本文以还原氧化石墨烯(rGO)为载体制备了片状NiO/rGO和球形NiO/N-rGO结构的氧还原催化剂.通过X-射线衍射(XRD)、Raman(拉曼)测试、X-射线光电子能谱(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等方法表征了两种催化剂的结构和形貌...本文以还原氧化石墨烯(rGO)为载体制备了片状NiO/rGO和球形NiO/N-rGO结构的氧还原催化剂.通过X-射线衍射(XRD)、Raman(拉曼)测试、X-射线光电子能谱(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等方法表征了两种催化剂的结构和形貌.采用循环伏安法(CV)、Tafel曲线、线性扫描伏安法(LSV)、旋转圆盘电极(RDE)和旋转环盘电极(RRDE)等技术测试研究了两种催化剂的电化学催化氧还原性能.研究结果表明,球形NiO/N-rGO催化剂催化氧还原的峰电流密度和起始电位(0.89 V vs.RHE)与商业化的Pt/C(20%)催化剂相近.旋转圆盘电极(RDE)和旋转环盘电极(RRDE)测试证明,在碱性电解液中NiO/rGO和NiO/N-rGO催化的氧还原反应均主要通过4-电子途径反应途径发生,球形NiO/N-rGO催化剂展现出替代Pt/C基催化剂的潜力.展开更多
Background Internet addition disorder （lAD） is currently becoming a serious mental health problem among Chinese adolescents. The pathogenesis of lAD, however, remains unclear. The purpose of this study applied regio...Background Internet addition disorder （lAD） is currently becoming a serious mental health problem among Chinese adolescents. The pathogenesis of lAD, however, remains unclear. The purpose of this study applied regional homogeneity （ReHo） method to analyze encephalic functional characteristic of lAD college students under resting state. Methods Functional magnetic resonanc image （fMRI） was performed in 19 lAD college students and 19 controls under resting state. ReHo method was used to analyze the differences between the average ReHo in two groups. Results The following increased ReHo brain regions were found in lAD group compared with control group： cerebellum, brainstem, right cingulate gyrus, bilateral parahippocampus, right frontal lobe （rectal gyrus, inferior frontal gyrus and middle frontal gyrus）, left superior frontal gyrus, left precuneus, right postcentral gyrus, right middle occipital gyrus, right inferior temporal gyrus, left superior temporal gyrus and middle temporal gyrus. The decreased ReHo brain regions were not found in the lAD group compared with the control group. Conclusions There are abnormalities in regional homogeneity in lAD college students compared with the controls and enhancement of synchronization in most encephalic regions can be found. The results reflect the functional change of brain in lAD college students. The connections between the enhancement of synchronization among cerebellum, brainstem, limbic lobe, frontal lobe and apical lobe may be relative to reward pathways.展开更多
The hydraulic characteristics at the side inlet/outlet of pumped storage plants is studied by numerical simulations,covering the flow distribution,head loss,vortex,and others.Based on the physical model test,the reali...The hydraulic characteristics at the side inlet/outlet of pumped storage plants is studied by numerical simulations,covering the flow distribution,head loss,vortex,and others.Based on the physical model test,the realizable k-εturbulence model is used in the 3-D simulation of the side inlet/outlet.A new scheme is suggested to obtain the uneven flow distribution over three branch orifices.The variation of the free surface with the reservoir water level under the pumped condition is simulated,with results consistent with the experimental results.展开更多
基金Financial support for this work was provided by the Shandong Natural Science Foundation(No.ZR2018MB036 and ZR2017QB009)Science Development Project of Shandong Provincial(2017GGX40115 and 2016GGX102038)+1 种基金Project of Shandong Province Higher Educational Science and Technology Program(J17KA094,J13LD08)Scientific research fund of University of Jinan(XBS1644)
文摘本文以还原氧化石墨烯(rGO)为载体制备了片状NiO/rGO和球形NiO/N-rGO结构的氧还原催化剂.通过X-射线衍射(XRD)、Raman(拉曼)测试、X-射线光电子能谱(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等方法表征了两种催化剂的结构和形貌.采用循环伏安法(CV)、Tafel曲线、线性扫描伏安法(LSV)、旋转圆盘电极(RDE)和旋转环盘电极(RRDE)等技术测试研究了两种催化剂的电化学催化氧还原性能.研究结果表明,球形NiO/N-rGO催化剂催化氧还原的峰电流密度和起始电位(0.89 V vs.RHE)与商业化的Pt/C(20%)催化剂相近.旋转圆盘电极(RDE)和旋转环盘电极(RRDE)测试证明,在碱性电解液中NiO/rGO和NiO/N-rGO催化的氧还原反应均主要通过4-电子途径反应途径发生,球形NiO/N-rGO催化剂展现出替代Pt/C基催化剂的潜力.
基金This project was supported by grants of the National Natural Science Foundation of China （No. 30830046, No. 30670751 and No. 30570695）, the National Science and Technology Program of China （No. 2007BAI17B02）, the National 973 Program of China （No. 2009CB918303）, Natural Science Foundation of Hunan Province （No. 07JJ3042） and Department of Public Health of Hunan Province （No. B2005048）.
文摘Background Internet addition disorder （lAD） is currently becoming a serious mental health problem among Chinese adolescents. The pathogenesis of lAD, however, remains unclear. The purpose of this study applied regional homogeneity （ReHo） method to analyze encephalic functional characteristic of lAD college students under resting state. Methods Functional magnetic resonanc image （fMRI） was performed in 19 lAD college students and 19 controls under resting state. ReHo method was used to analyze the differences between the average ReHo in two groups. Results The following increased ReHo brain regions were found in lAD group compared with control group： cerebellum, brainstem, right cingulate gyrus, bilateral parahippocampus, right frontal lobe （rectal gyrus, inferior frontal gyrus and middle frontal gyrus）, left superior frontal gyrus, left precuneus, right postcentral gyrus, right middle occipital gyrus, right inferior temporal gyrus, left superior temporal gyrus and middle temporal gyrus. The decreased ReHo brain regions were not found in the lAD group compared with the control group. Conclusions There are abnormalities in regional homogeneity in lAD college students compared with the controls and enhancement of synchronization in most encephalic regions can be found. The results reflect the functional change of brain in lAD college students. The connections between the enhancement of synchronization among cerebellum, brainstem, limbic lobe, frontal lobe and apical lobe may be relative to reward pathways.
基金Project supported by the National Natural Science Foundation of China (Grant No. 50579048)
文摘The hydraulic characteristics at the side inlet/outlet of pumped storage plants is studied by numerical simulations,covering the flow distribution,head loss,vortex,and others.Based on the physical model test,the realizable k-εturbulence model is used in the 3-D simulation of the side inlet/outlet.A new scheme is suggested to obtain the uneven flow distribution over three branch orifices.The variation of the free surface with the reservoir water level under the pumped condition is simulated,with results consistent with the experimental results.
