Based on the two-energy equation model, taking into account viscous dissipation due to the interaction between solid skeleton and pore fluid flow, temperature expressions of the solid skeleton and pore fluid flow are ...Based on the two-energy equation model, taking into account viscous dissipation due to the interaction between solid skeleton and pore fluid flow, temperature expressions of the solid skeleton and pore fluid flow are obtained analytically for the thermally developing forced convection in a saturated porous medium parallel plate channel, with walls being at constant temperature. It is proved that the temperatures of the two phases for the local thermal nonequilibrium approach to the temperature derived from the one-energy equation model for the local thermal equilibrium when the heat exchange coefficient goes to infinite. The temperature profiles are shown in figures for different dimensionless parameters and the effects of the parameters on the local thermal nonequilibrium are revealed by parameter study.展开更多
The waste referred to includes solid waste and sludge. Solid waste is mainly from urban garbage and industrial waste. Sludge is from water treatment factories, paper mills, chemical factories, pharmaceutical factories...The waste referred to includes solid waste and sludge. Solid waste is mainly from urban garbage and industrial waste. Sludge is from water treatment factories, paper mills, chemical factories, pharmaceutical factories, rivers and lakes. The waste and sludge are very harmful to water organisms, human health and drinking water, and directly affect the environment. Sludge and waste also occupy large areas of land. There are several methods to treat waste and sludge, such as burial, chemical treatment and incineration. Incineration is more effective than the展开更多
In light of China s Ninth Five-year Plan (1996-2000) for Electric Power Industry & the Long Term Targets by the Year 2010, the paper considers the strategy for developing China’s thermal power in the 21st century...In light of China s Ninth Five-year Plan (1996-2000) for Electric Power Industry & the Long Term Targets by the Year 2010, the paper considers the strategy for developing China’s thermal power in the 21st century shall be the efficiency and cleaning technology of coal use. Especially important is the structure of power sources and configuration of technology process, and secondly the implementation of energy saving and environmental protection ideology in the various stages of thermal power construction and design work.展开更多
Developing materials with ultrahigh thermal conductivity is crucial for thermal management and energy conversion.The recent development of generative models and machine learning(ML)holds great promise for predicting n...Developing materials with ultrahigh thermal conductivity is crucial for thermal management and energy conversion.The recent development of generative models and machine learning(ML)holds great promise for predicting new functional materials.However,these data-driven methods are not tailored to identifying energetically stable structures and accurately predicting their thermal properties,as they lack physical constraints and information about the complexity of atomic many-body interactions.Here,we show how combining deep generative models of crystal structures with quantum-accurate,fast ML interatomic potentials can accelerate the prediction of materials with ultrahigh lattice thermal conductivity while ensuring energy optimality.We exploit structural symmetry and similarity metrics derived from atomic coordination environments to enable fast exploration of the structural space produced by the generative model.Additionally,we propose an active-learning-based protocol for the on-the-fly training of ML potentials to achieve high-fidelity predictions of stability and lattice thermal conductivity in prospective materials.Applying this method to carbon materials,we screen 100,000 candidates and identify 34 carbon polymorphs,approximately a quarter of which had not been previously predicted,to have lattice thermal conductivity above 800 W m^(−1)K^(−1),reaching up to 2,400 W m^(−1)K^(−1)aside from diamond.These findings provide a viable pathway toward the ML-assisted prediction of periodic materials with exceptional thermal properties.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 10272070) and the Shanghai Leading Academic Discipline Project (No.Y0103)
文摘Based on the two-energy equation model, taking into account viscous dissipation due to the interaction between solid skeleton and pore fluid flow, temperature expressions of the solid skeleton and pore fluid flow are obtained analytically for the thermally developing forced convection in a saturated porous medium parallel plate channel, with walls being at constant temperature. It is proved that the temperatures of the two phases for the local thermal nonequilibrium approach to the temperature derived from the one-energy equation model for the local thermal equilibrium when the heat exchange coefficient goes to infinite. The temperature profiles are shown in figures for different dimensionless parameters and the effects of the parameters on the local thermal nonequilibrium are revealed by parameter study.
文摘The waste referred to includes solid waste and sludge. Solid waste is mainly from urban garbage and industrial waste. Sludge is from water treatment factories, paper mills, chemical factories, pharmaceutical factories, rivers and lakes. The waste and sludge are very harmful to water organisms, human health and drinking water, and directly affect the environment. Sludge and waste also occupy large areas of land. There are several methods to treat waste and sludge, such as burial, chemical treatment and incineration. Incineration is more effective than the
文摘In light of China s Ninth Five-year Plan (1996-2000) for Electric Power Industry & the Long Term Targets by the Year 2010, the paper considers the strategy for developing China’s thermal power in the 21st century shall be the efficiency and cleaning technology of coal use. Especially important is the structure of power sources and configuration of technology process, and secondly the implementation of energy saving and environmental protection ideology in the various stages of thermal power construction and design work.
基金supported by the National Natural Science Foundation of China(Nos.52425601,52250273,52327809,U20A20301,and 82361138571)National Key Research and Development Program of China(No.2023YFB4404104)Beijing Natural Science Foundation(No.L233022).
文摘Developing materials with ultrahigh thermal conductivity is crucial for thermal management and energy conversion.The recent development of generative models and machine learning(ML)holds great promise for predicting new functional materials.However,these data-driven methods are not tailored to identifying energetically stable structures and accurately predicting their thermal properties,as they lack physical constraints and information about the complexity of atomic many-body interactions.Here,we show how combining deep generative models of crystal structures with quantum-accurate,fast ML interatomic potentials can accelerate the prediction of materials with ultrahigh lattice thermal conductivity while ensuring energy optimality.We exploit structural symmetry and similarity metrics derived from atomic coordination environments to enable fast exploration of the structural space produced by the generative model.Additionally,we propose an active-learning-based protocol for the on-the-fly training of ML potentials to achieve high-fidelity predictions of stability and lattice thermal conductivity in prospective materials.Applying this method to carbon materials,we screen 100,000 candidates and identify 34 carbon polymorphs,approximately a quarter of which had not been previously predicted,to have lattice thermal conductivity above 800 W m^(−1)K^(−1),reaching up to 2,400 W m^(−1)K^(−1)aside from diamond.These findings provide a viable pathway toward the ML-assisted prediction of periodic materials with exceptional thermal properties.
