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991.
992.
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
993.
994.
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
995.
996.
Molecular switches that are controllable, reversible and readable at molecular level are an essential compo-nent of molecular electronics1 and chemical sensors.2-6 Of particular interest are the molecules which show dramatic and reversible changes in color and/or lumi-nescence in visible spectral region upon exposure to specific substrates. A number of chromophore- spacer-receptor systems that can selectively recognize specific guest molecules at their receptor site and pro-duce measurable col… 相似文献
997.
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
998.
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
999.
1000.