本文中研究了QBe2.0电刷丝/滑环摩擦副在不同电流强度条件下的载流摩擦学性能.研究结果显示:随着电流强度的增加,摩擦副平均摩擦系数增加,接触电阻下降,电刷丝磨损表面温度升高,平均硬度降低,电刷丝磨损表面材料软化,磨损面积增大.在摩...本文中研究了QBe2.0电刷丝/滑环摩擦副在不同电流强度条件下的载流摩擦学性能.研究结果显示:随着电流强度的增加,摩擦副平均摩擦系数增加,接触电阻下降,电刷丝磨损表面温度升高,平均硬度降低,电刷丝磨损表面材料软化,磨损面积增大.在摩擦热、电阻热和电弧热的共同作用下,刷丝磨损表面氧化磨损加剧,磨损量增加,粗糙度变大. SEM (扫描电镜)分析显示,磨屑表面出现电弧烧蚀引起的孔洞和熔融喷溅现象,电刷丝磨损面上观察到熔融产生的氧化物颗粒和龟裂现象.随着电流强度的增加,虽然摩擦副摩擦磨损性能下降,但是其接触稳定性和导电性能得到改善.展开更多
The CuO-doped ZnO thick films were prepared by the screen printing technique. The CuO doped ZnO composite materials were obtained by mixing AR grade （99.9% pure） Zinc Oxide powder mechanochemically in acetone medium...The CuO-doped ZnO thick films were prepared by the screen printing technique. The CuO doped ZnO composite materials were obtained by mixing AR grade （99.9% pure） Zinc Oxide powder mechanochemically in acetone medium with various weight percentages of Copper Chloride （CulCI2.2H20） powder （1, 3, 5, 7 and 9wt.%）. The prepared materials were sintered at 1,000 ℃ for 12 h in air ambience and ball milled to ensure sufficiently fine particle size. The films were characterized by different techniques with respect to their surface morphology and compositional property by means of SEM （scanning electron microscope） and EDXA （energy dispersive x-ray analysis）. The surface morphology of the films was studied by SEM and it shows the films are porous in nature and petal-shaped grains of sizes varies from 220 nm to 250 nm were observed. The final composition of each film was determined by the EDXA analysis. The gas response of undoped ZnO and CuO doped ZnO films was studied for different gases such as CO, C12, NH3, Ethanol, H2S and LPG at operating temperature ranging from 50 ℃ to 400 ℃. The 7wt.% CuO-doped ZnO film shows good response to H2S gas （100 ppm） at 250 ℃.展开更多
The construction of flexible platform possessing the functions of immobilizing, separating, rinsing, and high-throughput analysis plays a significant role in biological and clinical research. Herein, hollow- channel t...The construction of flexible platform possessing the functions of immobilizing, separating, rinsing, and high-throughput analysis plays a significant role in biological and clinical research. Herein, hollow- channel technique was integrated with lab-on-paper for the simultaneous determination of two different concentrations of Zn2＋ based on the origami principle, in which microfiuidic channels were first patterned on a cellulose paper using commercial solid-state wax printer. Hollow-channels were created by laser cutting method as the role of both injecting ending and reaction tank. After screen printing three elec- trodes system, the resulting planar paper sheets were then folded into steric structures and functional- ized by in-situ synthesized reduced graphene oxide. As a proof-of-concept, such lab-on-paper device was employed in the ratiometric electrochemical monitoring of zinc ion from the environment and HepG2 cells extract, by combining with co-catalysis of porous metal-organic frameworks and hemin/ G-quadruplex toward H202 in the linear range of 0.1-7,000 nmol/L. The results indicated that integrating hollow-channel with steric lab-on-paper offered a new methodological approach for the development of metal ions monitoring research. It is believed that it could be useful for various point-of-care related research fields, such as, on-site environmental monitoring, food safety, and disease diagnosis.展开更多
文摘本文中研究了QBe2.0电刷丝/滑环摩擦副在不同电流强度条件下的载流摩擦学性能.研究结果显示:随着电流强度的增加,摩擦副平均摩擦系数增加,接触电阻下降,电刷丝磨损表面温度升高,平均硬度降低,电刷丝磨损表面材料软化,磨损面积增大.在摩擦热、电阻热和电弧热的共同作用下,刷丝磨损表面氧化磨损加剧,磨损量增加,粗糙度变大. SEM (扫描电镜)分析显示,磨屑表面出现电弧烧蚀引起的孔洞和熔融喷溅现象,电刷丝磨损面上观察到熔融产生的氧化物颗粒和龟裂现象.随着电流强度的增加,虽然摩擦副摩擦磨损性能下降,但是其接触稳定性和导电性能得到改善.
文摘The CuO-doped ZnO thick films were prepared by the screen printing technique. The CuO doped ZnO composite materials were obtained by mixing AR grade （99.9% pure） Zinc Oxide powder mechanochemically in acetone medium with various weight percentages of Copper Chloride （CulCI2.2H20） powder （1, 3, 5, 7 and 9wt.%）. The prepared materials were sintered at 1,000 ℃ for 12 h in air ambience and ball milled to ensure sufficiently fine particle size. The films were characterized by different techniques with respect to their surface morphology and compositional property by means of SEM （scanning electron microscope） and EDXA （energy dispersive x-ray analysis）. The surface morphology of the films was studied by SEM and it shows the films are porous in nature and petal-shaped grains of sizes varies from 220 nm to 250 nm were observed. The final composition of each film was determined by the EDXA analysis. The gas response of undoped ZnO and CuO doped ZnO films was studied for different gases such as CO, C12, NH3, Ethanol, H2S and LPG at operating temperature ranging from 50 ℃ to 400 ℃. The 7wt.% CuO-doped ZnO film shows good response to H2S gas （100 ppm） at 250 ℃.
基金supported by the National Natural Science Foundation of China(51502112,21475052)Key Research and Development Program of Shandong Province,China(2016GGX102035)Postdoctoral Science Foundation of University of Jinan,China(XBH1511)
文摘The construction of flexible platform possessing the functions of immobilizing, separating, rinsing, and high-throughput analysis plays a significant role in biological and clinical research. Herein, hollow- channel technique was integrated with lab-on-paper for the simultaneous determination of two different concentrations of Zn2＋ based on the origami principle, in which microfiuidic channels were first patterned on a cellulose paper using commercial solid-state wax printer. Hollow-channels were created by laser cutting method as the role of both injecting ending and reaction tank. After screen printing three elec- trodes system, the resulting planar paper sheets were then folded into steric structures and functional- ized by in-situ synthesized reduced graphene oxide. As a proof-of-concept, such lab-on-paper device was employed in the ratiometric electrochemical monitoring of zinc ion from the environment and HepG2 cells extract, by combining with co-catalysis of porous metal-organic frameworks and hemin/ G-quadruplex toward H202 in the linear range of 0.1-7,000 nmol/L. The results indicated that integrating hollow-channel with steric lab-on-paper offered a new methodological approach for the development of metal ions monitoring research. It is believed that it could be useful for various point-of-care related research fields, such as, on-site environmental monitoring, food safety, and disease diagnosis.
