非线性守恒方程的两种稳定化谱元方法

考虑非线性守恒方程的高阶数值解法,介绍了基于谱元法的两种稳定性方法,一种是谱粘性消去法(SVV),另一种是过滤法.在SVV方法中,我们推广并分析了传统的基于单区域的SVV算子的定义.在过滤法中,我们分析了SVV-H elm holtz过滤算子的性质.文中从分析和计算两方面对两种方法进行了比较,建立了两者之间的关系.最后通过一系列数值试验说明方法的有效性.     

红光激发下掺Ho3+氟化物薄膜的上转换发光

利用激光脉冲沉淀法制备了稀土Ho~(3 )掺杂的氟化物薄膜。观测到处于薄膜中的Ho~(3 )离子在632.8nm红光激发下的上转换发射。这些上转换发射包括:~5S_2→~5I_7,~5F_4→~5I_7和~5S_2→~5I_8。     

Lie symmetries and conserved quantities of controllable nonholonomic dynamical systems

This paper concentrates on studying the Lie symmetries and conserved quantities of controllable nonholonomic dynamical systems. Based on the infinitesimal transformation, we establish the Lie symmetric determining equations and restrictive equations and give three definitions of Lie symmetries before the structure equations and conserved quantities of the Lie symmetries are obtained. Then we make a study of the inverse problems. Finally, an example is presented for illustrating the results.     

Indriect Determination of CTMAB with Sodium Chloride and Ammonium Thiocyanate by Floatation and Separation of Zine

A new method for indirect determination of cetyl-trimethyl ammonium bromide (CTMAB) with NaCl and NH4SCH by floatation and separation of zinc has been studied.The study shows that Zn(Ⅱ） can associate with NH4SCN and CTMAB to form insoluble ternary ion-association complex,and the precipitate can float on the surface of the liquid phase.A good linear relationship is observed between the floatation yield(E%) of Zn(Ⅱ） and the amount of CTMAB.On the ground,CTMAB Can be indirectly determined by determining E% of Zn(Ⅱ）.The results were satisfactory.     

X波段盘圈加速结构热阴极微波电子枪的研究

介绍了采用盘圈(DAW)加速结构在11.43GHz下研制的热阴极微波电子枪注入器，分析了注入器中DAW加速结构支撑杆对于微波特性的影响以及加速结构中的模式重叠问题. 针对该结构的强腔间耦合以及次临近耦合不能忽略的特点，对其调谐方法进行了分析研究.给出了该长腔链热阴极微波电子枪注入器的物理设计及粒子动力学计算结果，电子能量为5—6MeV，脉冲流强为40mA，电子束发射度为3.4πmm.mrad. 该微波电子枪的加工焊接已经完成，文中给出了其冷测结果.     

Silica Hybrid Containing (R)-2,2′-Binaphtho-20-crown-6 Moieties via the Sol-Gel Process

IntroductionThesol gelprocessconstitutesoneofthemostimpor tantrouteforthepreparationofinorganicamorphoussolids.1,2 Themildreactionconditionsofthesol gelap proachallowadeliberatetailoringofhybridorganic inor ganicmaterialsbyhydrolysisandpolycondensationofmolecularprecursorsfunctionalizedbyhydrolysabletri ethoxysilanegroups .3Suchsilicahybridmaterialsconsist ingofcovalentlylinkedorganicandinorganiccomponentsarewelldefinedatthemolecularlevel.Theyhavereceivedconsiderableattentionindifferentresearc…     

沉积铁钝化膜的傅立叶变换表面增强拉曼光谱

利用恒电流沉积技术、傅立叶变换表面增强拉曼散射技术现场研究了0 1mol/LNaOH溶液中铁金属电极在不同电位下的表面氧化物的组成。结果表明,在电极预钝化区,表面首先生成的Fe(OH)2可由拉曼谱图中出现的550cm-1表征,证实了以往的研究结果。进入钝化区,表面二价氧化物逐步转化为高价氧化物Fe3O4及α 、δ 和γ FeOOH。在电位回扫的过程中,各氧化产物的还原以及铁表面SERS活性的逐渐消失导致谱峰强度降低。     

Proton Fraction in Neutron Star Matter and Three-Body Force Effects

The three-body force effects on the equation of state and its iso-spin dependence of asymmetric nuclear matter and on the proton fraction in neutron star matter have been investigated[1] within Brueckner Hartree-Fock (BHF) approach by using a microscopic three-body force. It is shown that, even in the presence of the three-body force, the empirical parabolic law of the energy per nucleon vs. isospin asymmetry β=(N-Z)/A is fulfilled in the whole asymmetry range 0 ≤β ≤1 and also up to high density. The three-body force provides a strong enhancement of symmetry energy at high density in agreement with relativistic approaches. Thecalculated proton fraction in β stable neutron star matter is given in Fig.l, where the thick solid line is the BHF prediction using AV18 TBF, while the dotted one is the BHF result using AVis. The thin solid line is the prediction of the Dirac-Brueckner approach taken from Ref.[2]. The results extracted according to the phenomenological paramete rizations of the symmetry energy suggested in Ref.[3] are also plotted. It is seen from     

异方差回归中的广义方差比检验

在同方差假设之下,线性模型在回归分析的理论与应用方面起着突出的作用,很受许多研究工作者的青睐.然而,回归模型中同方差性这一标准假设不一定总是成立的.因此我们考虑了用一类基于似残差的方法来检验异方差情形下线性模型拟合观测数据的情况.本文既给出了大量的模拟,又给出了实际数据作为应用的例子.效果都很好.     

有界对称域上的Dp乘子

设Ω是Cⁿ中包含原点的有界对称域。本文在Ω上得到了关于D^p空间的两个乘子定理。