NaA zeolite membranes were prepared by secondary growth method on the outer surface of α-Al2O3 hollow fiber supports. Vacuum seeding method was used for planting zeolite seeds on the support surfaces. Hydrothermal cr...NaA zeolite membranes were prepared by secondary growth method on the outer surface of α-Al2O3 hollow fiber supports. Vacuum seeding method was used for planting zeolite seeds on the support surfaces. Hydrothermal crystallization was then carried out in a synthesis solution with molar ratio of Al2O3：SiO2：Na2O：H2O = 1：2：2：120 at 100 ℃ for 4 h. Effects of seeding conditions on preparation of hollow fiber NaA zeolite membranes were extensively investigated. Moreover, hollow fiber membrane modules with packing membrane areas of ca. 0.1 and 0.2 m2 were fabricated to separate ethanol/water mixture. It is found that the thickness of seed layer is obviously affected by seed suspension concentration, coating time and vacuum degree. Close-packing seed layer is required to obtain high-quality membranes. The optimized seeding conditions （seed suspension mass concentration of 0.5%-0.7% coating time of 5 s and vacuum degree of 10 kPa） lead to dense NaA zeolite layer with a thickness of 6-8 gin. Typically, an as-synthesized hollow fiber NaA zeolite membrane exhibits good pervaporation performance with a permeation flux of 7.02 kg· m^- 2· h^- 1 and separation factor 〉 10000 for sepa- ration of 90%; （by mass） ethanol/water mixture at 75 ℃ High reproducibility has been achieved for batch-scale production of hollow fiber NaA zeolite membranes by the hydrothermal synthesis approach.展开更多
Molecular docking is an important tool in screening large libraries of compounds to determine the interactions between potential drugs and the target proteins. The molec- ular docking problem is how to locate a good c...Molecular docking is an important tool in screening large libraries of compounds to determine the interactions between potential drugs and the target proteins. The molec- ular docking problem is how to locate a good conformation to dock a ligand to the large molecule. It can be formulated as a parameter optimization problem consisting of a scoring function and a global optimization method. Many docking methods have been developed with primarily these two parts varying. In this paper, a variety of particle swarm optimization （PSO） variants were introduced to cooperate with the semiempir- ical free energy force field in AutoDock 4.05. The search ability and the docking accu- racy of these methods were evaluated by multiple redocking experiments. The results demonstrate that PSOs were more suitable than Lamarckian genetic algorithm （LGA）. Among all of the PSO variants, FIPS takes precedence over others. Compared with the four state-of-art docking methods-GOLD, DOCK, FlexX and AutoDock with LGA, AutoDock cooperated with FIPS is more accurate. Thus, FIPS is an efficient PSO vari- ant which has promising prospects that can be expected in the application to virtual screening.展开更多
基金Supported by the National Basic Research Program of China(2009CB623403)the National Natural Science Foundation of China(21176117,21222602)+3 种基金the Key Project of Chinese Ministry of Education(212060)the Outstanding Young Fund of Jiangsu Province(BK2012040)the"Six Top Talents"of Jiangsu Province,the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(09KJA530002)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘NaA zeolite membranes were prepared by secondary growth method on the outer surface of α-Al2O3 hollow fiber supports. Vacuum seeding method was used for planting zeolite seeds on the support surfaces. Hydrothermal crystallization was then carried out in a synthesis solution with molar ratio of Al2O3：SiO2：Na2O：H2O = 1：2：2：120 at 100 ℃ for 4 h. Effects of seeding conditions on preparation of hollow fiber NaA zeolite membranes were extensively investigated. Moreover, hollow fiber membrane modules with packing membrane areas of ca. 0.1 and 0.2 m2 were fabricated to separate ethanol/water mixture. It is found that the thickness of seed layer is obviously affected by seed suspension concentration, coating time and vacuum degree. Close-packing seed layer is required to obtain high-quality membranes. The optimized seeding conditions （seed suspension mass concentration of 0.5%-0.7% coating time of 5 s and vacuum degree of 10 kPa） lead to dense NaA zeolite layer with a thickness of 6-8 gin. Typically, an as-synthesized hollow fiber NaA zeolite membrane exhibits good pervaporation performance with a permeation flux of 7.02 kg· m^- 2· h^- 1 and separation factor 〉 10000 for sepa- ration of 90%; （by mass） ethanol/water mixture at 75 ℃ High reproducibility has been achieved for batch-scale production of hollow fiber NaA zeolite membranes by the hydrothermal synthesis approach.
基金This work was under Grand by the Natural Science Foundation of China （No. 60803074）, and the Fundamental Research Funds for the Central Universi- ties （No. DUT10JR06）.
文摘Molecular docking is an important tool in screening large libraries of compounds to determine the interactions between potential drugs and the target proteins. The molec- ular docking problem is how to locate a good conformation to dock a ligand to the large molecule. It can be formulated as a parameter optimization problem consisting of a scoring function and a global optimization method. Many docking methods have been developed with primarily these two parts varying. In this paper, a variety of particle swarm optimization （PSO） variants were introduced to cooperate with the semiempir- ical free energy force field in AutoDock 4.05. The search ability and the docking accu- racy of these methods were evaluated by multiple redocking experiments. The results demonstrate that PSOs were more suitable than Lamarckian genetic algorithm （LGA）. Among all of the PSO variants, FIPS takes precedence over others. Compared with the four state-of-art docking methods-GOLD, DOCK, FlexX and AutoDock with LGA, AutoDock cooperated with FIPS is more accurate. Thus, FIPS is an efficient PSO vari- ant which has promising prospects that can be expected in the application to virtual screening.
