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Molecular dynamics simulation of atomic hydrogen diffusion in strained amorphous silica

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Chinese Physics B 2020年第2期29卷 407-413页

作者： fu-Jie Zhang Bao-Hua Zhou Xiao Liu Yu Song Xu zuo College of Electronic Information and Optical Engineering Nankai UniversityTianjin 300071China Microsystem and Terahertz Research Center China Academy of Engineering PhysicsChengdu 610200China Institute of Electronic Engineering China Academy of Engineering PhysicsMianyang 621999China Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin Tianjin 300350China

Understanding hydrogen diffusion in amorphous SiO2(a-SiO2),especially under strain,is of prominent importance for improving the reliability of semiconducting devices,such as metal-oxide-semiconductor field effect *** this work,the diffusion of hydrogen atom in a-SiO2 under strain is simulated by using molecular dynamics(MD)with the ReaxFF force field.A defect-free a-SiO2 atomic model,of which the local structure parameters accord well with the experimental results,is *** is applied by using the uniaxial tensile method,and the values of maximum strain,ultimate strength,and Young's modulus of the a-SiO2 model under different tensile rates are *** diffusion of hydrogen atom is simulated by MD with the ReaxFF,and its pathway is identified to be a series of hops among local energy ***,the calculated diffusivity and activation energy show their dependence on *** diffusivity is substantially enhanced by the tensile strain at a low temperature(below 500 K),but reduced at a high temperature(above 500 K).The activation energy decreases as strain *** research shows that the tensile strain can have an influence on hydrogen transportation in a-SiO2,which may be utilized to improve the reliability of semiconducting devices.

关键词： molecular dynamics tensile strain amorphous SiO2 hydrogen diffusion

Recent advances and practical challenges of high-energy-density flexible lithium-ion batteries

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Frontiers of Chemical Science and Engineering 2024年第8期18卷 79-98页

作者： Guangxiang Zhang Xin Chen Yulin Ma Hua Huo Pengjian zuo Geping Yin Yunzhi Gao Chuankai fu State Key Laboratory of Space Power-Sources Harbin Institute of TechnologyHarbin 150001China MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China

With the rapid iteration and update of wearable flexible devices,high-energy-density flexible lithium-ion batteries are rapidly ***,energy density,and safety are all important indicators for flexible lithium-ion batteries,which can be determined jointly by material selection and structural ***,recent progress on high-energy-density electrode materials and flexible structure designs are *** electrode materials and the next-generation high-energy-density electrode materials are analyzed in *** electrolytes with high safety and excellent flexibility are classified and *** strategies to increase the mass loading of active materials on the electrodes by designing the current collector and electrode structure are discussed with keys of representative *** the novel configuration structures to enhance the flexibility of batteries are *** the end,it is pointed out that it is necessary to quantify the comprehensive performance of flexible lithium-ion batteries and simultaneously enhance the energy density,flexibility,and safety of batteries for the development of the next-generation high-energy-density flexible lithium-ion batteries.

关键词： lithium-ion batteries flexibility high energy density safety

Ab initio calculations on oxygen vacancy defects in strained amorphous silica

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Chinese Physics B 2020年第4期29卷 420-429页

作者： Bao-Hua Zhou fu-Jie Zhang Xiao Liu Yu Song Xu zuo College of Electronic Information and Optical Engineering Nankai UniversityTianjin 300071China Microsystem and Terahertz Research Center China Academy of Engineering PhysicsChengdu 610200China Institute of Electronic Engineering China Academy of Engineering PhysicsMianyang 621999China Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin Tianjin 300350China

The effects of uniaxial tensile strain on the structural and electronic properties of positively charged oxygen vacancy defects in amorphous silica(a-SiO2)are systematically investigated using ab-initio calculation based on density functional *** types of positively charged oxygen vacancy defects,namely the dimer,unpuckered,and puckered four-fold(4×),and puckered five-fold(5×)configurations have been *** is shown by the calculations that applying uniaxial tensile strain can lead to irreversible transitions of defect structures,which can be identified from the fluctuations of the curves of relative total energy versus *** by strain,a positively charged dimer configuration may relax into a puckered 5×configuration,and an unpuckered configuration may relax into either a puckered 4×configuration or a forward-oriented ***,the Fermi contacts of the defects remarkably increase and the defect levels shift under *** Fermi contacts of the puckered configurations also increase under strain to the values close to that of Eα′center in *** addition,it is shown by the calculations that the relaxation channels of the puckered configurations after electron recombination are sensitive to strain,that is,those configurations are more likely to relax into a two-fold coordinated Si structure or to hold a puckered structure under strain,both of which may raise up the thermodynamic charge-state transition levels of the defects into Si band *** strain induces more puckered configurations with the transition levels in Si band gap,it may facilitate directly the development of oxide charge accumulation and indirectly that of interface charge accumulation by promoting proton generation under ionization *** work sheds a light on understanding the strain effect on ionization damage at an atomic scale.

关键词： amorphous silica first-principles calculation strain oxygen vacancy defects

Relation of overexpression of S phase kinase-associated protein 2 with reduced expression of p27 and PTEN in human gastric carcinoma

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World Journal of Gastroenterology 2005年第42期11卷 6716-6721页

作者： Xiu-Mei Ma Ying Liu Jian-Wen Guo Jiang-Hui Liu Lian-fu zuo The Fourth Affiliated Hospital of Hebei Medical University Shijiazhuang 050011 Hebei Province China

AIM： TO investigate the significance of S phase kinase- associated protein 2 （Skp2） expression in human gastric carcinoma and the relation between expressions of Skp2, p27 and PTEN. METHODS： Immunohistochemical analysis was performed on 138 gastric carcinoma specimens, their paired adjacent mucosa specimens, 102 paired lymphatic metastatic carcinoma tissue specimens, 30 dysplasia specimens, 30 intestinal metaplasia specimens, 10 chronic superficial gastritis specimens and 5 normal gastric mucosa specimens for Skp2 expression and on 138 gastric carcinoma specimens for p27 and PTEN expression. RESULTS： Skp2 labeling frequency was significantly higher in intestinal rnetaplasia （12.68±0.86） and adjacent rnucosa （19.324±1.22） than in normal gastric rnucosa （0.53±0.13） and chronic superficial gastritis （0.47±0.19）（P = 0.000）, in dysplasia （16.74±0.82）than in intestinal metaplasia （P = 0.000）; in gastric primary carcinoma （31.34±2.17） than in dysplasia and adjacent rnucosa （P = 0.000）, in metastasis gastric carcinoma in lymph nodes （39.76±2.00） than in primary gastric carcinoma （P = 0.037）, respectively. Skp2 labeling frequency was positively associated with differentiation degree （rho = 0.315, P = 0.000）, vessel invasion （rho = 0.303, P = 0.000） and lymph node metastasis （rho = 0.254, P = 0.000） of gastric cancer. Expression of Skp2 was negatively associated with p27 （rho = -0.451, P = 0.000） and PTEN （rho = -0.480, P = 0.000） expression in gastric carcinoma, p27 expression was positively associated with PTEN expression in gastric carcinoma （rho = 0.642, P = 0.000）.CONCLUSION： Skp2 overexpression may be involvedin carcinogenesis and progression of human gastric carcinoma in vivo, possibly via p27 proteolysis. PTEN may regulate the expression of p27 by negatively regulating Skp2 expression.

关键词： Gastric carcinoma Skp2 p27 PTEN

Analyzing Influencing Factors of Rural Poverty in Typical Poverty Areas of Hainan Province: A Case Study of Lingao County

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Chinese Geographical Science 2018年第6期28卷 1061-1076页

作者： ZHANG Jinping zuo Feng ZHOU Yanmei ZHAI Mengxiao MEI Lin fu Yidi CHENG Yeqing College of Geography and Environmental Sciences Hainan Normal University College of International Education Hainan Normal University

Rural poverty and poverty reduction are not only the focal issues that have attracted worldwide attention, but also the vital issues on people's livelihood that has attached great importance and aimed to be solved by the central and local governments of China. Based on the survey data of 354 farming households, this paper, taking the national poverty county of Lingao County, Hainan Province for an example, examined the characteristics of rural poverty of the county. Moreover, this paper established the spatial lag model(SLM) from five dimensions, namely, status of the household head, household structure, health status, income composition and traffic accessibility, to analyze the main influencing factors of rural poverty according to the values of Moran's I and the diagnosis of spatial dependence of the OLS model. It is found that the poor farming households gathered mainly in five towns in the north and southwest of the county, and the rural poverty have the characteristics of low educational level of the heads, more minor children, high population of farming peasants, high incidence of disease and low proportion of household wage-equivalent income. The results also showed that the variables such as the number of minor children, the number of migrant worker, the number of farming peasants and the proportion of wage-equivalent income have significant effectiveness on rural poverty, while the status of the household head, health status and traffic accessibility have little influence. It is an important way to realize the goal of poverty alleviation by controlling the number of farmers' fertility, strengthening the vocational skills training of farmers, vigorously developing specialization and large-scale agriculture and increasing the employment opportunities of farmers.

关键词： rural poverty targeted poverty alleviation spatial lag model Lingao County China

Large‑Sized High‑Efficiency Fiber Perovskite Solar Cells Fabricated by Automatic Thin‑Film Coating on Curved Surfaces

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Advanced Fiber Materials 2023年第5期5卷 1799-1809页

作者： Qi Qi Zhiguang Liu Zhuang zuo Zongyang Peng Yongping fu Shaocong Hou Dechun Zou Key Laboratory of Polymer Chemistry and Physics of Ministry of Education Center for Soft Matter Science and EngineeringCollege of Chemistry and Molecular EngineeringBeijing National Laboratory for Molecular SciencesPeking UniversityBeijing 100871China School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China

Perovskite solar cells in a fiber format have great potential for wearable electronics due to their excellent flexibility,efficient light harvesting,and potentially high power conversion efficiency(PCE).However,the fabrication of large-sized fiber perovskite solar cells(FPSCs)while maintaining high efficiency remains a major challenge because of the difficulty in the formation of uniform crystalline perovskite films on highly curved ***,we report a scale-up automatic approach for the fabrication of large-sized FPSCs via sequential coating of active layers on fiber substrates and posttreatment of perovskite *** focus on understanding the perovskite film formation process on fibers and manage to control the film thickness,morphology,and crystallinity by adjusting the coating speed,precursor solution aging time,and *** a result,a 20.0-cm-long FPSC with a PCE of 7.63%is achieved,and this length is almost ten times longer than those of the previously reported *** work represents a breakthrough in fabricating large-sized high-efficiency FPSCs,which will ultimately lead to practical applications of FPSCs.

关键词： Fiber electronics Perovskite solar cells Large size High efficiency Automatic fabrication

Upregulation of Nogo receptor expression induces apoptosis of retinal ganglion cells in diabetic rats

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Neural Regeneration Research 2014年第8期9卷 815-820页

作者： Xuezheng Liu Zhongfu zuo Wanpeng Liu Zhiyun Wang Yang Hou Yunjie fu Yuzhi Han Department of Anatomy Liaoning Medical University Scientific Experimental Center Liaoning Medical University

The Nogo receptor is an essential factor for neuronal apoptosis, but the changes in Nogo receptor expression in the retina and the effects of the Nogo receptor on retinal ganglion cell apoptosis in diabetes mellitus remain unclear. We found that Nogo receptor expression was mainly visible in retinal ganglion cells of a rat model of diabetes mellitus induced by streptozotocin. At 12 weeks after onset of diabetes mellitus, Nogo receptor and Rho kinase expression signiifcantly increased in the retina, and retinal ganglion cell apoptosis was apparent. When RNA interference was used to suppress Nogo receptor expression in rat retina, Rho kinase expression was obviously inhibit-ed, and retinal ganglion cell apoptosis was evidently reduced in rats with diabetes mellitus. These results indicate that upregulation of Nogo receptor expression is an important mechanism of retinal ganglion cell apoptosis in rats with diabetes mellitus.

关键词： nerve regeneration diabetes mellitus diabetic retinopathy visual acuity retinal ganglioncells apoptosis Nogo receptor Rho kinase myelin-associated protein NSFC grant neural regeneration

Effect of New Dayuan powder on methicillin-resistant Staphylococcus aureus biofilms in vitro

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Journal of Traditional Chinese Medicine 2019年第6期39卷 794-799页

作者： Zhu Li Liu Chang zuo Xue fu Zheng Wang Yinghui Wang Yi Qi Wensheng Guang'anmen Hospital Beijing University of Chinese MedicineBeijing 100029China Department of Emergency Guang'anmen HospitalChina Academy of Chinese Medical SciencesBeijing 100053China Experimental Research Center China Academy of Chinese Medical SciencesBeijing 100700China 不详

OBJECTIVE:To observe the effects of New Dayuan powder(NDYP)on Methicillin-resistant Staphylococcus aureus(MRSA)biofilms and the embedded bacteria in ***:2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2 H-tetrazolium-5-carboxanilide(XTT)assays were used to study the effects of NDYP on developing MRSA biofilms:100μL of bacterial culture and100μL drug solution were added to wells of96-well *** 24 h of incubation,the plates were washed and XTT-phenazine methyl sulfate(PMS)was added to enable counting of the number of live bacteria in biofilms using a microplate *** assays were also used to explore the effects of NDYP on mature MRSA biofilms:100μL of bacterial culture were added to wells of 96-well *** were cultured in the plates for 24 h,and then drug solution was *** plates were cultured for another 24 h,and then XTT-PMS was added to detect the number of live bacteria in the *** electron microscopy(SEM)was used to observe the effects of NDYP on mature MRSA biofilms:washed and sterilized glass coverslips were added to 24-well *** culture was *** 24 h of incubation,drug solution was *** another 24 h of incubation,the samples were observed by ***:XTT assays showed that the number of live bacteria in both developing and mature MRSA biofilms decreased significantly(P<0.01)after the administration of *** images showed that NDYP could destroy the structure of the bacteria and resulted in uneven thickness of MRSA ***:In vitro,NDYP has obvious inhibitory effects on the formation of MRSA biofilms and on mature biofilms.

关键词： Methicillin-resistant Staphylococcus aureus Biofilms In vitro techniques New Dayuan powder

Large-Scale Circulation Features Typical of Wintertime Extensive and Persistent Low Temperature Events in China

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Atmospheric and Oceanic Science Letters 2011年第4期4卷 235-241页

作者： BUEH Cholaw fu Xian-Yue XIE zuo-Wei International Center for Climate and Environment Sciences （ICCES） Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics （LASG） Institute of At- mospheric Physics Chinese Academy of Sciences Beijing 100029 China

A pair of northeast-southwest-tilted mid-tropospheric ridges and troughs on the continental scale was observed to be the key circulation feature common among wintertime extensive and persistent low tempera-ture events (EPLTE) in *** the persistence of such anomalous circulations,the split flow over the inner Asian continent and the influent flow over the southeast-ern coast of China correspond well to the expanded and amplified Siberian high with tightened sea level pressure gradients and hence,a strong,cold advection over south-eastern *** western Pacific subtropical high tends to expand northward during the early stages of most EPLTEs.

关键词： extensive and persistent low temperature event Siberian high tilted ridge and trough