在无机盐和阴离子表面活性剂存在下2-(5-溴-2-噻唑偶氮)-5-二乙氨基苯甲酸与镍显色反应的研究

本文合成了新显色剂2-(5-溴-2-噻唑偶氮)-5-二乙氨基苯甲酸(简称5-Br-TAEB),利用光度法测定了试剂的三级质子化常数,研究了它与镍显色反应的最佳条件,同时对表面活性剂及无机盐的作用机理进行了初步探讨。实验结果表明,在NaCl和NaDS存在下,pH=5.0～8.0范围内,5-Br-TAEB与镍形成稳定的蓝色络合物,络合比为Ni~(2+):5-Br-TAEB=1:2,摩尔吸光系数ε_(642)=1.23×10~5 SL·mol~(-1)·cm~(-1)。镍浓度在0～10μg/25ml范围内服从比尔定律,方法用于铝合金中镍的测定,结果满意。     

二连通偶图的周长

本文给出了二连通偶图 G 的周长的下界的新的形式及 G 为哈密尔顿的新的充分条件.     

Un modèle stochastique pour l'étude du bruit de fond dans un réacteur contrôlé par un dispositif de réglage automatique

Résumé On essaie de trouver l'équation du mouvement de la barre de contrôle d'un réacteur en théorie ponctuelle à un groupe de neutrons retardés à partir des principes stochastiques.     

Bornes quasi-inferieures et bornes superieures de la pression de ruine des coques de revolution par la methode des elements finis et par la programmation non-lineaire

This work is concerned with rigid-plastic limit analysis of shells of revolution subject to rotationally symmetric loadings. These shells, of arbitrary shape, are discretized into a series of finite elements, each being a conical shell. The von Mises condition, valid for sandwich shells, is used to compare the results obtained with existing values. After assembling the finite elements, the limit analysis program is reduced to a simple application of the non-linear programming technique where both the sequential unconstrained minimization technique (SUMT) and feasible conjugate direction (FCD) are utilized respectively for statically admissible and kinematically admissible approaches. Therefore, upper bounds and lower bounds of the collapse loads are found for some sample problems : conical, spherical, ellipsoidal, torispherical shells etc. These numerical results are illustrated and compared with existing ones described in the literature.     

Controlling synthesis of BiIn dendritic nanocrystals by solution dispersion

In this study, we report a novel and simple solution-phase route for one-dimensional metal nanocrystals. BiIn nanocrystals were prepared by directly dispersing melting BiIn alloy at an appropriate solvent. The as-obtained BiIn nanocrystals with a dendritic shape possess a good crystalline phase. The morphology of the nanocrystals can be greatly modified by changing the reaction parameters. This strong UV emission might arise from the quantum-confined In2O3 particles.     

Bilepton production in $ e^-\gamma $ collisions

We study the production of bileptons, new gauge bosons of lepton number two, in the minimal 3-3-1 model in high energy collisions. If the bilepton masses are in the range of 300 GeV the reaction will give observable cross-sections in future colliders.Received: 5 August 2003, Published online: 23 March 2004Dang Van Soa: On leave of absence from Department of Physics, Hanoi University of Education, Hanoi, VietnamHoang Ngoc Long: On leave of absence from Institute of Physics, NCST, P.O. Box 429, Bo Ho, Hanoi 10000, Vietnam     

New Deformation of Para-Bose Statistics

We propose commutation relations for a single mode -deformed para-Bose oscillator. In this new deformation of para-Bose statistics the distribution function has the same form as in the para-Bose statistics. Furthermore, we show analogies between the coherent states of -deformed and q-deformed para-Bose statistics.     

Computing an Integer Point of a Class of Convex Sets

A simplicial algorithm is proposed for computing an integer point of a convex set ^CRn satisfying

非线性左手材料中的二次谐波

基于电磁场理论，推导了无耗非线性左手材料中二次谐波的曼利－诺关系，及相位匹配条件下正向基波与逆向二次谐波的能量转换过程及其空间分布.验证了可将无耗非线性左手材料的入射面作为反射镜，把能量以二次谐波的形式反射.同时分别给出有限厚度介质板中基波和二次谐波的场强分布数值结果，验证了结论的正确性.最后从相位失配角度说明了相位匹配是分析非线性左手材料二次谐波的重要条件.这为研究左手材料的非线性理论奠定了基础.