采用溶胶-凝胶法制备出一种新型钛柱撑型光催化剂,并研究了它在模拟汽油体系中的光催化氧化深度脱硫性能。反应体系以氧气为氧化剂,自制光催化剂,紫外光激发,在正辛烷和乙腈两相中反应,硫化物被氧化为极性物质从正辛烷进入乙腈萃取相,从而达到深度脱硫的目的。采用 X 射线衍射、傅立叶变换红外光谱等对制备的催化剂进行了结构表征。对不同热处理条件下的催化剂催化性能、反应时间、催化剂用量以及剂油比等因素影响进行了考察。结果表明:经350℃热处理的催化剂具有较好的光催化性能,6小时内,可将模拟物系中的硫含量由400μg/g 降到30μg/g。
The influence of water on protein conformation was investigated by simulating the molecular dynamics of a model protein lysozyme in different water systems.The lysozyme-water system with TIP3P water model and lysozyme-water cluster system with six-ring water model were evaluated.In addition,the radial distribution function of solvent around lysozyme was calculated.It is found that the distribution of water molecules around lysozyme is similar to that of water clusters.The analyses of dihedral angles and disulfide bonds of lysozyme show that the conformation of lysozyme is severely damaged in the lysozyme-water cluster system compared with that in the lysozyme-water system.This difference can be attributed to the formation of larger number of intermolecular hydrogen bonds between lysozyme and water cluster.It is in agreement with the analysis that water clusters can change the degree of denaturation in the process of heat denaturation of lysozyme.
Microcystis aeruginosa FACHB 905 was used as a model organism to study the effects of small water clusters(SWCs) on the growth and microcystin(MC) production of toxic cyanobacteria.The results showed that SWCs were able to stimulate the growth of Microcystis aeruginosa,which resulted in increased cell numbers and higher specific growth rates after a 30-d treatment.The cell morphology indicated that Microcystis aeruginosa was in a better state of growth,and it was more prone to divide in SWCs than in normal water clusters.The SWCs treatment up-regulated MC synthesis and exudation in 10 d in Microcystis aeruginosa,and the intra-cellular MC content decreased after the 20th day subsequently.Moreover,the cellular photosynthetic pigment contents were temporarily stimulated by SWCs.A possible reason is that SWCs stimulated the growth by promoting photosynthesis,whereas the increased MC production was relevant to pigment contents.
