Thermal protective clothing has been recognized as the primary shielding against emergency fire hazard and inflammable gas leakage. Therefore,the thermal response of human covered with thermal protective clothing unde...Thermal protective clothing has been recognized as the primary shielding against emergency fire hazard and inflammable gas leakage. Therefore,the thermal response of human covered with thermal protective clothing under high temperature is the key work to investigate the thermal insulation of thermal protective clothing. A coupling model composed of thermal protective clothing,air gap and human skin is established and the temperature of the micro-system is numerically solved via the finite element method( FEM).Especially,the heat transfer of air gap located between clothing and human skin considering conduction and radiation is established while the human skin layers involve the effect of blood perfusion. Then the effect of thermophysical properties( thermal conductivity and volumetric capacity) of fabric and thickness of fabric and air on the thermal response of the micro-system is elucidated and compared.The results indicate that the volumetric heat capacity of fabric is the key parameter to affect the thermal shielding performance of thermal protective clothing,and the thicker fabric thickness and air gap thickness can improve the thermal protective properties of the micro-system.展开更多
Aerogel materials possess a wide variety of excellent functions,hence a striking number of applications have developed for them.In this paper,we present a historic review of the aerogel materials,showing the main conc...Aerogel materials possess a wide variety of excellent functions,hence a striking number of applications have developed for them.In this paper,we present a historic review of the aerogel materials,showing the main concepts,research methods,important scientific problems,formation mechanism,structure characteristics and essence of aerogel.More applications are evolving as the scientific and engineering community,which becomes familiar with the unusual and exceptional physical properties of aerogels.In addition,we also discuss the huge development potential and prospect of polysaccharide aerogels as the research trend in the future.展开更多
High-power electric actuators are generally used on solid propellant motors,which further enhances the requirement on onboard supply voltage and output power of a launch vehicle.In this paper,combined with the electri...High-power electric actuators are generally used on solid propellant motors,which further enhances the requirement on onboard supply voltage and output power of a launch vehicle.In this paper,combined with the electrical demand of China’s new generation solid-liquid bundled launch vehicle(LM-6 A),high-voltage battery technology,high-power switch control technology,insulation protection technology under low pressure are studied,and the key technologies and schemes are presented.The flight test of LM-6 A shows that the high-voltage power supply and distribution technology adopted is reasonable and feasible,and can be used as a reference for the designs of other launch vehicles or spacecrafts.展开更多
基金National Natural Science Foundations of China(Nos.51306095,51273097,51403112)China Postdoctoral Science Foundations(Nos.2014M561887,2015T80697)+1 种基金Qingdao Postdoctoral Application Research Funded Project,China(No.14-2-4-1-JCH)Qingdao Application Basic Research Funded Project,China(No.15-9-1-41-JCH)
文摘Thermal protective clothing has been recognized as the primary shielding against emergency fire hazard and inflammable gas leakage. Therefore,the thermal response of human covered with thermal protective clothing under high temperature is the key work to investigate the thermal insulation of thermal protective clothing. A coupling model composed of thermal protective clothing,air gap and human skin is established and the temperature of the micro-system is numerically solved via the finite element method( FEM).Especially,the heat transfer of air gap located between clothing and human skin considering conduction and radiation is established while the human skin layers involve the effect of blood perfusion. Then the effect of thermophysical properties( thermal conductivity and volumetric capacity) of fabric and thickness of fabric and air on the thermal response of the micro-system is elucidated and compared.The results indicate that the volumetric heat capacity of fabric is the key parameter to affect the thermal shielding performance of thermal protective clothing,and the thicker fabric thickness and air gap thickness can improve the thermal protective properties of the micro-system.
基金supported by the National Natural Science Foundation of China(31471704 and 31271837)Major Project of the Department of Science and Technology of Fujian Province(2013N5003)
文摘Aerogel materials possess a wide variety of excellent functions,hence a striking number of applications have developed for them.In this paper,we present a historic review of the aerogel materials,showing the main concepts,research methods,important scientific problems,formation mechanism,structure characteristics and essence of aerogel.More applications are evolving as the scientific and engineering community,which becomes familiar with the unusual and exceptional physical properties of aerogels.In addition,we also discuss the huge development potential and prospect of polysaccharide aerogels as the research trend in the future.
文摘High-power electric actuators are generally used on solid propellant motors,which further enhances the requirement on onboard supply voltage and output power of a launch vehicle.In this paper,combined with the electrical demand of China’s new generation solid-liquid bundled launch vehicle(LM-6 A),high-voltage battery technology,high-power switch control technology,insulation protection technology under low pressure are studied,and the key technologies and schemes are presented.The flight test of LM-6 A shows that the high-voltage power supply and distribution technology adopted is reasonable and feasible,and can be used as a reference for the designs of other launch vehicles or spacecrafts.
