In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperatur...In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperature sensors on the position around end filling area, and filling time difference between the various cavities can be calculated. Then the melt temperature of each hot nozzle can be adjusted automatically by a control strategy established based on the Fuzzy Theory and a program compiled with LABVIEW software. Temperature changes the melt mobility, so the adjustment of temperature can equalize the filling time of the melt in each cavity, which can reduced the mass deviation between each cavity and make product properties of each cavity consistent. The conclusion of the experiment is as follows： For this contact lens box of a four-cavity Hot Runner mold, by applying hot runner temperature compensation control system, time difference can be reduced from 0.05 s to 0.01 s at each cavity, and the mass Standard deviation of the four cavity can be improved from 0.006 to 0.002. The ratio of imbalance can be reduced from 20% to 4%. Hence, the hot runner temperature compensation control system has significant feasibility and high potential in improving melt flow balance of multi-cavity molding application.展开更多
Energy is introduced as an entanglement witness to describe the entanglement property of a quantum system. The thermal equilibrium system is guaranteed to be entangled when system is cooled down below the entanglement...Energy is introduced as an entanglement witness to describe the entanglement property of a quantum system. The thermal equilibrium system is guaranteed to be entangled when system is cooled down below the entanglement temperature TE. By virtue of this concept we exploit the minimum separable state energy and entanglement temperature TE of the bilinear-biquadratic antiferromagnetic spin-1 chain model. We numerically calculate TE for arbitrary values of the strength of biquadratic exchange interaction Q up to N=7. We find TE decreases with Q for fixed N when Q is between -3 and 1/3 （J = 1）. In this regime TE also decreases with N for fixed Q and varies slowly for large N. While the thermal system is always entangled when Q is smaller than -3.展开更多
Heat balance of urban ecosystem is a key point for the study of urban climate and micro-climate pattern and its change mechanism. Urban heat island effect is becoming increasingly serious,which is mainly caused by the...Heat balance of urban ecosystem is a key point for the study of urban climate and micro-climate pattern and its change mechanism. Urban heat island effect is becoming increasingly serious,which is mainly caused by the change of the earth's surface cover and the anthropogenic heat release. In this study,the simulation experiment for the anthropogenic heat release was designed according to the heat balance principle. A set of buildings of miniature city were used to constitute the residential area,U grooves were applied to simulate the single building,and the fluorescent lamps in the U groove were regarded as the heat sources of the anthropogenic heat release. The simulation experiment was launched with long-short wave sun photometer,sonic anemothermometer and heat flow gauge in the experiment site. Then the net solar radiation,sensible heat flux and heat flux into the ground were determined. The quantities of the anthropogenic heat release were calculated based on the heat balance principle,and were compared with the theoretical power consumption of the fluorescent lamps. The root mean square error( RMSE) of the simulation for the anthropogenic heat release reaches0. 078 W·m- 2,a comparatively high precision,which showes that the anthropogenic heat release can be accurately determined through the simulation experiments. This study provided a scientific method for the purpose of monitoring the anthropogenic heat release.展开更多
At low temperatures the configurational phase space of a macroscopic complex system （e.g., a spin-glass） of N - 10^23 interacting particles may split into an exponential number Ωs - exp（const × N） of ergodic...At low temperatures the configurational phase space of a macroscopic complex system （e.g., a spin-glass） of N - 10^23 interacting particles may split into an exponential number Ωs - exp（const × N） of ergodic sub-spaces （thermodynamic states）. It is usually assumed that the equilibrium collective behavior of such a system is determined by its ground thermodynamic states of the minimal free-energy density, and that the equilibrium free energies follow the distribution of exponentied decay. But actually for some complex systems, the equilibrium free-energy values may follow a Gaussian distribution within an intermediate temperature range, and consequently their equilibrium properties are contributed by excited thermodynamic states. Based on this analysis, the re-weighting parameter y in the cavity approach of spin-glasses is easily understood. Depending on the free-energy distribution, the optimal y can either be equal to or be strictly less than the inverse temperature β.展开更多
By taking into account thermic emission current from hot dust surface, the problem involved in dust charging and levitation of dust grains in plasma sheath has been researched. The results are compared to that without...By taking into account thermic emission current from hot dust surface, the problem involved in dust charging and levitation of dust grains in plasma sheath has been researched. The results are compared to that without including thermal emission current while the system parameters are same. It is found that the thermal emission current has played a significant role on modifying the dust charging and balance levitations. Both of the charging numbers of dust and the dust radius in balance are dramatically reduced. The stability of dust levitation is also analyzed and discussed.展开更多
Based on the state-of-the-art studies of solar-soil source heat pump compound system, operation patterns of solar-soil compound system were analyzed, particularly the advantages of parallel operation pattern. It is fo...Based on the state-of-the-art studies of solar-soil source heat pump compound system, operation patterns of solar-soil compound system were analyzed, particularly the advantages of parallel operation pattern. It is found that parallel operation pattern is better for solar-soil compound system. Furthermore, the heat balance issue of solar-soil compound system was emphatically analyzed from four aspects, which were annual analysis of heating and cooling load, the heat exchange of ground heat exchanger, capacity determination of solar-assisted heat sottrce and heat balance calculation of solar-soil compound system. Moreover, annual rate of heat balance in a solar-soil source heat pump compound system was calculated with a case study. It is shown that the annual heat unbalance ratio is 19%, which is less than 20%. As a result, the practical solar-soil compound system can basically maintain the heat balance of soil.展开更多
"Active" components can be introduced into a passive system to completely change its physical behavior from its typical behavior at thermodynamic equilibrium. To reveal the interaction mechanisms between ind..."Active" components can be introduced into a passive system to completely change its physical behavior from its typical behavior at thermodynamic equilibrium. To reveal the interaction mechanisms between individuals, researchers have designed unique self-propelled particles to mimic the collective behavior of biological systems. This review focuses on recent theoretical and experimental advances in the study of self-propelled particle systems and their individual and collective behaviors. The potential applications of active particles in chemical, biological and environmental sensing and single particle imaging are discussed.展开更多
The human basal state,a non-equilibrium steady state,is analysed in this paper in the light of the First and Second Laws of Thermodynamics whereby the thermodynamic significance of the basal metabolic rate and its dis...The human basal state,a non-equilibrium steady state,is analysed in this paper in the light of the First and Second Laws of Thermodynamics whereby the thermodynamic significance of the basal metabolic rate and its distinction to the dissipation function and exergy loss are identified.The analysis demonstrates the correct expression of the effects of the blood flow on the heat balance in a human-body bio-heat model and the relationship between the basal metabolic rate and the blood perfusion.展开更多
文摘In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperature sensors on the position around end filling area, and filling time difference between the various cavities can be calculated. Then the melt temperature of each hot nozzle can be adjusted automatically by a control strategy established based on the Fuzzy Theory and a program compiled with LABVIEW software. Temperature changes the melt mobility, so the adjustment of temperature can equalize the filling time of the melt in each cavity, which can reduced the mass deviation between each cavity and make product properties of each cavity consistent. The conclusion of the experiment is as follows： For this contact lens box of a four-cavity Hot Runner mold, by applying hot runner temperature compensation control system, time difference can be reduced from 0.05 s to 0.01 s at each cavity, and the mass Standard deviation of the four cavity can be improved from 0.006 to 0.002. The ratio of imbalance can be reduced from 20% to 4%. Hence, the hot runner temperature compensation control system has significant feasibility and high potential in improving melt flow balance of multi-cavity molding application.
基金The project supported by the National Fundamental Research Program of China under Grant No. 2001CB309310 and National Natural Science Foundation of China under Grant No. 60573008.We are grateful to MA Xiao-San and CA0 Ya for helpful discussions.
文摘Energy is introduced as an entanglement witness to describe the entanglement property of a quantum system. The thermal equilibrium system is guaranteed to be entangled when system is cooled down below the entanglement temperature TE. By virtue of this concept we exploit the minimum separable state energy and entanglement temperature TE of the bilinear-biquadratic antiferromagnetic spin-1 chain model. We numerically calculate TE for arbitrary values of the strength of biquadratic exchange interaction Q up to N=7. We find TE decreases with Q for fixed N when Q is between -3 and 1/3 （J = 1）. In this regime TE also decreases with N for fixed Q and varies slowly for large N. While the thermal system is always entangled when Q is smaller than -3.
基金supported by the National Natural Science Foundation of China ( No. 40971187 and 41472243 )the Funded By Open Research Fund Program of Key Laboratory of Digital Mapping and Land Information Application Engineering,National Administration of Surveying,Mapping and Geoinformation ( No. GCWD201402 )
文摘Heat balance of urban ecosystem is a key point for the study of urban climate and micro-climate pattern and its change mechanism. Urban heat island effect is becoming increasingly serious,which is mainly caused by the change of the earth's surface cover and the anthropogenic heat release. In this study,the simulation experiment for the anthropogenic heat release was designed according to the heat balance principle. A set of buildings of miniature city were used to constitute the residential area,U grooves were applied to simulate the single building,and the fluorescent lamps in the U groove were regarded as the heat sources of the anthropogenic heat release. The simulation experiment was launched with long-short wave sun photometer,sonic anemothermometer and heat flow gauge in the experiment site. Then the net solar radiation,sensible heat flux and heat flux into the ground were determined. The quantities of the anthropogenic heat release were calculated based on the heat balance principle,and were compared with the theoretical power consumption of the fluorescent lamps. The root mean square error( RMSE) of the simulation for the anthropogenic heat release reaches0. 078 W·m- 2,a comparatively high precision,which showes that the anthropogenic heat release can be accurately determined through the simulation experiments. This study provided a scientific method for the purpose of monitoring the anthropogenic heat release.
基金supported by National Natural Science Foundation of China under Grant No.10774150
文摘At low temperatures the configurational phase space of a macroscopic complex system （e.g., a spin-glass） of N - 10^23 interacting particles may split into an exponential number Ωs - exp（const × N） of ergodic sub-spaces （thermodynamic states）. It is usually assumed that the equilibrium collective behavior of such a system is determined by its ground thermodynamic states of the minimal free-energy density, and that the equilibrium free energies follow the distribution of exponentied decay. But actually for some complex systems, the equilibrium free-energy values may follow a Gaussian distribution within an intermediate temperature range, and consequently their equilibrium properties are contributed by excited thermodynamic states. Based on this analysis, the re-weighting parameter y in the cavity approach of spin-glasses is easily understood. Depending on the free-energy distribution, the optimal y can either be equal to or be strictly less than the inverse temperature β.
文摘By taking into account thermic emission current from hot dust surface, the problem involved in dust charging and levitation of dust grains in plasma sheath has been researched. The results are compared to that without including thermal emission current while the system parameters are same. It is found that the thermal emission current has played a significant role on modifying the dust charging and balance levitations. Both of the charging numbers of dust and the dust radius in balance are dramatically reduced. The stability of dust levitation is also analyzed and discussed.
基金Project(50838009) supported by the National Natural Science Foundation of ChinaProject(2010DFA72740-05) supported by the International Science & Technology Cooperation Program of China
文摘Based on the state-of-the-art studies of solar-soil source heat pump compound system, operation patterns of solar-soil compound system were analyzed, particularly the advantages of parallel operation pattern. It is found that parallel operation pattern is better for solar-soil compound system. Furthermore, the heat balance issue of solar-soil compound system was emphatically analyzed from four aspects, which were annual analysis of heating and cooling load, the heat exchange of ground heat exchanger, capacity determination of solar-assisted heat sottrce and heat balance calculation of solar-soil compound system. Moreover, annual rate of heat balance in a solar-soil source heat pump compound system was calculated with a case study. It is shown that the annual heat unbalance ratio is 19%, which is less than 20%. As a result, the practical solar-soil compound system can basically maintain the heat balance of soil.
基金supported by the National Natural Science Foundation of China (21425519)the Tsinghua University Startup Fund
文摘"Active" components can be introduced into a passive system to completely change its physical behavior from its typical behavior at thermodynamic equilibrium. To reveal the interaction mechanisms between individuals, researchers have designed unique self-propelled particles to mimic the collective behavior of biological systems. This review focuses on recent theoretical and experimental advances in the study of self-propelled particle systems and their individual and collective behaviors. The potential applications of active particles in chemical, biological and environmental sensing and single particle imaging are discussed.
文摘The human basal state,a non-equilibrium steady state,is analysed in this paper in the light of the First and Second Laws of Thermodynamics whereby the thermodynamic significance of the basal metabolic rate and its distinction to the dissipation function and exergy loss are identified.The analysis demonstrates the correct expression of the effects of the blood flow on the heat balance in a human-body bio-heat model and the relationship between the basal metabolic rate and the blood perfusion.
