Na2SnO3系催化剂在甲烷氧化偶联反应中的催化性能及表面碱性的探讨

1982年Keller和Bhasin以金属氧化物为催化剂从甲烷制得少量乙烯和乙烷的工作引起了各国研究工作者的重视,此后报道了许多有研究价值的催化剂,其中添加碱金属对提高催化性能所起的作用引起了普遍的关注.Lunsford等首先用添加Li~+的MgO作催化剂,发现催化剂表面碱性增强的同时,生成C_2烃类产物的选择性明显增加.随后Iwamatu等在MgO中添加Na~+及Rb~+盐,Jones等在Mn~(4+)/SiO_2中添加Na~+,Otsuka等在Sm_2O_3中添加LiCl作为甲烷氧化偶联催化剂进行了研究,这些结果均表明,因添加碱金属使催化剂呈现     

The study of the partitioning mechanism of methyl orange in an aqueous two-phase system

An aqueous two-phase system of dodecyl triethylammonium bromide (C₁₂NE, cationic surfactant) and sodium dodecyl sulfate (SDS, anionic surfactant) mixture is proposed for the extraction of some dyes and porphyrin compounds. Transparent two phase-systems are formed when the surfactant concentrations and C₁₂NE/SDS ratios are in certain regions. In this study, the aqueous two phase-systems were prepared by mixing 0.1 mol l⁻¹ C₁₂NE and SDS with a molar ratio of 1.7:1.0. The results showed that negatively charged chlorophyll (sodium copper chlorophyllin) and positively charged dye (methyl violet) were efficiently extracted into the upper phase. The negatively charged methyl orange (pH>7) was moved into the upper phase mostly while amphoteric methyl orange (pH<3) was distributed in the two phases uniformly. Except for hydrophobic force, charge interaction between solute and surfactant also play an important role in the extraction process.     

蛋白质—四氯苯醌荷移反应的分光光度研究

本文用分光光度法研究了蛋白质—四氯苯醌荷移反应。通过对影响反应各因素的研究,确立了以四氯苯醌形成荷移络合物的方法测定蛋白质的最佳条件,测定了最大结合数及反应平衡常数。     

四苯基卟啉及其衍生物的表面光电压谱

酞菁和卟啉染料是一类典型的分子半导体材料,由于其在生命过程、癌的治疗等生物学上的探索及其化学传感、光电特性在固体电子学器件研究中占有很重要的地位。尤以这类染料的光电性质深受人们的重视,这与太阳能光电池、光MOS晶体管等的应用前景是分     

Preparation of AgBiVMoO/-Al2O3 Catalysts for the Partial Oxidation of Propane

A novel mixed sol method was developed for the preparation of supported catalysts. Analyses by means of XRD and BET show that a 40%AgBiVMoO/γ-Al2O3 catalyst prepared by this method possessed high specific surface area and high dispersion of the active phase. As a result, high acrylic acid selectivity of 8.5% was obtained when the catalyst was used in the reaction of propane partial oxidation to acrylic acid in a fixed-bed reactor.     

多功能沸点仪的研究

本文提出了两种新型沸点仪——CP-Ⅰ型和CP-Ⅱ型沸点仪, 阐述了仪器各部分结构的设计思想和原理, 并对仪器的性能和各部分功能进行了较为完整的实验考核, 获得了预期的效果。     

双安息香缩乙二胺的合成及其配位性质

合成了双安息香缩乙二胺及其与 Ni( )、Pd( )、Pt( )、Zn( )、Cd( )和 Hg( )的配合物 ,并经质谱、红外光谱、元素分析和电子光谱等方法所表征 ;测定了溶液中配合物的稳定常数 ,并就该配体的特殊配位性质进行了讨论。     

Kinetics of uranium(VI) extraction by bis(octylsulfinyl)methane

The kinetics and mechanism of uranium(VI) extraction from nitric acid solution by bis(octylsulfinyl)methane (BOSM) are studied with the method of stationary interface cell. The effects of temperature, extractant and nitric acid concentrations are discussed. The results showed that the extraction process is controlled by the following reaction: UO₂(NO₃)₂ + BOSM_(i)⇄_k1 ^k-1UO₂(NO₃)₂BOSM_(i). The variation of enthalpy associated with the extraction is -22.1±2.1 kJ/mol. This revised version was published online in July 2006 with corrections to the Cover Date.