The on-orhit transient temperature of reflector laminate film was analyzed by using finite element method （FEM）. Numerical simulation was used by FEM software ANSYS. Results reveal that the temperature levels of the...The on-orhit transient temperature of reflector laminate film was analyzed by using finite element method （FEM）. Numerical simulation was used by FEM software ANSYS. Results reveal that the temperature levels of the laminate composite membrane alternate greatly in the orbital period, which is about±80℃. This range exceeds the material ＇ s operating temperature level. So it is necessary to put effective thermal control into effect to the laminate composite membrane. There is temperature gradient in the thickness direction of the laminate composite membrane; there is a light change in Kevlar/Epoxy layer. The temperature of the laminate composite membrane is obviously lower than the seam＇ s temperature. Results provide reference to the thermal control of the inflatable reflector with high precision requirement.展开更多
The extreme temperature differences in fiat steel box girder of a cable-stayed bridge were studied.Firstly,by using the long-term measurement data collected by the structural health monitoring system installed on the ...The extreme temperature differences in fiat steel box girder of a cable-stayed bridge were studied.Firstly,by using the long-term measurement data collected by the structural health monitoring system installed on the Runyang Cable-stayed Bridge,the daily variations as well as seasonal ones of measured temperature differences in the box girder cross-section area were summarized.The probability distribution models of temperature differences were further established and the extreme temperature differences were estimated with a return period of 100 years.Finally,the temperature difference models in cross-section area were proposed for bridge thermal design.The results show that horizontal temperature differences in top plate and vertical temperature differences between top plate and bottom plate are considerable.All the positive and negative temperature differences can be described by the weighted sum of two Weibull distributions.The maximum positive and negative horizontal temperature differences in top plate are 10.30 ℃ and -13.80 ℃,respectively.And the maximum positive and negative vertical temperature differences between top plate and bottom plate are 17.30 ℃ and-3.70 ℃,respectively.For bridge thermal design,there are two vertical temperature difference models between top plate and bottom plate,and six horizontal temperature difference models in top plate.展开更多
The existence of thermocline changes the acoustic structure and effects the direction of the stared rays. This paper analyzes the working processs of the active sorer, and the mathematical models. The detection probai...The existence of thermocline changes the acoustic structure and effects the direction of the stared rays. This paper analyzes the working processs of the active sorer, and the mathematical models. The detection probaility of the active sonar under thenmoline is studied. First, the detection distance without thermocline is estimat- ed, then the effect of thermocline＇s depth and sound velocity changes on detecting submarine probability are discussed, and based on this, the effects of the sea condition on searching submarine probability is discussed, lastly the distance of active sonar is calculatod under thermocline. The results indicate that tufter thennocline, the distance of the active sonar becomes obvious short, and with the sea condition becoming rough, the effect is more dear.展开更多
The structural and thermodynamic properties of Zr2A1C at high pressure and high temper- ature are investigated by first principles density functional theory method. The calculated lattice parameters of Zr2A1C are in g...The structural and thermodynamic properties of Zr2A1C at high pressure and high temper- ature are investigated by first principles density functional theory method. The calculated lattice parameters of Zr2A1C are in good agreement with the available theoretical data. The pressure dependences of the elastic constants, bulk modulus, shear modulus, Young＇s mod- ulus, and Vickers hardness of Zr2A1C are successfully obtained. The elastic anisotropy is examined through the computation of the direction dependence of Young＇s modulus. By using the quasiharmonic Debye model, the thermodynamic properties including the Debye temperature, heat capacity, volume thermal expansion coefficient, and Griineisen parameter at high pressure and temperature are predicted for the first time.展开更多
Terms of synthesis were defined for the creation of new generation chelate fertilizers and for their experimental testing. Glutamine acid and citric acid containing chelate citrates of the general formulae M.gI.HL＇nH...Terms of synthesis were defined for the creation of new generation chelate fertilizers and for their experimental testing. Glutamine acid and citric acid containing chelate citrates of the general formulae M.gI.HL＇nHO were synthesized, where, M = Mn, Zn, Fe, Co, Cu; n = 0; 1; 1.5; gl-glutamine acid; HL-citric acid anion. Identity and composition of synthesized compounds were determined by microelemental analysis, melting temperature and X-ray diffraction analysis. X-ray diffraction analysis of the compounds and glutamine acid and citric acid （H4L） was used to determine their crystalline structure and roentgen-amorphous and iso-structural orders. Their solubility was studied in various solvents.展开更多
Geological structure and gas expansion when gas pressure was released can affect the distribution of infrared radiation energy or temperature at coal rock surface. From this, the foundation of roadway infrared surveyi...Geological structure and gas expansion when gas pressure was released can affect the distribution of infrared radiation energy or temperature at coal rock surface. From this, the foundation of roadway infrared surveying technical was formed. According to the thermodynamic principle of ideal gas and the law of energy conservation, the relation was established between gas gushing amount from coal rock and air temperature to fall in roadway. At the same time, this paper has analyzed coal rock density change that geological structure aroused and the change exerted influences on infrared radiation power at surface, as well as, has analyzed the infrared radiation feature of gas gushing at geological structure district. Application results show that infrared survey technology can be used to analyze and forecast the change of coal rock gas gushing effectively, and to guide the enforcement of the roadway gas project of prevention and handling economically.展开更多
A detailed investigation of a thermodynamic process in a structured packing distillation column is of great impor- tance in prediction of process efficiency. In order to keep the simplicity of an equilibrium stage mod...A detailed investigation of a thermodynamic process in a structured packing distillation column is of great impor- tance in prediction of process efficiency. In order to keep the simplicity of an equilibrium stage model and the accu- racy of a non-equilibrium stage model, a hybrid model is developed to predict the structured packing column in cryogenic air separation. A general solution process for the equilibrium stage model is developed to solve the set of equations of the hybrid model, in which a separation efficiency function is introduced to obtain the resulting tri-diagonal matrix and its solution by the Thomas algorithm. As an example, the algorithm is applied to analyze an upper column of a cryogenic air separation plant with the capacity of 17000 m3·h-1. Rigorous simulations are conducted using Aspen RATEFRAC module to validate the approach. The temperature and composition distributions are in a good agreement with the two methods. The effects of inlet/outlet position and flow rate on the temperature and composition distributions in the column are analyzed. The results demonstrate that the hybrid model and the solution algorithms are effective in analvzin~ the distillation process for a a cryogenic structured packing column.展开更多
Hypersonic flow-field measurement techniques have been studied for about 50 years. Despite truly remarkable progress with a probe or other device to measure the temperature, pressure or velocity, there are still serio...Hypersonic flow-field measurement techniques have been studied for about 50 years. Despite truly remarkable progress with a probe or other device to measure the temperature, pressure or velocity, there are still serious problems for these "intrusive" techniques. The intrusive measurement techniques introduce unexpected shock waves or flow-field structures, even make the boundary layer transition earlier and show a converse result. In recent years, nonintrusive diagnostics have been in urgent demand to give a more accurate and comprehensive flow-field for hypersonic testing. In this paper, an overview of some advanced nonintrusive measurement techniques such as embedded thermocouples for heat flux measurement, Pressure Sensitive Paint(PSP), Particle Image Velocimetry(PIV), infrared thermographs, and focusing Schlieren system are introduced. All of these techniques are nonintrusive and provide measurement of various parameters such as temperature, static pressure, dynamic pressure, flow velocity and visualization of flow structure, which gives us an exact and direct understanding of the hypersonic flow.展开更多
The structural health monitoring of a dam is important for maintaining the safe operation and longevity of the dam system. The structural health of a large dam can be monitored from the measured static deformation. Th...The structural health monitoring of a dam is important for maintaining the safe operation and longevity of the dam system. The structural health of a large dam can be monitored from the measured static deformation. This paper presents an investigation of the parameter variations of the identified model of the measured long-term static deformation for the structural health monitoring of Fui-Tsui Dam, which is located in a very active seismic zone of Taiwan. The measured static deformation is characterized as a function of the measured physical parameters, including the effects of hydrostatic pressure and temperature variation. The identified parameters, associated with the effects of hydrostatic pressure and temperature variation, change with environmental factors, such as flooding, earthquake and foundation change.展开更多
A novel Ti-based Ti-Mn composite anode used for electrolytic manganese dioxide(EMD) fabrication was developed by a two-step heating manganizing technique.The effects of sintering temperature on the manganized microstr...A novel Ti-based Ti-Mn composite anode used for electrolytic manganese dioxide(EMD) fabrication was developed by a two-step heating manganizing technique.The effects of sintering temperature on the manganized microstructure and the performance of the composite anode were studied by scanning electron microscopy(SEM),mechanical properties tests at room temperature and electrochemical methods.The results show that the thickness of the diffusion layer increases with the increase of sintering temperature up to 1 100 °C;whereas,the surface Mn content increases and reaches the maximum at 1 000 °C and then decreases thereafter.Lower surface Mn content is beneficial for the enhanced corrosion resistance and lowered open cell voltage in electrolytic process.The new anode prepared under the optimized conditions has been applied in industry and exhibits superior economic benefits to conventional Ti anodic materials.展开更多
A singlemode-multimode-singlemode （SMS） fiber structure for temperature measurement using an optical time domain reflectometer （OTDR）-based interrogation system is proposed. A temperature measurement range of 40 ...A singlemode-multimode-singlemode （SMS） fiber structure for temperature measurement using an optical time domain reflectometer （OTDR）-based interrogation system is proposed. A temperature measurement range of 40 ℃-195 ℃ with a resolution of 0.12 ℃ and a linearity of 0.992 could be achieved for the multimode fiber （MMF） graded index with a length of 60mm. It was also demonstrated that two-point temperature measurement with two SMS fiber structures as temperature sensors could be made. The proposed temperature measurement system offered a high resolution and also benefited from a simple configuration with a capability of multi-point temperature measurement.展开更多
文摘The on-orhit transient temperature of reflector laminate film was analyzed by using finite element method （FEM）. Numerical simulation was used by FEM software ANSYS. Results reveal that the temperature levels of the laminate composite membrane alternate greatly in the orbital period, which is about±80℃. This range exceeds the material ＇ s operating temperature level. So it is necessary to put effective thermal control into effect to the laminate composite membrane. There is temperature gradient in the thickness direction of the laminate composite membrane; there is a light change in Kevlar/Epoxy layer. The temperature of the laminate composite membrane is obviously lower than the seam＇ s temperature. Results provide reference to the thermal control of the inflatable reflector with high precision requirement.
基金Project(51178100)supported by the National Natural Science Foundation of ChinaProject(1105007001)supported by the Foundation of the Priority Academic Development Program of Higher Education Institute of Jiangsu Province,ChinaProject(3205001205)supported by the Teaching and Research Foundation for Excellent Young Teachers of Southeast University,China
文摘The extreme temperature differences in fiat steel box girder of a cable-stayed bridge were studied.Firstly,by using the long-term measurement data collected by the structural health monitoring system installed on the Runyang Cable-stayed Bridge,the daily variations as well as seasonal ones of measured temperature differences in the box girder cross-section area were summarized.The probability distribution models of temperature differences were further established and the extreme temperature differences were estimated with a return period of 100 years.Finally,the temperature difference models in cross-section area were proposed for bridge thermal design.The results show that horizontal temperature differences in top plate and vertical temperature differences between top plate and bottom plate are considerable.All the positive and negative temperature differences can be described by the weighted sum of two Weibull distributions.The maximum positive and negative horizontal temperature differences in top plate are 10.30 ℃ and -13.80 ℃,respectively.And the maximum positive and negative vertical temperature differences between top plate and bottom plate are 17.30 ℃ and-3.70 ℃,respectively.For bridge thermal design,there are two vertical temperature difference models between top plate and bottom plate,and six horizontal temperature difference models in top plate.
基金supported by the National Natural Science Foundation of China(No.50979009)Doctoral Fund of Ministry of Education of China(No.200801510002)the Major State Basic Research Development Program of China(973Program)(No.2009CB320805)
文摘The existence of thermocline changes the acoustic structure and effects the direction of the stared rays. This paper analyzes the working processs of the active sorer, and the mathematical models. The detection probaility of the active sonar under thenmoline is studied. First, the detection distance without thermocline is estimat- ed, then the effect of thermocline＇s depth and sound velocity changes on detecting submarine probability are discussed, and based on this, the effects of the sea condition on searching submarine probability is discussed, lastly the distance of active sonar is calculatod under thermocline. The results indicate that tufter thennocline, the distance of the active sonar becomes obvious short, and with the sea condition becoming rough, the effect is more dear.
基金This work was supportted by the National Natural Science Foundation of China （No.11447176 and No.11447152）, the National Natural Science Foundation of China and the China Academy of Engineering Physics （No.U1230201）, and the Doctor Foundation of Southwest University of Science and Technology （No.13zx7137 and No.14zx7167）.
文摘The structural and thermodynamic properties of Zr2A1C at high pressure and high temper- ature are investigated by first principles density functional theory method. The calculated lattice parameters of Zr2A1C are in good agreement with the available theoretical data. The pressure dependences of the elastic constants, bulk modulus, shear modulus, Young＇s mod- ulus, and Vickers hardness of Zr2A1C are successfully obtained. The elastic anisotropy is examined through the computation of the direction dependence of Young＇s modulus. By using the quasiharmonic Debye model, the thermodynamic properties including the Debye temperature, heat capacity, volume thermal expansion coefficient, and Griineisen parameter at high pressure and temperature are predicted for the first time.
基金We thank Science ＆ Technology Center in Ukraine and Shota Rustaveli National Science Foundation. The work was implemented with the support of Science ＆ Technology Center in Ukraine Project Proposal #5461 and Shota Rustaveli National Science Foundation Grant #30/06.
文摘Terms of synthesis were defined for the creation of new generation chelate fertilizers and for their experimental testing. Glutamine acid and citric acid containing chelate citrates of the general formulae M.gI.HL＇nHO were synthesized, where, M = Mn, Zn, Fe, Co, Cu; n = 0; 1; 1.5; gl-glutamine acid; HL-citric acid anion. Identity and composition of synthesized compounds were determined by microelemental analysis, melting temperature and X-ray diffraction analysis. X-ray diffraction analysis of the compounds and glutamine acid and citric acid （H4L） was used to determine their crystalline structure and roentgen-amorphous and iso-structural orders. Their solubility was studied in various solvents.
文摘Geological structure and gas expansion when gas pressure was released can affect the distribution of infrared radiation energy or temperature at coal rock surface. From this, the foundation of roadway infrared surveying technical was formed. According to the thermodynamic principle of ideal gas and the law of energy conservation, the relation was established between gas gushing amount from coal rock and air temperature to fall in roadway. At the same time, this paper has analyzed coal rock density change that geological structure aroused and the change exerted influences on infrared radiation power at surface, as well as, has analyzed the infrared radiation feature of gas gushing at geological structure district. Application results show that infrared survey technology can be used to analyze and forecast the change of coal rock gas gushing effectively, and to guide the enforcement of the roadway gas project of prevention and handling economically.
基金Supported by the Major State Basic Research Development Program of China(2011CB706501)the National Natural Science Foundation of China(51276157)
文摘A detailed investigation of a thermodynamic process in a structured packing distillation column is of great impor- tance in prediction of process efficiency. In order to keep the simplicity of an equilibrium stage model and the accu- racy of a non-equilibrium stage model, a hybrid model is developed to predict the structured packing column in cryogenic air separation. A general solution process for the equilibrium stage model is developed to solve the set of equations of the hybrid model, in which a separation efficiency function is introduced to obtain the resulting tri-diagonal matrix and its solution by the Thomas algorithm. As an example, the algorithm is applied to analyze an upper column of a cryogenic air separation plant with the capacity of 17000 m3·h-1. Rigorous simulations are conducted using Aspen RATEFRAC module to validate the approach. The temperature and composition distributions are in a good agreement with the two methods. The effects of inlet/outlet position and flow rate on the temperature and composition distributions in the column are analyzed. The results demonstrate that the hybrid model and the solution algorithms are effective in analvzin~ the distillation process for a a cryogenic structured packing column.
文摘Hypersonic flow-field measurement techniques have been studied for about 50 years. Despite truly remarkable progress with a probe or other device to measure the temperature, pressure or velocity, there are still serious problems for these "intrusive" techniques. The intrusive measurement techniques introduce unexpected shock waves or flow-field structures, even make the boundary layer transition earlier and show a converse result. In recent years, nonintrusive diagnostics have been in urgent demand to give a more accurate and comprehensive flow-field for hypersonic testing. In this paper, an overview of some advanced nonintrusive measurement techniques such as embedded thermocouples for heat flux measurement, Pressure Sensitive Paint(PSP), Particle Image Velocimetry(PIV), infrared thermographs, and focusing Schlieren system are introduced. All of these techniques are nonintrusive and provide measurement of various parameters such as temperature, static pressure, dynamic pressure, flow velocity and visualization of flow structure, which gives us an exact and direct understanding of the hypersonic flow.
文摘The structural health monitoring of a dam is important for maintaining the safe operation and longevity of the dam system. The structural health of a large dam can be monitored from the measured static deformation. This paper presents an investigation of the parameter variations of the identified model of the measured long-term static deformation for the structural health monitoring of Fui-Tsui Dam, which is located in a very active seismic zone of Taiwan. The measured static deformation is characterized as a function of the measured physical parameters, including the effects of hydrostatic pressure and temperature variation. The identified parameters, associated with the effects of hydrostatic pressure and temperature variation, change with environmental factors, such as flooding, earthquake and foundation change.
基金Projects(20476106,50721003 and 20636020) supported by the National Natural Science Foundation of ChinaProject(50825102) supported by the National Natural Science Funds for Distinguished Young Scholar of China+1 种基金Project(2006AA03Z511) supported by the National High Technology Research and Development Program of ChinaProject supported by the 111 Program of Chinese Ministry of Education
文摘A novel Ti-based Ti-Mn composite anode used for electrolytic manganese dioxide(EMD) fabrication was developed by a two-step heating manganizing technique.The effects of sintering temperature on the manganized microstructure and the performance of the composite anode were studied by scanning electron microscopy(SEM),mechanical properties tests at room temperature and electrochemical methods.The results show that the thickness of the diffusion layer increases with the increase of sintering temperature up to 1 100 °C;whereas,the surface Mn content increases and reaches the maximum at 1 000 °C and then decreases thereafter.Lower surface Mn content is beneficial for the enhanced corrosion resistance and lowered open cell voltage in electrolytic process.The new anode prepared under the optimized conditions has been applied in industry and exhibits superior economic benefits to conventional Ti anodic materials.
基金This work was supported Technology Research Grant Science Foundation. by Science and Indonesia Toray
文摘A singlemode-multimode-singlemode （SMS） fiber structure for temperature measurement using an optical time domain reflectometer （OTDR）-based interrogation system is proposed. A temperature measurement range of 40 ℃-195 ℃ with a resolution of 0.12 ℃ and a linearity of 0.992 could be achieved for the multimode fiber （MMF） graded index with a length of 60mm. It was also demonstrated that two-point temperature measurement with two SMS fiber structures as temperature sensors could be made. The proposed temperature measurement system offered a high resolution and also benefited from a simple configuration with a capability of multi-point temperature measurement.
