Catalytic combustion of chlorobenzene over V2O5/TiO2 catalysts prepared by the precipitation-deposition method

Catalytic combustion of chlorobenzene over supported vanadium oxides has been investigated. TiO₂ was prepared by the sol-gel method from titanium isopropoxide. The supported vanadium oxide catalysts have been prepared by precipitation-deposition and impregnation method and characterized by XRD, FT-Raman and TPR. In the VO_x/TiO₂catalysts prepared using the impregnation method, when vanadium loading reaches 3 wt.%, the activity shows a maximum. However, in the VO_x/TiO₂catalysts prepared by precipitation-deposition, when vanadium loading reaches 7 wt.%, the activity shows a maximum. This result suggests that the precipitation-deposition can yield a higher metal loading on the support and a high dispersion compared to the impregnation method. This revised version was published online in August 2006 with corrections to the Cover Date.     

镀金层识别及其厚度测定的X—荧光强度比值法

利用Ａｕ原子在Ｘ射线激发下所发射的Ｌβ线和Ｍ线的强度比值识别样品是镀金还是Ｋ金，同时利用这个比值测定镀金层的厚度，镀金层厚度的测定范围为０～４μｍ，测定值与标定值的相对误差小于１５％。     

杂原子B—ZSM—35沸石的干法合成,表征及CO＋H2反应性能的研究

首次利用吸附态模板剂在Ｎａ２Ｏ－ＳｉＯ２－Ｂ２Ｏ３－ＤＥＡ干粉体系中合成了杂原子Ｂ－ＳＺＭ－３５沸石，ＸＲＤ，ＳＥＭ，ＩＲ，及ＣＯ加氢反应研究了其物理化学特性。结果表明，Ｂ原子同晶取代Ａｌ原子进入ＺＳＭ－３５沸石骨加。     

恒电流库仑法测定基准试剂三氧化二砷的含量

用恒电流库仑法测定基准试剂三氧化二砷的含量，以恒电流通过含有碘化钾，基准试剂三氧化二砷试样的弱碱性水溶液，利用工作电极铂阳极上电生滴定剂I2与亚砷酸盐定量反应，以死停终点法确定滴定终点，测量出电解电流和电解时间，根据法拉第电解定律并利用EXCEL计算出基准试剂三氧化二砷的含量。方法的回收率为100％。     

A multireference configuration interaction method based on the separated electron pair wave functions

A multireference configurational interaction method based on the separated electron pair (SEP) wave functions, SEP‐CI approach, has been developed as an approximation to the traditional CASSCF method. It differs from the CASSCF method in that active orbitals are obtained from the SEP wave function without further optimization in the subsequent CI calculations, and the active space is automatically constructed according to the occupation coefficients of SEP natural orbitals. These features make the present SEP‐CI method computationally much less demanding than the CASSCF method. The applicability of the SEP‐CI method is illustrated with sample calculations on the insertion reaction of BeH₂ and dissociation energies of LiH, BH, FH, H₂O, and N₂. © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 39–47, 2006     

Assessment of the Fe-Sn-Zn phase diagram at 450°C

The Fe-Sn-Zn system is of interest because Sn is one element added to the Zn galvanizing bath to overcome the drawbacks due to the presence of Si in semi-killed steels. This work has been undertaken with the aim to understand the tin effect on the microstructure and the layers growth in batch galvanized coatings on low alloyed steels. Various experimental techniques such as metallography, scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDX) are used in order to characterize the microstructure and the properties of such coatings elaborated in a zinc bath enriched with tin. Solidification phenomena and layers growth mechanisms during galvanization are explained by means of the ternary phase diagram Fe-Sn-Zn at 450°C. The Calphad method allows to obtain this phase diagram from the three optimized binary phase diagrams Fe-Sn, Fe-Zn and Sn-Zn and some experimental data inside the ternary Fe-Sn-Zn system.     

茶叶中痕量硒的催化极谱法测定

茶叶中痕量硒的催化极谱法测定陈安民，江丽蓉（绵阳农业专科学校中心实验室，绵阳６２１０００）关键词：催化极谱法，痕量硒硒是人体必需的微量元素之一，富硒茶乃是一种很理想的富硒食品。在我国以陕西紫阳县及湖北恩施两地出产的茶叶含硒最高（平均０．７μｇ／ｇ），...     

二铬四醋酸基簇合物的定域分子轨道研究

利用ＩＮＤＯ自洽场半经验量子化学计算方法和Ｅｄｍｉｓｔｏｎ－Ｒｕｅｄｅｎｂｅｒｇ定域化方法，分别计算了没Ｃｒ－Ｃｒ键长的气相、固相Ｃｒ２（Ｏ２ＣＣＨ３）４分子和沿Ｃｒ－Ｃｒ方向有Ｈ２Ｏ配体的「Ｃｒ２（ＣＯ３）４（Ｈ２Ｏ２）２」＾４－离子的化学键性质，结果表明，Ｃｒ２（Ｏ２ＣＣＨ３）４在气相中存在ｄ四重键，而在固相中则不存在，揭示了四重键长之间的联系，直接给出Ｃｒ－Ｃｒｄ四重键的量子化学图象，并阐明     

XRD法研究CrO3与NaY、NaM分子筛的表面相互作用

负载于多孔性、高比表面载体上的三氧化铝是重要的工业催化剂，多年来人们对催化剂中Croa的存在状态以及与载体的相互作用进行了广泛的研究［‘－4］，发现CrO。能在载体表gn散成非晶相的表面化合物，非晶相Cr（VI）具有较高的催化活性．我们曾经对MoO。／NaY，MoO。／NaM体系进行过系统的研究，发现MOO。与分子筛载体间存在强表面相互作用［’］．在此研究基础上，选择了CrO3／NaY、CrO。／NaM体系，采用XRD法对上述体系进行了研究．结果表明170oC下晶相CrO。能在NaY、NaM分子筛上自发分散成非晶相Cr（VI），且分散量大．C…     

溶剂热法制备纳米氧化镍及其表征

以乙酰丙酮镍、油酸、油胺为原料，十八烯为溶剂，聚乙烯吡咯烷酮为表面活性剂，采用溶剂热法，在不同反应条件制备了纳米级氧化镍材料.通过X射线衍射（X-ray diffraction，XRD）、透射电子显微镜（Transmission electron microscope，TEM）、紫外-可见光吸收光谱（Ultraviolet-visible spectroscopy，UV-Vis）光谱分析以及塔菲尔（Tafel）测试考察了反应物比例、保温时间、表面活性剂（PVP）、油胺的量对产物微结构、粒径、形貌、光学以及电化学活性性能的影响.实验结果表明：在反应物n[Ni（acac）₂]∶n（OA）=1∶2、添加剂PVP质量分数为1.66%、油胺物质的量为30 mmol、200℃下保温8 h时，可获得粒径约为30～40 nm纯相氧化镍，具有最佳电化学活性，交换电流密度为J₀=1.23×10^-2 mA·cm^-2.