This contribution presents an outline of a new mathematical formulation for Classical Non-Equilibrium Thermodynamics (CNET) based on a contact structure in differential geometry. First a non-equilibrium state space is...This contribution presents an outline of a new mathematical formulation for Classical Non-Equilibrium Thermodynamics (CNET) based on a contact structure in differential geometry. First a non-equilibrium state space is introduced as the third key element besides the first and second law of thermodynamics. This state space provides the mathematical structure to generalize the Gibbs fundamental relation to non-equilibrium thermodynamics. A unique formulation for the second law of thermodynamics is postulated and it showed how the complying concept for non-equilibrium entropy is retrieved. The foundation of this formulation is a physical quantity, which is in non-equilibrium thermodynamics nowhere equal to zero. This is another perspective compared to the inequality, which is used in most other formulations in the literature. Based on this mathematical framework, it is proven that the thermodynamic potential is defined by the Gibbs free energy. The set of conjugated coordinates in the mathematical structure for the Gibbs fundamental relation will be identified for single component, closed systems. Only in the final section of this contribution will the equilibrium constraint be introduced and applied to obtain some familiar formulations for classical (equilibrium) thermodynamics.展开更多
There are four fundamental forces;gravitational force, electromagnetic force, strong force and weak force, in the well known physics. The unified field theory considers the constructive relations among these forces or...There are four fundamental forces;gravitational force, electromagnetic force, strong force and weak force, in the well known physics. The unified field theory considers the constructive relations among these forces or fields. In the present work the fundamental relations have been studied and trial has been made to derive more significant relations among the known fields. This gives out a generalized unification.展开更多
为丰富我国运动技能教育及青少年儿童健康促进研究的视角,运用系统评价方法,基于Web of Science和EBSCO数据库,收集2005—2016年间国外有关3~13岁儿童基本运动技能发展的研究文献。就基本运动技能发展对儿童身体活动与健康的影响进行分...为丰富我国运动技能教育及青少年儿童健康促进研究的视角,运用系统评价方法,基于Web of Science和EBSCO数据库,收集2005—2016年间国外有关3~13岁儿童基本运动技能发展的研究文献。就基本运动技能发展对儿童身体活动与健康的影响进行分析。结果表明:1)基本运动技能对儿童身体活动习惯、健康体重、心血管适能、肌肉力量耐力具有积极影响;2)以BMI指数论证基本运动技能与健康体重关系的精确程度、位移运动技能和目标控制技能对儿童身体活动及健康影响的差异、不同性别间的差异以及亚洲儿童运动技能发展等问题还需进一步深入研究;3)我国应重视基本运动技能促进儿童青少年健康的作用,重新认识儿童运动技能学习的阶段,加快学前运动技能教学研究,提高儿童运动技能学习效率,为青少年儿童终生运动习惯和健康生活奠定基础。展开更多
By using finite-time thermodynamics, the optimal performance of a Stirling heat engine with thermal resistance, heat leak and regenerative loss is studied. The fundamental optimal relation is derived and the bounds of...By using finite-time thermodynamics, the optimal performance of a Stirling heat engine with thermal resistance, heat leak and regenerative loss is studied. The fundamental optimal relation is derived and the bounds of power output and efficiency are deduced from it. Then the significance of the relation and bounds are revealed. The results obtained here may provide some new theoretical guides for the optimal design of Stirling heat engines.展开更多
文摘This contribution presents an outline of a new mathematical formulation for Classical Non-Equilibrium Thermodynamics (CNET) based on a contact structure in differential geometry. First a non-equilibrium state space is introduced as the third key element besides the first and second law of thermodynamics. This state space provides the mathematical structure to generalize the Gibbs fundamental relation to non-equilibrium thermodynamics. A unique formulation for the second law of thermodynamics is postulated and it showed how the complying concept for non-equilibrium entropy is retrieved. The foundation of this formulation is a physical quantity, which is in non-equilibrium thermodynamics nowhere equal to zero. This is another perspective compared to the inequality, which is used in most other formulations in the literature. Based on this mathematical framework, it is proven that the thermodynamic potential is defined by the Gibbs free energy. The set of conjugated coordinates in the mathematical structure for the Gibbs fundamental relation will be identified for single component, closed systems. Only in the final section of this contribution will the equilibrium constraint be introduced and applied to obtain some familiar formulations for classical (equilibrium) thermodynamics.
文摘There are four fundamental forces;gravitational force, electromagnetic force, strong force and weak force, in the well known physics. The unified field theory considers the constructive relations among these forces or fields. In the present work the fundamental relations have been studied and trial has been made to derive more significant relations among the known fields. This gives out a generalized unification.
文摘为丰富我国运动技能教育及青少年儿童健康促进研究的视角,运用系统评价方法,基于Web of Science和EBSCO数据库,收集2005—2016年间国外有关3~13岁儿童基本运动技能发展的研究文献。就基本运动技能发展对儿童身体活动与健康的影响进行分析。结果表明:1)基本运动技能对儿童身体活动习惯、健康体重、心血管适能、肌肉力量耐力具有积极影响;2)以BMI指数论证基本运动技能与健康体重关系的精确程度、位移运动技能和目标控制技能对儿童身体活动及健康影响的差异、不同性别间的差异以及亚洲儿童运动技能发展等问题还需进一步深入研究;3)我国应重视基本运动技能促进儿童青少年健康的作用,重新认识儿童运动技能学习的阶段,加快学前运动技能教学研究,提高儿童运动技能学习效率,为青少年儿童终生运动习惯和健康生活奠定基础。
文摘By using finite-time thermodynamics, the optimal performance of a Stirling heat engine with thermal resistance, heat leak and regenerative loss is studied. The fundamental optimal relation is derived and the bounds of power output and efficiency are deduced from it. Then the significance of the relation and bounds are revealed. The results obtained here may provide some new theoretical guides for the optimal design of Stirling heat engines.
