Gaseous hydrocarbon geochemistry research through a thermal simulation experiment in combination with the natural evolution process in which natural gases were formed from coal-measure source rocks revealed that the {...Gaseous hydrocarbon geochemistry research through a thermal simulation experiment in combination with the natural evolution process in which natural gases were formed from coal-measure source rocks revealed that the {δ{}+{13}C-1} values of methane vary from light to heavy along with the increase of thermal evolution degree of coal-measure source rocks, and the {δ{}+{13}C-2} values of ethane range from {-28.3‰} to {-20‰} (PDB). {δ{}+{13}C-2} value was {-28‰±} (R-O={0.45%}-{0.65%}) at the lower thermal evolution stage of coal-measure source rocks. After the rocks entered the main hydrocarbon-generating stage (R-O={0.65%}-{1.50%}), {δ{}+{13}C-2} values generally varied within the range of {-26‰}-{-23‰±}; with further thermal evolution of the rocks the carbon isotopes of ethane became heavier and heavier, but generally less than -20‰.; The partial carbon isotope sequence inversion of hydrogen gases is a characteristic feature of mixing of natural gases of different origins. Under the condition of specially designated type of organic matter, hydrogen source rocks may show this phenomenon via their own evolution.; In the lower evolution stages of the rocks, it is mainly determined by organic precursors that gaseous hydrocarbons display partial inversion of the carbon isotope sequence and the carbon isotopic values of ethane are relatively low. These characteristic features also are related to the geochemical composition of primary soluble organic matter.展开更多
In order to study the indoor thermal environments in university classrooms in Tianjin,a field study and a questionnaire survey for a main teaching building are carried out.First,the thermal sensations of participants ...In order to study the indoor thermal environments in university classrooms in Tianjin,a field study and a questionnaire survey for a main teaching building are carried out.First,the thermal sensations of participants in the typical classrooms are studied by 180 questionnaires.Then,based on the measured data,the temperature changes in the classrooms during a year are simulated by the DeST software.The results show that the indoor thermal environments in the northern classrooms on the first floor are better than those in other classrooms.And the measurement results accord with the simulation results.These results can be used as a reference for the study of the indoor thermal environments in other seasons.展开更多
Thermal transport in the FPU model with Kutta algorithm. The heat flux, local temperature profile, that temperature gradient scales behave as N-1 linearly. FK on-site potential is studied by using fourth-order Runge- ...Thermal transport in the FPU model with Kutta algorithm. The heat flux, local temperature profile, that temperature gradient scales behave as N-1 linearly. FK on-site potential is studied by using fourth-order Runge- and heat conductivity axe simulated and analyzed. It is found The divergence of heat conductivity ~ with system size N is in term of κ ∝ N^α with α = 0.44. It is shown that thermal transport is mainly dependent on the FPU nonlinear and the FK interactions.展开更多
Thermal management is one of the key technologies for high-power Light emitting diode(LED)entering into the general illuminating field.Successful thermal management depends on optimal packaging structure and selected ...Thermal management is one of the key technologies for high-power Light emitting diode(LED)entering into the general illuminating field.Successful thermal management depends on optimal packaging structure and selected packaging materials.In this paper,the aluminum is employed as a substrate of LED,3×3 array chips are placed on the substrate,heat dissipation performance is simulated using finite element analysis(FEA)software,analyzed are the influences on the temperature of the chip with different convection coefficient,and optical properties are simulated using optical analysis software.The results show that the packaging structure can not only effectually improve the thermal performance of high-power LED array but also increase the light extraction efficiency.展开更多
Cooling strength is one of the important factors affecting microstructure and properties of gas cylinders during quenching process,and reasonable water spray volume can effectively improve the quality of gas cylinders...Cooling strength is one of the important factors affecting microstructure and properties of gas cylinders during quenching process,and reasonable water spray volume can effectively improve the quality of gas cylinders and reduce production costs.To find the optimal water spray parameters,a fluid-solid coupling model with three-phase flow was established in consideration of water-vapor conversion.The inner and outer walls of gas cylinder with the dimensions of d914 mm×38 mm×12000 mm were quenched using multi-nozzle water spray system.The internal pressure,average heat transfer coefficient(have)and stress of the gas cylinder under different water spray volumes during quenching process were studied.Finally,the mathematical model was experimentally verified.The results show that both the internal pressure and have increase along with the increase of spray volume.The internal pressure increases slowly first and then rapidly,but have increases rapidly first and then slowly.To satisfy hardenability of gas cylinders,the minimum spray volume should not be less than 40 m^3/(h·m).The results of stress indicate that water spray quenching will not cause deformation of bottle body in the range of water volume from 40 to 290 m^3/(h·m).展开更多
The authors examine the Indian Ocean sea surface temperature(SST) biases simulated by a Flexible Regional Ocean Atmosphere Land System(FROALS) model.The regional coupled model exhibits pronounced cold SST biases in a ...The authors examine the Indian Ocean sea surface temperature(SST) biases simulated by a Flexible Regional Ocean Atmosphere Land System(FROALS) model.The regional coupled model exhibits pronounced cold SST biases in a large portion of the Indian Ocean warm pool.Negative biases in the net surface heat fluxes are evident in the model,leading to the cold biases of the SST.Further analysis indicates that the negative biases in the net surface heat fluxes are mainly contributed by the biases of sensible heat and latent heat flux.Near-surface meteorological variables that could contribute to the SST biases are also examined.It is found that the biases of sensible heat and latent heat flux are caused by the colder and dryer near-surface air in the model.展开更多
Differential scanning calorimetry （DSC） has been used extensively to study different solid state reactions. The signals measured in DSC are associated with the growth and dissolution of different precipitates during...Differential scanning calorimetry （DSC） has been used extensively to study different solid state reactions. The signals measured in DSC are associated with the growth and dissolution of different precipitates during a specific heat cycle. The time-temperature dependence of heat cycles and the corresponding heat flow evolution measured in the sample by DSC provide valuable experimental information about the phase evolution and the precipitation kinetics in the material. The thermo-kinetic computer simulation was used to predict the DSC signals of samples taken from 6xxx and 2xxx alloys. In the model, the evolution of different metastable and stable phases and the role and influence of excess quenched-in vacancies in the early stage of precipitation were taken into account. Transmission electron microscopy （TEM） and high-resolution TEM were used to verify the existence of precipitates, their size and number density at specific points of the DSC curves.展开更多
The performance of spectral nudging in an investigation of the 2010 East Asia summer monsoon was assessed using the Weather Research and Forecasting (WRF) model, forced by 1-degree NCEP Global Final Analysis (FNL). Tw...The performance of spectral nudging in an investigation of the 2010 East Asia summer monsoon was assessed using the Weather Research and Forecasting (WRF) model, forced by 1-degree NCEP Global Final Analysis (FNL). Two pairs of experiments were made, spectral nudging (SP) and non-spectral nudging (NOSP), with five members in each group. The members were distinguished by different initial times, and the analysis was based on the ensemble mean of the two simulation pairs. The SP was able to constrain error growth in large-scale circulation in upper-level, during simulation, and generate realistic regional scale patterns. The main focus was the model ability to simulate precipitation. The Tropical Rainfall Measuring Mission (TRMM) 3B42 product was used for precipitation verification. Mean precipitation magnitude was generally overestimated by WRF. Nevertheless, SP simulations suppressed overestimation relative to the NOSP experiments. Compared to TRMM, SP also improved model simulation of precipitation in spatial and temporal distributions, with the ability to reproduce movement of rainbands. However, extreme precipitation events were suppressed in the SP simulations.展开更多
A two-dimensional numerical model is proposed to simulate the thermal discharge from a power plant in Jiangsu Province. The equations in the model consist of two-dimensional non-steady shallow water equations and ther...A two-dimensional numerical model is proposed to simulate the thermal discharge from a power plant in Jiangsu Province. The equations in the model consist of two-dimensional non-steady shallow water equations and thermal waste transport equations. Finite volume method （FVM） is used to discretize the shallow water equations, and flux difference splitting （FDS） scheme is applied. The calculated area with the same temperature increment shows the effect of thermal discharge on sea water. A comparison between simulated results and the experimental data shows good agreement. It indicates that this method can give high precision in the heat transfer simulation in coastal areas.展开更多
The method of numerical simulation was applied to investigate the effects of jet impinging plate thickness and its thermal conductivity on the local heat flux distribution along the impinging plate. The results show t...The method of numerical simulation was applied to investigate the effects of jet impinging plate thickness and its thermal conductivity on the local heat flux distribution along the impinging plate. The results show that the two factors have great effects on the heat flux distribution. The non-uniformity of the local heat-flux on the impinging plate surface gets more profound as the plate becomes thicker and thermal conductivity gets larger. When Reynolds number is 5000, the ratio of nozzle-to-plate spacing to nozzle diameter is 5 and thermal conductivity is 16W/(m·K), and even for the plate with only 25μm in thickness, the non-uniformity of the heat flux cannot be neglected. When the plate thickness is 50 μm, only when thermal conductivity is as small as 1W/(m·K), the heat flux curve can be approximately treated as an iso-heat-flux boundary. In the experimental research, a real non-iso-heat-flux boundary is treated as an iso-heat-flux boundary, which would result in under-estimated Nusselt number value in the stagnation zone and an over-estimated value outside. Such an experimental Nusselt number distribution is taken to evaluate turbulent model, and the conclusion would be drawn that the turbulent model over-predicts the stagnation heat transfer. This is one of the important reasons why many literatures reported that k-ε turbulent model dramatically over-predicts the impinging jet heat transfer in the stagnation region.展开更多
The observed meridional overtuming circula- tion （MOC） and meridional heat transport （MHT） estimated from the Rapid Climate Change/Meridional Circu- lation and Heat Flux Array （RAPID/MOCHA） at 26.5°N are us...The observed meridional overtuming circula- tion （MOC） and meridional heat transport （MHT） estimated from the Rapid Climate Change/Meridional Circu- lation and Heat Flux Array （RAPID/MOCHA） at 26.5°N are used to evaluate the volume and heat transport in the eddy-resolving model LASG/IAP Climate system Ocean Model （LICOM）. The authors find that the Florida Cur- rent transport and upper mid-ocean transport of the model are underestimated against the observations. The simulated variability of MOC and MHT show a high correlation with the observations, exceeding 0.6. Both the simulated and observed MOC and MHT show a significant seasonal variability. According to the power spectrum analysis, LICOM can represent the mesoscale eddy characteristic of the MOC similar to the observation. The model shows a high correlation of 0.58 for the internal upper mid-ocean transport （MO） and a density difference between the western and eastern boundaries, as noted in previous studies.展开更多
Steam mining method was injecting hot steam into the borehole to heat the hydrate strata at the same time of depressurization mining,which could promote further decomposition and expand mining areas of gas hydrate. St...Steam mining method was injecting hot steam into the borehole to heat the hydrate strata at the same time of depressurization mining,which could promote further decomposition and expand mining areas of gas hydrate. Steam heat calculation would provide the basis for the design of heating device and the choice of the field test parameters. There were piping heat loss in the process of mining. The heat transfer of steam flowing in the pipe was steady,so the heat loss could be obtained easily by formula calculation. The power of stratum heating should be determined by numerical simulation for the process of heating was dynamic and the equations were usually nonlinear. The selected mining conditions were 500-millimeter mining radius,10 centigrade mining temperature and 180 centigrade steam temperature. Heat loss and best heating power,obtained by formula calculation and numerical simulation,were 21. 35 W/m and 20 kW.展开更多
We determine the dependence of key inertial confinement fusion （ICF） hot spot properties on the deuterium-tritium （DT） fuel adiabat accomplished by addition of heat to the cold shell. Our main result is to observe...We determine the dependence of key inertial confinement fusion （ICF） hot spot properties on the deuterium-tritium （DT） fuel adiabat accomplished by addition of heat to the cold shell. Our main result is to observe that variation of this parameter reduces the simulation to experiment discrepancy in several experimentally inferred quantities. Simulations are continued from capsule only l D simulations using the Lawrence Livermore National Laboratory ICF code, HYDRA. The continuations employ the high energy density physics （HEDP） University of Chicago code, FLASH, and a hydro only code, FronTier, modified with a radiation equation of state （EOS） model. Hot spot densities, burn-weighted ion temperatures and pressures show a decreasing trend, while the hot spot radius shows an increasing trend in response to added heat to the cold shell. Instantaneous quantities are assessed at the time of maximum neutron production within each simulation.展开更多
基金This research projectwas financiallysupported jointlybythe National Bas-ic Research (973) Programof China (No.2001CB209102) and the ImportantDirection Project of Knowledge Innovation in Resources and EnvironmentField sponsored by the Chinese Academy of Sciences (KZCX3-SW-128).
文摘Gaseous hydrocarbon geochemistry research through a thermal simulation experiment in combination with the natural evolution process in which natural gases were formed from coal-measure source rocks revealed that the {δ{}+{13}C-1} values of methane vary from light to heavy along with the increase of thermal evolution degree of coal-measure source rocks, and the {δ{}+{13}C-2} values of ethane range from {-28.3‰} to {-20‰} (PDB). {δ{}+{13}C-2} value was {-28‰±} (R-O={0.45%}-{0.65%}) at the lower thermal evolution stage of coal-measure source rocks. After the rocks entered the main hydrocarbon-generating stage (R-O={0.65%}-{1.50%}), {δ{}+{13}C-2} values generally varied within the range of {-26‰}-{-23‰±}; with further thermal evolution of the rocks the carbon isotopes of ethane became heavier and heavier, but generally less than -20‰.; The partial carbon isotope sequence inversion of hydrogen gases is a characteristic feature of mixing of natural gases of different origins. Under the condition of specially designated type of organic matter, hydrogen source rocks may show this phenomenon via their own evolution.; In the lower evolution stages of the rocks, it is mainly determined by organic precursors that gaseous hydrocarbons display partial inversion of the carbon isotope sequence and the carbon isotopic values of ethane are relatively low. These characteristic features also are related to the geochemical composition of primary soluble organic matter.
文摘In order to study the indoor thermal environments in university classrooms in Tianjin,a field study and a questionnaire survey for a main teaching building are carried out.First,the thermal sensations of participants in the typical classrooms are studied by 180 questionnaires.Then,based on the measured data,the temperature changes in the classrooms during a year are simulated by the DeST software.The results show that the indoor thermal environments in the northern classrooms on the first floor are better than those in other classrooms.And the measurement results accord with the simulation results.These results can be used as a reference for the study of the indoor thermal environments in other seasons.
基金Supported by the Natural Science Foundation of China under Grant No.10774053the Natural Science Foundation of Hubei Province of China under Grant No.2007ABA035
文摘Thermal transport in the FPU model with Kutta algorithm. The heat flux, local temperature profile, that temperature gradient scales behave as N-1 linearly. FK on-site potential is studied by using fourth-order Runge- and heat conductivity axe simulated and analyzed. It is found The divergence of heat conductivity ~ with system size N is in term of κ ∝ N^α with α = 0.44. It is shown that thermal transport is mainly dependent on the FPU nonlinear and the FK interactions.
基金Key Scientific and Technological Research Projects of Henan Province(072102240027)Dr Foundation of Henan Polytechnic University(648602)Postgraduate Degree Thesis Innovation Foundation of Henan Polytechnic University(644005)
文摘Thermal management is one of the key technologies for high-power Light emitting diode(LED)entering into the general illuminating field.Successful thermal management depends on optimal packaging structure and selected packaging materials.In this paper,the aluminum is employed as a substrate of LED,3×3 array chips are placed on the substrate,heat dissipation performance is simulated using finite element analysis(FEA)software,analyzed are the influences on the temperature of the chip with different convection coefficient,and optical properties are simulated using optical analysis software.The results show that the packaging structure can not only effectually improve the thermal performance of high-power LED array but also increase the light extraction efficiency.
基金Project(51674096)supported by the National Natural Science Foundation of ChinaProject(E2016203119)supported by Hebei Natural Science Foundation of ChinaProject(18211045)supported by the Key Research and Development Foundation in Hebei Province of China
文摘Cooling strength is one of the important factors affecting microstructure and properties of gas cylinders during quenching process,and reasonable water spray volume can effectively improve the quality of gas cylinders and reduce production costs.To find the optimal water spray parameters,a fluid-solid coupling model with three-phase flow was established in consideration of water-vapor conversion.The inner and outer walls of gas cylinder with the dimensions of d914 mm×38 mm×12000 mm were quenched using multi-nozzle water spray system.The internal pressure,average heat transfer coefficient(have)and stress of the gas cylinder under different water spray volumes during quenching process were studied.Finally,the mathematical model was experimentally verified.The results show that both the internal pressure and have increase along with the increase of spray volume.The internal pressure increases slowly first and then rapidly,but have increases rapidly first and then slowly.To satisfy hardenability of gas cylinders,the minimum spray volume should not be less than 40 m^3/(h·m).The results of stress indicate that water spray quenching will not cause deformation of bottle body in the range of water volume from 40 to 290 m^3/(h·m).
基金supported by the National High Technology Research and Development Program of China (863 Program,Grant No.2010AA012304)
文摘The authors examine the Indian Ocean sea surface temperature(SST) biases simulated by a Flexible Regional Ocean Atmosphere Land System(FROALS) model.The regional coupled model exhibits pronounced cold SST biases in a large portion of the Indian Ocean warm pool.Negative biases in the net surface heat fluxes are evident in the model,leading to the cold biases of the SST.Further analysis indicates that the negative biases in the net surface heat fluxes are mainly contributed by the biases of sensible heat and latent heat flux.Near-surface meteorological variables that could contribute to the SST biases are also examined.It is found that the biases of sensible heat and latent heat flux are caused by the colder and dryer near-surface air in the model.
基金Financial support by the Austrian Federal Government (in particular from Bundesministerium für Verkehr, Innovation und Technologie and Bundesministerium für Wirtschaft, Familie und Jugend) represented by sterreichische Forschungsfrderungsgesellschaft mbHthe Styrian and the Tyrolean Provincial Government, represented by Steirische Wirtschaftsfrderungsgesellschaft mbH and Standortagentur Tirol, within the framework of the COMET Funding Programme is gratefully acknowledged
文摘Differential scanning calorimetry （DSC） has been used extensively to study different solid state reactions. The signals measured in DSC are associated with the growth and dissolution of different precipitates during a specific heat cycle. The time-temperature dependence of heat cycles and the corresponding heat flow evolution measured in the sample by DSC provide valuable experimental information about the phase evolution and the precipitation kinetics in the material. The thermo-kinetic computer simulation was used to predict the DSC signals of samples taken from 6xxx and 2xxx alloys. In the model, the evolution of different metastable and stable phases and the role and influence of excess quenched-in vacancies in the early stage of precipitation were taken into account. Transmission electron microscopy （TEM） and high-resolution TEM were used to verify the existence of precipitates, their size and number density at specific points of the DSC curves.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q11-02)
文摘The performance of spectral nudging in an investigation of the 2010 East Asia summer monsoon was assessed using the Weather Research and Forecasting (WRF) model, forced by 1-degree NCEP Global Final Analysis (FNL). Two pairs of experiments were made, spectral nudging (SP) and non-spectral nudging (NOSP), with five members in each group. The members were distinguished by different initial times, and the analysis was based on the ensemble mean of the two simulation pairs. The SP was able to constrain error growth in large-scale circulation in upper-level, during simulation, and generate realistic regional scale patterns. The main focus was the model ability to simulate precipitation. The Tropical Rainfall Measuring Mission (TRMM) 3B42 product was used for precipitation verification. Mean precipitation magnitude was generally overestimated by WRF. Nevertheless, SP simulations suppressed overestimation relative to the NOSP experiments. Compared to TRMM, SP also improved model simulation of precipitation in spatial and temporal distributions, with the ability to reproduce movement of rainbands. However, extreme precipitation events were suppressed in the SP simulations.
文摘A two-dimensional numerical model is proposed to simulate the thermal discharge from a power plant in Jiangsu Province. The equations in the model consist of two-dimensional non-steady shallow water equations and thermal waste transport equations. Finite volume method （FVM） is used to discretize the shallow water equations, and flux difference splitting （FDS） scheme is applied. The calculated area with the same temperature increment shows the effect of thermal discharge on sea water. A comparison between simulated results and the experimental data shows good agreement. It indicates that this method can give high precision in the heat transfer simulation in coastal areas.
基金Project(50376076) supported by the National Natural Science Foundation of China
文摘The method of numerical simulation was applied to investigate the effects of jet impinging plate thickness and its thermal conductivity on the local heat flux distribution along the impinging plate. The results show that the two factors have great effects on the heat flux distribution. The non-uniformity of the local heat-flux on the impinging plate surface gets more profound as the plate becomes thicker and thermal conductivity gets larger. When Reynolds number is 5000, the ratio of nozzle-to-plate spacing to nozzle diameter is 5 and thermal conductivity is 16W/(m·K), and even for the plate with only 25μm in thickness, the non-uniformity of the heat flux cannot be neglected. When the plate thickness is 50 μm, only when thermal conductivity is as small as 1W/(m·K), the heat flux curve can be approximately treated as an iso-heat-flux boundary. In the experimental research, a real non-iso-heat-flux boundary is treated as an iso-heat-flux boundary, which would result in under-estimated Nusselt number value in the stagnation zone and an over-estimated value outside. Such an experimental Nusselt number distribution is taken to evaluate turbulent model, and the conclusion would be drawn that the turbulent model over-predicts the stagnation heat transfer. This is one of the important reasons why many literatures reported that k-ε turbulent model dramatically over-predicts the impinging jet heat transfer in the stagnation region.
基金jointly supported by the National Basic Research Program of China (Grant No. 2010CB950502)"Strategic Priority Research Program-Climate Change: Carbon Budget and Related Issues" of the Chinese Academy of Sciences(Grant No. XDA05110302)+2 种基金the National High Technology Research and Development Program of China (863 Program, Grant No.2010AA012304)the National Natural Science Foundation of China (Grant No. 40975065)Data from the RAPID-MOCHA program are funded by the U.S. National Science Foundation
文摘The observed meridional overtuming circula- tion （MOC） and meridional heat transport （MHT） estimated from the Rapid Climate Change/Meridional Circu- lation and Heat Flux Array （RAPID/MOCHA） at 26.5°N are used to evaluate the volume and heat transport in the eddy-resolving model LASG/IAP Climate system Ocean Model （LICOM）. The authors find that the Florida Cur- rent transport and upper mid-ocean transport of the model are underestimated against the observations. The simulated variability of MOC and MHT show a high correlation with the observations, exceeding 0.6. Both the simulated and observed MOC and MHT show a significant seasonal variability. According to the power spectrum analysis, LICOM can represent the mesoscale eddy characteristic of the MOC similar to the observation. The model shows a high correlation of 0.58 for the internal upper mid-ocean transport （MO） and a density difference between the western and eastern boundaries, as noted in previous studies.
基金Supported by project of China Geological Surrey(No.GZHL20110326)
文摘Steam mining method was injecting hot steam into the borehole to heat the hydrate strata at the same time of depressurization mining,which could promote further decomposition and expand mining areas of gas hydrate. Steam heat calculation would provide the basis for the design of heating device and the choice of the field test parameters. There were piping heat loss in the process of mining. The heat transfer of steam flowing in the pipe was steady,so the heat loss could be obtained easily by formula calculation. The power of stratum heating should be determined by numerical simulation for the process of heating was dynamic and the equations were usually nonlinear. The selected mining conditions were 500-millimeter mining radius,10 centigrade mining temperature and 180 centigrade steam temperature. Heat loss and best heating power,obtained by formula calculation and numerical simulation,were 21. 35 W/m and 20 kW.
文摘We determine the dependence of key inertial confinement fusion （ICF） hot spot properties on the deuterium-tritium （DT） fuel adiabat accomplished by addition of heat to the cold shell. Our main result is to observe that variation of this parameter reduces the simulation to experiment discrepancy in several experimentally inferred quantities. Simulations are continued from capsule only l D simulations using the Lawrence Livermore National Laboratory ICF code, HYDRA. The continuations employ the high energy density physics （HEDP） University of Chicago code, FLASH, and a hydro only code, FronTier, modified with a radiation equation of state （EOS） model. Hot spot densities, burn-weighted ion temperatures and pressures show a decreasing trend, while the hot spot radius shows an increasing trend in response to added heat to the cold shell. Instantaneous quantities are assessed at the time of maximum neutron production within each simulation.
