高电导率的a—SiHY合金的低温电导特性

用射央求地在硅单晶衬底上沉积出电导率高达６０Ｓ／ｃｍ的ａ－ＳｉＨＹ合金薄膜。在２０－３００Ｋ，对于钇含量高的样品，其电导仍是热激活的。ｌｇσ与１／Ｔ的关系曲线能够被拟合成斜率不同的两条直线，直线的斜率和两直线间拐点所地 温度依赖于膜中钇的含量。但对钇含量低的薄膜，电导对温度的依赖关系度为σ∝ｅｘｐ（－１／Ｔ＾１／４）。结果表明，这些钇含量不同的样品在没的温度范围内具有不同的导电机制。     

LaNi4.7Al0.3单颗粒微电极电化学行为的研究

报道了一种单颗粒微电极制备新方法, 并研究了LaNi4.7Al0.3球形单颗粒微电极的电化学行为.     

电感耦合等离子体发射光谱测定稀土铝合金中稀土和非稀土元素

本工作用 ICP-AES 法测定稀土-6063变形铝合金中 La、Ce、Pr、Nd、Sm、Gd、Fe、Mg、Ti、Zn,Cu 和 Mn,本方法不用化学分离,可一次同时测定这些元素,并做了 ICP光源参数、基体量变化、酸度(HCl)变化、稀土总量变化、共存元素 Fe 和 Mg 量的变化对被测元素的影响。本方法速度快、准确度高(除 Cu 稍差)。回收率91.0～110.0%,相对标准偏差±1.4～8.0%。     

Ni-B和Ni-Ce-B超细非晶态合金的退火晶化及其催化性能

 采用XAFS,XRD和DTA方法研究了Ni－B和Ni－Ce－B超细非晶态合金在退火过程中的结构变化及其结构与催化性能的关系．活性结果表明,在退火温度为623K时,Ni－B和Ni－Ce－B样品的苯加氢催化反应转化率最高,分别为63％和81％,0．3％Ce的掺入提高了Ni－Ce－B的催化活性．DTA结果表明,Ni－B超细非晶态合金在598和653K有两个晶化峰,而Ni－Ce－B样品有548,603,696和801K四个晶化峰．XAFS和XRD结果进一步说明,在573K退火时,Ni－B样品晶化生成晶态Ni3B和纳米晶Ni,此时Ni－Ce－B仅有少量晶态Ni3B生成．在673K退火时,Ni－B样品中的Ni3B开始分解生成晶态Ni,同时纳米晶Ni聚集并形成大颗粒晶态Ni,而Ni－Ce－B样品晶化生成晶态Ni3B和纳米晶Ni．在773K和更高的温度退火处理后,Ni－B样品中Ni的局域环境结构与金属Ni箔基本一致,但Ni－Ce－B样品晶化生成的Ni晶格有较大畸变,同时Ni3B并未分解．说明0．3％的Ce对提高Ni－Ce－B样品的稳定性有显著作用．本文首次报道了Ni－B和Ni－Ce－B超细非晶态合金中苯加氢催化活性中心为纳米晶Ni和类似于金属Ni的Ni－B非晶态合金．     

Double Electric Layer on Liquid Sn-Ga Alloy in Acetonitrile Solutions of Electrolytes

The structure of the double electric layer (DEL) on a liquid dropping Sn-Ga electrode containing 8 at. % of Sn is studied in acetonitrile (AN) solutions of electrolytes. It is shown that the transition from aqueous to AN solutions of electrolytes makes it possible to expand the region of investigation of parameters of DEL on an Sn-Ga electrode from negative charges to a zero charge and to small positive charges. As follows from the obtained data, throughout the entire interval of charges studied, an excess, as compared with an Hg electrode, chemisorption interaction (Sn-Ga)-AN is absent. It is established that the distance of the closest approach of AN dipoles to an ionic core increases upon going from Hg to Sn-Ga to Ga. The Ga, Bi-Ga, and Sn-Ga electrodes, which possess close values of the “electrochemical work function,” are used as an example to show that the metal-solvent chemisorption interaction increases with decreasing distance of the closest approach of its dipoles to the ionic core of the metal. The effect of this factor becomes stronger as the donor number of the solvent increases.     

叠氮二乙基铝合成及其相关反应的研究

在芳烃溶剂中用氯化二乙基铝和叠氮化钠反应合成了叠氮化二乙基铝(DEAA),其产率高达87%,比文献值高出17%。在正己烷中没有合成出DEAA,在含30%四氢呋喃(THF)的正己烷中合成出DEAA·THF配合物。在芳烃溶剂中,随着苯环上甲基数目的增加,DEAA的收率增加。测定了氯化二乙基铝、氯化二乙基铝的正己烷溶液、氯化二乙基铝的甲苯溶液的 ²⁷Al NMR谱。由 ²⁷Al NMR谱数 据确定了氯化二乙基铝在甲苯中解离平衡式,计算了氯化二乙基铝在甲苯中解离平衡的热力学数据。用DEAA与苯甲酸甲酯直接合成了苯甲酰叠氮,并表征了其结构。这是一个新反应,至今无文献报导。用实验证明了在正己烷溶液中,用氯化二乙基铝、叠氮化钠与苯甲酸甲酯合成苯甲酰叠氮,没有经过氯化二乙基铝和叠氮化钠反应生成中间体DEAA的这一步。依据实验事实建立了上述三种反应的反应机理。     

无火焰原子吸收测定血清中的铝

用无火焰原子吸收法测定血清中的铝,样品用高纯水十倍稀释后,用标准加入法进行测定,不需使用基体改进剂和氘灯扣除背景。方法简单、准确、灵敏度高。用含铝20ng/ml的一份十倍稀释血清样,重复测十次,变异系数5%左右。     

Stabilization of p-block organoelement terminal hydroxides, thiols, and selenols requires newer synthetic strategies

Metal hydroxides represent a very interesting and highly useful class of compounds that have been known to chemists for a very long time. While alkali and alkaline earth metal hydroxides (s‐block) are commonplace chemicals in terms of their abundance and their use in a chemical laboratory as bases, the interest in Brønsted acidic molecular terminal hydroxides of p‐block elements, such as aluminum and silicon, has been of recent origin, with respect to the variety of applications these compounds can offer both in materials science and catalysis. Moreover, these systems are environmentally friendly, relative to the metal halides, owing to their ‐OH functionality (resembling that of water). Design and conceptualization of the corresponding terminal thiols, selenols, and tellurols (M? SH, M? SeH, and M? TeH) offer even more challenging problems to synthetic inorganic chemists. This concept summarizes some of the recent strategies developed to stabilize these otherwise very unstable species. The successful preparation of a number of silicon trihydroxides a few years back resulted in the generation of several model compounds for metal–silicates. The recent synthesis of unusual aluminum compounds such as RAl(OH)₂, RAl(SH)₂, and RAl(SeH)₂ with terminal EH (E=O, Se, or Se) groups is likely to change the ways in which some of the well‐known catalytic conversions are being carried out. The need for very flexible and innovative synthetic strategies to achieve these unusual compounds is emphasized in this concept.     

Structures and electrochemical characteristics of several kinds of alloys

The structures and the electrochemical characteristics of La_0.7−x Ce_xMg_0.3Ni_2.8Co_0.5 (x = 0.1–0.5) alloy, Ti_0.25−x Zr_xV_0.35Cr_0.1Ni_0.3 (x = 0.05–0.15) alloy and AB_3<x<5-type alloy, which are the representative examples of AB₃-type alloy, solid solution alloy and non-AB₅-type alloy, respectively, have been investigated, and the performances of MH-Ni battery in which AB_3<x<5 type alloy is used as the negative electrode material are examined at relatively low temperature.     

加速剂对化学镀镍层组成与结构的影响

加速剂对化学镀镍层组成与结构的影响方景礼，武勇，韩克平，张敏（南京大学应用化学研究所配位化学国家重点实验室南京２１００９３）关键词化学镀镍，Ｎｉ０Ｐ合金，加速剂，硫脲化学镀镍磷合金具有耐蚀性、可焊性、厚度均匀和硬度高等优点，已得到广泛应用。为提高生产...