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   898篇
  免费   70篇
  国内免费   44篇
化学   56篇
晶体学   1篇
力学   54篇
综合类   9篇
数学   438篇
物理学   454篇
  2023年   3篇
  2022年   7篇
  2021年   11篇
  2020年   23篇
  2019年   26篇
  2018年   31篇
  2017年   25篇
  2016年   20篇
  2015年   18篇
  2014年   34篇
  2013年   61篇
  2012年   31篇
  2011年   43篇
  2010年   40篇
  2009年   48篇
  2008年   42篇
  2007年   60篇
  2006年   47篇
  2005年   56篇
  2004年   43篇
  2003年   49篇
  2002年   55篇
  2001年   25篇
  2000年   35篇
  1999年   40篇
  1998年   22篇
  1997年   14篇
  1996年   8篇
  1995年   7篇
  1994年   6篇
  1993年   6篇
  1992年   7篇
  1991年   5篇
  1989年   4篇
  1988年   1篇
  1987年   3篇
  1986年   4篇
  1985年   4篇
  1984年   7篇
  1983年   5篇
  1982年   6篇
  1981年   3篇
  1980年   3篇
  1979年   5篇
  1978年   6篇
  1977年   4篇
  1976年   2篇
  1975年   4篇
  1973年   1篇
  1969年   1篇
排序方式: 共有1012条查询结果,搜索用时 0 毫秒
971.
Tingting Ji 《中国物理 B》2022,31(7):70504-070504
The quantum search on the graph is a very important topic. In this work, we develop a theoretic method on searching of single vertex on the graph [$Phys. Rev. Lett$. 114 110503 (2015)], and systematically study the search of many vertices on one low-connectivity graph, the joined complete graph. Our results reveal that, with the optimal jumping rate obtained from the theoretical method, we can find such target vertices at the time $Oleft({sqrt N } right)$, where $N$ is the number of total vertices. Therefore, the search of many vertices on the joined complete graph possessing quantum advantage has been achieved.  相似文献   
972.
Consider a class of nonlocal problems $$ \left \{\begin{array}{ll} -(a-b\int_{\Omega}|\nabla u|^2dx)\Delta u= f(x,u),& \textrm{$x \in\Omega$},\u=0, & \textrm{$x \in\partial\Omega$}, \end{array} \right. $$ where $a>0, b>0$,~$\Omega\subset \mathbb{R}^N$ is a bounded open domain, $f:\overline{\Omega} \times \mathbb R \longrightarrow \mathbb R $ is a Carath$\acute{\mbox{e}}$odory function. Under suitable conditions, the equivariant link theorem without the $(P.S.)$ condition due to Willem is applied to prove that the above problem has infinitely many solutions, whose energy increasingly tends to $a^2/(4b)$, and they are neither large nor small.  相似文献   
973.
Based on the FS(Finnis-Sinclair) many-body potential model, the rapid cooling process of a system, which consists of 375 Cu atoms and 125 Au atoms, controlled by period boundary condition was simulated. The dependence of pair distribution function of melten compound AuCu3 on the temperature under these conditions was researched. It can be concluded that the noncrystal exists under 700 K, and the liquid-glass transition temperature is approximately 680 K according to the Abraham′s method. Furthermore, the feature of version of cluster in melten AuCu3 was investigated by Honeycutt pair analysis technique. It is demonstrated that the structural configuration in melten AuCu3 has remarkable variation during the formation of noncrystal according to the relationship between the bonded pairs and polyhedron and temperatures. The defective polyhedra in liquid AuCu3 have greatest changes accompanying the changing temperatures.  相似文献   
974.
975.
In this paper we deal with systems of infinitely many particles in 3, given by a two-body, short-range potential and an external potential, depending on the position of the particles. We show the existence of dynamics for a set of initial configurations, which has measure one with respect to the Gibbs measure induced by a suitable family of Hamiltonians.  相似文献   
976.
This paper proposes an algorithm for the Lie symmetries investigation in the case of a 2D Hamiltonian system. General Lie operators are deduced firstly and, in the the next step, the associated Lie invariants are derived. The 2D Yang-Mills mechanical model is chosen as a test model for this method. PACS: 05.45.-a; 02.30.Ik  相似文献   
977.
978.
An updated analysis of vector and axial-vector spectral functions is presented. The resonant contributions to the spectral integrals are shown to be expressible as multiples of 4π2fπ2, encoding the scale of spontaneous chiral symmetry breaking in QCD. Up to order T2 this behavior carries over to the case of finite temperature.  相似文献   
979.
In this paper, we obtain approximate analytical solutions of the Dirac equation for the shifted Hulthén potential within the framework of spin and pseudospin symmetry limits for arbitrary spin–orbit quantum number κ using the supersymmetry quantum mechanics. The energy eigenvalues and the corresponding Dirac wave functions are obtained in closed forms.  相似文献   
980.
M.L. Gandarias 《Physica A》2008,387(10):2234-2242
In this paper we derive new potential symmetries that seem not to be recorded in the literature. These potential symmetries are determined by considering a generalized potential system, rather than the natural potential system or a general integral variable. An inhomogeneous diffusion equation, a porous medium equation and the Fokker-Planck equation have been considered as application of this procedure.  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