The increase of micro and nano devices has led to the miniaturization and multi-functionalization of micro-mechanical, communication, imaging, sensing, chemical analytical and biomedical devices. The devices so mentio...The increase of micro and nano devices has led to the miniaturization and multi-functionalization of micro-mechanical, communication, imaging, sensing, chemical analytical and biomedical devices. The devices so mentioned above need power sources that are portable, have short charging time, longevity, high energy density and are environmentally friendly. Chemical batteries hitherto used to be the major power source for these devices but have a drawback of having low energy density. The energy density of the most improved lithium-ion battery was in the region of 0.2 kWh/kg. Micro-combustor is one of the most important components of the micro thermophotovoltaic (MTPV) conversion device. This work used numerical simulation to investigate the effect of Micro pin fin arrays on combustion. Using a micro combustor with micro pin-fin arrays inserted, it was observed the fins widened the region of combustion and extended the blow-off limit in the combustor. The fins exerted great influence on combustion as flow rate increased and thus improved the temperature distribution of the wall. The combustor with fins possessed higher heat flux in comparison with combustor without fins. There was combustion stability at inlet velocity of 4 m/s making the micro pin-fin array configuration ideal for MTPV application. The results obtained will be useful in designing a MTPV.展开更多
CeO2 is an important porous material with a wide range of applications in the abatement of volatile organic compounds （VOCs）. In this paper, we prepared a series of novel three-dimensional （3D） micro/nanostructure...CeO2 is an important porous material with a wide range of applications in the abatement of volatile organic compounds （VOCs）. In this paper, we prepared a series of novel three-dimensional （3D） micro/nanostructured CeO2 materials via a solvothermal method. Organic acid-assisted synthesis and inorganic acid post-treatment were used to adjust the Ce02 microstructures. The size of the 3D micro/nanostructures could be controlled in the range from 180nm to 1.5 μm and the surface morphology changed from rough to smooth with the use of different organic acids. The CeO2 synthesized with acetic acid featured a hierarchical porosity and showed good performance for toluene catalytic combustion： a T50 of 187 ℃ and a T90 of 195 ℃. Moreover, the crystallite size, textural properties, and surface chemical states could be tuned by inorganic acid modification. After treatment with HNO3, the modified CeO2 materials exhibited improved catalytic activity, with a T50 of-175 ℃ and a T90 of -187 ℃. We concluded that the toluene combustion activity is related to the porosity and the amount of surface active oxygen of the CeO2. Both these features can be tuned by the co-work of organic and inorganic acids.展开更多
文摘The increase of micro and nano devices has led to the miniaturization and multi-functionalization of micro-mechanical, communication, imaging, sensing, chemical analytical and biomedical devices. The devices so mentioned above need power sources that are portable, have short charging time, longevity, high energy density and are environmentally friendly. Chemical batteries hitherto used to be the major power source for these devices but have a drawback of having low energy density. The energy density of the most improved lithium-ion battery was in the region of 0.2 kWh/kg. Micro-combustor is one of the most important components of the micro thermophotovoltaic (MTPV) conversion device. This work used numerical simulation to investigate the effect of Micro pin fin arrays on combustion. Using a micro combustor with micro pin-fin arrays inserted, it was observed the fins widened the region of combustion and extended the blow-off limit in the combustor. The fins exerted great influence on combustion as flow rate increased and thus improved the temperature distribution of the wall. The combustor with fins possessed higher heat flux in comparison with combustor without fins. There was combustion stability at inlet velocity of 4 m/s making the micro pin-fin array configuration ideal for MTPV application. The results obtained will be useful in designing a MTPV.
基金This work was financially supported by the Natural Science Foundation of China （21576054）, the Scientific Project of Guangdong Province （2014A010106030, 2016A010104017,2016B020241003）, and the Foundation of Higher Education of Guangdong Province （201 SICFSCX027） of China.
文摘CeO2 is an important porous material with a wide range of applications in the abatement of volatile organic compounds （VOCs）. In this paper, we prepared a series of novel three-dimensional （3D） micro/nanostructured CeO2 materials via a solvothermal method. Organic acid-assisted synthesis and inorganic acid post-treatment were used to adjust the Ce02 microstructures. The size of the 3D micro/nanostructures could be controlled in the range from 180nm to 1.5 μm and the surface morphology changed from rough to smooth with the use of different organic acids. The CeO2 synthesized with acetic acid featured a hierarchical porosity and showed good performance for toluene catalytic combustion： a T50 of 187 ℃ and a T90 of 195 ℃. Moreover, the crystallite size, textural properties, and surface chemical states could be tuned by inorganic acid modification. After treatment with HNO3, the modified CeO2 materials exhibited improved catalytic activity, with a T50 of-175 ℃ and a T90 of -187 ℃. We concluded that the toluene combustion activity is related to the porosity and the amount of surface active oxygen of the CeO2. Both these features can be tuned by the co-work of organic and inorganic acids.
