NiMo-based materials have been identified as potential candidates of Pt/C electrocatalysts for hydrogen evolution reaction(HER)due to appropriate binding energy to hydrogen,and good resistance to corrosive environment...NiMo-based materials have been identified as potential candidates of Pt/C electrocatalysts for hydrogen evolution reaction(HER)due to appropriate binding energy to hydrogen,and good resistance to corrosive environments.However,little work has been carried out to enhance the catalytic performance in large-scale water-alkali electrolysis.The NoMo amorphous coating,as a highefficient and cost-effective catalyst toward HER,was synthesized by a facile electrodeposition strategy in this study.The effects of the pH value of electrolyte on the structure and HER activity of NiMo coating were investigated.The as-prepared NiMo_((pH10))exhibited the highest HER activity with overpotentials of 63.9 and 157.1 mV(vs.RHE,with 80%potential drop due to electrical resistance(iR)compensation)at the current density of-10 mA·cm^(-2)and-100 mA·cm^(-2).This NiMo_((pH10))coating also had excellent long-term durability of up to100 h stable operation under the constant current density of-100 mA·cm^(-2).The rapid HER kinetics and outstanding endurance can be ascribed to the NiMo compact coating with amorphous structures as well as good contact between NiMo coating and Ni foam substrate,endowing it grand feasibility in practical industrial applications.展开更多
In this paper, a thin calcium phosphate layer was prepared on the surface of Ti4oZr10Cu36Pd14 bulk metallic glasses （BMGs）. All samples were dipped in HNO3 aqueous solution and boiled in 1.2 mol-L-I NaOH aqueous sol...In this paper, a thin calcium phosphate layer was prepared on the surface of Ti4oZr10Cu36Pd14 bulk metallic glasses （BMGs）. All samples were dipped in HNO3 aqueous solution and boiled in 1.2 mol-L-I NaOH aqueous solution. After the two preliminary treatment steps, they were soaked in simulated body fluid （SBF） to form an apatite layer on the surface. After immersion for 12 days, a coating composed mainly of Ca-P particles was rapidly deposited on the surface of Ti40Zr10Cu36Pd14 bulk metallic glasses. The surfaces of chemically treated sam- ples and the samples after immersion in SBF were char- acterized by X-ray diffraction （XRD）, X-ray photoemission spectroscopy （XPS）, field emission scanning electron microscopy （FESEM）, and energy dispersive spectroscopy （EDS）. Analysis results indicate that this apatite coating consists of Ca-P particles with different diameters. In addition, the Ca/P ratio of the apatite coatings immersed for 14 days is 1.62, which is close to that of hydroxyapatite （HA）.展开更多
[目的]筛选柴胡田适用的茎叶除草剂。[方法]采用茎叶喷雾法,室内测定了18种茎叶除草剂对柴胡的安全性,并在此基础上,进行了田间药效试验。[结果]108 g/L高效氟吡甲禾灵乳油40.50 g a.i./hm^(2)、13%烯草酮乳油63.38 g a.i./hm^(2)、15%...[目的]筛选柴胡田适用的茎叶除草剂。[方法]采用茎叶喷雾法,室内测定了18种茎叶除草剂对柴胡的安全性,并在此基础上,进行了田间药效试验。[结果]108 g/L高效氟吡甲禾灵乳油40.50 g a.i./hm^(2)、13%烯草酮乳油63.38 g a.i./hm^(2)、15%炔草酯微乳剂50.63 g a.i./hm^(2)和42%草除灵悬浮剂89.33 g a.i./hm^(2)水平下对柴胡幼苗安全;108 g/L高效氟吡甲禾灵乳油40.50 g a.i./hm^(2)、13%烯草酮乳油63.38 g a.i./hm^(2)、15%炔草酯微乳剂50.63 g a.i./hm^(2)剂量下对禾本科杂草有较好防效;42%草除灵悬浮剂178.61 g a.i./hm^(2)剂量下对阔叶杂草有较好防效;4种除草剂均对柴胡幼苗安全。[结论]108 g/L高效氟吡甲禾灵乳油、13%烯草酮乳油和15%炔草酯微乳剂、42%草除灵悬浮剂可用于防除柴胡田杂草。展开更多
The daily life of people in the intelligent age is inseparable from electronic device,and a number of bacteria on touch screens are increasingly threatening the health of users.Herein,a photocatalytic TiO_(2)/Ag thin ...The daily life of people in the intelligent age is inseparable from electronic device,and a number of bacteria on touch screens are increasingly threatening the health of users.Herein,a photocatalytic TiO_(2)/Ag thin film was synthesized on a glass by atomic layer deposition and subsequent in situ reduction.Ultraviolet-visible(UV-Vis)spectra showed that this film can harvest the simulated solar light more efficiently than that of pristine TiO_(2).The antibacterial tests in vitro showed that the antibacterial efficiency of the TiO_(2)/Ag film against S.aureus and E.coli was 98.2%and 98.6%,under visible light irradiation for 5 min.The underlying mechanism was that the in-situ reduction of Ag on the surface of TiO_(2)reduced the bandgap of TiO_(2)from 3.44 to 2.61 eV due to the formation of Schottky heterojunction at the interface between TiO_(2)and Ag.Thus,TiO_(2)/Ag can generate more reactive oxygen species for bacterial inactivation on the surface of electronic screens.More importantly,the TiO_(2)/Ag film had great biocompatibility with/without light irradiation.The platform not only provides a more convenient choice for the traditional antibacterial mode but also has limitless possibilities for application in the field of billions of touch screens.展开更多
The phenomenon of gamma-ray burst （GRB） spectral lags is very common, but a definitive explanation has not yet been given. From a sample of 82 GRB pulses we find that the spectral lags are correlated with the pulse ...The phenomenon of gamma-ray burst （GRB） spectral lags is very common, but a definitive explanation has not yet been given. From a sample of 82 GRB pulses we find that the spectral lags are correlated with the pulse widths, however, there is no correlation between the relative spectral lags and the relative pulse widths. We suspect that the correlations between spectral lags and pulse widths might be caused by the Lorentz factor of the GRBs concerned. Our analysis on the relative quantities suggests that the intrinsic spectral lag might reflect other aspect of pulses than the aspect associated with the dynamical time of shocks or that associated with the time delay due to the curvature effect.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51771131)
文摘NiMo-based materials have been identified as potential candidates of Pt/C electrocatalysts for hydrogen evolution reaction(HER)due to appropriate binding energy to hydrogen,and good resistance to corrosive environments.However,little work has been carried out to enhance the catalytic performance in large-scale water-alkali electrolysis.The NoMo amorphous coating,as a highefficient and cost-effective catalyst toward HER,was synthesized by a facile electrodeposition strategy in this study.The effects of the pH value of electrolyte on the structure and HER activity of NiMo coating were investigated.The as-prepared NiMo_((pH10))exhibited the highest HER activity with overpotentials of 63.9 and 157.1 mV(vs.RHE,with 80%potential drop due to electrical resistance(iR)compensation)at the current density of-10 mA·cm^(-2)and-100 mA·cm^(-2).This NiMo_((pH10))coating also had excellent long-term durability of up to100 h stable operation under the constant current density of-100 mA·cm^(-2).The rapid HER kinetics and outstanding endurance can be ascribed to the NiMo compact coating with amorphous structures as well as good contact between NiMo coating and Ni foam substrate,endowing it grand feasibility in practical industrial applications.
基金financially supported by the Key Project in the Science & Technology Pillar Program of Tianjin (No. 09ZCKFGX29100)the Research Fund for the Doctoral Program of Higher Education of China (No. 20110032110023)
文摘In this paper, a thin calcium phosphate layer was prepared on the surface of Ti4oZr10Cu36Pd14 bulk metallic glasses （BMGs）. All samples were dipped in HNO3 aqueous solution and boiled in 1.2 mol-L-I NaOH aqueous solution. After the two preliminary treatment steps, they were soaked in simulated body fluid （SBF） to form an apatite layer on the surface. After immersion for 12 days, a coating composed mainly of Ca-P particles was rapidly deposited on the surface of Ti40Zr10Cu36Pd14 bulk metallic glasses. The surfaces of chemically treated sam- ples and the samples after immersion in SBF were char- acterized by X-ray diffraction （XRD）, X-ray photoemission spectroscopy （XPS）, field emission scanning electron microscopy （FESEM）, and energy dispersive spectroscopy （EDS）. Analysis results indicate that this apatite coating consists of Ca-P particles with different diameters. In addition, the Ca/P ratio of the apatite coatings immersed for 14 days is 1.62, which is close to that of hydroxyapatite （HA）.
文摘[目的]筛选柴胡田适用的茎叶除草剂。[方法]采用茎叶喷雾法,室内测定了18种茎叶除草剂对柴胡的安全性,并在此基础上,进行了田间药效试验。[结果]108 g/L高效氟吡甲禾灵乳油40.50 g a.i./hm^(2)、13%烯草酮乳油63.38 g a.i./hm^(2)、15%炔草酯微乳剂50.63 g a.i./hm^(2)和42%草除灵悬浮剂89.33 g a.i./hm^(2)水平下对柴胡幼苗安全;108 g/L高效氟吡甲禾灵乳油40.50 g a.i./hm^(2)、13%烯草酮乳油63.38 g a.i./hm^(2)、15%炔草酯微乳剂50.63 g a.i./hm^(2)剂量下对禾本科杂草有较好防效;42%草除灵悬浮剂178.61 g a.i./hm^(2)剂量下对阔叶杂草有较好防效;4种除草剂均对柴胡幼苗安全。[结论]108 g/L高效氟吡甲禾灵乳油、13%烯草酮乳油和15%炔草酯微乳剂、42%草除灵悬浮剂可用于防除柴胡田杂草。
基金financially supported by the National Natural Science Foundation of China(Nos.82002303,51871162 and 51932002)the China National Funds for Distinguished Young Scientists(No.51925104)+2 种基金Scientific Research Foundation of Peking University Shenzhen Hospital(No.KYQD2021064)Beijing Municipal Health Commission(Nos.BMHC-2021-6,BMHC-2019-9,BMHC-2018-4 and PXM2020_026275_000002)the National Key R&D Program of China(No.R&D#2018YFA0703100)
文摘The daily life of people in the intelligent age is inseparable from electronic device,and a number of bacteria on touch screens are increasingly threatening the health of users.Herein,a photocatalytic TiO_(2)/Ag thin film was synthesized on a glass by atomic layer deposition and subsequent in situ reduction.Ultraviolet-visible(UV-Vis)spectra showed that this film can harvest the simulated solar light more efficiently than that of pristine TiO_(2).The antibacterial tests in vitro showed that the antibacterial efficiency of the TiO_(2)/Ag film against S.aureus and E.coli was 98.2%and 98.6%,under visible light irradiation for 5 min.The underlying mechanism was that the in-situ reduction of Ag on the surface of TiO_(2)reduced the bandgap of TiO_(2)from 3.44 to 2.61 eV due to the formation of Schottky heterojunction at the interface between TiO_(2)and Ag.Thus,TiO_(2)/Ag can generate more reactive oxygen species for bacterial inactivation on the surface of electronic screens.More importantly,the TiO_(2)/Ag film had great biocompatibility with/without light irradiation.The platform not only provides a more convenient choice for the traditional antibacterial mode but also has limitless possibilities for application in the field of billions of touch screens.
基金the National Natural Science Foundation of China.
文摘The phenomenon of gamma-ray burst （GRB） spectral lags is very common, but a definitive explanation has not yet been given. From a sample of 82 GRB pulses we find that the spectral lags are correlated with the pulse widths, however, there is no correlation between the relative spectral lags and the relative pulse widths. We suspect that the correlations between spectral lags and pulse widths might be caused by the Lorentz factor of the GRBs concerned. Our analysis on the relative quantities suggests that the intrinsic spectral lag might reflect other aspect of pulses than the aspect associated with the dynamical time of shocks or that associated with the time delay due to the curvature effect.
