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。     

Multiple—Scattering of Near—Edge x—ray Absorption Fine Structure of Sulphur—Passivated InP（100） Surface

We use the multiple-scattering cluster method to calculated the sulphur 1s near-edge x-ray absorption fine structure (NEXAFS) of S-passivated InP(100) surface.The physical origins of the resonances in the NEXAFS have been unveiled.It is shown that the most important resonance is attributed to the photoelectron scattering between the central sulphur and the nearest indium atoms.The studies show that two S-S dimers with the bond lengths of 2.05A and 3.05A coexist in the surface,meanwhile the bridge and antibridge site adsorption of single S could not be ruled out.We support the scanning tunnelling microscopy result that the S-passivated InP(100) surface exhibits significant discorder.     

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。     

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.     

C2（a 3Πu）+NO 的反应机理研究

在G2 (CC ,MP2 )理论水平上研究了C2 (a3 Πu)自由基与NO分子的反应 .计算了反应体系最低二重态势能面上各驻点的构型参数、振动频率和能量 ,揭示了此反应存在两种反应机理 :由NO中的O原子进攻C2 自由基形成CCON中间体的CCON机理和NO中的N进攻C2 自由基形成CCNO中间体的CCNO机理 ,分析了对应与这两种反应机理的五个可能的反应通道 ,得出了由NO中的N原子进攻3 C2 自由基 ,生成中间体CCNO自由基 ,最终得到产物CN +CO的通道是最有利的通道 .     

Crystal Structure of Adduct 2-Phenyl-imidazo [ 4,5-f ] 1,10-phenanthroline Methanol

The structure of the title adduct comprises a phenanthroline derivative 2-phenyl-imidazo[4,5-f]1,10-phenanthroline and a methanol.The composition of the crystalline adduct was characterized as C19H12N4.CH3OH.It belongs to orthorhombic system,space group Pna21 with a=1.3693(4)nm,b=2.2988(7)nm,c=0.51338(15)nm,V=1.6160(8)nm^3.Z=4,and final R1=0.0423.wR2=0.1012 .Crystal structure shows that all the 19 carbon atoms and 4 nitrogen atoms are coplanar.The bond length data indicated that a very extensive conjugation system was formed.This conjugation makes the compound being a potentially excellent energy transformer used for luminescent materials.     

ICP-AES同时测定混合矿物素中的磷、钙、铁、铜、锌、锰、镁、钴

采用ICP－AES法测定混合矿物素中的磷、钙、铁、铜、锌、锰、镁、钴元素含量，并对样品的溶解酸和酸用量、元素分析线的选择以及共存元素间的干扰进行了研究。该法简便、快速，精密度和准确度较好。