ALMOST GLOBAL EXISTENCE OF DIRICHLETINITIAL-BOUNDARY VALUE PROBLEM FORNONLINEAR ELASTODYNAMIC SYSTEMOUTSIDE A STAR-SHAPED DOMAIN

This paper deals with the mixed initial-boundary value problem of Dirichlet type for the nonlinear elastodynamic system outside a star-shaped domain. The almost global existence of solution with small initial data to this problem is proved and a lower bound for the lifespan of solutions is given.     

直觉模糊集的σ-相似度和σ-包含度及其相互诱导关系

相似度与包含度是度量模糊集的两个重要指标。介绍在有限论域上直觉模糊集的相似度与包含度的定义,重点研究σ-相似度和σ-包含度的性质,分别给出σ-相似度和σ-包含度的一些等价条件,进而给出σ-相似度与σ-包含度之间的相互诱导关系。     

也谈中学生自学能力的培养

利用自编学案诱导学生分步自学,培养学生的自学习惯;加强学生阅读能力的培养,结合物理学科知识的联系,让学生比较、归纳,促使学生掌握自学方法;强化信息题的训练,培养信息处理能力,实现自学能力的有效提升.     

Λ-Shaped optoelectronic materials based on Trger's base

Trger's base (TB) is a well-known chiral molecule with rigid concave shape that makes it applicable in different areas such as superamolecular chemistry,molecular recognition,biological labeling,and so on.In this article,we briefly summarize some recent research progress in the optoelectronic properties of novel TB analogues and their applications in optoelectronic field with emphasis on the developments achieved in our group.     

水热法合成ZnS∶Au,Cu超细X射线发光粉

报道了水热法合成的高强度ZnS∶Au,Cu超细X射线发光粉及其光致发光(PL)和X射线激发发光(XEL)的光谱特性。200℃水热处理12h直接合成样品的纳米晶粒约15nm,尺寸分布窄,分散性好,具有纯立方相的类球形结构。氩气保护下1000℃焙烧1h后的样品存在一定的团聚,但团聚后尺寸为1～2μm,为超细X射线发光粉,此时样品为纯六角相的类球形为主的结构。所有样品的PL和XEL光谱均为宽带谱,水热法直接合成样品的XEL强度最强时,样品的Cu/Zn,Au/Cu比值分别为3×10-5和2。在此比值条件下,1000℃焙烧1h样品的XEL发光最强,此时其2个峰值分别位于445和513nm,且与未焙烧前相比强度增强了10倍左右。另外通过比较PL光谱与XEL光谱特性,讨论了PL和XEL光谱的发光机理和其不同的激发机制。     

辐照三烷基氧化膦萃取锶和铯的研究

研究了γ辐照后的３０％％ＲＰＯ－煤油－ＨＮＯ３体系萃取Ｓr和Ｃs的性能。利用ＩＣＰ－ＡＥＳ及ＡＡＳ分别测定两相中Ｓr和Ｃs浓度，分配比。试验了辐照剂量对分配比的影响。结果表明，γ射线辐照对ＴＲＰＯ的萃取笥能无显著影响。     

Two-Parameter Stochastic Resonance in a Model of Electrodissolution of Fe in H_2SO_4

IntroductionStochastic resonance (SR) is a nonlinear effect which describes the optimal detection of a weak periodic signal by the action of external noise in nonlinear systems. SR was originally proposed to account for periodicity in the Earth's ice ages1, and it has been observed in a wide range of biological2-4 , physical5 and chemical6 systems. The systems mentioned above which may give rise to SR have a denominator despite many examples of SR in different scientific areas. It is noted…     

Intersubband optical absorption in two-level quantum wells embedded in a planar microcavity

A theoretical analysis of the optical absorption including both the linear and third-order non-linearity arising from intersubband transitions in two-level quantum wells, which are embedded in a planar microcavity, has been performed. Starting from the Maxwell–Lorentz equations, the expressions of the field in each layer are explicitly given, and the field in the quantum wells is determined via an integral equation, in which the third-order non-linearity is included. Then, by matching the boundary conditions, the field in the quantum-well microcavity structure is rigorously determined, and the absorption coefficient is thus obtained. Detailed numerical calculations show that the optical intersubband absorption can be significantly modified due to the coupling between the quantum wells and the microcavity. This revised version was published online in November 2006 with corrections to the Cover Date.     

富Ca富Cu的Bi(Pb)-Sr-Ca-Cu-O超导电性

采用普通固态反应法制备了名义组分为Bi_2.0-xPb_xSr_1.9Ca_2.2Cu_3.3O_y超导体,并系统研究了样品的X射线衍射谱。结果表明:富Ca富Cu加速了2223相形成,拓宽了Bi系的单相化烧结温区,并获得了品质优良的110K单相多晶样品;低温退火有助于提高样品的单相化程度。 关键词：     

高纯氧化镨样品ICP摄谱分析时光谱干扰校正方法的研究

本文提出了Pr_6O_(11)样品ICP摄谱分析时干扰系数法校正光谱干扰的方法和相应的计算机软件系统。建立了Pr基体对14种稀土杂质元素24条灵敏分析线的干扰系数表(KCT),利用所提出的方法分析了Pr_6O_(11)合成样品,由91个实验点所得回收结果可知,回收率在90～110%之间的占93.4%。可见校正是相当有效和十分必要的。