We study the localized coherent structures ofa generally nonintegrable (2+ 1 )-dimensional KdV equation via a variable separation approach. In a special integrable case, the entrance of some arbitrary functions leads ...We study the localized coherent structures ofa generally nonintegrable (2+ 1 )-dimensional KdV equation via a variable separation approach. In a special integrable case, the entrance of some arbitrary functions leads to abundant coherent structures. However, in the general nonintegrable case, an additional condition has to be introduced for these arbitrary functions. Although the additional condition has been introduced into the solutions of the nonintegrable KdV equation, there still exist many interesting solitary wave structures. Especially, the nonintegrable KdV equation possesses the breather-like localized excitations, and the similar static ring soliton solutions as in the integrable case. Furthermor,in the integrable case, the interaction between two travelling ring solitons is elastic, while in the nonintegrable case we cannot find even the single travelling ring soliton solution.展开更多
In this paper,the existence and propagation characteristics of Rossby waves in a two-layer cylindrical fluid are studied.Firstly,based on the dimensionless baroclinic quasi-geostrophic vortex equations including exoge...In this paper,the existence and propagation characteristics of Rossby waves in a two-layer cylindrical fluid are studied.Firstly,based on the dimensionless baroclinic quasi-geostrophic vortex equations including exogenous and dissipative,we derive new(2+1)-dimensional coupled Boussinesq equations describing wave propagation in polar coordinates by employing a multiscale analysis and perturbation method.Then,the Lie symmetries and conservation laws of the coupled Boussinesq equations are analyzed.Subsequently,by using the(G’/G)-expansion method,the exact solutions of the(2+1)-dimensional coupled Boussinesq equations are obtained.Finally,the effects of coupling term coefficients on the propagation characteristics of Rossby waves are analyzed.展开更多
This paper is to investigate the extended(2+1)-dimensional Konopelchenko-Dubrovsky equations,which can be applied to describing certain phenomena in the stratified shear flow,the internal and shallow-water waves, plas...This paper is to investigate the extended(2+1)-dimensional Konopelchenko-Dubrovsky equations,which can be applied to describing certain phenomena in the stratified shear flow,the internal and shallow-water waves, plasmas and other fields.Painleve analysis is passed through via symbolic computation.Bilinear-form equations are constructed and soliton solutions are derived.Soliton solutions and interactions are illustrated.Bilinear-form Backlund transformation and a type of solutions are obtained.展开更多
Up to now,fluid inclusion is still a powerful tool to estimate the temperature and pressure of various geological processes.CO_2-bearing inclusions are commonly found in many environments.Among the CO_2-bearing inclus...Up to now,fluid inclusion is still a powerful tool to estimate the temperature and pressure of various geological processes.CO_2-bearing inclusions are commonly found in many environments.Among the CO_2-bearing inclusions,the most typical are the ternary CO_2-H_20-NaCl inclusions.These saltbearing CO_2 V-L inclusions at room temperatures are coexisting H_2O liquid +CO_2 liquid +CO_2 vapor or coexisting H_20 liquid +CO_2 liquid(or vapor).On heating they often finally homogenize to liquid phase by the bubble disappearance,and they may form CO_2 hydrate and ice during cooling.This paper reports the application of thermodynamic models,including equations of state,to ternary CO_2-H_20-NaCl fluid inclusions.Some simple equations for pressure-temperature-salinity relation on the CO_2 hydrate-liquid-vapor(liquid) surface are developed to calculate the NaCl contents(salinities) of inclusions.With these relations and the latest CO_2 solubility and PVTx models,a new iterative approach is presented to calculate the CO_2 contents of CO_2-H_20-NaCl inclusions on the assumption that the bulk molar volume of an inclusion keeps constant at the disappearances of CO_2 hydrate and vapor bubble.A prominent merit of this method is that the compositions,molar volumes and homogenization pressures of CO_2-H_20-NaCl inclusions can be simultaneously obtained without using experimental optical volume fractions of vapor bubbles at the dissociation temperatures of CO_2 hydrates.Meanwhile,the homogenization pressures and isochores of CO_2-H_2O-NaCl fluid inclusions from updated models are briefly discussed.Calculation program code for the ternary CO_2-H_2O-NaCl inclusions with microthermometric measurement and Raman analysis data as input variables can be obtained from the author.展开更多
Modulational instability is an important area of research with important practical and theoretical significance in fluid mechanics,optics,plasma physics,and military and communication engineering.In this paper,using m...Modulational instability is an important area of research with important practical and theoretical significance in fluid mechanics,optics,plasma physics,and military and communication engineering.In this paper,using multiscale analysis and a perturbation expansion method,starting from the quasi-geostrophic potential vortex equation,a new(2+1)-dimensional highorder nonlinear Schrodinger equation describing Rossby waves in stratified fluids is obtained.Based on this equation,conditions for the occurrence of modulational instability of Rossby waves are analyzed.Moreover,the effects of factors such as the dimension and order of the equation and the latitude at which Rossby waves occur on modulational instability are discussed.It is found that the(2+1)-dimensional equation provides a good description of the modulational instability of Rossby waves on a plane.The high-order terms affect the modulational instability,and it is found that instability is more likely to occur at high latitudes.展开更多
The Blume-Capel model in the presence of external magnetic field H has been simulated using a cellular automaton algorithm improved from the Creutz cellular automaton in three-dimension lattice. The field critical exp...The Blume-Capel model in the presence of external magnetic field H has been simulated using a cellular automaton algorithm improved from the Creutz cellular automaton in three-dimension lattice. The field critical exponent 5 is estimated using the power law relations and the finite size scaling functions for the magnetization and the susceptibility in the range -0.1≤ h = H/J ≤0. The estimated value of the field critical exponent 5 is in good agreement with the universal value （δ = 5） in three dimensions. The simulations are carried out on a simple cubic lattice under periodic boundary conditions.展开更多
A 2D stress strength interference model (2D-SSIM) considering that the fatigue reliability of engineering structural components has close relationship to load asymmetric ratio and its variability to some extent is put...A 2D stress strength interference model (2D-SSIM) considering that the fatigue reliability of engineering structural components has close relationship to load asymmetric ratio and its variability to some extent is put forward. The principle, geo-metric schematic and limit state equation of this model are presented. Reliability evaluation for a kind of diesel engine crankshaft was made based on this theory, in which multi-axial loading fatigue criteria was employed. Because more important factors, i.e. stress asymmetric ratio and its variability, are considered, it theoretically can make more accurate evaluation for structural com-ponent reliability than the traditional interference model. Correspondingly, a Monte-Carlo Method simulation solution is also given. The computation suggests that this model can yield satisfactory reliability evaluation.展开更多
Acoustic rhinometry could numerically describe up- per airway condition of air draft by drawing a graph plotting the distance from the nostril vs. the cross-sectional area. Some decreases on the graph correspond to th...Acoustic rhinometry could numerically describe up- per airway condition of air draft by drawing a graph plotting the distance from the nostril vs. the cross-sectional area. Some decreases on the graph correspond to the typical anatomic structures of human nasal cavity. The 3-dimensional, computing fluid dynamic model of the same person was developed based on computed tomography scans. The veracity of the CFD model was valued by contrasting the relevant areas of stenosis site between the model and the AR graph. The aim in this study is to make clear how to use an AR to help improve and enrich the CFD model with the information of graph acquired from the measurement. The combination of AR and CT can be used to establish a living human nasal cavity model with higher significant information content.展开更多
Based on the difference of wave impedance between sand layer and surrounding rock, the seismic wave numerical simulation software, Tesseral-2D is used to establish the sandstone formation model containing water, oil a...Based on the difference of wave impedance between sand layer and surrounding rock, the seismic wave numerical simulation software, Tesseral-2D is used to establish the sandstone formation model containing water, oil and gas respectively, and the three models are treated by post-stack time offset under the conditions of defined channel spacing, wavelet frequency and wave velocity of different rock mass, and the root means square amplitude difference attribute profile under the condition of water-filled oil-filled and gas-filled oil-filled is obtained. From this, it can be obtained that after oil-gas substitution occurs in weak non-mean reservoirs, the root-mean-square amplitude difference from the reservoir to the lower part of the reservoir experiences a mutation process from a positive maximum to a negative maximum, while after oil-water substitution, the root-mean-square amplitude difference from the reservoir to the lower part of the reservoir experiences a mutation process from zero to a positive maximum. For a strong heterogeneous reservoir. Therefore, for Weak inhomogeneous media similar to tight sandstone, the root-mean-square amplitude difference attribute can be used to detect the distribution of fluid in the actual gas drive or water drive oil recovery process.展开更多
文摘We study the localized coherent structures ofa generally nonintegrable (2+ 1 )-dimensional KdV equation via a variable separation approach. In a special integrable case, the entrance of some arbitrary functions leads to abundant coherent structures. However, in the general nonintegrable case, an additional condition has to be introduced for these arbitrary functions. Although the additional condition has been introduced into the solutions of the nonintegrable KdV equation, there still exist many interesting solitary wave structures. Especially, the nonintegrable KdV equation possesses the breather-like localized excitations, and the similar static ring soliton solutions as in the integrable case. Furthermor,in the integrable case, the interaction between two travelling ring solitons is elastic, while in the nonintegrable case we cannot find even the single travelling ring soliton solution.
基金Supported by the Nature Science Foundation of Shandong Province of China(ZR2018MA017)。
文摘In this paper,the existence and propagation characteristics of Rossby waves in a two-layer cylindrical fluid are studied.Firstly,based on the dimensionless baroclinic quasi-geostrophic vortex equations including exogenous and dissipative,we derive new(2+1)-dimensional coupled Boussinesq equations describing wave propagation in polar coordinates by employing a multiscale analysis and perturbation method.Then,the Lie symmetries and conservation laws of the coupled Boussinesq equations are analyzed.Subsequently,by using the(G’/G)-expansion method,the exact solutions of the(2+1)-dimensional coupled Boussinesq equations are obtained.Finally,the effects of coupling term coefficients on the propagation characteristics of Rossby waves are analyzed.
基金Supported by the National Natural Science Foundation of China under Grant No.60772023the Open Fund under Grant No.SKLSDE-2011KF-03+2 种基金Supported project under Grant No.SKLSDE-2010ZX-07 of the State Key Laboratory of Software Development Environment,Beijing University of Aeronautics and Astronauticsthe National High Technology Research and Development Program of China(863 Program) under Grant No.2009AA043303the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.200800130006,Chinese Ministry of Education
文摘This paper is to investigate the extended(2+1)-dimensional Konopelchenko-Dubrovsky equations,which can be applied to describing certain phenomena in the stratified shear flow,the internal and shallow-water waves, plasmas and other fields.Painleve analysis is passed through via symbolic computation.Bilinear-form equations are constructed and soliton solutions are derived.Soliton solutions and interactions are illustrated.Bilinear-form Backlund transformation and a type of solutions are obtained.
文摘Up to now,fluid inclusion is still a powerful tool to estimate the temperature and pressure of various geological processes.CO_2-bearing inclusions are commonly found in many environments.Among the CO_2-bearing inclusions,the most typical are the ternary CO_2-H_20-NaCl inclusions.These saltbearing CO_2 V-L inclusions at room temperatures are coexisting H_2O liquid +CO_2 liquid +CO_2 vapor or coexisting H_20 liquid +CO_2 liquid(or vapor).On heating they often finally homogenize to liquid phase by the bubble disappearance,and they may form CO_2 hydrate and ice during cooling.This paper reports the application of thermodynamic models,including equations of state,to ternary CO_2-H_20-NaCl fluid inclusions.Some simple equations for pressure-temperature-salinity relation on the CO_2 hydrate-liquid-vapor(liquid) surface are developed to calculate the NaCl contents(salinities) of inclusions.With these relations and the latest CO_2 solubility and PVTx models,a new iterative approach is presented to calculate the CO_2 contents of CO_2-H_20-NaCl inclusions on the assumption that the bulk molar volume of an inclusion keeps constant at the disappearances of CO_2 hydrate and vapor bubble.A prominent merit of this method is that the compositions,molar volumes and homogenization pressures of CO_2-H_20-NaCl inclusions can be simultaneously obtained without using experimental optical volume fractions of vapor bubbles at the dissociation temperatures of CO_2 hydrates.Meanwhile,the homogenization pressures and isochores of CO_2-H_2O-NaCl fluid inclusions from updated models are briefly discussed.Calculation program code for the ternary CO_2-H_2O-NaCl inclusions with microthermometric measurement and Raman analysis data as input variables can be obtained from the author.
基金supported by the National Natural Science Foundation of China(No.11975143)。
文摘Modulational instability is an important area of research with important practical and theoretical significance in fluid mechanics,optics,plasma physics,and military and communication engineering.In this paper,using multiscale analysis and a perturbation expansion method,starting from the quasi-geostrophic potential vortex equation,a new(2+1)-dimensional highorder nonlinear Schrodinger equation describing Rossby waves in stratified fluids is obtained.Based on this equation,conditions for the occurrence of modulational instability of Rossby waves are analyzed.Moreover,the effects of factors such as the dimension and order of the equation and the latitude at which Rossby waves occur on modulational instability are discussed.It is found that the(2+1)-dimensional equation provides a good description of the modulational instability of Rossby waves on a plane.The high-order terms affect the modulational instability,and it is found that instability is more likely to occur at high latitudes.
文摘The Blume-Capel model in the presence of external magnetic field H has been simulated using a cellular automaton algorithm improved from the Creutz cellular automaton in three-dimension lattice. The field critical exponent 5 is estimated using the power law relations and the finite size scaling functions for the magnetization and the susceptibility in the range -0.1≤ h = H/J ≤0. The estimated value of the field critical exponent 5 is in good agreement with the universal value （δ = 5） in three dimensions. The simulations are carried out on a simple cubic lattice under periodic boundary conditions.
文摘A 2D stress strength interference model (2D-SSIM) considering that the fatigue reliability of engineering structural components has close relationship to load asymmetric ratio and its variability to some extent is put forward. The principle, geo-metric schematic and limit state equation of this model are presented. Reliability evaluation for a kind of diesel engine crankshaft was made based on this theory, in which multi-axial loading fatigue criteria was employed. Because more important factors, i.e. stress asymmetric ratio and its variability, are considered, it theoretically can make more accurate evaluation for structural com-ponent reliability than the traditional interference model. Correspondingly, a Monte-Carlo Method simulation solution is also given. The computation suggests that this model can yield satisfactory reliability evaluation.
文摘Acoustic rhinometry could numerically describe up- per airway condition of air draft by drawing a graph plotting the distance from the nostril vs. the cross-sectional area. Some decreases on the graph correspond to the typical anatomic structures of human nasal cavity. The 3-dimensional, computing fluid dynamic model of the same person was developed based on computed tomography scans. The veracity of the CFD model was valued by contrasting the relevant areas of stenosis site between the model and the AR graph. The aim in this study is to make clear how to use an AR to help improve and enrich the CFD model with the information of graph acquired from the measurement. The combination of AR and CT can be used to establish a living human nasal cavity model with higher significant information content.
文摘Based on the difference of wave impedance between sand layer and surrounding rock, the seismic wave numerical simulation software, Tesseral-2D is used to establish the sandstone formation model containing water, oil and gas respectively, and the three models are treated by post-stack time offset under the conditions of defined channel spacing, wavelet frequency and wave velocity of different rock mass, and the root means square amplitude difference attribute profile under the condition of water-filled oil-filled and gas-filled oil-filled is obtained. From this, it can be obtained that after oil-gas substitution occurs in weak non-mean reservoirs, the root-mean-square amplitude difference from the reservoir to the lower part of the reservoir experiences a mutation process from a positive maximum to a negative maximum, while after oil-water substitution, the root-mean-square amplitude difference from the reservoir to the lower part of the reservoir experiences a mutation process from zero to a positive maximum. For a strong heterogeneous reservoir. Therefore, for Weak inhomogeneous media similar to tight sandstone, the root-mean-square amplitude difference attribute can be used to detect the distribution of fluid in the actual gas drive or water drive oil recovery process.
