A polymerizable photoredox initiation system for vinyl photopolymerization

A polymerizable photoredox system consisting of 4-methacryl oxbenzophenone (MABP) and N,N-dimethlaminoethyl methacrylate (DMAEMA) used for the photopolymerization of acrylonitrile (AN) was studied. It was found that the polymerization rate is proportional to the 0.93th power for the AN concentration, the 0.28th power for the MABP concentration, and the 0.25th power for the DMAEMA concentration. The overall activation energy of the polymerization obtained is 30.43 kJ/mol. The recorded ESR spectrum indicates that the excited-state MABP abstraets hydrogen mainly from the methyl group of the dimethylamino moiety. The comparison of the initiation ability of polymeric MABP or polymeric DMAEMA with their monomeric forms has also been done and the results indicate that in good solvents P (MABP) has a much higher initiation ability than that of monomeric MABP, but monomeric DMAEMA and P (DMAEMA) display almost the same initiation ability. In poor solvent, the initiation ability of P (MABP) is not so obviously higher than that in good solvents. The result of UV analysis of P (AN) initiated by the MABP–DMAEMA system indicates that both MABP and DMAEMA not only initiate the photopolymerization of AN, but also enter into P (AN) polymer chains. © 1994 John Wiley & Sons, Inc.     

Kinetic Monte-Carlo simulation of network formation

Summary the simulation described in Part I was applied to random step polyaddition of a trifunctional monomer and the results were compared with exact solution for an infinite system. The gel point conversions, the weight-average degree of polymerization before (P _w) and beyond (P _w,sol) the gel point, the sol fraction and the cycle rank were used for comparison. The best way for detection of the gel point conversion is the extrapolation of the gel fraction, w _g, to w _g=0. The largest fluctuations are exhibited by P _w and P _w,sol. To get results closer to the exact ones, one can repeat several experiments with smaller number of units or increase the number of units, the former way being somewhat more economical. Typical orders of magnitude used were 10⁷ monomeric units.     

CAPP系统中工艺卡片生成过程的研究

以AutoCAD2 0 0 0为开发平台、VC + + 6 0为开发环境、ObjectARX2 0 0 0为开发工具、SQLServer为后台数据库 ,通过编写writeText、fillGykztb、fillGykjtb等自定义函数 ,生成工艺卡片 ,并实现工序内容在工艺卡片中的分页显示等功能。     

Depression in college students: Personality and experiential factors.

In this study we examined the nature of college-student depression and its relation to personality variables and to experiences unique to college life. Thirty-five depressed and 39 nondepressed students completed a depression inventory, a series of personality scales, and a survey developed to investigate the impact of potentially distressing components of college life. Results revealed that college-student depression, though mild in intensity, represents a serious problem: Three quarters of depressed students had been depressed for more than 3 months, and half had contemplated suicide. Both personality characteristics and experiential variables were found to be significantly related to depression, together accounting for approximately half the variance. We examined individual personality traits and experiential variables that were found to differ between depressed and nondepressed subjects, and we discuss the implications of the findings for counseling and for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A study on the interaction between ibuprofen and bilayer lipid membrane

Ibuprofen is a well-known nonsteroidal anti-inflammatory drug, which can interact with lipid membranes. In this paper, the interaction of ibuprofen with bilayer lipid membrane was studied by UV-vis spectroscopy, cyclic voltammetry and AC impedance spectroscopy. UV-vis spectroscopy data indicated directly that ibuprofen could interact with lipid vesicles. In electrochemical experiments, ibuprofen displayed a biphasic behavior on bilayer lipid membrane supported on a glassy carbon electrode. It could stabilize the lipid membrane in low concentration, while it induced defects formation, even removed off bilayer lipid membrane from the surface of the electrode with increasing concentration. The mechanism about the interaction between ibuprofen and supported bilayer lipid membrane was discussed.     

三体磨料塑变磨损中磨粒运动方式的研究

对三体磨料磨损中磨粒的运动方式做了进一步的理论分析，基于三体磨料磨损中塑变疲劳磨损起主要作用，为突出塑变疲劳磨损的作用，选择圆形磨料进行研究，分析了圆整磨料在三体磨料磨损界面中滚动、滑动的判定，提出了相对滑动界面的判定。