铅黄铜合金激光诱导击穿谱特性的实验研究

本文系统地研究了靶点位置、激光功率密度以及缓冲气体对铅黄铜样品中激光诱导击穿谱(LIBS)特性的影响;并分析了不同环境气体下LIBS信号的时间分辨特性,确定了将LIBS用于铅黄铜合金样品杂质元素定量分析时的最佳实验条件.     

Formation of Pd-Ni Based Bulk Metallic Glasses

Bulk metallic glasses are prepared in Pd4o.sNi4o.sSixP19-x （x = 0-14 at.%） alloys by a combination of flux treatment and water quenching technique. It is found that the thermal stability of the Pd4o.sNi4o.sSixP19=x glassy alloys depends on the addition of Si content. Among the Pd4o.sNi4o.sSixP19=x glassy alloys studied, the Pd4o.sNi4o.sSisPls bulk metallic glass exhibits the largest supercooled liquid region （△T = 119 K） and the highest activation energy of crystallization （283.3k J/tool）, showing enhanced glass formation ability and extraordinary glassy thermal stability.     

James空间的推广

R.H.Lohman和P.G.Casazza[2]就自反的、具有对称的块P——Hilbert基的Banach空间进行了讨论,给出了一阶次自反Banach空间的一种构造方法。本文在一类具有IS型基的Banach空间上进行了推广,并给出了构造一阶次自反空间的更一般性的方法。 以下记号S、的意义同[2],文中IS序列、ESA序列、SA序列及单调基、正规基的定义可见[2]、[3]。并总设E是Banach空间,{x_i}是E之IS型单调正规基。 一般的James空间定义类似[2],区别在于对于a=(a_i)∈S和我们定义:     

纳米晶(CeO2)1-x(BiO1.5)x固溶体的水热合成

在240℃水热体系中首次合成出系列纳米晶固溶体(CeO     

可聚合手性酰胺类单体的合成

以S-(+)-1-甲基环己乙胺或S-(-)-1-甲基苯乙胺为手性源,分别与甲基丙烯酰氯和10-十一烯酰氯酰胺化合成了4个典型的可聚合手性酰胺类单体,其结构经NMR,IR和元素分析表征。     

企业声誉在电子商务消费者信任建立过程的作用机制

声誉是企业的一项重要无形资产,能够增进企业对消费者的吸引力。本文从消费者视野探索企业声誉在电子商务消费者信任建立过程的作用机制。将感知的安全性引入技术接受模型,建立了理论模型及假设,并应用结构方程模型分析软件进行了检验。结果表明,企业声誉通过消费者感知的安全性、有用性和易用性正向影响消费者信任,消费者感知的安全性、易用性也通过感知的有用性影响消费者信任。     

颗粒超导体中静电效应的非对角项对有序转变的影响

本文用有限温自洽类声子近似,对引入静电能的非对角项后颗粒超导体中相有序转变的影响进行了计算。发现比不考虑非对角项时,其相有序转变温度T_c~*降低,相有序的出现临界值α_c提高。     

STUDIES ON RESPONSE CHARACTERISTICS OF DRUG ISE''''S (Ⅳ) SELECTIVITY OF, DRUG ISE''''S WITH HETERO-POLY ACID ANION SITE TOWARD METAL IONS

The relationship between the selectivity of six drug ion-selective electrodes with anionic species of hetero-poly acid as exchange site and the structural and thermodynamical parameters of the metal ion has been investigated experimentally and theoretically. The electrode selectivity is controlled mainly by the extractibility or hydrophobicity of the metal ion, but not by the ion-association-complex formation process. Linear relationship exists between the pK_(ij) value and the structural parameter z~2/(r + 0.85) and the thermodynamic parameter of hydration (△G_h) of the metal ion. Better correlation is obtained for the pK_(ij)vs. (z~2/r)~(-k) relationship.     

Comparative Characterization of InGaN/GaN Multiple Quantum Wells by Transmission Electron Microscopy, X-Ray Diffraction and Rutherford Backscattering

The composition, elastic strain and structural defects of InCaN/CaN multiple quantum wells （MQWs） are comparatively investigated by using x-ray diffraction （XRD）, transmission electron microscopy and Rutherford backscattering/channelling. The InGaN well layers are fully strained on CaN, i.e. the degree of relaxation is zero. The multilayered structure has a clear defined periodic thickness and abrupt interfaces. The In composition is deduced by XRD simulation. We show how the periodic structure, the In composition, the strain status and the crystalline quality of the InGaN/GaN MQ, Ws can be determined and cross-checked by various techniques.     

耀州窑青瓷白色中间层和化妆土的微观结构

采用体视显微镜和偏光显微镜,对比观察了耀州窑北宋青瓷白色中间层和唐代、五代青瓷化妆土之间的微观结构.结果显示,在体视显微镜下中间层和化妆土层均为白色薄层,但在偏光显微镜下明显可见化妆土层,未见中间层.并探讨了这些现象与二者的化学组成和形成机理的关系.