在乳液体系里制备过氧化氫基聚苯乙烯及其在接枝聚合上的应用

用不同分子量的聚苯乙烯在乳液体系中进行过氧化氢基化反应,然后测定这些产品的特性粘数,HPO值(每1,000个苯乙烯结构单元中所合的过氧化氢基平均数目)等。在过氧化氢基聚苯乙烯的红外光谱里,可以在3,200—3,600厘米~(-1)吸收区里观察到过氧化氢基的吸收带,其吸收强度随着HPO值的增大而加强。最后用这些大分子过氧化物引发甲基丙烯酸甲酯及苯乙烯聚合,得到接枝聚合物。经过分离提纯后,用下列的方法: (1)浊度滴定; (2)热机械性能的测试; (3)水解后测定交换量; (4)红外吸收光谱;证明它们是接枝共聚物。     

二茂铁衍生物电子传递剂键合的溶胶-凝胶葡萄糖生物传感器

The sol-gel derived glucose biosensor was developed, and the sol-gel membrane was organically modified by N-（3-triethoxysilylpropyl）-ferrocenylmethylamine （FcSi） as sol-gel precursor to make electrochemical biosensor. The structure of biosensor was sol-gel/FcSi＋GOx/GC type （glucose oxidase, GOx）. The ferrocene mediator was chemically immobilized to the silane network, and GOx was entrapped to the sol-gel glass network. Therefore, these structures prevented mediator leakage and retained the enzyme activity. Additionally, pH of electrolyte, temperature effects, and interference of positive substances with biosensor were investigated. And the electrochemical performance of biosensor was studied by amperometry. The results indicated that the linear range, detection limit. and response slope of biosensor was 2.00×10^-4-1.57×10^-3 mol·L^-1, 2.0×10^-4 mol·L^-1 and 5.06×10^5 nA·mol^- 1·L, respectively.     

Application of the Model for Thermal Transport in Tokamaks

The anomalous electron thermal transport model baaed on collisionleas plasma instabilities driven by electron temperature gradient is applied to tokamak plasma with auxiliary heating. The steady state electron equation is solved and the results ahow good agreement with experimental observations including the principle of profile consltency, various scaling laws, and even some results for detached plasmas.     

Self-Dual Yang-Mills Theory as a Two-Dimensional Chiral Model and Its Conservation Laws

The self-dual Yang-Mills field theories in two-dimensional representations are formulated. The Biicklund transformation and the conservation law are given in the framework of the prolongation theory. Furthermore, we derive the conserved current algebras which are in essence the Yang-Baxter relations.     

Propylene Polymerization by TiCl_4 Supported on Mg(OEt)_2 Activating with Ethanol/CO_2 System

For the preparation of high-active and high-isospecific catalysts for propylenepolymerization,various supports such as Mg-alkyls[1 ] ,Mg( OH) 2 [2 ] ,Mg O[3] ,Mg Cl2 [4] .Grignard compounds[5] ,or magnesium alkoxide[6] had been used.Lately,Mg( OEt) 2 -supported Ti Cl4catalysts including an organic chloride and/ or an internal donor preparedby physical milling method and chemical reaction method were studied and it was foundthat Mg( OEt) 2 is converted to Mg Cl2 by reaction with Ti Cl4a…     

应用ICP消解氟里昂的优越性及其处理效率的初步研究

讨论了应用高频电感耦合等离子体(ICP)消解氟里昂类废弃物的可行性及与国际先进技术的比较;应用低功率ICP系统进行氟里昂12的模拟消解,用GC-ECD方法对尾气中的残余成分和浓度进行分析,证明该系统对氟里昂12的处理效率高于99.9%,可以发展成为未来环保废物处理领域的一项新技术。     

ChemInform Abstract: The Infrared Spectrum of F-·H2O.

The geometry and vibrational frequencies of the F-·H₂O system are determined by ab initio calculations (SCF and CISD levels of theory).     

气相色谱法在中草药及其制剂中痕量有机氯类农药残留分析上的应用进展

综述了中草药及其制剂中有饥氯类农药残留的气相色谱分析技术．包括样品前处理方法,气相色谱分离分析及确证鉴定技术．对近几年来该领域研究进展进行了总结和讨沦。     

微波合成PtRu/C纳米催化剂及其对甲醇电化学氧化性能

PtRu/carbon nanosized catalyst with PtRu loading of 26.4wt% (Rt∶Ru=1.0∶1.0～1.1) was rapidly synthesized by the microwave polyol process employing the ethylene glycol solution of H₂PtCl₆ and RuCl₃ as precursors in the presence of XC-72 carbon support. TEM observations demonstrated that microwave-prepared PtRu nanoparticles were narrowly distributed and highly dispersed on the carbon with an average size of 3.9 nm. Electrochemical experiments showed that microwave-synthesized PtRu/carbon catalyst exhibited very high catalytic activity for electro-oxidation of liquid methanol at room temperature.     

NUMERICAL STUDIES OF TRANSITIONAL TURBULENT PULSATILE FLOW IN PIPES WITH RING–TYPE CONSTRICTIONS

Pulsatile flows in the vicinity of mechanical ring-type constrictions in pipes were studied for transitional turbulent flow with a Reynolds number (Re) of the order of 10⁴. The Womersley number (Nw) is in the range 30–50, with a corresponding Strouhal number (St) range of 0·0143–0·0398. The pulsatile flows considered are a pure sinusoidal flow, a physiological flow and an experimental pulsatile flow profile for mechanical aortic valve flow simulations. Transitional laminar and turbulent flow characteristics in an alternating manner within the pulsatile flow fields were studied numerically. It was observed that fluid accelerations tend to suppress the development of flow disturbances. All the instantaneous maximum values of turbulent kinetic energy, turbulent viscosity and turbulent shear stress are smaller during the acceleration phase than during the deceleration period. Various parametric equations have been formulated through numerical experimentation to better describe the relationships between the instantaneous flow rate (Q), the pressure loss (ΔP), the maximum velocity (V_max), the maximum vorticity (ζ_max), the maximum wall vorticity (ζ_w,max), the maximum shear stress (τ_max) and the maximum wall shear stress (τ_w,max) for turbulent pulsatile flow in the vicinity of constrictions in the vascular tube. An elliptic relationship has been found to exist between the instantaneous flow rate and the instantaneous pressure gradient. Other linear and quadratic relations between various flow parameters were also obtained.