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991.
Gonçalves Luciana R. B. Suzuki Glória S. Giordano Roberto C. Giordano Raquel L. C. 《Applied biochemistry and biotechnology》2001,91(1-9):691-702
Applied Biochemistry and Biotechnology - Kinetic and mass transport parameters were estimated for maltotriose hydrolysis using glucoamylase immobilized on macroporous silica and wrapped in pectin... 相似文献
992.
993.
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995.
An action spectrum was obtained for lethal photosensitization of Candida albicans that had been pre-irradiated with a sub-lethal low dose of broad-band UV-A after incubation with 8-methoxypsoralen and then washed to remove any non-photobound 8-methoxypsoralen. The resultant spectrum with a peak in the 320-335 nm region was similar to that obtained by a conventional method (single irradiation only) and also to the absorption spectrum of the 4',5'-monoadduct. These data support the hypothesis that the chromophore for lethal photosensitization by 8-methoxypsoralen is the 8-methoxypsoralen/DNA 4',5'-monoadduct rather than 8-methoxypsoralen itself. 相似文献
996.
Hong-Bing Tsai Yu-Der Lee 《Journal of polymer science. Part A, Polymer chemistry》1987,25(8):2195-2206
The kinetics of interfacial polycondensation of bisphenol A with isophthaloyl chloride and terephthaloyl chloride in dichloromethane with triethylbenzylammonium chloride (TEBAC) as the catalyst was investigated via measurements of bisphenolate concentration by UV. The reaction was found to be second order with respect to bisphenolate. The dependence of the rate constant on stirring speed, amount of TEBAC, and reaction temperature was studied. The rate constant was increased with an increase of stirring speed, quantity of TEBAC added, as well as the reaction temperature. The activation energy was found to be 7.7 kcal/mol at a stirring speed of 700 rpm in the presence of 0.160 of TEBAC. The role of TEBAC was found to be interesting. It did not alter the equilibrium (the partition coefficient remained the same in the presence of TEBAC), but it did enhance the transfer rate of bisphenolate. 相似文献
997.
Julie P. Harmon Sanboh Lee J. C. M. Li 《Journal of polymer science. Part A, Polymer chemistry》1987,25(12):3215-3229
The effect of cold work on the transport of liquid methanol in crosslinked PMMA disks has been determined at temperatures from 35–56°C. Deformed samples absorb at fast rates with kinetics that approach those of Fickian diffusion. Undeformed samples sorb at lower rates and the kinetics tend toward those of Case II transport. Shape recovery accompanied swelling in deformed samples. Samples saturated with methanol were desorbed in cyclohexanol. Resorption of desorbed samples showed fast rates for both deformed and undeformed samples and matched those of the absorption cycle in deformed samples. An analogy is made between the microstructure due to cold work and due to swelling. 相似文献
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999.
Chi-So Lee 《中国化学会会志》1987,34(3):207-210
A differential pulse polarographic method for the determination of nitrate ion has been developed. With 0.5 M CaCl2 as supporting electrolyte, NO?3 is reduced to give a peak with E1/2=–1.836 Volt vs. the Ag/AgCl electrode. The differential pulse polarographic peak height is proportional to the nitrate concentration from 20 to 60 ppm. The detection limit for nitrate is 2 ppm in pure aqueous solution. In the determination of 40 ppm nitrate a relative precision (relative standard deviation) of less than 2% was achieved. Nitrite interferes seriously and should be absent if accurate results are required. The method has been applied to the determination of nitrate in Ammonium Uranyl Tricarbonate (AUT) Solution, results obtained by this method are compared to those obtained by ion chromatography. The agreement between the two sets of results suggests that the DPP method can be used with a fair degree of confidence. 相似文献
1000.
Kazufumi Takahashi Raymond N. Castle Milton L. Lee 《Journal of heterocyclic chemistry》1987,24(4):977-979
The four acridinecarbaldehydes, namely, acridine-1-carbaldehyde, acridine-2-carbaldehyde, acridine-3-carbaldehyde, and acridine-4-carbaldehyde have been synthesized for the first time. 相似文献