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 共查询到18条相似文献,搜索用时 78 毫秒
1.
对N秩可分离势加库仑势理论中的相移公式提出了改进,并择取了N=2的可分势模型,确定了尽可能简洁的形状因子,建立了离壳与在壳T矩阵间的媒介,计算了各态的相移值。改进后的公式物理意义突出,具有解析形式。  相似文献   

2.
以Lense-Thirring场为例,讨论其引力场同电磁场耦合的干涉相移,特别是在Lense-Thirring场同磁场矢势耦合情况下,得到了干涉相移同天体旋转角动量的直接显式。  相似文献   

3.
对电子与氦原子相互作用的模型势进行了修正.用修正前后的模型势计算低能电子被氦原子散射使得S分波相移与实验结果一致,把同样的模型势(忽略交换势)应用到低能正电子被氦原子散射,得到了低能正电子的分波相移、弹性散射截面、动量转移截面.结果表明,用修正后的模型势所得到的结果与实验值符合得很好.从而说明对模型势的修正是合理的.  相似文献   

4.
该文分析了核子-核子系统EST可分离势近似方法的在壳及离壳性质,计算了3S1-3D1道的相移值及半离壳函数值,与实验数据比较,指出了EST方法的局限性.由于EST方法缺陷在于将势模型半离壳R矩阵元供作可分离势的形状因子,从而提出克服缺陷的方案,对可分近似作出相应的改进.  相似文献   

5.
用与半经典交换势不同的三种交换势计算了低能e-He弹性散射的相移,结果表明,这三种均在不同程度上改善了SCE势的结果。  相似文献   

6.
本文采用萄清泉等人设计的五参数原子解析波函数,对电子在L_1~+离子场中的库仑势,极化势,交换势进行了计算。并且通过计算机计算了慢电子与L_1~+离子弹性散射相移δ_1,并与其他计算结果进行了比较。  相似文献   

7.
对晶体管的超相移因子提出一种简单、迅速、精确的计算机计算方法,设计了完整的计算程序。根据决定晶体管性能的关键参数,如:锘区宽度、基区少子扩散系数和基区少子扩散长度等,对晶体管超相移因子进行计算,得到精确的结果。  相似文献   

8.
基于薛定谔方程离心项的Pekeris型近似,研究了具有变形Woods-Saxon势的薛定谔方程的散射态问题,得到了归一化的散射态波函数和相应的散射相移,同时得到了散射振幅解析极点相应的束缚态能级.  相似文献   

9.
本文在原有的半经典交换势(SCE)基础上,考虑高阶修正后给出新的半经典交换势,并利用这种新的交换势计算了e-He弹性散射,发现在低能区的相移和微分截面都有明显改进,并与实验和其它理论值符合较好.  相似文献   

10.
计算了核子- 核子散射的总相移, 包括夸克- 胶子交换的总的相移、夸克- 胶子瞬时势的贡献以及单, 双交换提供的总的相移. 相移的计算值与实验结果的比较曲线表明它们是一致的, 同时表明夸克- 胶子交换作用在核子相互作用中起重要作用, 尤其在近程范围内.  相似文献   

11.
设H是复可分无穷维Hilbert空间,W、V分别是H上具有不同权序列的有界本性正规单的单侧加权移位算子.本文刻画T=W+V的(U+K)-轨道的范数闭包.  相似文献   

12.
Hart RA  Xu X  Legere R  Gibble K 《Nature》2007,446(7138):892-895
The collision of two ultracold atoms results in a quantum mechanical superposition of the two possible outcomes: each atom continues without scattering, and each atom scatters as an outgoing spherical wave with an s-wave phase shift. The magnitude of the s-wave phase shift depends very sensitively on the interaction between the atoms. Quantum scattering and the underlying phase shifts are vitally important in many areas of contemporary atomic physics, including Bose-Einstein condensates, degenerate Fermi gases, frequency shifts in atomic clocks and magnetically tuned Feshbach resonances. Precise experimental measurements of quantum scattering phase shifts have not been possible because the number of scattered atoms depends on the s-wave phase shifts as well as the atomic density, which cannot be measured precisely. Here we demonstrate a scattering experiment in which the quantum scattering phase shifts of individual atoms are detected using a novel atom interferometer. By performing an atomic clock measurement using only the scattered part of each atom's wavefunction, we precisely measure the difference of the s-wave phase shifts for the two clock states in a density-independent manner. Our method will enable direct and precise measurements of ultracold atom-atom interactions, and may be used to place stringent limits on the time variations of fundamental constants.  相似文献   

13.
With quantum scattering theory the slowing down of low-velocity ions in an electron gas is investigated. Choosing an atomic IPM potential, the authors have calculated the phase shifts and stopping power of the ions in the electron gas, and compared the results with experimental data and with those given by a nonlinear density-functional formalism.  相似文献   

14.
A distributed feedback (DFB) semiconductor laser with three phase shifts based on reconstruction equivalent chirp (REC) tech-nology is proposed and investigated numerically. With the combination of multiple phase shifts and corrugation pitch modulated (CPM) structure, we also propose a novel and more complex structure named dual CPM, which has a flatter light power distribution along the laser cavity compared with the true double phase shifts DFB laser diode (LD), while the P-I curves are nearly the same. The proposed dual CPM structure is also designed and analyzed based on REC technology. The simulation results show that, the DFB semiconductor laser with complex structure such as phase shifts, or even arbitrary variation of the grating period can be achieved equivalently and easily by changing the sampling structure. But its external characteristics are almost the same as those DFB lasers with true phase shifts, or true arbitrary variation of the grating period. The key advantage of the REC technology is that it varies only the sampling structure and keeps the seed grating (actual grating in sampling structure) period constant. So its fabrication needs only low-cost and standard holographic exposure technology. Therefore we believe this method can achieve the high-end and low-cost DFB LD for mass production.  相似文献   

15.
利用菲涅耳衍射原理研究了同轴双光束Z扫描现象,建立了同轴双光束Z扫描的衍射理论模型,并且对大、小非线性相移两种情况进行了数值模拟.研究结果发现,当非线性相移较大时,传统Z扫描理论的计算易出现振荡,而菲涅尔衍射模型则无此缺陷,可用于不同相移情况下的Z扫描实验.  相似文献   

16.
研究了仿紧局部可分空间在一些L映射下象的性质后,文章继续讨论仿紧局部可分空间的映象问题。给出了点可数k覆盖与sL系之间的关系并进一步得到仿紧局部可分空间在一些紧覆盖映射下的象与k覆盖以及与sL系之间的关系,探讨了仿紧局部可分空间在2-序列覆盖L-映射下的象与序列开覆盖之间的联系,建立了仿紧局部可分空间的一些L-映象之间的联系。  相似文献   

17.
阵列天线阵元位置误差、通道不一致性和互耦的校正   总被引:7,自引:0,他引:7  
章宏  陈荆花  周希朗 《上海交通大学学报》2002,36(9):1284-1287,1290
采用单个连续波校正源,通过旋转阵列天线在多个校正方位测得校正数据,通过求解可分离的非线性优化问题,得到了阵元位置参数和包含通道幅度相位参数与阵元间互耦参数校正矩阵的估计,计算机模拟实验证实了该方法的健壮性和实用性。  相似文献   

18.
讨论了一类称之为强Gδ集的子集,证明了在某些集论公理假设下可分空间不能包含有这样的Gδ子集.以及第一可数、可分空间包含有强Gδ集等价于存在不可度量化的可分、正规Moore空间。  相似文献   

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