The lattice Boltzmann model with coupled chemical reaction was proposed to simulate the ion exchange process of rare earth leaching and verified by comparison with both empirical correlation of mass transfer coefficie...The lattice Boltzmann model with coupled chemical reaction was proposed to simulate the ion exchange process of rare earth leaching and verified by comparison with both empirical correlation of mass transfer coefficient and unreacted-core shrinking model. By simulation, the zonation phenomenon of leaching reagent in the leaching column was presented, and the breakthrough curve of leaching reagent was obtained. When t=50 s, there existed the saturated and exchange zones, and the leaching reagent concentration decreased gradually from 20 to 9.3 g/L. In accordance with the breakthrough curve, the breakthrough capacity of ion-type rare earth ore and the adsorbed ion concentration of leaching reagent were derived, the time of t=25 s was the breakthrough point of ammonium ion in leaching reagent and the breakthrough capacity of the rare earth ore was 125 g/L. Besides, the chemical kinetics parameters used for the solute transfer process of rare earth leaching were obtained by the simulation and then were used to determine the rate-limiting steps of rare earth leaching process.展开更多
Under 5 keV Ar ion bombardment of a 92Mo-100Mo target, we have investigated isotopic angular effects by means of the static and the dynamic Monte Carlo programs. Our calculated results are in quantitative agreement wi...Under 5 keV Ar ion bombardment of a 92Mo-100Mo target, we have investigated isotopic angular effects by means of the static and the dynamic Monte Carlo programs. Our calculated results are in quantitative agreement with the measured and other calculated results. The conclusion consistences among theories. simulations and measurements are also discussed.展开更多
We extend the third perturbation theory to study the polarization control behavior of the intermediate state absorption in Nd^（3＋）ions. The results show that coherent interference can occur between the single-photo...We extend the third perturbation theory to study the polarization control behavior of the intermediate state absorption in Nd^（3＋）ions. The results show that coherent interference can occur between the single-photon and three-photon excitation pathways, and depends on the central frequency of the femtosecond laser field. Moreover,single-photon and three-photon absorptions have different polarization control efficiencies, and the relative weight of three-photon absorption in the whole excitation processes can increase with increasing the laser intensity.Therefore, the enhancement or suppression of the intermediate state absorption can be realized and manipulated by properly designing the intensity and central frequency of the polarization modulated femtosecond laser field.This research can not only enrich theoretical research methods for the up-conversion luminescence manipulation of rare-earth ions, but also can provide a clear physical picture for understanding and controlling multi-photon absorption in a multiple energy level system.展开更多
The dependences of radiation induced defects on irradiation temperature up to 700℃ at 15 dpa and on irradiation dose up to 85 dpa at room temperature have been investigated by the heavy ion irradiation and the positr...The dependences of radiation induced defects on irradiation temperature up to 700℃ at 15 dpa and on irradiation dose up to 85 dpa at room temperature have been investigated by the heavy ion irradiation and the positron annihilation lifetime spectroscopy for the CLAM. A void size peak is observed at -500℃ where the vacancy cluster contains 9 vacancies and has an average diameter of 0.59 nm. The size of the vacancy clusters increases with the increase of irradiation dose at room temperature, and the vacancy cluster at 85 dpa consists of 9 vacancies and reaches a size of 0.60 nm in diameter. The absolute values of the void size at the peak and the increase of void size with dose in the CLAM steel are negligible compared to those of the normal stainless steels, indicating that the CLAM steel has good radiation resistant property.展开更多
In order to illustrate the ion transport mechanism of chloride channel（Cl C） protein,a type of Cl C protein,Cl C-ec1,from Escherichia coli is embedded into an explicit membranewater system by using software VMD. The...In order to illustrate the ion transport mechanism of chloride channel（Cl C） protein,a type of Cl C protein,Cl C-ec1,from Escherichia coli is embedded into an explicit membranewater system by using software VMD. Then a parallel molecular dynamics（MD） simulation is employed to equilibrate the Cl C-ec1 structure for 27.5 ns at temperature 298.15 K. Based on this equilibrated structure,we compute the channel geometric size variation and electrostatic potential distribution along the channel. Meanwhile,Cl^- transport process is simulated using oriented random walk method under variable external potential. The simulation result shows that Cl^- transport velocity depends on the width of the narrowest channel region. Mutation of negative glutamate E148 can produce positive potential,which is beneficial for Cl^- transport,around external Cl^- binding region in the channel. The simulated current-voltage curves about Cl^- transporting in Cl C-ec1 protein agree with Jayaram＇s experimental results.展开更多
The shock wave acceleration of ions driven by laser-heated thermal pressure is studied through one-dimensional particle-in-cell simulation and analysis. The generation of high-energy mono-energetic protons in recent e...The shock wave acceleration of ions driven by laser-heated thermal pressure is studied through one-dimensional particle-in-cell simulation and analysis. The generation of high-energy mono-energetic protons in recent experiments （D. Haberberger et al., 2012 Nat. Phys. 8 95） is attributed to the use of exponentially decaying density profile of the plasma target. It does not only keep the shock velocity stable but also suppresses the normal target normal sheath acceleration. The effects of target composition are also examined, where a similar collective velocity of all ion species is demonstrated. The results also give some reference to future experiments of producing energetic heavy ions.展开更多
We present an extended update on the status of a particle-in-cellwithMonte Carlo collisions(PIC-MCC)gun code developed at LosAlamos for the study of surfaceconverter H−ion sources.The programis fully kinetic.Some of t...We present an extended update on the status of a particle-in-cellwithMonte Carlo collisions(PIC-MCC)gun code developed at LosAlamos for the study of surfaceconverter H−ion sources.The programis fully kinetic.Some of the program’s features include:solution of arbitrary electrostatic and magnetostatic fields in an axisymmetric(r,z)geometry to describe the self-consistent time evolution of a plasma;simulation of a multi-species(e^(−),H^(+),H^(+)_(2),H^(+)_(3),H^(−))plasma discharge from a neutral hydrogen gas and filament-originated seed electrons;full 2-dimensional(r,z)3-velocity(v_(r),v_(z),vφ)dynamics for all species;detailed collision physics between charged particles and neutrals and the ability to represent multiple smooth(not stair-stepped)electrodes of arbitrary shape and voltage whose surfaces may be secondary-particle emitters(H^(−)and e^(−)).The status of this development is discussed in terms of its physics content and current implementation details.展开更多
基金supported by the National Natural Science Foundation of China(51674125,51776212,91434113)National Key Basic Research Program of China(2015CB251402)Chinese Academy of Sciences(QYZDB-SSW-SYS029)and Outstanding Doctoral Dissertation Project Fund of JXUST(YB2016001)
文摘The lattice Boltzmann model with coupled chemical reaction was proposed to simulate the ion exchange process of rare earth leaching and verified by comparison with both empirical correlation of mass transfer coefficient and unreacted-core shrinking model. By simulation, the zonation phenomenon of leaching reagent in the leaching column was presented, and the breakthrough curve of leaching reagent was obtained. When t=50 s, there existed the saturated and exchange zones, and the leaching reagent concentration decreased gradually from 20 to 9.3 g/L. In accordance with the breakthrough curve, the breakthrough capacity of ion-type rare earth ore and the adsorbed ion concentration of leaching reagent were derived, the time of t=25 s was the breakthrough point of ammonium ion in leaching reagent and the breakthrough capacity of the rare earth ore was 125 g/L. Besides, the chemical kinetics parameters used for the solute transfer process of rare earth leaching were obtained by the simulation and then were used to determine the rate-limiting steps of rare earth leaching process.
文摘Under 5 keV Ar ion bombardment of a 92Mo-100Mo target, we have investigated isotopic angular effects by means of the static and the dynamic Monte Carlo programs. Our calculated results are in quantitative agreement with the measured and other calculated results. The conclusion consistences among theories. simulations and measurements are also discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51132004,11474096,11604199,U1704145 and 11747101the Science and Technology Commission of Shanghai Municipality under Grant No 14JC1401500+1 种基金the Henan Provincial Natural Science Foundation of China under Grant No 182102210117the Higher Education Key Program of He’nan Province of China under Grant Nos 17A140025 and 16A140030
文摘We extend the third perturbation theory to study the polarization control behavior of the intermediate state absorption in Nd^（3＋）ions. The results show that coherent interference can occur between the single-photon and three-photon excitation pathways, and depends on the central frequency of the femtosecond laser field. Moreover,single-photon and three-photon absorptions have different polarization control efficiencies, and the relative weight of three-photon absorption in the whole excitation processes can increase with increasing the laser intensity.Therefore, the enhancement or suppression of the intermediate state absorption can be realized and manipulated by properly designing the intensity and central frequency of the polarization modulated femtosecond laser field.This research can not only enrich theoretical research methods for the up-conversion luminescence manipulation of rare-earth ions, but also can provide a clear physical picture for understanding and controlling multi-photon absorption in a multiple energy level system.
基金supported by the State Major Basic Research Development Program in China(No.2009GB109000)National Science Foundation of China(No.11005158)
文摘The dependences of radiation induced defects on irradiation temperature up to 700℃ at 15 dpa and on irradiation dose up to 85 dpa at room temperature have been investigated by the heavy ion irradiation and the positron annihilation lifetime spectroscopy for the CLAM. A void size peak is observed at -500℃ where the vacancy cluster contains 9 vacancies and has an average diameter of 0.59 nm. The size of the vacancy clusters increases with the increase of irradiation dose at room temperature, and the vacancy cluster at 85 dpa consists of 9 vacancies and reaches a size of 0.60 nm in diameter. The absolute values of the void size at the peak and the increase of void size with dose in the CLAM steel are negligible compared to those of the normal stainless steels, indicating that the CLAM steel has good radiation resistant property.
基金Supported by the National Natural Science Foundation of China(11304123)the Scientific Research Foundation of Jianghan University(2013016)
文摘In order to illustrate the ion transport mechanism of chloride channel（Cl C） protein,a type of Cl C protein,Cl C-ec1,from Escherichia coli is embedded into an explicit membranewater system by using software VMD. Then a parallel molecular dynamics（MD） simulation is employed to equilibrate the Cl C-ec1 structure for 27.5 ns at temperature 298.15 K. Based on this equilibrated structure,we compute the channel geometric size variation and electrostatic potential distribution along the channel. Meanwhile,Cl^- transport process is simulated using oriented random walk method under variable external potential. The simulation result shows that Cl^- transport velocity depends on the width of the narrowest channel region. Mutation of negative glutamate E148 can produce positive potential,which is beneficial for Cl^- transport,around external Cl^- binding region in the channel. The simulated current-voltage curves about Cl^- transporting in Cl C-ec1 protein agree with Jayaram＇s experimental results.
基金Project supported by the Shanghai Natural Special Foundation for Outstanding Young Teachers in University,China(Grant No.yyy10043)
文摘The shock wave acceleration of ions driven by laser-heated thermal pressure is studied through one-dimensional particle-in-cell simulation and analysis. The generation of high-energy mono-energetic protons in recent experiments （D. Haberberger et al., 2012 Nat. Phys. 8 95） is attributed to the use of exponentially decaying density profile of the plasma target. It does not only keep the shock velocity stable but also suppresses the normal target normal sheath acceleration. The effects of target composition are also examined, where a similar collective velocity of all ion species is demonstrated. The results also give some reference to future experiments of producing energetic heavy ions.
基金This research is supported by the US Department of Energy through contract DE-AC52-06NA25396.
文摘We present an extended update on the status of a particle-in-cellwithMonte Carlo collisions(PIC-MCC)gun code developed at LosAlamos for the study of surfaceconverter H−ion sources.The programis fully kinetic.Some of the program’s features include:solution of arbitrary electrostatic and magnetostatic fields in an axisymmetric(r,z)geometry to describe the self-consistent time evolution of a plasma;simulation of a multi-species(e^(−),H^(+),H^(+)_(2),H^(+)_(3),H^(−))plasma discharge from a neutral hydrogen gas and filament-originated seed electrons;full 2-dimensional(r,z)3-velocity(v_(r),v_(z),vφ)dynamics for all species;detailed collision physics between charged particles and neutrals and the ability to represent multiple smooth(not stair-stepped)electrodes of arbitrary shape and voltage whose surfaces may be secondary-particle emitters(H^(−)and e^(−)).The status of this development is discussed in terms of its physics content and current implementation details.
