扩展Skyrme力的自洽半经典计算与原子核电模式isovector巨共振性质

利用自洽半经典(SCSC)计算确定的基态核子分布,讨论了电模式isovector巨共振性质.特别是,我们不仅考虑了△T_3=0的模式,而且考虑了△T_3=±1模式,从而讨论了此类巨共振的同位旋性质,给出了它们的增强因子及Centroid能量的同位旋分裂.其中增强因子和HF+RPA计算结果相一致,而Centroid能量的同位旋分裂则和实验事实相近.     

Correlation Between the IR Transmission Spectra and the CdZnTe Qualities

Tens of Cd0.9Zn0.1Te wafers from three ingots grown by the vertical Bridgman method (VBM) are characterized by infrared (IR) transmission. Four types of distinct IR transmission spectra are found for these wafers. Each of them corresponds to one kind of wafers with specified quaJities. At the same time, approximate mathematical relations exist between the wafer dislocation density and their IR transmissions at the wavenumber 4000cm^-1, as well as between the resistivity and the IR transmissions at the wavenumber 500cm^-1. The reasons of the above results are attempted to be given.     

CdZnTe Energy Levels Induced by Doping of Indium

Photoluminescence (PL) and infrared transmission spectra are used to characterize In-doped Gd0.9Zn0.1 Te (GdZnTe:In).The PL spectrum reveals that there are two other strong emissions situated at 1.54 eV and 1.62 eV as well as the near band edge emission.This indicates that the doped In can lead to two donor levels of 0.12eV and 0.04eV in the CdZnTe band construction,respectively.The IR transmission spectra show that when the wavenumber is larger than 1000cm^-1,the CdZnTe:In was almost opaque to the IR emission.Then its IR transmission rapidly increases to 52% when the wavenumber is decreased to 350cm^-1 and then holds constant.This confirms the existence of the donor level of 0.12 eV.     

模糊度量空间的强嵌入北大核心CSCD

本文定义了George和Veeramani意义下的模糊度量空间的强嵌入,证明了可强嵌入的模糊度量空间能够粗嵌入到Hilbert空间.另外还证明了强嵌入在模糊度量空间的粗范畴下是不变的,并给出了模糊度量空间强嵌入的一些等价刻画.     

Oscillation of Quasi-Steady Earth＇s Magnetosphere

A three-dimensional magnetohydrodynamics （MHD） code is designed specially for global simulations of the solar wind-magnetosphere-ionosphere system. The code possesses a high resolution in capturing MHD shocks and discontinuities and a low numerical dissipation in examining possible instabilities inherent in the system. The ionosphere is approximated by a spherical shell with uniform height-integrated conductance. The solar wind is steady, and the interplanetary magnetic field is either due northward or due southward. The code is then run to find solutions of the whole system. It is found that the system has never reached a steady state, but keeps oscillating with a period of about one hour in terms of density variation at the geosynchronous orbit. However, if a certain artificial resistivity is added either in the whole numerical box or in the reconnection sites only, the reconnections change from intermittent to steady regime and the oscillation disappears accordingly. We conclude that the Earth＇s magnetosphere tends to be in a ceaseless oscillation status because of the low dissipation property inherent in the magnetospheric plasma, and the oscillation may be driven by intermittent magnetic reconnections that occur somewhere in the magnetopause and/or the magnetotail.     

创设探究情景培养问题能力

教师要选准探究内容、创设探究情境、提出探究问题、营造探究氛围、启迪探究思维,通过创设适当的问题情境,让学生去思考、去体验、去发现,从而激发和强化学生的求知欲望,培养学生的学习兴趣,让学生通过主动学习形成自我反思、自我反馈的学习能力.(1)创设带有趣味的问题情境,激发学生积极思维.生动而有趣的学习材料是学习的最佳刺激,以趣引思,能使学生处于兴奋状态和积极思维状态,有利于学生对知识的理解和掌握.例如,在讲等比数列前n项和时,用“古印度人达依尔发明了国际象棋而使当朝的国王十分开心,国王决定重赏他,……”的故事来引入课题,…     

有限温度自洽半经典方程及其虚时迭代解

利用Skyrme力和半经典近似,推导了有限温度自洽半经典(FTSCSC)方程,即通常所说的Euler-Lagrange方程。利用虚时迭代方程对此方程作数值求解,以确定热核的核子密度,并研究其部分静态性质。 关键词：     

自洽半经典方法与有限温度微观光学势 II虚部

以自洽半经典方法及定域密度近似为基础,计算并讨论了不同温度和能量下微观核子-核光学势的虚部.通过和以前工作的比较,强调了采用温度有关核密度的必要性.     

自洽半经典方法与有限温度微观光学势I.实部

从扩展Skyrme力出发,利用自洽半经典(Scsc)方法确定了热核⁴⁰Ca和²⁰⁸Pb的核子密度ρ_q(q=n,p);由核物质近似及定域密度近似(LDA)推导了有限温度微观光学势的计算公式.利用这些公式及上述密度,具体计算了不同能量和温度下的核子-核光学势.这样得到的光学势是完全自洽和微观的,并且较完整地考虑了温度对光学势的影响.本文仅讨论光学势的实部.