Aims and Scope: Numerical Mathematics:Theory, Methods and Applications (NM-TMA) publishes high-quality original research papers on the construction,analysis and application of numerical methods for solving scientific ...Aims and Scope: Numerical Mathematics:Theory, Methods and Applications (NM-TMA) publishes high-quality original research papers on the construction,analysis and application of numerical methods for solving scientific problems.Important research and expository papers devoted to the numerical solution of mathematical problems arising in all areas of science and technology are expected.The journal originates from the journal Numerical Mathematics:A Journal of Chinese Universities (English Edition).展开更多
Numerical simulation or evolutionary history of an oil and gas-bearing basin is to repeat geological and thermodyanomic history of basin evolution on a computer and then to quantitate petroleum generation,accumulatio...Numerical simulation or evolutionary history of an oil and gas-bearing basin is to repeat geological and thermodyanomic history of basin evolution on a computer and then to quantitate petroleum generation,accumulation and migration.The mathemat-ical model describing geological and thermodynamic history of the basin evolution ischaracterised by an initial-boundary value problem of a system of nonlinear partial dif-ferential equations. In the present paper, a numerical method for three-dimensionalproblem and the analysis of its stability are established and a numerical result for apractical model is given, which shows that the abnormal pressure and paleo-temperat-ure computed are reasonable and display physical characteristics clearly as well.展开更多
This paper introduces a new spontaneous potential log model for the case in which formation resistivity is not piecewise constant. The spontaneous potential satisfies an elliptic boundary value problem with jump condi...This paper introduces a new spontaneous potential log model for the case in which formation resistivity is not piecewise constant. The spontaneous potential satisfies an elliptic boundary value problem with jump conditions on the interfaces. It has beer/ shown that the elliptic interface problem has a unique weak solution. Furthermore, a jump condition capturing finite difference scheme is proposed and applied to solve such elliptic problems. Numerical results show validity and effectiveness of the proposed method.展开更多
We presented a cardiac work rate for one cycle cardiac based on the area of a Pressure Phase Plane, the velocity of activation and relaxation of the pressure curve, the interval of time and the variation of the pressu...We presented a cardiac work rate for one cycle cardiac based on the area of a Pressure Phase Plane, the velocity of activation and relaxation of the pressure curve, the interval of time and the variation of the pressure measurement on that cycle. We established an algebraic model to the Pressure Phase Plane area with a complete correlation of that model and the laboratory data for normal hypertensive and hypertrophied rat hearts (r = 0.99). We have obtained disjoint intervals for the cardiac work rate of the control group and the hypertrophied rat hearts as a consequence of the application of our algebraic model in those data acquisition.展开更多
Optimizing the layout of the urban street canyon to achieve the maximum environmental benefits should become a new idea for modem urban street design and planning. This paper aims to find out the optimized street cany...Optimizing the layout of the urban street canyon to achieve the maximum environmental benefits should become a new idea for modem urban street design and planning. This paper aims to find out the optimized street canyon from a viewpoint of environmental protection by using the two-dimensional numerical simulation model with the κ-ω turbulence model, coupling with the mathematical optimization method. The total pollutant concentration within and at top of the specific street canyons was taken as the objective function, and the height of one side of the canyon as the constrained condition. A nonlinearly improved constrained variable metric solver was used. The effect of the height of the leeward building and windward building on the integrated pollutant dispersion was studied to achieve the most beneficial configuration of the urban geometry. The optimization of layout for an asymmetrical street canyon was obtained. It is further found that the step-down street canyon with a large height difference is generally a good layout favoring to reduce the concentration accumulation in the street canyon.展开更多
In this paper, mathematical models of smooth and enhanced tubes were established. A new mathematical model in evaluating single-tube falling film absorption effect outside enhanced tubes is proposed. The liquid film o...In this paper, mathematical models of smooth and enhanced tubes were established. A new mathematical model in evaluating single-tube falling film absorption effect outside enhanced tubes is proposed. The liquid film outside enhanced tubes is assumed to consist of two layers, i.e. internal and external layers. The analytical solutions to the distribution of the velocity, temperature and concentration in the internal layer are obtained by means of theoretical analysis, while the solutions in the external layer are calculated by using numerical method. The governing equations of the two layers are coupled using a second-order coupling method. The effects of the height and the angle of the ribs on the performances of the heat and mass transfer of the liquid film are discussed. It is shown that the agreement is good between the calculation results and the experimental data.展开更多
文摘Aims and Scope: Numerical Mathematics:Theory, Methods and Applications (NM-TMA) publishes high-quality original research papers on the construction,analysis and application of numerical methods for solving scientific problems.Important research and expository papers devoted to the numerical solution of mathematical problems arising in all areas of science and technology are expected.The journal originates from the journal Numerical Mathematics:A Journal of Chinese Universities (English Edition).
文摘Numerical simulation or evolutionary history of an oil and gas-bearing basin is to repeat geological and thermodyanomic history of basin evolution on a computer and then to quantitate petroleum generation,accumulation and migration.The mathemat-ical model describing geological and thermodynamic history of the basin evolution ischaracterised by an initial-boundary value problem of a system of nonlinear partial dif-ferential equations. In the present paper, a numerical method for three-dimensionalproblem and the analysis of its stability are established and a numerical result for apractical model is given, which shows that the abnormal pressure and paleo-temperat-ure computed are reasonable and display physical characteristics clearly as well.
基金supported by the National Natural Science Foundation of China (No. 10431030)the Shanghai Natural Science Foundation (No. 08ZR1401100)
文摘This paper introduces a new spontaneous potential log model for the case in which formation resistivity is not piecewise constant. The spontaneous potential satisfies an elliptic boundary value problem with jump conditions on the interfaces. It has beer/ shown that the elliptic interface problem has a unique weak solution. Furthermore, a jump condition capturing finite difference scheme is proposed and applied to solve such elliptic problems. Numerical results show validity and effectiveness of the proposed method.
基金supported by a scholarship from CAPESsupported by a grant from the CAPES,PRONEX/FAPES/CNPqsupported by grants from CAPES.
文摘We presented a cardiac work rate for one cycle cardiac based on the area of a Pressure Phase Plane, the velocity of activation and relaxation of the pressure curve, the interval of time and the variation of the pressure measurement on that cycle. We established an algebraic model to the Pressure Phase Plane area with a complete correlation of that model and the laboratory data for normal hypertensive and hypertrophied rat hearts (r = 0.99). We have obtained disjoint intervals for the cardiac work rate of the control group and the hypertrophied rat hearts as a consequence of the application of our algebraic model in those data acquisition.
基金Project supported by the National Natural Science Foundation of China (Grant No: 50208011)
文摘Optimizing the layout of the urban street canyon to achieve the maximum environmental benefits should become a new idea for modem urban street design and planning. This paper aims to find out the optimized street canyon from a viewpoint of environmental protection by using the two-dimensional numerical simulation model with the κ-ω turbulence model, coupling with the mathematical optimization method. The total pollutant concentration within and at top of the specific street canyons was taken as the objective function, and the height of one side of the canyon as the constrained condition. A nonlinearly improved constrained variable metric solver was used. The effect of the height of the leeward building and windward building on the integrated pollutant dispersion was studied to achieve the most beneficial configuration of the urban geometry. The optimization of layout for an asymmetrical street canyon was obtained. It is further found that the step-down street canyon with a large height difference is generally a good layout favoring to reduce the concentration accumulation in the street canyon.
文摘In this paper, mathematical models of smooth and enhanced tubes were established. A new mathematical model in evaluating single-tube falling film absorption effect outside enhanced tubes is proposed. The liquid film outside enhanced tubes is assumed to consist of two layers, i.e. internal and external layers. The analytical solutions to the distribution of the velocity, temperature and concentration in the internal layer are obtained by means of theoretical analysis, while the solutions in the external layer are calculated by using numerical method. The governing equations of the two layers are coupled using a second-order coupling method. The effects of the height and the angle of the ribs on the performances of the heat and mass transfer of the liquid film are discussed. It is shown that the agreement is good between the calculation results and the experimental data.
