The high compacted density LiNi<sub>0.5-x</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub>Mg<sub>x</sub>O<sub>2</sub> cathode material for lithium-ion batteries was syn...The high compacted density LiNi<sub>0.5-x</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub>Mg<sub>x</sub>O<sub>2</sub> cathode material for lithium-ion batteries was synthesized by high temperature solid-state method, taking the Mg element as a doping element and the spherical Ni<sub>0.5</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub> (OH)<sub>2</sub>, Li<sub>2</sub>CO<sub>3</sub> as raw materials. The effects of calcination temperature on the structure and properties of the products were investigated. The structure and morphology of cathode materials powder were analyzed by X-ray diffraction spectroscopy (XRD) and scanning electronmicroscopy (SEM). The electrochemical properties of the cathode materials were studied by charge-discharge test and cyclic properties test. The results show that LiNi<sub>0.4985</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub> Mg<sub>0.0015</sub>O<sub>2</sub> cathode material prepared at calcination temperature 930°C has a good layered structure, and the compacted density of the electrode sheet is above 3.68 g/cm<sup>3</sup>. The discharge capacity retention rate is more than 97.5% after 100 cycles at a charge-discharge rate of 1C, displaying a good cyclic performance.展开更多
Ge_(50-x)Sb_xTe_(50) and Ge_(50-x)Bi_xTe_(50) ternary alloys were synthesized by vacuum melting at 1273 K with the starting materials of Ge, Bi, Sb, and Te. The lattice structures were analyzed based on X-ray ...Ge_(50-x)Sb_xTe_(50) and Ge_(50-x)Bi_xTe_(50) ternary alloys were synthesized by vacuum melting at 1273 K with the starting materials of Ge, Bi, Sb, and Te. The lattice structures were analyzed based on X-ray diffraction patterns, which could all be indexed to R3m rhombic structure. Electrical properties measurements revealed that the Ge-Sb-Te ternary alloys were p-type semiconductors with high electrical conductivity of 4.5×10~5S?m^(-1) near room temperature. And the maximum electrical property was obtained at Ge_45Sb_5Te_50, with the power factor of 2.49×10^(-3)W?m^(-1)K^(-2) at 640 K. Due to the existence of secondary phases, the electrical conductivity of Ge-Bi-Te system was lower and Seebeck coefficient was higher comparing with those of Ge-Sb-Te system.展开更多
作为层状金属磷硫属化合物的典型代表,MnPSe_(3)以其直接带隙特性、高载流子迁移率以及大的吸收系数而备受关注,在光电领域展现了巨大潜力.本文中,我们对化学气相输运法制备的单晶进行机械剥离从而获得了高质量的二维MnPSe_(3)纳米片,...作为层状金属磷硫属化合物的典型代表,MnPSe_(3)以其直接带隙特性、高载流子迁移率以及大的吸收系数而备受关注,在光电领域展现了巨大潜力.本文中,我们对化学气相输运法制备的单晶进行机械剥离从而获得了高质量的二维MnPSe_(3)纳米片,利用角分辨偏振拉曼光谱对MnPSe_(3)的晶格振动进行了系统的研究,并根据拉曼选择定则和晶体的对称性确定了其拉曼振动模式.我们构建的基于二维MnPSe_(3)纳米片的光电探测器对紫外光的响应度和探测度分别高达22.7 A W^(-1)和2.4×10^(11)Jones.在紫外区域优异的探测能力表明二维MnPSe_(3)有望应用于未来紫外光电探测领域.展开更多
Due to uncertainties in water supply,there is growing demand for water resource management in enterprises.In this study,we evaluated the effects of companies’water-saving reconstruction projects.We used Hina Advanced...Due to uncertainties in water supply,there is growing demand for water resource management in enterprises.In this study,we evaluated the effects of companies’water-saving reconstruction projects.We used Hina Advanced Materials Company as a case to construct an investment decision model to(1)calculate the internal and external costs of water resources based on circular economic value analysis theory,and(2)locate the level of water resources circulation.We adopted gray situation decision analysis to identify the typical problems that occur in water resource utilization.Moreover,we demonstrated optimization plans for different potential improvements,thereby providing guidance and references for water resource cost management and the comprehensive optimization of environmental benefits.We concluded that the circulation economic value analysis model can effectively display the flow and amount of value derived from water resource flows,thereby providing guidance and suggestions for optimizing water resource flows.展开更多
Dielectric barrier discharge(DBD)plasma applied as surface treatment technology was employed for the modification of Ag_(2)O and graphitic carbon nitride(g-C_(3)N_(4))powders.Subsequently,the pretreated powders were s...Dielectric barrier discharge(DBD)plasma applied as surface treatment technology was employed for the modification of Ag_(2)O and graphitic carbon nitride(g-C_(3)N_(4))powders.Subsequently,the pretreated powders were sequentially loaded onto TiO_(2)nanorods(TiO_(2)-NRs)via electro-deposition,followed by calcination at N_(2)atmosphere.The results indicated that at the optimal plasma discharge time of 5 min for modification of g-C_(3)N_(4)and Ag_(2)O,photocurrent density of ternary composite was 6 times to bare TiO_(2)-NRs under UV-visible light irradiation.Phenol was degraded by using DBD plasma-modified g-C_(3)N_(4)/Ag_(2)O/TiO_(2)-NRs electrode to analyze the photoelectrocatalytic performance.The removal rate of phenol for g-C_(3)N_(4)-5/Ag_(2)O-5/TiO_(2)-NRs electrode was about 3.07 times to that for TiO_(2)-NRs electrode.During active species scavengers'analysis,superoxide radicals and hydroxyl radicals were the main oxidation active species for pollutants degradation.A possible electron-hole separation and transfer mechanism of ternary composite with high photoelectrocatalytic performance was proposed.展开更多
文摘The high compacted density LiNi<sub>0.5-x</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub>Mg<sub>x</sub>O<sub>2</sub> cathode material for lithium-ion batteries was synthesized by high temperature solid-state method, taking the Mg element as a doping element and the spherical Ni<sub>0.5</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub> (OH)<sub>2</sub>, Li<sub>2</sub>CO<sub>3</sub> as raw materials. The effects of calcination temperature on the structure and properties of the products were investigated. The structure and morphology of cathode materials powder were analyzed by X-ray diffraction spectroscopy (XRD) and scanning electronmicroscopy (SEM). The electrochemical properties of the cathode materials were studied by charge-discharge test and cyclic properties test. The results show that LiNi<sub>0.4985</sub>Co<sub>0.2</sub>Mn<sub>0.3</sub> Mg<sub>0.0015</sub>O<sub>2</sub> cathode material prepared at calcination temperature 930°C has a good layered structure, and the compacted density of the electrode sheet is above 3.68 g/cm<sup>3</sup>. The discharge capacity retention rate is more than 97.5% after 100 cycles at a charge-discharge rate of 1C, displaying a good cyclic performance.
基金Funded by the Science and Technology Plan of Taizhou City of Zhejiang Province(1601KY69)
文摘Ge_(50-x)Sb_xTe_(50) and Ge_(50-x)Bi_xTe_(50) ternary alloys were synthesized by vacuum melting at 1273 K with the starting materials of Ge, Bi, Sb, and Te. The lattice structures were analyzed based on X-ray diffraction patterns, which could all be indexed to R3m rhombic structure. Electrical properties measurements revealed that the Ge-Sb-Te ternary alloys were p-type semiconductors with high electrical conductivity of 4.5×10~5S?m^(-1) near room temperature. And the maximum electrical property was obtained at Ge_45Sb_5Te_50, with the power factor of 2.49×10^(-3)W?m^(-1)K^(-2) at 640 K. Due to the existence of secondary phases, the electrical conductivity of Ge-Bi-Te system was lower and Seebeck coefficient was higher comparing with those of Ge-Sb-Te system.
基金supported by the National Natural Science Foundation of China(21825103)Hubei Provincial Natural Science Foundation(2019CFA002)+1 种基金the Fundamental Research Funds for the Central Universities(2019kfyXMBZ018)the support from the Analytical and Testing Center of Huazhong University of Science and Technology。
文摘作为层状金属磷硫属化合物的典型代表,MnPSe_(3)以其直接带隙特性、高载流子迁移率以及大的吸收系数而备受关注,在光电领域展现了巨大潜力.本文中,我们对化学气相输运法制备的单晶进行机械剥离从而获得了高质量的二维MnPSe_(3)纳米片,利用角分辨偏振拉曼光谱对MnPSe_(3)的晶格振动进行了系统的研究,并根据拉曼选择定则和晶体的对称性确定了其拉曼振动模式.我们构建的基于二维MnPSe_(3)纳米片的光电探测器对紫外光的响应度和探测度分别高达22.7 A W^(-1)和2.4×10^(11)Jones.在紫外区域优异的探测能力表明二维MnPSe_(3)有望应用于未来紫外光电探测领域.
基金This research was supported by the projects of the National Social Funds of China(Grant No.18BJY085).
文摘Due to uncertainties in water supply,there is growing demand for water resource management in enterprises.In this study,we evaluated the effects of companies’water-saving reconstruction projects.We used Hina Advanced Materials Company as a case to construct an investment decision model to(1)calculate the internal and external costs of water resources based on circular economic value analysis theory,and(2)locate the level of water resources circulation.We adopted gray situation decision analysis to identify the typical problems that occur in water resource utilization.Moreover,we demonstrated optimization plans for different potential improvements,thereby providing guidance and references for water resource cost management and the comprehensive optimization of environmental benefits.We concluded that the circulation economic value analysis model can effectively display the flow and amount of value derived from water resource flows,thereby providing guidance and suggestions for optimizing water resource flows.
基金the Zhejiang Provincial Natural Science Foundation of China(Nos.LY16B060001 and LY21B070003)the National Natural Science Foundation of China(No.21876154)。
文摘Dielectric barrier discharge(DBD)plasma applied as surface treatment technology was employed for the modification of Ag_(2)O and graphitic carbon nitride(g-C_(3)N_(4))powders.Subsequently,the pretreated powders were sequentially loaded onto TiO_(2)nanorods(TiO_(2)-NRs)via electro-deposition,followed by calcination at N_(2)atmosphere.The results indicated that at the optimal plasma discharge time of 5 min for modification of g-C_(3)N_(4)and Ag_(2)O,photocurrent density of ternary composite was 6 times to bare TiO_(2)-NRs under UV-visible light irradiation.Phenol was degraded by using DBD plasma-modified g-C_(3)N_(4)/Ag_(2)O/TiO_(2)-NRs electrode to analyze the photoelectrocatalytic performance.The removal rate of phenol for g-C_(3)N_(4)-5/Ag_(2)O-5/TiO_(2)-NRs electrode was about 3.07 times to that for TiO_(2)-NRs electrode.During active species scavengers'analysis,superoxide radicals and hydroxyl radicals were the main oxidation active species for pollutants degradation.A possible electron-hole separation and transfer mechanism of ternary composite with high photoelectrocatalytic performance was proposed.