Eight beams of 0.35 μm laser with pulse duration of 1 ns and total energy of 2 kJ enter into a hohlraum to create intense X-ray radiation of 140 eV on the Shenguang ΙΙ laser facility. Plastic foam (C6H12) and coppe...Eight beams of 0.35 μm laser with pulse duration of 1 ns and total energy of 2 kJ enter into a hohlraum to create intense X-ray radiation of 140 eV on the Shenguang ΙΙ laser facility. Plastic foam (C6H12) and copper-doped foam (C6H12Cu0.394) with a density of 50 mg/cm3 are heated by X-ray radiation emitted from the hohlraum. The breakout time of the radiation wave is measured by a tri-chromatic streaked X-ray spectrometer (TCS) that consists of a set of three imaging pinholes and an array of three transmission gratings coupled with an X-ray streak camera (XSC). At one shot, the simultaneous measurements of the delay of the drive source and the radiation transport at two energies (210 eV, 840 eV) through the foam have been made for the first time. The experimental results indicate that the time delays vary with photon energies. With a transmission grating spectrometer (TGS), the spectra transmitting foams were measured, and the lower limit of the optical depth was measured. The radiation at energy of 210 eV propagates through plastic foam at a faster velocity, compared with the radiation at energy of 840 eV; while the results of copper-doped foam are reverse. The optical depth in the plastic foam is less than 1, and in the doped foam it is more than 1.展开更多
Bioactive glasses(BG)play a vital role in angiogenesis and osteogenesis through releasing functional ions.However,the rapid ion release in the early stage will cause excessive accumulation of metal ions,which in turn ...Bioactive glasses(BG)play a vital role in angiogenesis and osteogenesis through releasing functional ions.However,the rapid ion release in the early stage will cause excessive accumulation of metal ions,which in turn leads to obvious cytotoxicity,long-term inflammation,and bone repair failure.Inspired by the vibration exciter,small extracellular vesicles(sEVs)obtained by treating mesenchymal stem cells with copper-doped bioactive glass(CuBG-sEVs),is prepared as a nano-vibration exciter.The nano-vibration exciter can convert the ion signals of CuBG into biochemical factor signals through hypoxia-inducible factor 1(HIF-1)signaling pathway and its activated autophagy,so as to better exert the osteogenic activity of BG.The results showed that CuBG extracts could significantly improve the enrichment of key miRNAs and increase the yield of CuBG-sEVs by activating HIF-1 signaling pathway and its activated autophagy.Cell experiments showed that CuBG-sEVs are favor to cell recruitment,vascularization and osteogenesis as the enrichment of key miRNAs.The animal experiments results showed that CuBG-sEVs stimulated angiogenesis mediated by CD31 and promoted bone regeneration by activating signaling pathways related to osteogenesis.These findings underscored the significant potential of sEVs as alternative strategies to better roles of BG.展开更多
Although perovskite solar cells with power conversion efficiencies(PCEs) more than 22% have been realized with expensive organic charge-transporting materials, their stability and high cost remain to be addressed. In ...Although perovskite solar cells with power conversion efficiencies(PCEs) more than 22% have been realized with expensive organic charge-transporting materials, their stability and high cost remain to be addressed. In this work, the perovskite configuration of MAPbX(MA = CH_3 NH_3,X = I_3, Br_3, or I_2Br) integrated with stable and low-cost Cu:Ni Oxhole-transporting material, ZnO electron-transporting material, and Al counter electrode was modeled as a planar PSC and studied theoretically. A solar cell simulation program(wx AMPS), which served as an update of the popular solar cell simulation tool(AMPS: Analysis of Microelectronic and Photonic Structures), was used. The study yielded a detailed understanding of the role of each component in the solar celland its effect on the photovoltaic parameters as a whole. The bandgap of active materials and operating temperature of the modeled solar cell were shown to influence the solar cell performance in a significant way. Further, the simulation results reveal a strong dependence of photovoltaic parameters on the thickness and defect density of the light-absorbing layers. Under moderate simulation conditions, the MAPb Br_3 and MAPbI _2 Br cells recorded the highest PCEs of 20.58 and 19.08%, respectively, while MAPbI_3 cell gave a value of 16.14%.展开更多
Reducing the secondary electron yield(SEY)of Ag-plated aluminum alloy is important for high-power microwave components.In this work,Cu doped carbon films are prepared and the secondary electron emission characteristic...Reducing the secondary electron yield(SEY)of Ag-plated aluminum alloy is important for high-power microwave components.In this work,Cu doped carbon films are prepared and the secondary electron emission characteristics are studied systematically.The secondary electron coefficientδ_(max) of carbon films increases with the Cu contents increasing at first,and then decreases to 1.53 at a high doping ratio of 0.645.From the viewpoint of surface structure,the higher the content of Cu is,the rougher the surface is,since more cluster particles appear on the surface due to the small solid solubility of Cu in the amorphous carbon network.However,from viewpoint of the electronic structure,the reduction of the sp2 hybrid bonds will increase the SEY effect as the content of Cu increases,due to the decreasing probability of collision with free electrons.Thus,the two mechanisms would compete and coexist to affect the SEY characteristics in Cu doped carbon films.展开更多
The propagation of a supersonic heat-wave through copper-doped foam with a density of 50 mg/cm^3 was experimentally investigated. The wave is driven by 140 eV Holhraum radiations generated in a cylindrical gold cavity...The propagation of a supersonic heat-wave through copper-doped foam with a density of 50 mg/cm^3 was experimentally investigated. The wave is driven by 140 eV Holhraum radiations generated in a cylindrical gold cavity heated by a 2 kJ, ins laser pulse （0.35 μm）. The delayed breakout time of the radiation waves from the rear side of the foam is measured by a three-chromatic streaked x-ray spectrometer （TCS） consisting of a set of three-imaging pinholes and an array of three transmission gratings coupled with an x-ray streak camera （XSC）. With one shot, simultaneous measurements of the delays of the drive source and the radiation with two different energies （210 eV, 840 eV） through the foam have been made for the first time. The experimental results indicate that the time delays vary with photon energies. The radiation with an energy of 210 eV propagates at a lower velocity. The radiating heat wave propagates with a velocity that is larger than the sound speed. Using TGS, the transmitting spectrum was measured, and then lower limit of the optical depth which is more than 1, was obtained. The experimental data were in agreement with numerical simulations.展开更多
Photocatalytic degradation of paraquat using mesoporous-assembled Cu-TiO2 /SBA15 under UV and visible light was investigated.The catalyst was synthesized by impregnation of Cu-TiO2 colloids onto SBA-15.The colloids of...Photocatalytic degradation of paraquat using mesoporous-assembled Cu-TiO2 /SBA15 under UV and visible light was investigated.The catalyst was synthesized by impregnation of Cu-TiO2 colloids onto SBA-15.The colloids of Cu-TiO2 were prepared via solgel method while the mesoporous support was prepared using hydrothermal technique.The catalyst was characterized using X-ray diffraction,nitrogen adsorption-desorption,transmission electron microscopy,UV diffuse reflectance spectroscopy,Zeta potential and X-ray adsorption spectroscopy.Results from characterizations showed that Cu doped TiO2 had a small crystalline size and was welldispersed on SBA-15.The inclusion of SBA-15 significantly enhanced the photocatalytic activity of the catalyst.Among the three types of undoped catalyst in this study （P25,TiO2,TiO_2 /SBA-15）,TiO2 /SBA-15 yielded the highest degradation of paraquat for all pH under UV illumination.Meanwhile 2 wt.% Cu-TiO2 /SBA-15 yielded the highest activity under visible light.展开更多
文摘Eight beams of 0.35 μm laser with pulse duration of 1 ns and total energy of 2 kJ enter into a hohlraum to create intense X-ray radiation of 140 eV on the Shenguang ΙΙ laser facility. Plastic foam (C6H12) and copper-doped foam (C6H12Cu0.394) with a density of 50 mg/cm3 are heated by X-ray radiation emitted from the hohlraum. The breakout time of the radiation wave is measured by a tri-chromatic streaked X-ray spectrometer (TCS) that consists of a set of three imaging pinholes and an array of three transmission gratings coupled with an X-ray streak camera (XSC). At one shot, the simultaneous measurements of the delay of the drive source and the radiation transport at two energies (210 eV, 840 eV) through the foam have been made for the first time. The experimental results indicate that the time delays vary with photon energies. With a transmission grating spectrometer (TGS), the spectra transmitting foams were measured, and the lower limit of the optical depth was measured. The radiation at energy of 210 eV propagates through plastic foam at a faster velocity, compared with the radiation at energy of 840 eV; while the results of copper-doped foam are reverse. The optical depth in the plastic foam is less than 1, and in the doped foam it is more than 1.
基金supported by the National Key R&D Program of China(2023YFB3810200)the National Natural Science Foundation of China(Grant No.52272276,52073103,52203164)+2 种基金the Fundamental Research Funds for the Central Universities(No.2022ZYGXZR105)the Project funded by China Postdoctoral Science Foundation(No.2022M711183)the Science and Technology Planning Project of Guangzhou(2023A04J0971).
文摘Bioactive glasses(BG)play a vital role in angiogenesis and osteogenesis through releasing functional ions.However,the rapid ion release in the early stage will cause excessive accumulation of metal ions,which in turn leads to obvious cytotoxicity,long-term inflammation,and bone repair failure.Inspired by the vibration exciter,small extracellular vesicles(sEVs)obtained by treating mesenchymal stem cells with copper-doped bioactive glass(CuBG-sEVs),is prepared as a nano-vibration exciter.The nano-vibration exciter can convert the ion signals of CuBG into biochemical factor signals through hypoxia-inducible factor 1(HIF-1)signaling pathway and its activated autophagy,so as to better exert the osteogenic activity of BG.The results showed that CuBG extracts could significantly improve the enrichment of key miRNAs and increase the yield of CuBG-sEVs by activating HIF-1 signaling pathway and its activated autophagy.Cell experiments showed that CuBG-sEVs are favor to cell recruitment,vascularization and osteogenesis as the enrichment of key miRNAs.The animal experiments results showed that CuBG-sEVs stimulated angiogenesis mediated by CD31 and promoted bone regeneration by activating signaling pathways related to osteogenesis.These findings underscored the significant potential of sEVs as alternative strategies to better roles of BG.
基金supported partially by National Natural Science Foundation of China (Grant Nos. 51772096, 51372082, 51402106, and 11504107)Beijing Natural Science Foundation (17L20075)+4 种基金Joint Funds of the Equipment Pre-Research and Ministry of Education (6141A020225)National High-tech R&D Program of China (863 Program, No. 2015AA034601)Par-Eu Scholars ProgramBeijing Municipal Science and Technology Project (Z161100002616039)the Fundamental Research Funds for the Central Universities (2016JQ01, 2017ZZD02)
文摘Although perovskite solar cells with power conversion efficiencies(PCEs) more than 22% have been realized with expensive organic charge-transporting materials, their stability and high cost remain to be addressed. In this work, the perovskite configuration of MAPbX(MA = CH_3 NH_3,X = I_3, Br_3, or I_2Br) integrated with stable and low-cost Cu:Ni Oxhole-transporting material, ZnO electron-transporting material, and Al counter electrode was modeled as a planar PSC and studied theoretically. A solar cell simulation program(wx AMPS), which served as an update of the popular solar cell simulation tool(AMPS: Analysis of Microelectronic and Photonic Structures), was used. The study yielded a detailed understanding of the role of each component in the solar celland its effect on the photovoltaic parameters as a whole. The bandgap of active materials and operating temperature of the modeled solar cell were shown to influence the solar cell performance in a significant way. Further, the simulation results reveal a strong dependence of photovoltaic parameters on the thickness and defect density of the light-absorbing layers. Under moderate simulation conditions, the MAPb Br_3 and MAPbI _2 Br cells recorded the highest PCEs of 20.58 and 19.08%, respectively, while MAPbI_3 cell gave a value of 16.14%.
基金supported by the National Key Laboratory Foundation(Grant Nos.2018SSFNKLSMT04,614241101010117 and 6142411191110)the National 111 Project of China(Grant No.B14040)。
文摘Reducing the secondary electron yield(SEY)of Ag-plated aluminum alloy is important for high-power microwave components.In this work,Cu doped carbon films are prepared and the secondary electron emission characteristics are studied systematically.The secondary electron coefficientδ_(max) of carbon films increases with the Cu contents increasing at first,and then decreases to 1.53 at a high doping ratio of 0.645.From the viewpoint of surface structure,the higher the content of Cu is,the rougher the surface is,since more cluster particles appear on the surface due to the small solid solubility of Cu in the amorphous carbon network.However,from viewpoint of the electronic structure,the reduction of the sp2 hybrid bonds will increase the SEY effect as the content of Cu increases,due to the decreasing probability of collision with free electrons.Thus,the two mechanisms would compete and coexist to affect the SEY characteristics in Cu doped carbon films.
基金The project supported by National High Technique Development Project (863) No.2002AA843130Scientific Fund of CAEP No. 20030214
文摘The propagation of a supersonic heat-wave through copper-doped foam with a density of 50 mg/cm^3 was experimentally investigated. The wave is driven by 140 eV Holhraum radiations generated in a cylindrical gold cavity heated by a 2 kJ, ins laser pulse （0.35 μm）. The delayed breakout time of the radiation waves from the rear side of the foam is measured by a three-chromatic streaked x-ray spectrometer （TCS） consisting of a set of three-imaging pinholes and an array of three transmission gratings coupled with an x-ray streak camera （XSC）. With one shot, simultaneous measurements of the delays of the drive source and the radiation with two different energies （210 eV, 840 eV） through the foam have been made for the first time. The experimental results indicate that the time delays vary with photon energies. The radiation with an energy of 210 eV propagates at a lower velocity. The radiating heat wave propagates with a velocity that is larger than the sound speed. Using TGS, the transmitting spectrum was measured, and then lower limit of the optical depth which is more than 1, was obtained. The experimental data were in agreement with numerical simulations.
基金funded by the National Research University Project of Thailand Office of Higher Education Commission
文摘Photocatalytic degradation of paraquat using mesoporous-assembled Cu-TiO2 /SBA15 under UV and visible light was investigated.The catalyst was synthesized by impregnation of Cu-TiO2 colloids onto SBA-15.The colloids of Cu-TiO2 were prepared via solgel method while the mesoporous support was prepared using hydrothermal technique.The catalyst was characterized using X-ray diffraction,nitrogen adsorption-desorption,transmission electron microscopy,UV diffuse reflectance spectroscopy,Zeta potential and X-ray adsorption spectroscopy.Results from characterizations showed that Cu doped TiO2 had a small crystalline size and was welldispersed on SBA-15.The inclusion of SBA-15 significantly enhanced the photocatalytic activity of the catalyst.Among the three types of undoped catalyst in this study （P25,TiO2,TiO_2 /SBA-15）,TiO2 /SBA-15 yielded the highest degradation of paraquat for all pH under UV illumination.Meanwhile 2 wt.% Cu-TiO2 /SBA-15 yielded the highest activity under visible light.
