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   87篇
  免费   83篇
  国内免费   73篇
化学   3篇
晶体学   2篇
综合类   12篇
数学   6篇
物理学   220篇
  2024年   3篇
  2023年   4篇
  2022年   2篇
  2021年   9篇
  2020年   2篇
  2019年   1篇
  2016年   4篇
  2015年   2篇
  2014年   7篇
  2013年   7篇
  2012年   2篇
  2011年   8篇
  2010年   14篇
  2009年   14篇
  2008年   10篇
  2007年   7篇
  2006年   18篇
  2005年   14篇
  2004年   13篇
  2003年   14篇
  2002年   16篇
  2001年   6篇
  2000年   4篇
  1999年   11篇
  1998年   6篇
  1997年   3篇
  1996年   2篇
  1995年   8篇
  1994年   3篇
  1993年   11篇
  1992年   3篇
  1991年   6篇
  1990年   3篇
  1989年   3篇
  1988年   1篇
  1983年   1篇
  1982年   1篇
排序方式: 共有243条查询结果,搜索用时 15 毫秒
41.
给出了具有Kratzer型标量势与矢量势的Klein-Gordon方程和Dirac方程的s波束缚态解.  相似文献   
42.
徐靖  陈鸿  章豫梅  冯伟国 《物理学报》2000,49(8):1550-1555
用玻色化技术和量子自洽方法研究了spin-Peierls系统的低能量激发谱,计算了二聚化相的基态、单粒子激发态和双粒子束缚态的能量、阻挫对其低能量行为的影响及其各自的自旋-自旋关联函数.结果表明,随着阻挫的增大,spin-Peierls系统中的基态能会逐渐减小,单粒子激发态能隙和双粒子束缚态能隙却会增大.双粒子束缚态和基态的关联函数具有类似的短程关联,而单粒子激发态的关联函数具有长程关联.因此导出,单粒子激发态为自旋三重态,双粒子束缚态与基态类似为自旋单态,它存在于双粒子连续激发态的下边.该结果与Ain等 关键词: spin-Peierls系统 束缚态 关联函数  相似文献   
43.
陈明  闵锐  周俊明  胡浩  林波  缪灵  江建军 《物理学报》2010,59(7):5148-5153
采用分子动力学方法研究了不同温度下碳纳米胶囊中水分子及其氢键的聚集密度分布,讨论了水分子内部键角及其取向规律.计算结果表明,由于碳纳米胶囊的束缚作用,水分子主要聚集在与胶囊形状相似的三个薄层中,随着温度的升高,聚集密度峰均会展宽并向管壁移动.氢键的分布规律与水分子聚集密度类似并对其取向角分布有明显影响.与通常情况不同,在1000K高温时仍存在相当数量的氢键.在3100 K附近,碳纳米胶囊发生破裂,溢出少量水分子后自动愈合.  相似文献   
44.
徐聪  陈鹏  金光日 《大学物理》2023,42(3):4-8+19
一维有限深方势阱能量本征方程的求解受限于超越方程,无法严格求解.本文将奇、偶宇称情况的超越方程归结为一个方程,自洽地给出两种近似解析解:一阶泰勒级数解和二次近似解.分析二者适用范围并做误差分析,发现泰勒级数解可以很好地理解能谱随量子数n平方变化的数值解(即,所谓n平方律),但在特定参数R下失效,该参数正比于势阱宽度乘以势阱高度开方.二次近似解对所有参数R都适用,能谱在大R极限下,可退化为精确求解的无限深势阱情况.对于任意参数R,二次近似波函数的保真度始终大于99.7%.  相似文献   
45.
The Breit interaction contains singular terms which may lead to an instability in quark-antiquark bound state calculations. We regularize the Breit interaction by multiplying the singular terms in momentum space by the form factor μ^2/(q^2+μ^2) such that the interaction is not singular at the origin and the intermediate-and long-range parts of the interaction remain unchanged. The singular terms in the Breit potential find their stable contributions in the calculations after being multiplied by the form factor with different powers. Such a regularized Breit potential with a linear and a relativistically corrected confining potential are applied to the study of qq^- bound states. The spectra for most familiar mesons are consistently obtained and agree well with the experimental data.  相似文献   
46.
We obtain the bound-state energy of the Klein-Gordon equation for some examples of quasi-exactly solvable potentials within the framework of asymptotic iteration method (AIM). The eigenvalues are calculated for type- 1 solutions. The whole quasi-exactly solvable potentials are generated from the defined relation between the vector and scalar potentials.  相似文献   
47.
Recently, the mixing of scalar mesons was introduced into the chiral SU(3) quark model and also dynamically applied to the baryon-baryon system. The results show that the nucleon-nucleon and hyperon-nucleon scattering data can be reasonably described for different mixing cases, one is ideal mixing and the other is θs= 19° mixing. In the present work, by taking the above parameters, the possible candidate of deltaron bound state is further predicted. We find that the contributions from σ and ε exchange to binding energy of deltaron are different, that the contribution from ε exchange is negligible, and that σ exchange is dominant. We also find that the binding energy of deltaron is very stable, around several tens of MeV, no matter what kind of mixing is adopted.  相似文献   
48.
We investigate the transport properties of a pair of Majorana bound states in a T-shaped junction, where two normal leads are coupled with an identical Majorana bound state. Both the scattering matrix and the recursive Green function method show that the peak value of the differential conductance (Gpeak) in units of e2/h and the shot noise Fano factor in the zero bias limit (F0), which are measured at the same lead and zero temperature, satisfy a linear relation as F0=1+Gpeak/2, independent of the magnitude or symmetry of the coupling strengths to the leads. Therefore, combined measurements of the differential conductance and shot noise in the T-shaped geometry can serve as a characteristic signature in probing Majorana bound states.  相似文献   
49.
In this paper, we establish the existence and concentration of solutions of a class of nonlinear Schr?dinger equation $$- \varepsilon ^2 \Delta u_\varepsilon + V\left( x \right)u_\varepsilon = K\left( x \right)\left| {u_\varepsilon } \right|^{p - 2} u_\varepsilon e^{\alpha _0 \left| {u_\varepsilon } \right|^\gamma } , u_\varepsilon > 0, u_\varepsilon \in H^1 \left( {\mathbb{R}^2 } \right),$$ where 2 < p < ∞, α 0 > 0, 0 < γ < 2. When the potential function V (x) decays at infinity like (1 + |x|)?α with 0 < α ≤ 2 and K(x) > 0 are permitted to be unbounded under some necessary restrictions, we will show that a positive H 1(?2)-solution u ? exists if it is assumed that the corresponding ground energy function G(ξ) of nonlinear Schr?dinger equation $- \Delta u + V\left( \xi \right)u = K\left( \xi \right)\left| u \right|^{p - 2} ue^{\alpha _0 \left| u \right|^\gamma }$ has local minimum points. Furthermore, the concentration property of u ? is also established as ? tends to zero.  相似文献   
50.
Bound states, such as qq and q^-q, may exist the volume of the bound states may evoke a reduction in investigate qualitatively the volume effect on the properties states start to be completely melted.  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