Phospholipid complexes with molybdate

Phosphorus-containing organic-compounds combine directly with molybdate to form complexes analogous to phosphomolybdate. These complexes are extractable by organic solvents such as ethyl acetate or butanol. The ability of chloroform-ethanol mixtures in extracting only the phospholipid-molybdate complexes but not those of water-soluble phosphates may find some useful applications.     

高性能钼酸锌/碱式钼酸锌微粉合成研究*

探讨了合成高性能钼酸锌/碱式钼酸锌的新工艺。利用X射线衍射（XRD）、扫描电镜（SEM）、电感耦合等离子体原子发射光谱对钼酸锌/碱式钼酸锌的结构、形貌和元素进行表征和分析。合成工艺及条件：三氧化钼和氧化锌在乙醇溶液中在30 ℃反应30 min,过滤所得滤饼在110 ℃干燥,之后采用程序控温合成钼酸锌/碱式钼酸锌。该方法具有大幅度缩短合成时间和节约电能的优点,钼酸锌/碱式钼酸锌的收率可以达到94%以上。     

Corrosion inhibition by sodium molybdate

The ability of sodium molybdate to inhibit corrosion of mild steel is demonstrated using laboratory and field test data. Initial evidence is also presented indicating that molybdate inhibits the corrosion of copper and aluminium. Environmental aspects including fish toxicity data are discussed as is the likely mechanism of molybdate inhibition.     

Surface modifications,perspectives, and challenges of scheelite metal molybdate photocatalysts for removal of organic pollutants in wastewater

Semiconductor-mediated photocatalysis is a promising green technology which has been widely adopted for solving energy and environmental issues. Among the semiconductor photocatalysts, the scheelite tetragonal structure of metal molybdate materials have attracted tremendous research attention in the application for photocatalytic degradation of organic pollutants due to their diverse band gaps, unique physical and chemical properties, ecofriendly characters, abundant sources of molybdenum (Mo) element, and low cost. However, the fast recombination of photogenerated electron-hole pairs results in decreased efficiency of the photocatalysis. Thus, this review covers the progresses in various unmodified and modified scheelite metal molybdate photocatalysts, which include PbMoO₄, BaMoO₄, CaMoO₄, SrMoO₄, and CdMoO₄. The modification methods are categorized into morphology control, facet modification, doped, plasmonic, and heterojunction, which are devoted to the degradation of organic pollutants (mostly, dyes and drugs) and to overcome the rapid recombination of electron-hole pairs. Furthermore, the challenges and future direction as well as the perspectives toward the designation for more efficient scheelite metal molybdate photocatalysts are discussed through extensive literature review.     

钼酸钠干燥机理研究

本文介绍了在恒定干燥条件下钼酸钠干燥速率曲线的测定方法。通过对其干燥机理的研究,得出最佳工艺条件及其主要影响因素,并介绍了不同干燥阶段的强化方法。     

Liquid Crystalline Polymers

Abstract

In this article emphasis will be placed on selectively from 45 papers presented at the spring meeting and 33 papers also presented at the fall meeting.     

铁钛结晶剂对釉面性能的影响

本研究利用单因素实验和正交实验考察了铁钛结晶剂含量对铁钛结晶釉釉面效果的影响。当氧化钛加入量为8%～11%,氧化铁加入量为6%～8%时,得到的釉面效果很好,釉面底色为黄色且析出密而大的晶花。     

Crystalline Thorium Borate

Crystalline thorium borate (ThB₂O₅) has been synthesized by the reaction of thoria with boric oxide at elevated temperatures; crystals of size suitable for single-crystal X-ray studies were grown in molten boric oxide at 1300°C. Crystallographic, chemical, and some physical properties of thorium borate crystals are presented as well as the results of a preliminary phase study of the system ThO₂-B₂O₃. Amorphous thorium borate gel, formed by reaction of aqueous solutions of borax and thorium nitrate, is transformed into crystalline thorium borate and thoria on firing at elevated temperatures. Boric oxide does not appear to react with either zirconium oxide or uranium dioxide to form any crystalline compounds. The fact that uranium dioxide does not react with boric oxide, but thoria does, affords a basis for effecting a chemical separation of the two oxides from thoria-urania solid solutions. Preliminary data on the reactions between boric oxide and different thoria-urania solid solutions are given.     

Crystalline furanic polyisocyanates

Summary 2-Furfuryl isocyanate and 2-furyl isocyanate were polymerized with several anionic initiators. Cyclic trimers and linear polymers were obtained. These products were characterized by elementary analysis, IR and ¹H-NMR spectroscopy, DSC, TGA, polarized-light microscopy, vapour-pressure osmometry and vacuum pyrolysis. The polymers possess a high degree of crystallinity. Their thermal decomposition yields the monomer and the cyclic trimer.     

钼酸铵生产酸洗废水的治理

调查分析了国内外目前钼酸铵酸洗废水综合治理的状况。并根据所用钼的矿型,钼的产品及生产工艺的不同,提出了钼酸铵生产酸洗废水的处理方法,指出:对于钼酸铵生产废水的治理不能仅考虑末端治理达标排放,而是要采用综合治理方案回收和利用其中钼元素和铵盐。认为较理想的处理钼酸铵生产废酸液的工艺流程应为:过滤,离子交换,中和和沉淀。     

钼酸铵与LaHY固相反应机理

采用TG-DSC技术研究了钼酸铵和LaHY在空气气氛中的失重行为,考察了钼酸铵与LaHY的固相反应机理,用XRD、BET和NH₃-TPD对其物相结构、比表面积和表面酸性进行了表征。结果表明,（NH₄）₆Mo₇O₂₄·4H₂O分解产生的表相Mo物种借助固相反应以金属-氧簇定位在LaHY分子筛体相笼中形成nMoO_x·LaHY单相复合体,引起分子筛的晶胞收缩,晶胞参数a₀减小,比表面积下降。制备的nMoO_x·LaHY较相应LaHY分子筛的弱酸中心变化较小,中强酸中心增加,强酸中心略有减少,总酸量增加。以质量分数为0.6%的二苯并噻吩/正癸烷溶液为模型反应物,评价了制备的nMoO_x·LaHY催化剂的加氢脱硫性能。负载Mo质量分数为5.0%制得的nMoO_x·LaHY催化剂在反应压力4.0 MPa,反应液时空速20 h^-1,H₂/原料液体积比500:1的实验条件下,290℃和310℃的二苯并噻吩加氢脱硫转化率达到了56.38%和88.79%,较相应负载Mo质量分数为20.0%制备的MoO₃/Al₂O₃催化剂分别提高了约12个百分点和28个百分点,表现出了较高的二苯并噻吩加氢脱硫反应活性。     

Adsorption of chromate and molybdate by cetylpyridinium bentonite

Bentonite was modified with cetylpyridinium bromide (CPBr) and investigated by elemental analysis, IR, X-ray diffraction, thermogravimetric analysis, specific surface area (BET) and electrokinetic mobility measurements. The surfactant was adsorbed on the montmorillonite in a bilayer structure. The organo-bentonite removed the oxyanions of Cr(VI) and Mo(VI) from aqueous solutions. The adsorption followed a pseudo-second-order kinetics and adsorption capacities of 0.7 and 1.4 mmol/g for Cr(VI) and Mo(VI) were recorded. E_a = 5.34 and 14.50 kJ/mol for the adsorption of Cr(VI) and Mo(VI) indicated an ion exchange mechanism. The standard free energy values (ΔG°) of − 2.11 and − 3.40 kJ/mol for Cr(VI) and Mo(VI) indicated a spontaneous adsorption process. Column studies showed the suitability of the organo-bentonite for operation in continuous flow systems.     

钼酸铋半导体光催化剂的研究新进展

钼酸铋拥有典型的Aurivillius型结构,主要由(Bi_2O_2)~(2+)层及MoO_6钙钛片层状结构组成,显示出良好的光催化性能,广泛用于有机污染物的降解,成为近年来最受关注的一类可见光催化材料。综述钼酸铋半导体光催化剂的制备方法,以及通过构建异质结、掺杂、固溶体、金属沉积、量子点等改性措施提高其光催化活性,归纳和总结钼酸铋光催化剂在催化氧化反应、降解有机废水、电化学储能和CO_2的还原、气体传感器等方面的应用,并对钼酸铋光催化剂发展进行展望。     

Oxidative dehydrogenation of propane over magnesium molybdate catalysts

Catalytic activities of magnesium molybdates were investigated for the oxidative dehydrogenation of propane with and without molecular oxygen under atmospheric pressure. Catalytic properties drastically changed with the catalyst composition, and it turned out that Mg_0.95MoO_x catalysts having slight excess molybdenum showed the highest activity in the oxidative dehydrogenation of propane, which gave 61% selectivity to propene at 22% conversion of propane at 515°C. The catalytic activities strongly depended on the acidic properties of the catalysts. It was also revealed that the lattice oxide ions of the catalysts participated as an active oxygen in the oxidative dehydrogenation of propane.     

钼酸盐的制备及其光催化性能研究进展

综述了近些年不同钼酸盐材料的典型制备方法,分析了不同钼酸盐材料在可见光催化降解等方面的性能特点.详细总结了钼酸盐在光催化反应机理方面的研究进展,并在此基础上总结了钼酸盐光催化性能的改进方法.阐述了钼酸盐光催化剂的优势与缺点,试图为高性能钼酸盐催化剂的研究提供基础参考.     

复合型钼酸盐缓蚀剂性能研究

由Na3PO4、ZnSO4、钼酸钠、BTA等配制软化水缓蚀剂,通过挂片实验,考察了缓蚀剂成分用量对缓蚀性能的影响。结果表明,当Na3PO4含量为6²0 mg,ZnSO4含量为520 mg,ZnSO4含量为5³0 mg,钼酸钠含量为1.2530 mg,钼酸钠含量为1.25¹0 mg,BTA含量为010 mg,BTA含量为0⁵ mg时,缓蚀剂的缓蚀率均≥92%。     

Oxidative dehydrogenation of isobutane over magnesium molybdate catalysts

A series of Mo-Mg-O catalysts with different crystalline phases (pure and mixtures) have been studied in the oxidative dehydrogenation of isobutane. X-ray diffraction, UV–Vis spectroscopy and temperature programmed reduction were applied to characterise the samples. In addition, the kinetics of the lattice oxygen exchange with labelled C¹⁸O₂ was measured for all samples. It has been found that the MgMoO₄ phase contains the surface active sites suitable for the adsorption of isobutane and for its dehydrogenation to isobutene with the minimum of cracking reaction. Moreover, for this reaction the migration of lattice oxygen ions is not a key parameter in the control of the catalytic properties of these materials.     

晶粒与颗粒

晶粒与颗粒是两个概念完全不同的名词，在材料科学研究中，它们常用于描述材料的微观形貌和结构特征，经常容易被混淆。本文比较了晶粒和颗粒的定义，并归纳总结了晶粒尺寸及其形貌和颗粒粒度的测试方法．