首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1442篇
  免费   70篇
  国内免费   6篇
化学   874篇
晶体学   15篇
力学   43篇
数学   373篇
物理学   213篇
  2023年   16篇
  2022年   65篇
  2021年   67篇
  2020年   62篇
  2019年   68篇
  2018年   78篇
  2017年   57篇
  2016年   90篇
  2015年   71篇
  2014年   81篇
  2013年   104篇
  2012年   121篇
  2011年   99篇
  2010年   65篇
  2009年   51篇
  2008年   58篇
  2007年   41篇
  2006年   43篇
  2005年   43篇
  2004年   32篇
  2003年   22篇
  2002年   15篇
  2001年   7篇
  2000年   8篇
  1999年   4篇
  1998年   6篇
  1997年   3篇
  1996年   6篇
  1995年   3篇
  1994年   6篇
  1993年   7篇
  1992年   5篇
  1991年   6篇
  1990年   10篇
  1989年   4篇
  1988年   9篇
  1987年   4篇
  1986年   8篇
  1985年   8篇
  1984年   6篇
  1983年   3篇
  1982年   9篇
  1981年   6篇
  1980年   8篇
  1979年   4篇
  1977年   3篇
  1976年   4篇
  1975年   4篇
  1972年   5篇
  1971年   3篇
排序方式: 共有1518条查询结果,搜索用时 10 毫秒
161.
We study the pair production of scalar quark in a muon collider within the MSSM with CP violation. We show that including the CP phases can strongly affect the cross section of the process: \(\mu^{+}\mu^{-}\rightarrow \tilde{q}_{i}\bar{\tilde{q}}_{j}\). This could have an important impact on the search for squarks and the determination of the MSSM parameters at future colliders.  相似文献   
162.
Photoluminescence properties of various CVD-grown ZnO nanostructures   总被引:3,自引:0,他引:3  
We have studied systematically room-temperature photoluminescence (PL) properties of many nanostructured ZnO samples grown by chemical vapour deposition (CVD). Their PL spectra consist of two emissions peaked in the ultraviolet (UV) and green regions. The relative intensity of these emissions depends on the excitation energy density, size and morphology of ZnO nanostructures. Based on the excitation-density dependence of the integrated intensity ratio of UV-to-green emission, we could classify PL spectra of ZnO nanostructures into three groups characteristic of size and morphology. Our study also reveals that with increasing excitation density, the UV-peak position shifts slightly towards longer wavelengths while the green emission around 514-520 nm is almost unchanged. This green-luminescence emission is dominant when the nanostructure sizes range from 20 to 200 nm, which is related to a large surface-to-volume ratio.  相似文献   
163.
164.
165.
Phan  Tuoc 《Potential Analysis》2020,52(3):393-425
Potential Analysis - This paper studies regularity estimates in Sobolev spaces for weak solutions of a class of degenerate and singular quasi-linear elliptic problems of the form...  相似文献   
166.
We establish local and global well-posedness of the 2D dissipative quasi-geostrophic equation in critical mixed norm Lebesgue spaces. The result demonstrates the persistence of the anisotropic behavior of the initial data under the evolution of the 2D dissipative quasi-geostrophic equation. The phenomenon is a priori nontrivial due to the nonlocal structure of the equation. Our approach is based on Kato's method using Picard's iteration, which can be adapted to the multi-dimensional case and other nonlinear non-local equations. We develop time decay estimates for solutions of fractional heat equation in mixed norm Lebesgue spaces that could be useful for other problems.  相似文献   
167.
The existence of exponential attractor for the diffusive Hindmarsh-Rose equations on a three-dimensional bounded domain in the study of neurodynamics is proved through uniform estimates and a new theorem on the squeezing property of the abstract reaction-diffusion equation established in this paper. This result on the exponential attractor infers that the global attractor whose existence has been proved in [22] for the diffusive Hindmarsh-Rose semiflow has a finite fractal dimension.  相似文献   
168.
Global dynamics for a new mathematical model in neurodynamics of the diffusive Hindmarsh-Rose equations on a bounded domain is investigated in this paper. The existence of a global attractor and its regularity are proved through uniform estimates showing the dissipative properties and the asymptotically compact and smoothing characteristics.  相似文献   
169.
Using elementary techniques, we prove a general transformation for theta series associated with the quadratic form \(x^2+ky^2.\) The transformation is then applied to establish several infinite families of identities involving theta series whose Fourier coefficients are interlinked.  相似文献   
170.
We investigate the global exponential stability of equilibrium solutions of a projected dynamical system for variational inequalities. Under strong pseudomonotonicity and Lipschitz continuity assumptions, we prove that the dynamical system has a unique equilibrium solution. Moreover, this solution is globally exponentially stable. Some examples are given to analyze the effectiveness of the theoretical results. The numerical results confirm that the trajectory of the dynamical system globally exponentially converges to the unique solution of the considered variational inequality. The results established in this paper improve and extend some recent works.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号