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101.
醋酸乙烯酯在硅橡胶上的辐射接枝研究 总被引:2,自引:0,他引:2
研究了不同溶剂中的醋酸乙烯酯在硅橡胶上的辐射接技状况及接枝后硅橡胶表面结构情况.结果表明:(1)在硅橡胶-乙酸乙酯-醋酸乙烯酯体系中,接枝有自加速效应;(2)适量加入对苯二酚,接枝诱导期延长,接枝速率下降,凝胶效应消失,辐射接技经验关联式为RP=0.27×[D](-0.560)×[I](0.490)×[C](0.920),接核反应为扩散控制反应;(3)不同的溶剂对硅橡胶接枝有不同的影响,如甲醇发生敏化作用,提高接枝速率,而苯发生惰化作用,降低接枝速率;(4)在合适的甲醇和苯配比时,接枝反应几乎恒速进行,用扫描电镜(SEM)观察断面,接枝区比较均一,出现微相分离. 相似文献
102.
投料顺序对动态硫化PP/EPDM性能影响及其机理的研究 总被引:12,自引:0,他引:12
针对PP降解在PP/EPDM动态硫化中对体系产生的不利影响。考察了四种不同投料顺序对PP/EPDM动态硫化物的冲击韧性,加工流动性,交联程度和断面形貌等宏观和微观性能,并进行了不同EPDM含量的动态硫化和非硫化PP/EPDM的性能比较。结果表明,优化投料顺序能实现对动态硫化体系中化学反应对象和化学反应程度的有效干预。 相似文献
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106.
Yongcheng Liu Haiying Liu Jianghong Qian Jiaqi Deng Tongyin Yu 《Fresenius' Journal of Analytical Chemistry》1996,355(1):78-82
Two enzmyes, glucose oxidase and peroxidase, were for the first time simultaneously immobilized in regenerated silk fibroin membrane. The structure and morphology of the regenerated silk fibroin membrane containing both glucose oxidase and peroxidase were investigated with IR spectra and SEM. The bienzymes do not change the structures of the regenerated silk fibroin in the membrane, which has an islands-sea structure. For the first time, an amperometric methylene green mediating sensor for glucose based on co-immobilization of both glucose oxidase and peroxidase in regenerated silk fibroin was constructed. Cyclic voltammetry and amperometry were used to test the suitability of methylene green shuttling electrons between peroxidase and the glassy carbon electrode. The bienzyme-based system offers fast response and high sensitivity of the sensor to glucose. The effects of pH, temperature, and the concentration of the mediator on the response current were evaluated, and the dependence of the Michaelis-Menten constant Kmapp on the concentration of the mediator was investigated. 相似文献
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108.
Taking a typical local and industry-orientated applied chemistry major as an example with focusing on the major changes in the form and content of the petrochemical industry, the way to reform the core curriculum system and teaching contents is presented. Based on the changing tendency of refinement of the petrochemical industry, a complete curriculum system with distinctive industry characteristics is set up according to the principles of the emerging engineering education (3E) with several reasonable suggestions. A new model for the construction of a 3E major in chemistry-related majors is suggested. It is a good reference for the construction of curriculum systems for other local and industry-orientated colleges who want to make 3E reform. 相似文献
109.
Qian K Diehl JW Dechert GJ DiSanzo FP 《European journal of mass spectrometry (Chichester, England)》2004,10(2):187-196
We report the first coupling of supercritical fluid chromatography (SFC) with field ionization time-of-flight high-resolution mass spectrometry (FI-ToF HRMS), in parallel with ultraviolet (UV) detection and flame ionization detection (FID), for rapid and quantitative analysis of petroleum middle distillates. SFC separates petroleum middle distillates into saturates and 1- to 3-ring aromatics. FI generates molecular ions for hydrocarbon species eluted from the SFC. The high resolution and exact mass measurements by ToF mass spectrometry provide elemental compositions of the molecules in the petroleum product. The amounts of saturates and aromatic ring types were quantified using the parallel SFC-FID assisted by SFC-UV. With a proper carbon-number calibration, the detailed composition of the petroleum middle distillate was rapidly determined. 相似文献
110.
Yong‐Qian Wu David C. Limburg Douglas E. Wilkinson Gregory S. Hamilton 《Journal of heterocyclic chemistry》2003,40(1):191-193
A mild and efficient synthesis of five‐ and six‐membered nitrogen containing heterocyclic compounds, in which di(imidazole‐1‐yl)methanimine serves as a one‐carbon source, is reported. 相似文献