An analytical method is presented to fit parameters of Jones-Wilkins-Lee （JWL） equation of state （EOS） for the chemical process of aluminum-polytetrafluoroethylene （ AI/PTFE ） mixture. Subroutine codes for both ...An analytical method is presented to fit parameters of Jones-Wilkins-Lee （JWL） equation of state （EOS） for the chemical process of aluminum-polytetrafluoroethylene （ AI/PTFE ） mixture. Subroutine codes for both strength model and EOS were developed in explicit-FE code AUTODYN. Firstly, the shock Hugoniot data of reactive A1/PTFE mixture was analytically derived by implemen- ting this methodology. The JWL EOS was verified to fit shock Hugoniot data of both reacted and un- reacted A1/PTFE mixture, which gives reasonable results. Furthermore, to numerically ascertain the reaction phases of ignition and growth and quasi detonation of A1/PTFE mixture, characterized ex- periment was setup to validate the reaction phases and coefficients of JWL EOS for A1/PTFE mix- ture. From the test, a promising example of reactive mixture A1/PTFE is capable to enhance lethality of weapons, the status computation in clude quasi-detonation pressure and temperature of A1/PTFE mixture in different chemical reaction phases is validated.展开更多
The thickness of vadose zone plays a critical role in vertical groundwater recharge. The decline of water table since the past decades due to long-term groundwater over-exploitation has resulted in deep vadose zone in...The thickness of vadose zone plays a critical role in vertical groundwater recharge. The decline of water table since the past decades due to long-term groundwater over-exploitation has resulted in deep vadose zone in North China Plain. One-dimensional variably saturated flow models were established by Hydrus-1D software and simulations were run under steady and continuous declining water table respectively to estimate the impact of increase in thickness of vadose zone on recharge process, quantity and recharge time. Luancheng area was selected to estimate recharge quantity considering steady and continuous declining water table. The simulation results show that the increase in thickness of vadose zone delays recharge process to water table. The recharge quantity decreases first and then remains stable with the decline of water table. Under the condition of declining water table, the evaluation of recharge by the flux at water table overestimates the recharge quantity. The average annual recharge rate of Luancheng area is 134 mm/a.展开更多
Nowadays, extractive distillation is the main technique to produce 1,3-butadiene. This study simulated the 1,3-butadiene production process with DMF extractive distillation by Aspen Plus. The solvent ratio is the most...Nowadays, extractive distillation is the main technique to produce 1,3-butadiene. This study simulated the 1,3-butadiene production process with DMF extractive distillation by Aspen Plus. The solvent ratio is the most important parameter to the extractive distillation process. The article has given out the proper solvent ratios, reflux ratios, distillate ratios, and bottom product ratios of the columns. It also discusses the thermal loads of several columns. The results of simulation are consequently compared with the plant data, which shows good accordance with each other.展开更多
Human immunodeficiency virus type 1 (HIV-1) integrase (IN) is an essential enzyme in the lifecycle of this virus and also an important target for the study of anti-HIV drugs. The binding mode of the wild type IN core ...Human immunodeficiency virus type 1 (HIV-1) integrase (IN) is an essential enzyme in the lifecycle of this virus and also an important target for the study of anti-HIV drugs. The binding mode of the wild type IN core domain and its G140S mutant with L-Chicoric acid (LCA) inhibitor were investigated by using multiple conformation molecular docking and molecular dynamics (MD) simulation. Based on the binding modes, the drug resistance mechanism was explored for the G140S mutant of IN with LCA. The results indicate that the binding site of the G140S mutant of IN core domain with LCA is different from that of the core domain of the wild type IN, which leads to the partial loss of inhibition potency of LCA. The flexibility of the IN functional loop region and the interactions between Mg2+ ion and the three key residues (i.e., D64, D116, E152) stimulate the biological operation of IN. The drug resistance also lies in several other important effects, such as the repulsion between LCA and E152 in the G140S mutant core domain, the weakening of K159 binding with LCA and Y143 pointing to the pocket of the G140S mutant. All of the above simulation results agree well with experimental data, which provide us with some helpful information for designing the drug of anti-HIV based on the structure of IN.展开更多
基金Supported by Specialized Research Fund for the Doctoral Program of Higher Education(20091101120009)the Project of State Key Laboratory of Science and Technology(YBKT09-03)+1 种基金the National Natural Science Foundation of China(11032002)National Basic Research Program of China(2010CB832706)
文摘An analytical method is presented to fit parameters of Jones-Wilkins-Lee （JWL） equation of state （EOS） for the chemical process of aluminum-polytetrafluoroethylene （ AI/PTFE ） mixture. Subroutine codes for both strength model and EOS were developed in explicit-FE code AUTODYN. Firstly, the shock Hugoniot data of reactive A1/PTFE mixture was analytically derived by implemen- ting this methodology. The JWL EOS was verified to fit shock Hugoniot data of both reacted and un- reacted A1/PTFE mixture, which gives reasonable results. Furthermore, to numerically ascertain the reaction phases of ignition and growth and quasi detonation of A1/PTFE mixture, characterized ex- periment was setup to validate the reaction phases and coefficients of JWL EOS for A1/PTFE mix- ture. From the test, a promising example of reactive mixture A1/PTFE is capable to enhance lethality of weapons, the status computation in clude quasi-detonation pressure and temperature of A1/PTFE mixture in different chemical reaction phases is validated.
基金financially supported by the National Basic Research Program of China (No. 2010CB428802)the National Natural Science Foundation of China (Nos. 41172218, 41272258)
文摘The thickness of vadose zone plays a critical role in vertical groundwater recharge. The decline of water table since the past decades due to long-term groundwater over-exploitation has resulted in deep vadose zone in North China Plain. One-dimensional variably saturated flow models were established by Hydrus-1D software and simulations were run under steady and continuous declining water table respectively to estimate the impact of increase in thickness of vadose zone on recharge process, quantity and recharge time. Luancheng area was selected to estimate recharge quantity considering steady and continuous declining water table. The simulation results show that the increase in thickness of vadose zone delays recharge process to water table. The recharge quantity decreases first and then remains stable with the decline of water table. Under the condition of declining water table, the evaluation of recharge by the flux at water table overestimates the recharge quantity. The average annual recharge rate of Luancheng area is 134 mm/a.
文摘Nowadays, extractive distillation is the main technique to produce 1,3-butadiene. This study simulated the 1,3-butadiene production process with DMF extractive distillation by Aspen Plus. The solvent ratio is the most important parameter to the extractive distillation process. The article has given out the proper solvent ratios, reflux ratios, distillate ratios, and bottom product ratios of the columns. It also discusses the thermal loads of several columns. The results of simulation are consequently compared with the plant data, which shows good accordance with each other.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 30500429 and 30670497) Beijing Natural Science Foundation (Grant No. S072002)
文摘Human immunodeficiency virus type 1 (HIV-1) integrase (IN) is an essential enzyme in the lifecycle of this virus and also an important target for the study of anti-HIV drugs. The binding mode of the wild type IN core domain and its G140S mutant with L-Chicoric acid (LCA) inhibitor were investigated by using multiple conformation molecular docking and molecular dynamics (MD) simulation. Based on the binding modes, the drug resistance mechanism was explored for the G140S mutant of IN with LCA. The results indicate that the binding site of the G140S mutant of IN core domain with LCA is different from that of the core domain of the wild type IN, which leads to the partial loss of inhibition potency of LCA. The flexibility of the IN functional loop region and the interactions between Mg2+ ion and the three key residues (i.e., D64, D116, E152) stimulate the biological operation of IN. The drug resistance also lies in several other important effects, such as the repulsion between LCA and E152 in the G140S mutant core domain, the weakening of K159 binding with LCA and Y143 pointing to the pocket of the G140S mutant. All of the above simulation results agree well with experimental data, which provide us with some helpful information for designing the drug of anti-HIV based on the structure of IN.
