GaN的补偿度与离子束沟道最小产额比的关系的研究

用ＲＢＳ／沟道技术对ＭＯＣＶＤ生长的未故意掺杂的ＧａＮ的结构性能进行了测试，同时用霍耳方法测试了样品的电学性能。结果表明：ＧａＮ薄膜的背散射沟道说与随机谱之比Ｘｍｉｎ和其补偿度存在一定的依赖关系。补偿度小的样品，其Ｘｍｉｎ小；随着样品补偿度的增大，Ｘｍｉｎ也逐渐增大；但它们之间的知系变化是非线性的。对这些结果给予了一定的解释。     

石墨炉原子吸收光谱法测定人工唾液中从镍铬合金牙冠浸出的镍离子

近年来,随着口腔修复材料和工艺的迅猛发展,人们将镍铬合金广泛应用于铸造牙冠桥及烤瓷牙冠桥的内冠上.随着人们健康意识的不断提高,对于长期放置在口腔中材料的生物安全性越来越重视.     

A New One-dimensional Dicyanamide Bridged Zinc(II) Complex Containing Nitronyl Nitroxide Radicals:Synthesis,Crystal Structure and Magnetic Properties

A new one-dimensional dicyanamide bridged zinc(II) complex containing nitronyl nitroxide radicals Zn(NO3)(NIT-1'-MeBzIm)(dca)n·(H2O)n(NIT-1'-MeBzIm = 2-{2'-(l'-me-thyl)benzimidazolyl}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, dca = dicyanamide anion) has been prepared and structurally characterized by single-crystal X-ray diffraction.The complex crystallizes in triclinic, space group P1, with a = 7.428(3), b = 9.839(3), c = 16.708(6), α = 93.270(4), β = 101.642(4), γ = 100.632(4)°, C17.5H21N8O5.5Zn, Mr = 496.79, V = 1169.7(7) 3, Dc = 1.411 g/cm3, μ(MoKα) = 1.096 mm-1, Z = 2, F(000) = 512, R = 0.0583 and wR = 0.1663 for 4295 observed reflections with I > 2σ(I).X-ray analysis reveals that the zinc(II) ion is six-coordinated with a distorted octahedral geometry.These units develop as 1D species where dicyanamide ligands bridge zinc(II) ions.In addition, molecules are linked by π-π piling interactions to form 1-D double-chains.Magnetic investigation indicates that the weak intramolecular interactions are antiferromagnetic with J =-0.27 cm?1, where the spin Hamitonian is defined as H =-2∑i,jJi,jSiS within the complex.     

A New ent-Kaurane Diterpenoid from Isodon enanderianus

Isodon enanderianus (Hand. -Mazz.) H. W. Li, has been used in folk medicine as anti-inflammatory and detoxified agent1. The Isodon genus is known to be rich in ent-kaurane diterpenoids, a series of new ent-kaurane diterpenoids have been isolated from the dried leaves of I. enanderianus2-4. In order to find more biologically active substances, we have carefully investigated the chemical constituents of I. enanderianus collected in Shiping county of Yunnan province, and as a result, enanderi…     

Studying the uptake of aniline vapor by active alumina through in-line monitoring a differential adsorption bed with near-infrared diffuse reflectance spectroscopy

Through non-invasive monitoring the uptake of aniline vapor by active alumina in a differential adsorption bed (DAB) with near-infrared diffuse reflectance spectroscopy (NIR-DRS), we have studied several features of the adsorption, including isotherm, kinetics and the chemical state of aniline molecules in aniline-alumina system. What is perhaps more important, since the information above is obtained synchronously, the proposed methodology could provide information about the type of adsorption (chemical or physical adsorption), the change of chemical state of aniline in the system during the adsorption process, whether the chemical adsorption and physical adsorption took place simultaneously, the rate of the chemical and physical adsorption, and so on.     

矩阵广义对角化的探讨

利用子空间关于矩阵的最小多项式研究了矩阵可广义对角化的充要条件,给出了矩阵可广义对角化的一种算法.     

微柱高效液相色谱与火焰光度检测器联用的初步研究

本文研究了常规高效液相色谱(HPLC)及微柱高效液相色谱(Micro-Column HPLC)与气相色谱火焰光度检测器(FPD)的联用技术及其应用.丁基锡等化合物经HPLC分离后,流出液通过FPD进行特效检测.接口采用将毛细管直接引入燃烧头的方式.文中对各有关参数进行了选择、优化和讨论, 对FPD作为HPLC的在线检测器的可能性作了初步探讨.     

对叔丁基杯[8]芳烃酯类衍生物的合成方法改进及其对酯型儿茶素的萃取性能

以酰氯为酰基化试剂,用三乙胺作缚酸剂和催化剂,制备了一系列对叔丁基杯[8]芳烃酯类衍生物(2a～2e),其结构经1H NMR, IR和元素分析表征.以2为萃取剂,考察了酯型儿茶素单体在二氯甲烷-水两相体系中的萃取分配行为.结果表明:2e的萃取效果最佳.     

N巴黎势和可能的p共振态(英文)

通过求解N巴黎光学势的复薛定谔方程,研究了N系统的近阈束缚和共振行为,得到了一个p系统的13P0共振态.发现其能量和宽度与最近BES用Breit Wigner(B W)公式分析J/ψ→γp衰变的实验数据给出的结果相容.讨论了这一结果的含义及进一步研究的建议.     

Orbital Instability of Standing Waves for the Klein-Gordon-Zakharov System

O Introduction We consider the orbital instability of standing waves for the Klein-Gordon-Zakharov system with different propagation speeds in three space dimensions