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   2067篇
  免费   260篇
  国内免费   242篇
化学   1435篇
晶体学   20篇
力学   90篇
综合类   4篇
数学   330篇
物理学   690篇
  2024年   7篇
  2023年   48篇
  2022年   75篇
  2021年   92篇
  2020年   101篇
  2019年   73篇
  2018年   64篇
  2017年   68篇
  2016年   96篇
  2015年   91篇
  2014年   96篇
  2013年   142篇
  2012年   164篇
  2011年   172篇
  2010年   92篇
  2009年   113篇
  2008年   125篇
  2007年   119篇
  2006年   92篇
  2005年   94篇
  2004年   54篇
  2003年   42篇
  2002年   40篇
  2001年   44篇
  2000年   46篇
  1999年   37篇
  1998年   26篇
  1997年   27篇
  1996年   42篇
  1995年   35篇
  1994年   34篇
  1993年   29篇
  1992年   24篇
  1991年   33篇
  1990年   25篇
  1989年   14篇
  1988年   15篇
  1987年   13篇
  1986年   11篇
  1985年   10篇
  1984年   11篇
  1983年   4篇
  1982年   8篇
  1981年   5篇
  1980年   4篇
  1979年   5篇
  1977年   2篇
  1975年   2篇
  1968年   1篇
  1957年   1篇
排序方式: 共有2569条查询结果,搜索用时 0 毫秒
91.
Journal of Thermal Analysis and Calorimetry - Differences of thermal decomposition characteristics and combustion properties between CL-20-based propellants and HMX-based propellants were...  相似文献   
92.
We study two-dimensional (2D) matter-wave solitons in the mean-field models formed by electric quadrupole particles with long-range quadrupole–quadrupole interaction (QQI) in 2D free space. The existence of 2D matter-wave solitons in the free space was predicted using the 2D Gross–Pitaevskii Equation (GPE). We find that the QQI solitons have a higher mass (smaller size and higher intensity) and stronger anisotropy than the dipole–dipole interaction (DDI) solitons under the same environmental parameters. Anisotropic soliton–soliton interaction between two identical QQI solitons in 2D free space is studied. Moreover, stable anisotropic dipole solitons are observed, to our knowledge, for the first time in 2D free space under anisotropic nonlocal cubic nonlinearity.  相似文献   
93.
In this paper, we (i) describe how several equilibrium problems can be uniformly modelled by a finite-dimensional asymmetric variational inequality defined over a Cartesian product of sets, and (ii) investigate the local and global convergence of various iterative methods for solving such a variational inequality problem. Because of the special Cartesian product structure, these iterative methods decompose the original variational inequality problem into a sequence of simpler variational inequality subproblems in lower dimensions. The resulting decomposition schemes often have a natural interpretation as some adjustment processes. This research was based on work supported by the National Science Foundation under grant ECS 811–4571.  相似文献   
94.
We study pre-equilibrium strangeness production at RHIC energies in a new parton cascade. Starting with the turbulent glue HIJING initial conditions we investigate the interplay between mini-jet and soft beam jet gluons for strangeness production prior to hadronization, and show the importance of soft beam jet gluons in the strangeness production.  相似文献   
95.
The Lanczos method with shift‐invert technique is exploited to approximate the symmetric positive semidefinite Toeplitz matrix exponential. The complexity is lowered by the Gohberg–Semencul formula and the fast Fourier transform. Application to the numerical solution of an integral equation is studied. Numerical experiments are carried out to demonstrate the effectiveness of the proposed method. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
96.
Error bounds for analytic systems and their applications   总被引:1,自引:0,他引:1  
Using a 1958 result of Lojasiewicz, we establish an error bound for analytic systems consisting of equalities and inequalities defined by real analytic functions. In particular, we show that over any bounded region, the distance from any vectorx in the region to the solution set of an analytic system is bounded by a residual function, raised to a certain power, evaluated atx. For quadratic systems satisfying certain nonnegativity assumptions, we show that this exponent is equal to 1/2. We apply the error bounds to the Karush—Kuhn—Tucker system of a variational inequality, the affine variational inequality, the linear and nonlinear complementarity problem, and the 0–1 integer feasibility problem, and obtain new error bound results for these problems. The latter results extend previous work for polynomial systems and explain why a certain square-root term is needed in an error bound for the (monotone) linear complementarity problem.The research of this author is based on work supported by the Natural Sciences and Engineering Research Council of Canada under grant OPG0090391.The research of this author is based on work supported by the National Science Foundation under grants DDM-9104078 and CCR-9213739 and by the Office of Naval Research under grant 4116687-01.  相似文献   
97.
98.
Normality and shared values   总被引:19,自引:0,他引:19  
LetF be a family of meromorphic functions on the unit disc Δ and leta andb be distinct values. If for everyfF,f andf′ sharea andb on Δ, thenF is normal on Δ. The first author was supported by NNSF of China approved no. 19771038 and by the Research Institute for Mathematical Sciences, Bar-Ilan University.  相似文献   
99.
This paper presents a globally convergent and locally superlinearly convergent method for solving a convex minimization problem whose objective function has a semismooth but nondifferentiable gradient. Applications to nonlinear minimax problems, stochastic programs with recourse, and their extensions are discussed.The research of the first author is based on work supported by the National Science Foundation under Grants DDM-9104078 and CCR-9213739. This research was carried out while he was visiting the University of New South Wales. The research of the second author is based on work supported by the Australian Research Council.  相似文献   
100.
Electrospinning, as a novel nontextile filament technology, is an important method to prepare continuous nanofibers and has shown its remarkable advantages, such as a broadly applicable material system, controllable fiber size and structure, and simple process. Electrospun nanofiber membranes prepared by electrospinning have shown promising applications in many fields, such as supercapacitors, lithium‐ion batteries, and sodium‐ion batteries, owing to their large specific surface area and adjustable network pore structure. The principle of electrospinning and key points relevant to its usage in the preparation of high‐performance electrochemical energy storage materials are reviewed herein based on recent publications, particularly focusing on research progress of relative materials. Also, this review describes a distinctive conclusion and perspective on the future challenges and opportunities in electrospun nanomaterials.  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