EACVD中热阴极直流放电特性的实验研究

本文针对ＥＡＣＶＤ过程中经常出现的放电振荡和不稳定现象，比较系统地研究了ＥＡＣＶＤ中热阴极直流放电特性及其与工艺参数之间的关系，分析和讨论了放电振荡和不稳定现象发生的原因，并给出了避免和控制的途径和措施。     

改进WKB近似的新方法

利用转移矩阵理论，在考虑层间一次反射和转折点处实际相移的基础上，导出了改进的ＷＫＢ公式，数值计算的结果表明本文所得公式的精度远优于传统的ＷＫＢ近似，而且能适用于接近于截止的模式和变化剧烈的折射率分布。     

IR AND ESR STUDIES OF THE REDUCED HETEROPOLYMOLYBDOVANADOPHOS PHORIC ACIDS H_(3+n)PMo_(12-n)V_nO_(40) (n=0,2,4)

The reducibility and isotope exchange ability of different oxygen bonds (O_b, O_p, O_t) in the Keggin structure of heteropolymolybdates (H_(3+n)PMo_(12-n)V_nO_(40)) containing zero, two or four vanadium atoms as well as the changes of structure of heteropolyacids during reduction were investigated by IR, ESR and ~(18)O isotope exchange. The results obtained showed that the order in the reducibility of different oxygen bonds is O_b>>O_p≈O_t, the replacement of Mo by V affects obviously the reducibility of various oxygen bonds: O_b increases while O_p and O_t decrease. ~(18)O exchange rate of O_b, O_p, O_t is not different, comparatively speaking, the isotope exchange of oxygen of the heteropolyacids containing vanadium atoms is more difficult than PMo_(12). The ESR spectra indicate that two kinds of Mo~(5+) ions with different coordinations are present in PMo_(12) (n=0) during reducing process, their g values are g_⊥~A=1.971, g_(?)~A=1.912 and g_⊥~B=1.965, g_(?)~B=1.861 belonging respectively to the d     

Embeddings of Kirkman Systems KS(2,4,v)

A balanced incomplete block design(BIBD)B(κ,λ;ν)is a pair(X,A),whereX is a v-set of elements(called points)and A is a collection of k-subsets of X(called blocks)such that every unordered pair of points of X appears in exactlyλ blocks of A.A B(κ,1;ν)is called a Steiner system and denoted by S(2,κ,ν). A parallel class in a BIBD is a set of blocks that forms a partition of the     

卡拉胶与槐豆胶协同相互作用及其凝胶化

讨论了卡拉胶与槐豆胶（ＬＢＧ）形成凝胶的共混比例、最佳膨化温度和膨化熟成时间，以及制备温度和体系盐离子浓度对凝胶化的影响．     

阻抗谱法确定扩散系数

给出了阻抗谱法确定扩散系数的理论和方法;以钒酸盐阴极材料Na_(1+x)V_3O_(?)(L.T.)为例,应用本方法计算给出了Li~+在阴极中的扩散系数为10~(?)-10~(-9)cm~2·s~(-1);最后还对误差来源进行了讨论. 关键词：     

碳涂覆光纤的最新进展

本文首先介绍了气密性光纤的发展过程，接着重点分析了碳涂覆光纤的两个重要参数：长期可靠性和抗氢渗透性。引入了新的衡量碳涂覆光纤抗氢渗参量－缺氢渗因子，最后介绍了西安应用光学研究所碳涂覆光纤“八．五”末的进展情况，以及国内外现状比较。     

ISOLATION AND PROPERTIES OF MOLYBDE-NUM SERIES OF HETEROPOLY BLUE WITH KEGGIN STRUCTURE

The present paper reports the methods for preparing and isolating 8 kinds of 1:12 molyb-denum series of heteropoly blue complexes K_yH_zXMo_(22)O_(40)·nH_2O (X=Si, P, As, Ge). Theproducts were characterized by elemental analyses, potential titration, polarograms, cyclicvoltammetry, IR spectra, visible--UV spectra, X--ray powder diffraction, XPS and ~(31)P NMR.The single crystal structure of 4-electron molybdenum--silicon heteropoly blue was measuredand the positions of reduced molybdenum atoms were determined, i.e. they were located atMo(3), Mo(7), Mo(8) and Mo(10). The experimental results show that the heteropoly blueremains Keggin structure. ESR spectra of heteropoly blue solids were first studied, fromwhich it was found that the delocalization extent of 2-electron heteropoly blue and 4--electronheteropoly blue is smaller than that of 1-electron heteropoly blue. The study of thermal prop-erties shows that the thermal stability increases with the increase of the reduction extentof heteropoly blue. Th