An analytical simulation based on a new model incorporating surface interaction is conducted to study the slip phenomenon in the Couette flow at different scales. The velocity profile is calculated by taking account o...An analytical simulation based on a new model incorporating surface interaction is conducted to study the slip phenomenon in the Couette flow at different scales. The velocity profile is calculated by taking account of the micro-force between molecules and macro-force from the viscous shearing effect, as they contribute to the achieve- ment of the slip length. The calculated results are compared with those obtained from the molecular dynamics simulation, showing an excellent agreement. Further, the effect of the shear rate on the slip is investigated. The results can well predict the fluid flow behaviors on a solid substrate, but has to be proved by experiment.展开更多
Many projects have recently been carried out and proposed for observing high energy electrons since it is realized that cosmic ray electrons are very important when studying the dark matter particles and the accelerat...Many projects have recently been carried out and proposed for observing high energy electrons since it is realized that cosmic ray electrons are very important when studying the dark matter particles and the acceleration mechanism of cosmic rays. An imaging calorimeter, BETS (Balloon-borne Electron Telescope with Scintillator fiber), has been developed for this purpose. Using pattern analysis of the shower development, the electrons can be selected from those primary cosmic ray proton events with flux heights one-tenth that of the electrons. The Monte-Carlo simulation is indispensable for the instrument design, the signal trigger and the data analysis. We present different shower simulation codes and compare the simulation results with the beam test and the flight data of BETS. We conclude that the code FLUKA2002 gives the most consistent results with the experimental data.展开更多
A linear steady model is constructed to investigate the response of the tropical atmosphere to diabatic heating.The basic equations are similar to those used by Gill(1980),but the long-wave approximation is removed an...A linear steady model is constructed to investigate the response of the tropical atmosphere to diabatic heating.The basic equations are similar to those used by Gill(1980),but the long-wave approximation is removed and periodic boundary conditions are taken in longitude.According to the features of the underlying surface temperature(including oceans and land),the heat sources(sinks)are given.Using this analytical model,we have simulated the climatological fields of wind and air pressure in the lower layers of the tropical and subtropical atmosphere in summer(June—August)and winter(December—February). The main features of observations are depicted in simulated fields.展开更多
This article studies novel soliton wave solutions of the nonlinear fractional ill-posed Boussinesq(NLFIPB)dynamic wave equation by applying the extended Riccati-expansion(ERE)method.Jacques Hadamard has formulated the...This article studies novel soliton wave solutions of the nonlinear fractional ill-posed Boussinesq(NLFIPB)dynamic wave equation by applying the extended Riccati-expansion(ERE)method.Jacques Hadamard has formulated the investigated model to figure out the dynamic characterizations of waves in shallow water under gravity.The obtained solutions are explained through some sketches in 2D and 3D and contour plots.At the same time,the results’accuracy is checked by comparing the obtained solutions with semianalytical solutions through the well-known Adomian decomposition(AD)method.The superiority of the ERE method over the original method is explained.All constructed solutions are checked by submitting them back into the original model through Mathematica 12 software.展开更多
In the Phase Ⅱ Project at the Hefei Light Source, a fourth-harmonic "Landau" cavity will be operated in order to suppress the coupled-bunch instabilities and increase the beam lifetime of the Hefei storage ring. In...In the Phase Ⅱ Project at the Hefei Light Source, a fourth-harmonic "Landau" cavity will be operated in order to suppress the coupled-bunch instabilities and increase the beam lifetime of the Hefei storage ring. Instabilities limit the utility of the higher-harmonic cavity when the storage ring is operated with a small momentum compaction. Analytical modeling and simulations show that the instabilities result from Robinson mode coupling. In the analytic modeling, we operate an algorithm to consider the Robinson instabilities. To study the evolution of unstable behavior, simulations have been performed in which macroparticles are distributed among the buckets. Both the analytic modeling and simulations agree for passive operation of the harmonic cavity.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 51305033the Ministry of National Defense of China under Grant No 9140C340506
文摘An analytical simulation based on a new model incorporating surface interaction is conducted to study the slip phenomenon in the Couette flow at different scales. The velocity profile is calculated by taking account of the micro-force between molecules and macro-force from the viscous shearing effect, as they contribute to the achieve- ment of the slip length. The calculated results are compared with those obtained from the molecular dynamics simulation, showing an excellent agreement. Further, the effect of the shear rate on the slip is investigated. The results can well predict the fluid flow behaviors on a solid substrate, but has to be proved by experiment.
基金Supported by the National Natural Science Foundation of China.
文摘Many projects have recently been carried out and proposed for observing high energy electrons since it is realized that cosmic ray electrons are very important when studying the dark matter particles and the acceleration mechanism of cosmic rays. An imaging calorimeter, BETS (Balloon-borne Electron Telescope with Scintillator fiber), has been developed for this purpose. Using pattern analysis of the shower development, the electrons can be selected from those primary cosmic ray proton events with flux heights one-tenth that of the electrons. The Monte-Carlo simulation is indispensable for the instrument design, the signal trigger and the data analysis. We present different shower simulation codes and compare the simulation results with the beam test and the flight data of BETS. We conclude that the code FLUKA2002 gives the most consistent results with the experimental data.
文摘A linear steady model is constructed to investigate the response of the tropical atmosphere to diabatic heating.The basic equations are similar to those used by Gill(1980),but the long-wave approximation is removed and periodic boundary conditions are taken in longitude.According to the features of the underlying surface temperature(including oceans and land),the heat sources(sinks)are given.Using this analytical model,we have simulated the climatological fields of wind and air pressure in the lower layers of the tropical and subtropical atmosphere in summer(June—August)and winter(December—February). The main features of observations are depicted in simulated fields.
基金We greatly thank Taif University for providing fund for this work through Taif University Researchers Supporting Project num-ber(TURSP-2020/52)Taif University,Taif,Saudi Arabia.
文摘This article studies novel soliton wave solutions of the nonlinear fractional ill-posed Boussinesq(NLFIPB)dynamic wave equation by applying the extended Riccati-expansion(ERE)method.Jacques Hadamard has formulated the investigated model to figure out the dynamic characterizations of waves in shallow water under gravity.The obtained solutions are explained through some sketches in 2D and 3D and contour plots.At the same time,the results’accuracy is checked by comparing the obtained solutions with semianalytical solutions through the well-known Adomian decomposition(AD)method.The superiority of the ERE method over the original method is explained.All constructed solutions are checked by submitting them back into the original model through Mathematica 12 software.
基金Supported by National Natural Science Foundation of China(10979045,11175180,11175182)
文摘In the Phase Ⅱ Project at the Hefei Light Source, a fourth-harmonic "Landau" cavity will be operated in order to suppress the coupled-bunch instabilities and increase the beam lifetime of the Hefei storage ring. Instabilities limit the utility of the higher-harmonic cavity when the storage ring is operated with a small momentum compaction. Analytical modeling and simulations show that the instabilities result from Robinson mode coupling. In the analytic modeling, we operate an algorithm to consider the Robinson instabilities. To study the evolution of unstable behavior, simulations have been performed in which macroparticles are distributed among the buckets. Both the analytic modeling and simulations agree for passive operation of the harmonic cavity.