Study on the Methyl Migration of 10-Methoxy-5,10-dihydrophenophosphazine 10-oxide

The title compound (1) was treated with NaH at room temperature in anhydrous DMF to give a sodium salt (containing nitrogen anion)which could shift the methyl group from oxygen to nitrogen atom to form N-methyl phosphinic acid as the reaction temperature was increased to 120 ℃.Three nitro derivatives containing 5,10-dihydrophenophosphazine ring system were prepared for the investigation on the above reaction mechanism which would be possible regarded as a special inter-molecular substitution.viz.,the nucleophilic nitrogen anion from one molecule of 1 attacked the cabon atom of the O-methyl of another 1.In addition,the chemical structures of seven compounds containing 5,10-dihydrophenophosphazine ring system involved in the experiment were confirmed by IR,^1 H NMR,^31P NMR and mass spectroscopy.     

Preparation and Catalytic Property of MoOx with Meso-porosity

A partially reduced molybdenum oxide (MoOx) with meso-porosity was prepared for the first time and its catalytic performance in n-heptane isomerization carried out in a fixed bed flow reactor has been studied. And the evolvement of MoOx formation has been characterized by X-ray diffraction and catalytic performance in n-heptane isomerization. The MoOx catalyst obtained from H2 reduction for 12 h, possessing a maximum pore volume at diameter ca. 4.1 nm, exhibited high activity in n-heptane isomerization. The composition of this catalyst is of the predominant MoOx phases, MoO2 phase and trace amount of metal Mo phase.     

One-pot synthesis of 2,5-disubstituted-1,3,4-thiadiazoles under ultrasonic irradiation

A facile one-pot synthesis of 2,5-disubstituted-1,3,4-thiadiazoles was achieved by ultrasonic irradiation of a mixture of 1- naphthylacetyl chloride,NH_4CNS,CH_2Cl_2 and PEG-400 for 1.5 h at 10-20℃and subsequent irradiation for 1.5h in the presence of N-arylglycine hydrazides.This method requires short time and gives thiadiazoles in high yields.     

On Chern–Simons and WZW Partition Functions

Direct analysis of the path integral reduces partition functions in Chern-Simons theory on a three-manifold M with group G to partition functions in a WZW model of maps from a Riemann surface ‡ to G. In particular, Chern-Simons theory on S³, S¹ 2 ‡, B³ and the solid torus correspond, respectively, to the WZW model of maps from S² to G, the G/G model for ‡, and Witten's gauged WZW path integral Ansatz for Chern-Simons states using maps from S² and from the torus to G. The reduction hinges on the characterization of {\cal A / G}_{n}$, the space of connections modulo those gauge transformations which are the identity at a point n, as itself a principal fiber bundle with affine-linear fiber.     

新型P,N-配体的合成及其在钯催化碳-氮键偶联反应中的应用

以三苯基膦为母体骨架,设计合成了在苯环上连有环状仲胺取代基的五种新型P,N-配体(L1～L5),利用核磁共振谱(1H,13C,31p)、红外光谱、高分辨质谱和X射线单晶衍射等对配体进行了表征,并将它们应用于Pd催化的C-N键偶联反应中.结果表明,三(2-吗啉基苯基)膦(L5)与三(二亚苄基丙酮)二钯(Pd2(dba)3...     

二维周期结构基本方程及其数值算例

在矢量衍射理论基础上导出了任意倾斜入射下二维周期结构的衍射方程和求解(m,n)级衍射波方向即衍射角和衍射方位角的公式,理论分析了这些表达式中包含的二维周期结构衍射级次(m,n)的限制条件,并给出了相应的数值算例结果表明,矢量衍射理论在光栅基本表达式的推导方面有独特优势.     

Laser dye stability part 1. Flash frequency and fluid filtration effects

A commercial coaxial xenon flashlamp was used to measure laser dye stability. The output energy of each lasing pulse was recorded and periodic measurements were made of the untuned lasing wavelength, the temporal flashlamp output, and the temporal lasing output. The present study demonstrates that it is possible to have a number of different types of apparent dye laser system “half-lifes” through the use of filtration and frequency of flash parameters. The use of near-zero flash frequency and moderate pore size filters allows a determination of the lifetime that is more representative of the dye as opposed to the lifetime of the dye laser system.     

A rapid method for the determination of sub-part per billion amounts of N-nitroso compounds in foodstuffs.

A new analytical clean-up technique, designed specifically for the analysis of N-nitroso compounds with a thermal energy analyzer and a gas Chromatograph, is described. Only two steps are required; vacuum distillation from mineral oil followed by extraction with dichloromethane. The sensitivity for N-nitroso compounds in foodstuffs is at the 5 μg kg^-1 level, but if a dichloromethane extract is concentrated on a Kuderna Danish evaporator, a 100-fold increase is attainable. The method can be used for any foodstuff or biological material, and the quantitation of any N-nitroso compounds amenable to gas chromatography is possible.     

用Eu3+作探针研究硼铅玻璃材料

利用Eu^3 离子探针技术对所设计的尔组分为（79.5-x)BO3/2-(20 x)PbF2-0.5Eu2O3(x=0,10,20,30,40)玻璃体系进行了研究。测量了不同组份玻璃的激发光谱,得到了各个配比玻璃样品的声子边带（PSB）谱,计算了电声子耦合常数g,讨论了g对组份的依赖关系。在此基础上讨论了该基质中稀土离子的无辐射跃迁行为。测量了在362nm激发下不同配比样品^5Do→^7Fo,^7F1,^7F2,的发射光谱,并利用发射光计算了Eu^3 离子在该玻璃体系中光学跃迁的J-O参量Ω2,进而讨论了其结构特性。