硫脲树脂分离钼,钨的研究

研究了硫脲树脂对钼，钨的吸附行为，提出了分离钼，钨的条件，可用于实际样品中２钼，钨的分离，回收率达９５％以上。     

硫氰酸盐光度法测定高温合金钢中钼、钨

硫氰酸盐光度法是测定钼、钨的经典方法。试样经溶解后,用氯化亚锡作还原剂,在硫酸介质中,Mo（Ⅵ）被还原为Mo（Ⅴ）,然后与SCN-形成显桔红色配合物,而钨不被还原,用强还原剂（如三氯化钛）钼可被还原到更低价,而不与SCN-显色：而钨被还原为五价与SCN-显色;因此在同一溶液中测定钨、钼。本文就该法的测定做进一步的阐述。     

五溴水合钼（Ⅲ）酸铵的电解合成

在过渡金属配合物的研究中,钼的配合物化学一直是化学工作者所密切注视的一个领域。尤其三价钼已被认为是某些生物过程和催化过程的参加者。近年来对钼(Ⅲ)配合物的合成、性能、结构的研究颇为广泛。因此,三价钼配合物合成的基本试剂五溴水合钼(Ⅲ)酸铵((NH_4)_2[MoBr_5(H_2O)])变得很重要,由它可以很方便地合成出一系列三价钼的配合物,当前国内市场尚无成品可供。作者对(NH_4)_2[MOBr_5(H_2O)]的电解合成作了较详细的研究,摸索出一套成功的合成工艺。     

X射线衍射K值法测定蓝色氧化钨中的WO_3、WO_（2．72）和WO_（2．90）

Ｘ射线衍射Ｋ值法测定蓝色氧化钨中的ＷＯ_３、ＷＯ_（２．７２）和ＷＯ_（２．９０）潘世伟（上海进出口商品检验局２０００ｇ２）蓝色氧化钨又名β－氧化钨（简称蓝钨），化学组分为ＷＯ２．９０，属四方晶系。由于蓝钨具比表面大、掺杂均匀、比ＷＯ３更易被还原、可适?..     

铁钴镍双组分氮化钼催化剂的制备和丙烷氨氧化性能的研究

以氢气和氮气的混合气体为氮化气体与铁钼、钴钼及镍钼双金属氧化物进行程序升温氮化反应合成了铁钼、钴钼及镍钼双金属氮化物催化剂。将铁钼、钴钼和镍钼氮化物分别用于催化丙烷氨氧化反应，研究结果表明，钴钼和镍钼双金属氮化物催化剂具有更高的催化活性和更高的丙烯腈选择性。     

硅钨杂多酸催化合成马来酸（2—2乙基己基）酯的研究

以硅钨杂多酸（HWSI）为催化剂，以顺丁烯二酸酐与仲辛醇为原料催化合成马来酸（2－2乙基己基）酯，研究了酯化和磺化反应中催化剂的用量，反应时间，醇酸摩尔比对反应的影响，催化剂能使用多，催化效果均好。     

利用离子交换树脂提取钨、钼的技术进展

对近年来利用离子交换树脂回收钨、钼离子进行了综述,分别讨论了回收钨、回收钼的树脂选用与使用条件,并且对分离含钨溶液中微量钼的技术进行了讨论。     

杂多酸（盐）催化合成己二酸双丁酯

本文报道了低温均相和非均相Ｄａｗｓｓｏｎ型及Ｋｅｇｇｉｎ型杂多酸（盐）催化合成己二酸双丁酯的研究结果。提出了酯化反应的最佳条件。实验表明：杂多酸（盐）催化合成己二酸双丁酯的活性高、选择性好，产品质量也好。对催化机理进行了初步探讨。实验发现，杂多酸（盐）液相均相催化酯化是表型和体型催化反应的叠加，而在非均相催化酯化反应中，杂多阴离子无催化活性。     

弱酸性阴离子交换纤维吸附钼（Ⅵ）的性能研究

研究了弱酸性阴离子交换纤维对钼（Ⅵ）的吸附性能,考察了酸度、温度和时间等因素对吸附性能的影响。实验结果表明在pH为3时吸附性能最好,离子交换纤维对钼（Ⅵ）的吸附以液膜扩散为主,交换速度很快,30 min即可达到吸附饱和,吸附速率常数为0.231 s-1,离子交换过程服从Freundlish等温式,温度和流速影响动态吸附性能,使得穿透曲线和穿透时间发生改变,具有吸附速度快、吸附量大的优点,且解吸性能良好,可以进行再生使用。     

一种1，2-双-（2-氨基苯氧基）-乙烷-N，N，N＇，N＇-四乙酸衍生物的合成研究

以4-二甲基氨基吡啶（DMAP）和碳化双（环己基亚胺）（DCC）催化酰化反应,合成了一种1,2-双-（2-氨基苯氧基）-乙烷一N,N,N＇,N’-四乙酸和谷氨酸二甲酯的缩合物,并采用波谱学方法对反应产物进行了结构鉴定。     

Ring-Opening Metathesis Polymerization of 5,6-Bis(Chloromethyl)-Norbornene by Tungsten(II) and Molybdenum(II) Complexes

The reaction of endo,endo-5,6-bis(chloromethyl)bicyclo[2.2.1]hept-2-ene in the presence of seven-coordinate tungsten(II) and molybdenum(II) complexes of the type [MCl(M'Cl₃)(CO)₃(NCMe)₂] (M'=W, Mo; M=Sn, Ge) leads to ring-opening metathesis polymerization and to the formation of high-molecular-weight soluble polymers with dispersity index in the range 1.4-2.0 and number average molecular weights in the range 300 000-790 000 g mol^-1. The geometric structure of these polymers was determined by means of ¹H- and ¹³C-NMR spectroscopy. Molybdenum catalysts gave polymers with lower cis vinylene content (20-50%), whereas tungsten catalysts gave polymers with higher cis vinylene content (84-95%).     

蒽醌法双氧水生产中加氢反应原理及其控制

概述蒽醌法双氧水生产中催化加氢反应原理和控制要点,从实际生产的角度,着重介绍了优化反应条件,遏制副反应,保持蒽醌稳定性的主要途径和意义。     

新一代后过渡金属聚乙烯催化剂研究的最新进展

对后过渡金属(Fe、Co、Ni、Pd)为中心金属的聚乙烯催化剂的最新进展进行了评述,讨论了它们的合成方法、结构特征和催化性能。     

轻油水蒸气转化制城市煤气催化剂研究

综述了轻油水蒸气转化制城市煤气镍系催化剂的研究进展 ,讨论了催化作用机理、催化剂构成及失活 ,分析了加入碱土金属氧化物、过渡金属氧化物和稀土氧化物的助催化作用     

直接酯化法合成PBT中钛系催化剂的研究

对钛系催化剂在直接酯化法合成PBT中的应用进行了研究.采用不同种类的催化剂和不同的催化剂含量进行实验.在催化剂对酯化反应速率、THF 生成量及缩聚反应速率的影响方面得出了一些规律性的结果.同时运用端羧基分析、DSC、恒温 TG 等方法测定了钛系催化剂对 PBT 热氧化稳定性的影响.     

Decomposition of NO on Tungsten Carbide and Molybdenum Carbide Surfaces

The decomposition of ¹⁵NO on C/W(111), C/W(110), and on monolayer and bulk C/Mo/W(111) surfaces is compared based on temperature-programmed desorption (TPD) and Auger electron spectroscopy (AES) measurements. Our results indicate that the decomposition of ¹⁵NO occurs readily over all surfaces, and the only ¹⁵N-containing reaction products are ¹⁵N₂ and ¹⁵N₂O under our experimental conditions. Much higher surface reactivity for ¹⁵NO decomposition was observed over the more open-structured C/W(111) surface, with a value of 0.68 ¹⁵NO/W, in contrast to the surface reactivity of 0.24 ¹⁵NO/W over the close-packed C/W(110) surface. The selectivity of these two ¹⁵N-containing reaction products depends on the structure of the substrates as well. The more open-structured C/W(111) surface favors the production of ¹⁵N₂, with a product selectivity of ¹⁵N₂ being approximately 87%. In contrast, the selectivity to ¹⁵N₂ is only about 52% on C/W(110). In addition, we have investigated the decomposition of ¹⁵NO on C/Mo surfaces that were epitaxially grown on W(111). The selectivity of ¹⁵N₂ on C/Mo/W(111) surfaces is 88%, which is very similar to that observed on C/W(111). Finally, the general similarity between the DeNOx chemistry on carbides and on Pt-group metals will also be discussed.     

用载体型钛催化剂合成高反式－1．4聚异成二烯

本文研究了载体型钛催化剂合成高反式－１．４聚异戊二烯（ＴＰＩ）的聚合活性，初期聚合速率并对所得ＴＰＩ微观结构进行了表征。结果表明在一定范围内该催化体系催化效率较高，可达３０００ｇＴＰＩ／ｇＴｉ。聚合表观活化能为３３．５ｋＪ／ｍｏｌ，聚合速率及分子量随温度升高同时增加，合成的ＴＰＩ反式－１．４结构含量可达９８％左右     

热处理温度对掺铁TiO2纳米粉体光催化性能的影响

以硫酸氧钛、九水硝酸铁、钛酸丁酯等为原料,采用均匀沉淀法和溶胶-凝胶法分别合成制备出单一的二氧化钛和掺铁的二氧化钛纳米粉体。利用X射线衍射仪(XRD)和可见光分光光度计等测试手段,研究了热处理温度对掺铁TiO2纳米粉体的晶型和光催化性能的影响,并对掺铁TiO2纳米粉体的晶型和光催化性能之间的相关性的进行了分析。实验数据表明,掺铁TiO2纳米粉体的适宜热处理温度约为400℃。     

Separation of Simulated Mixed Mo(VI) and V(V) From HNO3 and HCl Solutions by Selective Extraction and Stripping with Tri-N-Butyl Phosphate as Extractant

Equilibrium study was carried out to determine the optimum conditions required for Mo(VI) extraction from HNO₃ solutions and subsequently, simulated mixed Mo(VI), and V(V) were extracted from HNO₃ (pH = 1.0) and 6.0 mol L^?1 HCl solutions with TBP dissolved in n-hexane. The variation of pH (selective extraction) and selective stripping were investigated as methods of separation of Mo(VI) and V(V). The latter method was found inefficient for separations from HNO₃ solutions (pH = 1.0) except supplemented with selective stripping (back-extraction with 2.0 mol L^?1 H₂SO₄/14.5 mol L^?1 NH₄OH). While from 6.0 mol L^?1 HCl, selective stripping was adequate to quantitatively strip in turns the Mo(VI) and V(V) co-extracted into the TBP phase. About 100% of the co-extracted V(V) from the HCl medium was stripped in a two-stage process, in contrast to a single-stage required for Mo(VI) of the same result. The selective stripping method was found to be better because an initial appreciable co-extraction had occurred prior to stripping separation. Based on analytical and spectra data, the extracted complexes from HNO₃ and HCl media were formulated as ((MoO₂)_7–8n(VO₂)_2n · (NO₃)₁₆) ^(16–18)n- · m TBP (where n>m) and (MoO₂Cl₂ · VO₂ Cl) · xTBP, respectively.     

Symmetry-based Study of MoS2 and WS2 Nanotubes

The symmetry-based study of MS₂ (M=Mo, W) single-wall nanotubes (SWNTs) is reviewed. First, the structure and symmetry of MS₂ NTs is determined. Then, conserved quantum numbers and general forms of potentials are derived. The valence force-field method implemented into the POLSym code is used to calculate phonon dispersions. Phonons characterized by a zero angular-momentum quantum number are studied in detail. The functional dependence of the frequency of rigid layer modes on NT diameter and chirality are found, and Raman- and infrared-active modes are singled out. Electronic band structure calculations are performed by the symmetry-based density functional tight-binding (DFTB) method. Changes in the band-gap type and size with NT chirality and diameter are evaluated. Optical absorption spectra of individual NTs are calculated using DFTB wave functions for exact transition matrix element calculations. Diffraction patterns of MS₂ are predicted and NT characterization by different diffraction methods is discussed.