The Effect of the Chain Length on MMA Free Radicl Polymerization

It has been known that the propagation rate coefficient (kp) will change with monomer conversion, Friss, Hamielec et al.1-5 have proposed many formulas about kp to fit this change. In order to obtain the relation between Arrhenius parameters and monomer conversion, a group of kp values at the same monomer conversion must be measured. We adopted a new method through analysis of kp values measured by usual experimental techniques for this purpose. Firstly, we chose a value of monomer convers…     

Application of the Singularity-Separating Method to American Exotic Option Pricing

This paper is devoted to numerical methods for American barrier and lookback options, which are important examples of American exotic options. Since the singularity-separating method is adopted, accurate numerical results can be obtained very fast.     

早期复极综合征与锌的关系：附20例分析

分析了２０例早期复极综合征患者血锌，发现比正常值偏低。早期复极综合征可能与植物神经功能系统的微量元素平衡障碍有关。     

蒽酮高分子复合物发光体的光老化研究

通过５５５ｎｍ单色光照射下的２小时人工老化和露天中２６个月自然老化。研究了蒽酮高分子复合物发光体的光老化性质，经过２６个月的自然老化发光峰值强度下降了４８％，树脂的光透过度下降了４０％，表明光老化的原因主要是树脂老化引起的。     

STUDY OF THE COPRECIPITATED IRON/MANGANESE FISCHER-TROPSCH CATALYSTS

IntroductionInFTsynthesis,metalMnhasbeenregardedasanicepromotertoincreaselightolefinselectivity.Coprecipitationhasbeenusedextensivelyinthepreparationofcommercialcatalysts.AnumberofpublicationsdealingwiththerelationbetWcenphysical-chemistry'proPertiesofcatalystsandFTs}nthesishaveappeared,butdifferentcatal})stcompositionsandpreparationconditi0nsmakedifferentconclusions.Therearetu)omainrespects.0neisthatcarelystswithhighacivityandolefinselectivityhavedifferentMMieratiovaryingoverawiderange(Mn…     

A Numerical Approach for Arbitrary Cracks in a Fluid-Saturated Medium

A finite element method is proposed that can capture arbitrary discontinuities in a two-phase medium. The discontinuity is described in an exact manner by exploiting the partition-of-unity property of finite element shape functions. The fluid flow away from the discontinuity is modelled in a standard fashion using Darcy’s relation, while at the discontinuity a discrete analogon of Darcy’s relation is proposed. The results of this finite element model are independent of the original discretisation, as is demonstrated by an example of shear banding in a biaxial, plane-strain specimen.     

Hydrogen bonding in polymer mixtures

The enthalpy–infrared frequency shift correlation for simple acids and bases is extended to study hydrogen bonding in polymer systems. The acidity of a polymer is calibrated by comparing the shifts in hydroxyl absorption frequency of the acidic polymer when mixed with a series of bases with the corresponding spectral shifts of known acids with the same bases. The basicity of a polymer is calibrated by measuring the hydroxyl frequency shifts of known acids when mixed with the basic polymer. For polymers containing carbonyl groups, the shift in carbonyl absorption is also a measure of basicity. The acidity and basicity constants obtained for polymers are in good agreement with the values for small-molecule analogs. The enthalpies of hydrogen bond formation in polymer mixtures are calculated from the acidity or basicity constants.     

影响加工中心加工精度的因素

加工中心是高效自动化设备，为了充分利用机床的高效率、高精度、高自动化等特点，所以要考虑和了解影响加工中心加工精度的因素。     

The Experiment and Design of Confocal Laser Scanner for Biochip

In this article ,we chiefly discuss optical part and photoelectrical part, and analyze the result data to make out the relationship between pinhole and special resolution and the influence of PMT on the result data.