检索结果-南通市图书馆

Journal of Materials Science & Technology 2013年第9期29卷 830-834页

作者： yunfeng wu Dongping Liu Naisen Yu Yuanda Liu Hongwei Liang Guotong Du School of Physics and Optoelectronic Technology Dalian University of Technology School of Physics and Materials Engineering Dalian Nationalities University

ZnO thin films were grown on Si （111） substrates by low-pressure metal-organic chemical vapor deposition. The crystal structures and electrical properties of as-grown sample were investigated by scanning electron microscopy （SEM） and conductive atomic force microscopy （C-AFM）. It can be seen that with increasing growth temperature, the surface morphology of ZnO thin films changed from flake-like to cobblestones-like structure. The current maps were simultaneously recorded with the topography, which was gained by C-AFM contact mode. Conductivity for the off-axis facet planes presented on ZnO grains enhanced. Measurement results indicate that the off-axis facet planes were more electrically active than the c-plane of ZnO flakes or particles probably due to lower Schottky barrier height of the off-axis facet planes.

关键词： ZnO thin films Metal-organic chemical vapor deposition Conductive atomic force microscopy Scanning electron microscopy

骨化三醇通过磷脂酰肌醇3激酶/蛋白激酶B信号通路对糖尿病足溃疡大鼠创面愈合影响的研究

在线全文

学校读者我要写书评

暂无评论

中国糖尿病杂志 2024年第7期32卷 532-539页

作者：骆燕洪田宇武云凤李娇娇杨书香王翎睿谢婷婷阳琰蔡玉兰遵义医科大学第二附属医院内分泌科 563006

目的探讨骨化三醇干预糖尿病足溃疡(DFU)大鼠对磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(AKT)信号通路及创面愈合的影响。方法 32只雄性SD大鼠分为正常对照(Con)组、DFU组、骨化三醇低剂量(L)组、骨化三醇高剂量(H)组。各组大鼠左足背制造直径... 详细信息

目的探讨骨化三醇干预糖尿病足溃疡(DFU)大鼠对磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(AKT)信号通路及创面愈合的影响。方法 32只雄性SD大鼠分为正常对照(Con)组、DFU组、骨化三醇低剂量(L)组、骨化三醇高剂量(H)组。各组大鼠左足背制造直径5 mm、深达筋膜的圆形创面。HE染色观察创面组织病理学变化,免疫组织化学法比较各组创面组织CD34阳性细胞分布及p-PI3K、p-AKT表达,ELISA法检测血清IL-6、干扰素γ(IFN-γ)、TNF-α和IL-7含量,RT-PCR检测各组PI3K、AKT mRNA表达,Western blot法检测PI3K、p-PI3K、AKT、p-AKT及VEGF蛋白表达。结果与Con组比较,DFU、L、H组IL-6、IFN-γ、TNF-α、IL-7、CD34、PI3K mRNA、AKT mRNA、p-AKT蛋白表达、p-PI3K蛋白表达、p-PI3K/PI3K、p-AKT/AKT升高(P<0.05),PI3K蛋白表达降低(P<0.05),DFU、L组VEGF、AKT蛋白表达降低(P<0.05)。与DFU组比较,L、H组VEGF、AKT、PI3K蛋白表达升高(P<0.05),p-PI3K/PI3K、p-AKT/AKT降低(P<0.05),L组IL-6降低(P<0.05),H组CD34表达升高(P<0.05),IL-6、IFN-γ、TNF-α及IL-7、PI3K mRNA、AKT mRNA、p-AKT蛋白、p-PI3K蛋白表达降低(P<0.05)。与L组比较,H组CD34、VEGF蛋白、AKT蛋白、PI3K蛋白表达升高(P<0.05),IL-6、PI3K mRNA、AKT mRNA、p-AKT蛋白、p-PI3K蛋白、p-PI3K/PI3K、p-AKT/AKT降低(P<0.05)。结论骨化三醇干预可能通过下调PI3K/AKT信号通路活性,抑制炎症反应,促进DFU大鼠新生血管生成及创面愈合。

关键词：骨化三醇糖尿病足溃疡磷脂酰肌醇3激酶/蛋白激酶B信号通路炎症反应

Measurement of GaAs start duration in different solution concentration using infrared images

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2008年第6期53卷 932-936页

作者： LIU Lin YE YuTang wu yunfeng FANG Liang LU JiaJia School of Opto-Electronic Information University of Electronic Science and Technology of China Chengdu 610054 China

This paper proposes a new infrared method to measure the start duration of GaAs substrate in chemi- cal etching. When etching starts, the temperature of liquid-film will change because of heat release in the chemical reaction. As a result, the start duration of GaAs can be tested by collecting real-time in- frared thermal images in the course of temperature variation. Both theoretical analysis and experi- mental results show that the line shape liquid film of a 2-mm width is a good monitoring subject. By making use of the grey distribution change of a certain cross section of the line shape liquid film, the start duration of reaction between GaAs and H2SO4-H2O2-H2O is obtained. The start durations of reac- tion between GaAs substrate and H2SO4:H2O2:H2O (=5:1:50 and 15:3:50) solution are about 0.2 s and 0.3―0.4 s, respectively. This result and relative method will impulse the research of wet chemical etching technology of GaAs and so on.

关键词：红外线辐射时间实时监测液体薄膜砷化镓化学腐蚀

新冠Omicron变异株的人群感染数学模型研究

在线全文

学校读者我要写书评

暂无评论

中国科技论文在线精品论文

中国科技论文在线精品论文 2024年第1期17卷 91-98页

作者：桑晓倩林孟晨鲍贵栋吴云峰厦门大学信息学院福建厦门361005

本文建立了可预测Omicron变异株对社会人群感染的数学模型,通过模型参数描述了Omicron变异株的免疫逃逸特性,并采用下一代矩阵方法计算了模型的基本再生数,随后根据常微分方程的驻点稳定性理论分析,得出该模型的流行病稳态驻点解是全局... 详细信息

本文建立了可预测Omicron变异株对社会人群感染的数学模型,通过模型参数描述了Omicron变异株的免疫逃逸特性,并采用下一代矩阵方法计算了模型的基本再生数,随后根据常微分方程的驻点稳定性理论分析,得出该模型的流行病稳态驻点解是全局渐进稳定的结论。本文依据国家卫健委发布的疫情数据和厦门市的人口普查数据,对模型各参数进行赋值,仿真模拟了厦门市在2022年12月至2023年7月期间的社会人群新冠病毒感染趋势,为政府相关部门优化疫情防控策略提供数学模型技术支持。

关键词：传染病学基本再生数新型冠状病毒稳定性理论

Toposelective synthesis under thermodynamic control and bioactivities of topoisomers based on diethoxycarbonyl glycoluril derivatives

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第17期51卷 2164-2168页

作者： ZHOU Baohan YIN Guodong WANG Zhiguo CHEN yunfeng wu Anxin WAN Jian Key Laboratory of Pesticide and Chemical Biology Ministry of Education Department of Chemistry Central China Normal University Wuhan 430079 China

Six topoisomers consisting of diethoxy- carbonyl glycoluril have been successfully synthe- sized in one-pot by using a “figure-of-seven” building block through anti-connectivity and syn-connectivity reactions, respectively. The structures of all six topo- isomers were first determined by X-ray crystallogra- phy. The finding that (±) CT isomers are the dominant products under thermodynamic control can be ex- plained by the calculated relative energies of the six topoisomers. That the (±) CT isomers have the lowest energy is most likely due to the additional in- tramolecular electrostatic interactions between –NO2 and –OMe groups. The biological activities of the topoisomers were primitively investigated and the results of bioassay showed that the six topoisomers possessed obvious difference of herbicidal activity.

关键词：生物活性热力学控制生物化学 XRD

Coat protein of Chinese wheat mosaic virus upregulates and interacts with cytosolic glyceraldehyde-3-phosphate dehydrogenase,a negative regulator of plant autophagy,to promote virus infection

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2022年第8期64卷 1631-1645页

作者： Erbo Niu Chaozheng Ye Wanying Zhao Hideki Kondo yunfeng wu Jianping Chen Ida Bagus Andika Liying Sun State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection Northwest A&F UniversityXi'an 712100China Institute of Plant Science and Resources Okayama UniversityKurashiki 710‐0046Japan State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro‐products Institute of Plant VirologyNingbo UniversityNingbo 315211China College of Plant Health and Medicine Qingdao Agricultural UniversityQingdao 266109China

Autophagy is an intracellular degradation mechanism involved in antiviral defense,but the strategies employed by plant viruses to counteract autophagy-related defense remain unknown for the majority of the ***,we describe how the Chinese wheat mosaic virus(CWMV,genus Furovirus)interferes with autophagy and enhances its infection in Nicotiana *** two-hybrid screening and in vivo/in vitro assays revealed that the 19 k Da coat protein(CP19 K)of CWMV interacts with cytosolic glyceraldehyde-3-phosphate dehydrogenases(GAPCs),negative regulators of autophagy,which bind autophagy-related protein 3(ATG3),a key factor in ***19 K also directly interacts with ATG3,possibly leading to the formation of a CP19 K–GAPC–ATG3 ***19 K–GAPC interaction appeared to intensify CP19 K–ATG3 ***,CP19 K expression upregulated GAPC gene transcripts and reduced autophagic ***,the silencing of GAPC genes in transgenic *** reduced CWMV accumulation,whereas CP19 K overexpression enhanced ***,our results suggest that CWMV CP19 K interferes with autophagy through the promotion and utilization of the GAPC role as a negative regulator of autophagy.

关键词： antiviral defense autophagy plant virus protein interaction viral coat protein

Simplified quantitative analysis method and its application in the insitu synthesized copper-based azide chips

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 309-316页

作者： Jie Ren yunfeng Li Mingyu Li Xingyu wu Jiabao Wang Qingxuan Zeng State Key Laboratory of Explosion and Technology Beijing Institute of TechnologyBeijing 100081China

Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent ***,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA *** aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition *** this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through *** spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test *** optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content *** with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory ***,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was *** study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.

关键词： Copper-based azide chips Spectrophotometry Separation method Quantitative analysis Ignition ability

Spatiotemporal patterns of the daily relative risk of COVID-19 in China

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2021年第7期31卷 1039-1058页

作者： CHENG Changxiu JIANG Yifan SONG Changqing SHEN Shi wu yunfeng ZHANG Tianyuan State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Key Laboratory of Environmental Change and Natural Disaster Beijing Normal UniversityBeijing 100875China Center for Geodata and Analysis Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China National Tibetan Plateau Data Center Beijing 100101China

The coronavirus disease 2019(COVID-19)pandemic continues to threaten lives and the economy around the *** the risk of COVID-19 can help in predicting spreading trends,identifying risk areas,and making public health *** this study,we proposed a comparative risk assessment method to estimate comprehensive and dynamic COVID-19 risks by considering the pandemic severity and the healthcare system pressure and then employing the z-order curve and fractal *** took the COVID-19 cases from January 19-March 10,2020 in China as our research *** results and analysis revealed that(1)the proposed method demonstrated its feasibility to assess and illustrate pandemic risk;(2)the temporal patterns of the daily relative risk indices of 31 provinces were clustered into four groups(high-value,fluctuating-increase,inverted U-shaped,and low-stable);(3)the spatial distribution of the relative pandemic risk indicated a significant circular pattern centered on Hubei Province;and(4)healthcare system capacity is the key to reducing relative pandemic risk,and cases imported from abroad should be given more *** methods and results of this study will provide a methodological basis and practical guidance for regional pandemic risk assessment and public health decision-making.

关键词： COVID-19 risk assessment spatiotemporal patterns z-order curve fractal

Damage evolution and removal behaviors of GaN crystals involved in double-grits grinding

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第2期6卷 469-484页

作者： Chen Li Yuxiu Hu Zongze Wei Chongjun wu yunfeng Peng Feihu Zhang Yanquan Geng State Key Laboratory of Robotics and System(HIT) Harbin Institute of TechnologyHarbin 150001People’s Republic of China Key Laboratory of Microsystems and Microstructures Manufacturing(HIT) Harbin Institute of TechnologyHarbin 150001People’s Republic of China College of Mechanical Engineering Donghua UniversityShanghai 201620People’s Republic of China Department of Mechanical and Electrical Engineering Xiamen UniversityXiamen 361005People’s Republic of China

Elucidating the complex interactions between the work material and abrasives during grinding of gallium nitride(GaN)single crystals is an active and challenging research *** this study,molecular dynamics simulations were performed on double-grits interacted grinding of GaN crystals;and the grinding force,coefficient of friction,stress distribution,plastic damage behaviors,and abrasive damage were systematically *** results demonstrated that the interacted distance in both radial and transverse directions achieved better grinding quality than that in only one *** grinding force,grinding induced stress,subsurface damage depth,and abrasive wear increase as the transverse interacted distance ***,there was no clear correlation between the interaction distance and the number of atoms in the phase transition and dislocation *** interacted distances between abrasives can decrease grinding force,coefficient of friction,grinding induced stress,subsurface damage depth,and abrasive wear during the grinding *** results of grinding tests combined with cross-sectional transmission electron micrographs validated the simulated damage results,*** atoms,high-pressure phase transition,dislocations,stacking faults,and lattice *** results of this study will deepen our understanding of damage accumulation and material removal resulting from coupling between abrasives during grinding and can be used to develop a feasible approach to the wheel design of ordered abrasives.

关键词： grinding double-grits molecular dynamics damage material removal gallium nitride

代谢当量与无氧阈、氧通气当量的关系探讨及临床意义

在线全文

学校读者我要写书评

暂无评论

吉林医药学院学报 2024年第1期45卷 41-43页

作者：蒋欢魏方志邓美倩吴云峰曹慧玲博鳌一龄生命品质改善中心海南琼海571437

目的探讨代谢当量(metabolic equivalent,MET)与通气无氧阈(ventilatory anaerobic threshold,VAT)、氧通气当量(ventilatory equivalent for oxygen,VE/VO_(2))之间的关系及临床意义。方法回顾性分析近4个月64名无心肺及代谢疾病史、初步诊断为健康的体检人群,用法国Ergoline ErgoEelect 200负荷设备和MetaLyzer 3B-R3心肺功能检测系统进行心肺运动功能测试。计算MET与VAT、MET与VE/VO_(2)之间的相关系数,建立回归方程式。结果MET与VAT相关系数为0.51,回归方程为VAT=1.106 MET+6.885;MET与VE/VO_(2)相关系数为0.95,回归方程为MET=3.176 VE/VO_(2)+4.712。结论对健康体检者,可以用容易获得的MET初步推算出VAT和VE/VO_(2),进而获得VAT以下有氧运动的强度,为临床提供更便捷的评估数据。

关键词：代谢当量无氧阈氧通气当量