The mathematic calculation on two--body wear of austenitic manganese steel has been performed by means of the elastic contact theory,stress interferometer and SEM.Stress distribution in contacted area was calculated a...The mathematic calculation on two--body wear of austenitic manganese steel has been performed by means of the elastic contact theory,stress interferometer and SEM.Stress distribution in contacted area was calculated and the mechanism on two--body wear has been investigated through numerical quadrature.Results show that two--body wear is mainly plowing wear the cracks of abrasive dust originates from the region between 0.2αand 0.5α(αis radius of contacted round).Driving force to make crack extension along y axis is T_(yzmax)and extension direction is 45°with horizon.Driving forces to make crack extension along x axis is alternativeσ_x and T_(yzmax),the direction of crack extension is 37°with horizon.展开更多
This paper introduces a technique that has been used successfully in University College Dublin,Ireland and Fudan University in Shanghai,China,to teach the formal aspects of computer programming to undergraduate studen...This paper introduces a technique that has been used successfully in University College Dublin,Ireland and Fudan University in Shanghai,China,to teach the formal aspects of computer programming to undergraduate students.The technique,name and conquer,relies on the use of modelling small mathematical domains and allowing the results of these models to form the basis for the programming task.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The mathematic calculation on two--body wear of austenitic manganese steel has been performed by means of the elastic contact theory,stress interferometer and SEM.Stress distribution in contacted area was calculated and the mechanism on two--body wear has been investigated through numerical quadrature.Results show that two--body wear is mainly plowing wear the cracks of abrasive dust originates from the region between 0.2αand 0.5α(αis radius of contacted round).Driving force to make crack extension along y axis is T_(yzmax)and extension direction is 45°with horizon.Driving forces to make crack extension along x axis is alternativeσ_x and T_(yzmax),the direction of crack extension is 37°with horizon.
文摘This paper introduces a technique that has been used successfully in University College Dublin,Ireland and Fudan University in Shanghai,China,to teach the formal aspects of computer programming to undergraduate students.The technique,name and conquer,relies on the use of modelling small mathematical domains and allowing the results of these models to form the basis for the programming task.
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.
