An electronic-nose is developed based on eight quartz-crystal-microbalance (QCM) gas sensors in a sensor box, and is used to detect Chinese liquors at room temperature. Each sensor is a highly-accurate and highly-sens...An electronic-nose is developed based on eight quartz-crystal-microbalance (QCM) gas sensors in a sensor box, and is used to detect Chinese liquors at room temperature. Each sensor is a highly-accurate and highly-sensitive oscillator that has experienced airflow disturbances under the condition of varying room temperatures due to unstable flow-induced forces on the sensors surfaces. The three-dimensional (3D) nature of the airflow inside the sensor box and the interactions of the airflow on the sensors surfaces at different temperatures are studied by computational fluid dynamics (CFD) tools. Higher simulation accuracy is achieved by optimizing meshes, meshing the computational domain using a fine unstructural tetrahedron mesh. An optimum temperature, 30 ℃, is obtained by analyzing the distributions of velocity streamlines and the static pressure, as well as the flow-induced forces over time, all of which may be used to improve the identification accuracy of the electronic-nose for achieving stable and repeatable signals by removing the influence of temperature.展开更多
CoCO_(3) with high theoretical capacity has been considered as a candidate anode for the next generation of lithium-ion batteries(LIBs).However,the electrochemical performance of CoCO_(3) itself,especially the cyclic ...CoCO_(3) with high theoretical capacity has been considered as a candidate anode for the next generation of lithium-ion batteries(LIBs).However,the electrochemical performance of CoCO_(3) itself,especially the cyclic stability at high current density,hinders its application.Herein,pure phase CoCO_(3) particles with different particle and pore sizes were prepared by adjusting the solvents(diethylene glycol,ethylene glycol,and deionized water).Among them,CoCO_(3) synthesized with diethylene glycol(DG-CC)as the solvent shows the best electrochemical performance owing to the smaller particle size and abundant mesoporous structure to maintain robust structural stability.A high specific capacity of 690.7 mAh/g after 1000 cycles was achieved,and an excellent capacity retention was presented.The capacity was contributed by diverse electrochemical reactions and the impedance of DG-CC under different cycles was further compared.Those results provide an important reference for the structural design and stable cycle performance of pure CoCO_(3).展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.61876059 and U1501251)
文摘An electronic-nose is developed based on eight quartz-crystal-microbalance (QCM) gas sensors in a sensor box, and is used to detect Chinese liquors at room temperature. Each sensor is a highly-accurate and highly-sensitive oscillator that has experienced airflow disturbances under the condition of varying room temperatures due to unstable flow-induced forces on the sensors surfaces. The three-dimensional (3D) nature of the airflow inside the sensor box and the interactions of the airflow on the sensors surfaces at different temperatures are studied by computational fluid dynamics (CFD) tools. Higher simulation accuracy is achieved by optimizing meshes, meshing the computational domain using a fine unstructural tetrahedron mesh. An optimum temperature, 30 ℃, is obtained by analyzing the distributions of velocity streamlines and the static pressure, as well as the flow-induced forces over time, all of which may be used to improve the identification accuracy of the electronic-nose for achieving stable and repeatable signals by removing the influence of temperature.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(Nos.51772060,51372052,51672059,51621091,and 51902102)Natural Science Foundation of Hunan Province(No.2020JJ5042)Postdoctoral Science Foundation of China(No.2020M672478).
文摘CoCO_(3) with high theoretical capacity has been considered as a candidate anode for the next generation of lithium-ion batteries(LIBs).However,the electrochemical performance of CoCO_(3) itself,especially the cyclic stability at high current density,hinders its application.Herein,pure phase CoCO_(3) particles with different particle and pore sizes were prepared by adjusting the solvents(diethylene glycol,ethylene glycol,and deionized water).Among them,CoCO_(3) synthesized with diethylene glycol(DG-CC)as the solvent shows the best electrochemical performance owing to the smaller particle size and abundant mesoporous structure to maintain robust structural stability.A high specific capacity of 690.7 mAh/g after 1000 cycles was achieved,and an excellent capacity retention was presented.The capacity was contributed by diverse electrochemical reactions and the impedance of DG-CC under different cycles was further compared.Those results provide an important reference for the structural design and stable cycle performance of pure CoCO_(3).
