周家足 《数学物理学报(B辑英文版)》2011,31(2):361-366
Let M be a compact convex hypersurface of class C2, which is assumed to bound a nonempty convex body K in the Euclidean space Rn and H be the mean curvature of M. We obtain a lower bound of the total square of mean curvature M H2dA. The bound is the Minkowski quermassintegral of the convex body K. The total square of mean curvature attains the lower bound when M is an (n-1)-sphere. 相似文献
998.
In this article, we prove the boundedness of commutators generated by BochnerRiesz operators below the critical index and BMO functions on the class of radial functions in L p (R n ) with | 1/p -1/2 | < (1 + 2α)/(2n). 相似文献
999.
设G是一个图,a,b是整数且满足0≤a≤b.如果存在G的一个支撑子图F,使对任意的x∈V(G)有a≤d_F(x)≤b,则称F是G的一个[a,b]-因子.本文给出图中具有特定性质的[a,b]-因子的范-型条件.进一步指出这个结果是最好的. 相似文献
1000.