张国辉
,
陈金象
,
唐国有
,
施兆民
,
陈泽民
,
Yu.M.Gledenov
,
M.Sedysheva
,
G.Khuukhenkhuu
原子核物理评论
doi:10.3969/j.issn.1007-4627.2004.04.041
对本课题组十几年来的(n, x)反应实验研究工作进行了评述. 介绍了屏栅电离室的特点、构造与工作原理. 用屏栅电离室在北京大学4.5 MV静电加速器上测量了1-7 MeV中子6Li(n, t)4He和10B(n, α)7Li反应的微分截面与截面, 对实验结果进行了讨论.
关键词:
屏栅电离室
,
轻核
,
(n,x)反应
,
微分截面
Physica B-Condensed Matter
The perturbation formula of g factor for 3d(7) ion in cubic octahedral crystals has been obtained from a cluster approach. In the formula, the parameters related to the configuration interaction and the covalency reduction effect can be obtained from the optical spectra of the crystal under study and so no adjustable parameters are applied. From the formula, the g factors for Co2+ in fluoroperovskites LiBaF3, KMBF3, KZnF3 and CsCdF3 are calculated. The calculated results are in agreement with the observed values. The g factor following the order of LiBaF3 : Co2+ < KMgF3 : Co2+ < KZnF3: Co2+ < CsCdF3 : Co2+ is also explained. (C) 2000 Elsevier Science B.V. All rights reserved.
关键词:
electron paramagnetic resonance;crystal- and ligand-field theory;Co2+;LiBaF3;KMgF3;KZnF3;CsCdF3;perovskite;transition;impurities;crystals
庞晶
,
靳玲花
,
应孝梅
量子电子学报
doi:10.3969/j.issn.1007-5461.2011.06.005
近年来,变系数非线性发展方程受到越来越多的关注. 2008年王明亮等提出了一种新的方法,即(G’/G)展开法.将(G’/G)展开法首次尝试应用到变系数非线性发展方程中,并以广义变系数Burgers方程为例,成功得到了在系数满足一定条件时新的精确解；又尝试将该展开法进行新的扩展,再一次对广义变系数Burgers方程求解,又成功得到了一些新解.实践证明,该展开法不仅易于求解常系数非线性发展方程,而且对变系数非线性发展方程仍很高效、简洁、实用,并且具有广泛的应用前景.
关键词:
非线性发展方程
,
精确解
,
(G’/G)展开法
,
广义变系数Burgers方程
冯庆江
,
杨世玲
量子电子学报
doi:10.3969/j.issn.1007-5461.2013.06.007
应用改进的G/G'展开法构造出Zhiber-Shabat(ZS)方程的20组精确解,这些解的类型主要包含双曲函数通解、三角函数通解和有理函数通解三种形式.对解的性质进行了相应分析,当对双曲函数通解中的参数取特殊值时,可以得到孤立波解.当对三角函数通解中的参数取特殊值时,可以得到对应的周期波函数解.实践证明,应用改进的G/G'展开法能够得到方程一些新的精确解,扩大了解的范围.
关键词:
非线性方程
,
改进的G/G'展开法
,
ZS方程
,
孤立波解
,
周期波解
冯庆江
,
肖绍菊
连铸
doi:10.3969/j.issn.1007-5461.2015.01.006
应用改进的G'/G2展开法构造出Zakharov方程的18组精确解,这些解主要包括双曲函数通解、三角函数通解和有理函数通解三种形式.当对双曲函数通解中的参数取特殊值时,可以得到孤立波解.对三角函数通解中的参数取特殊值时,可以得到对应的周期波函数解.实践证明,应用改进的G'/G2展开法能够得到Zakharov方程一些新的精确解,扩大了解的范围,这种方法对于研究非线性光学和量子光学具有非常广泛的应用意义.
关键词:
非线性方程
,
改进的G'/G2展开法
,
Zakharov方程
,
孤立波解
Physica B-Condensed Matter
The temperature dependence of EPR g factor for MgO:V2+ crystal has been studied theoretically by considering both the static contribution due to the thermal expansion of crystal and the vibrational contributions due to the electron-phonon interaction of the acoustic and optical branches. The static contribution is calculated from the high-order perturbation formula of g factor and the thermal expansion coefficients alpha(T) at various temperatures. The vibrational contribution of acoustic phonons is obtained by using a Debye model for the lattice vibrations and that of optical phonons is calculated by use of a single frequency model. The calculated results show that for the g factor at various temperatures, the static contribution is dominant, but for the temperature dependence of g factor, i.e., (dg/dT)(p) or Delta g(T) = g(T) - g(0), the vibrational contributions from the acoustic and optical phonons are comparable with the static contribution due to thermal expansion. It appears that a reasonable theoretical explanation for the temperature dependence of g factor should take all of these contributions into account.
关键词:
impurities
