An ionic liquid-type carbon paste electrode and its polyoxometalate-modified properties

The replacement of a non-conductive organic binder with a conductive room temperature ionic liquid in fabricating carbon paste electrode has been made. This new electrode due to its enhanced conductivity presented very large current response from electroactive substrates. The novel carbon paste electrode was bulk-modified via the uniform dispersion of Keggin-type phospho polyoxomolybdate (PMo₁₂) in bulky carbons, which possessed excellent electrocatalytic activity for the reduction of nitrite. The pronounced multi-electron catalytic ability was ascribed to the used hydrophobic ionic liquid which constructed an excellent charge-transfer bridge in the bulk of carbon paste electrode, thus facilitated the intake of electrons from reduced PMo₁₂ mediators. In view of their prominent properties, the carbon paste electrode using ionic liquid binder and its bulk-modified electrode take on good prospects of the application in physical chemistry and electroanalytical chemistry fields.     

低分子量溴代聚苯乙烯的制备及应用

用溶液法合成了一系列低分子量的聚苯乙烯，其溴化产物（Ｂｒ－ＰＳ）的溴含量和热稳定性与美国同类产品Ｐｙｒｏ－Ｃｈｅｋ ＬＭ相当，分别用作聚苯乙烯树脂的阻燃剂，极限氧指数测定结果表明，其阻燃性也达到了Ｐｙｒｏ－Ｃｈｅｋ ＬＭ的水平。     

GC-FPD、GC-MS法分析血液样品中的毒鼠强

采用液-液提取方法及GC—FPD定量、GC—MS定性检测手段，对血液样品中毒鼠强的提取和检测方法进行了研究。时提取毒鼠强的溶剂类型、溶剂用量及质谱分析参数等因素进行了考察，建立了一种回收率高、重现性好、灵敏度佳、干扰少的毒鼠强分析方法。毒鼠强工作曲线的线性范围为0．01-0．2μg／μL，相关系数r=0．9999，空白血液的加标平均回收率为93．6％，测定结果的相对标准偏差为5．27％。该方法满足司法鉴定中生物样品的定性、定量检验要求。     

高效液相色谱蛋白质手性固定相

本文综述了近年文献中已报道的各种高效液相色谱蛋白质（酶）手性固定相及其在手性拆分中的应用，并阐述了蛋白质作为手性选择剂拆分机理的研究进展。     

Kinetic spectrophotometric determination of trace manganese (II) with dahlia violet in nonionic microemulsion medium

A new catalytic kinetic spectrophotometric method has been developed for the determination of trace amount of manganese (II) in nonionic microemulsion medium. The method is based on the catalytic effect of manganese (II) on the oxidation of dahlia violet by potassium periodate with nitrilotriacetic acid as an activitor in the presence of nonionic microemulsion. Under the optimum conditions, the calibration graph is linear in the range of 0.0004-0.0056 μg ml⁻¹ of manganese (II) at 580 nm. The detection limit achieved is 3.75×10⁻⁵ μg ml⁻¹. Manganese (II) in foodstuff samples was determined with satisfactory results.     

Alkyl- and aryl-substituted corroles. 4. Solvent effects on the electrochemical and spectral properties of cobalt corroles

Solvent effects on the electrochemistry and spectroscopic properties of alkyl- and aryl-substituted corroles in nonaqueous media are reported. The oxidation and reduction of six compounds containing zero to seven phenyl or substituted phenyl groups on the macrocycle were studied in four different nonaqueous solvents (CH(2)Cl(2), PhCN, THF, and pyridine) containing 0.1 M tetra-n-butylammonium perchlorate. Dimers were formed upon oxidation of all corroles in CH(2)Cl(2), but this was not the case in the other three solvents, where either monomers or dimers were formed upon oxidation depending upon the solvent Gutmann donor number and the number or location of aryl substituents on the macrocycle. The half-wave potentials were analyzed as a function of the number of aryl substituents on the macrocycle as well as the concentration of added pyridine to PhCN solutions of the compound, and these data were combined with data from the spectroelectrochemistry experiments to determine the stoichiometry of the species actually in solution after the first oxidation or first reduction of each compound. The results of these experiments indicate that reduction of the bispyridine adduct (Cor)Co(III)(py)(2) proceeds via the monopyridine complex (Cor)Co(III)(py) to give in each case the unligated cobalt(II) corrole [(Cor)Co(II)](-). In contrast, pyridine remains coordinated after electrooxidation, and the final product was characterized as [(Cor)Co(III)(py)(2)](+).     

Selective reduction of aromatic nitro compounds with stannous chloride in non acidic and non aqueous medium

Aromatic nitro compounds are readily reduced by SnCl₂, 2 H₂O in alcohol or ethyl acetate or by anhydrous SnCl₂ in alcohol where other reducible or acid sensitive groups such as aldehyde, ketone, ester, cyano, halogen and O-benzyl remain unaffected.     

一类联图的距离谱半径以及盖理论（英文）

令X=(n₁,n₂,…,n_t),Y=(m₁,m₂,…,m_t)是两个t维递减序列.如果对所有的j,1≤j≤t,都有∑_i=1~j、n_i≥∑_i=1~j m_i以及∑_i=1~t n_i=∑_i=1~t m_i,则称X可盖Y,记作X■Y.如果X≠Y,则记作X■Y.本文考虑联图G(n₁,n₂,…,n_t;a)=(K_n1∪_n2∪…∪K_nt)∨K_a的谱半径,这里n₁+n₂+…+n_t+a=n,(n₁,n     

Global axisymmetric classical solutions of full compressible magnetohydrodynamic equations with vacuum free boundary and large initial data

In this paper,the global existence of the classical solution to the vacuum free boundary problem of full compressible magnetohydrodynamic equations with large initial data and axial symmetry is studied.The solutions to the system(1.6)–(1.8) are in the class of radius-dependent solutions,i.e.,independent of the axial variable and the angular variable.In particular,the expanding rate of the moving boundary is obtained.The main difficulty of this problem lies in the strong coupling of the magnetic field,velocity,temperature and the degenerate density near the free boundary.We overcome the obstacle by establishing the lower bound of the temperature by using different Lagrangian coordinates,and deriving the uniform-in-time upper and lower bounds of the Lagrangian deformation variable r;by weighted estimates,and also the uniform-in-time weighted estimates of the higher-order derivatives of solutions by delicate analysis.     

平菇多糖稀溶液行为的研究

平菇多糖属生物高分子, 文章对平菇多糖稀溶液性质进行了研究。实验系采用Elias浊点滴定法测定平菇多糖溶液的θ组成, 用快速动态膜渗透计和粘度法测定平菇多糖的数均分子量、维利系数与分子链的构型参数。探讨其在θ条件下的分子形态及用Tung函数法等处理分级数据, 从而获得平菇多糖的分子量分布。