检索结果-南通市图书馆

Experimental investigation on the bursting of single molten droplet in coolant

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2007年第6期18卷 376-380页

作者： LI Tianshu YANG Yanhua yuan minghao HU Zhihua School of Mechanical Power Engineering Shanghai Jiaotong University Shanghai 200030 China

An experiment facility for observing low-temperature molten tin alloy droplet into water was es- tablished to investigate mechanisms of vapor explosion occurring in severe accidents of a fission nuclear *** vapor explosion behaviors of the molten material were observed by a high-speed video cam- era and the vapor explosion pressures were recorded by a pressure transducer mounted under the water *** results showed that the pressure reached a peak value when the molten metal temperature was 600℃-650℃,and the coolant temperature had an obvious decreasing effect on the droplet breakups.A model for single droplet fuel/coolant interaction is *** considers that in the case of Rayleigh-Taylor instability,the coolant that jets from opposite direction penetrates into the fuel and the vapor explosion occurs because of the rapid *** model explained the effect of metal droplet temperature and coolant temperature on vapor explosion.

关键词：蒸汽爆炸 FCI 实验装置冷却剂

Effects of molten material temperatures and coolant temperatures on vapor explosion

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2007年第5期18卷 311-315页

作者： LI Tianshu YANG Yanhua yuan minghao HU Zhihua School of Mechanical Power Engineering Shanghai Jiaotong University Shanghai 200240 China

An observable experiment facility for low-temperature molten materials to be dropped into water was set up in this study to investigate the mechanism of the vapor explosion. The effect of the fuel and coolant interaction (FCI) on the vapor explosion during the severe accidents of a fission nuclear reactor has been studied. The experiment results showed that the molten material temperature has an important effect on the vapor explosion behavior and pressure. The increase of the coolant temperature would decrease the pressure of the vapor explosion.

关键词：视觉实验设备蒸汽爆炸反应堆事故预防

Characteristics,sources and health risks assessment of VOCs in Zhengzhou,China during haze pollution season

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2021年第10期33卷 44-57页

作者： Dong Zhang Bing He minghao yuan Shijie Yu Shasha Yin Ruiqin Zhang College of Chemistry Zhengzhou UniversityZhengzhou 450001China Institute of Environmental Sciences Zhengzhou UniversityZhengzhou 450001China School of Ecology and Environment Zhengzhou UniversityZhengzhou 450001China Environmental Protection Monitoring Center Station of Zhengzhou Zhengzhou 450007China

Zhengzhou is one of the most haze-polluted cities in Central China with high organic carbon emission,which accounts for 15%-20%of particulate matter(PM_(2.5))in winter and causes significantly adverse health *** organic compounds(VOCs)are the precursors of secondary PM_(2.5)and O_(3)*** investigation of characteristics,sources and health risks assessment of VOCs was carried out at the urban area of Zhengzhou from 1^(st) to 31^(st) December,*** mean concentrations of total detected VOCs were 48.8±23.0 ***(22.0±10.4 ppbv),halocarbons(8.1±3.9 ppbv)and aromatics(6.5±3.9 ppbv)were the predominant VOC species,followed by alkenes(5.1±3.3 ppbv),oxygenated VOCs(3.6±1.8 ppbv),alkyne(3.5±1.9,ppbv)and sulfide(0.5±0.9 ppbv).The Positive Matrix Factorization model was used to identify and apportion VOCs *** major sources of VOCs were identified as vehicular exhaust,industrial processes,combustion,fuel evaporation,and solvent *** carcinogenic and non-carcinogenic risk values of species were *** carcinogenic and non-carcinogenic risks of almost all air toxics increased during haze *** total non-carcinogenic risks exceeded the acceptable *** VOC species posed no non-carcinogenic risk during three haze *** carcinogenic risks of chloroform,1,2-dichloroethane,1,2-dibromoethane,benzyl chloride,hexachloro-1,3-butadiene,benzene and naphthalene were above the acceptable level(1.0×10^(-6))but below the tolerable risk level(1.0×10^(-4)).Industrial emission was the major contributor to non-carcinogenic,and solvent use was the major contributor to carcinogenic risks.

关键词： Zhengzhou Positive Matrix Factorization Health risks VOC profiles

Recent development of a refined multiple air pollutant emission inventory of vehicles in the Central Plains of China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2019年第10期31卷 80-96页

作者： Xingke Gu Shasha Yin Xuan Lu Huan Zhang Lingling Wang Ling Bai Chen Wang Ruiqin Zhang minghao yuan Research Institute of Environmental Science College of Chemistry and Molecular Engineering Zhengzhou University Zhengzhou 450001China Henan Environmental Monitoring Center Zhengzhou 450004 China Environmental Protection Monitoring Center Station of Zhengzhou Zhengzhou 450007 China

Central Plains region of China,represented by Henan Province,is facing serious air pollution *** exhaust emissions had adverse impacts on the atmospheric *** first comprehensive and novel vehicle emission inventory for Henan Province using vehicle kilometers traveled,localized emission factors,and activity data at city-level was ***,3 km×3 km gridded emission and temporal variations were determined by using localized *** show that the total emissions of sulfur dioxide(SO2),nitrogen oxides(NOx),carbon monoxide(CO),particular matter with aerodynamic diameter<10μm(PM10),aerodynamic diameter<2.5μm(PM2.5),volatile organic compounds(VOCs),VOCs-evaporation and ammonia in 2015 were 9.1,533.4,1190.7,23.7,21.6,150.8,31.5 and 10.4 Gg,respectively,and the emission intensities of the above pollutants were 0.05,2.7,6.0,0.1,0.1,0.8,0.2 and 0.05 g/km,*** meeting the Primary China 1,China 3 and China 4 contributed 89.1%,82.7%,75.3%,75.5%,75.5%,68.2%,68.4%and 82.3%for SO2,NOx,CO,PM10,PM2.5,VOCs,VOCs-evaporation and ammonia emissions,***,Zhoukou,Nanyang,Luoyang,Shangqiu and Xinyang showed relatively higher emissions and contributed more than 50%of each *** spatial distribution indicated obvious characteristics of the road network,and high-level emission was concentrated in the downtown ***,the ozone formation potential(OFP)based on the estimated speciated VOC emissions was 569.6 Gg in Henan *** and aromatic hydrocarbons were the main species of VOCs,whereas olefins contributed the largest proportion of OFP,with 42.2%.

关键词： Vehicle Emission standard Gridded allocation Ozone formation potential Speciated volatile organic compounds

Enhanced mixing state of black carbon with nitrate in single particles during haze periods in Zhengzhou, China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第1期34卷 185-196页

作者： Qianni Zhou Chunlei Cheng Suxia Yang minghao yuan Jingjing Meng Haifeng Gong Qien Zhong Yao Zhang Yutong Xie Zhen Zhou Mei Li Institute of Mass Spectrometry and Atmospheric Environment Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air PollutionJinan UniversityGuangzhou 510632China Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality Guangzhou 510632China School of Environment and Planning Liaocheng UniversityLiaocheng 252000China Institute for Environment and Climate Research Jinan UniversityGuangzhou 510632China Zhengzhou Environmental Protection Monitoring Center Station Zhengzhou 450007China

Black carbon(BC)plays an important role in air quality and climate change,which is closely associated with its mixing state and chemical *** this work the mixing state of BC-containing single particles was investigated to explore the evolution process of ambient BC particles using a single particle aerosol mass spectrometer(SPAMS)in March 2018 in Zhengzhou,*** BC-containing particles accounted for 61.4%of total detected ambient single particles and were classified into five types including BC-nitrate(BC-N,52.3%)as the most abundant species,followed by BC-nitrate-sulfate(BC-NS,22.4%),BCOC(16.8%),BC-fresh(BC-F,4.5%)and BC-sulfate particles(BC-S,4.0%).With enhancement of the ambient nitrate concentration,the relative peak area(RPA)of nitrate in BC-N and BC–NS particles both increased,yet only the number fraction(N_(f))of BC–N particles increased while the N_(f) of BC-NS particles decreased,suggesting that the enhanced mixing state of BC with nitrate was mainly due to the increase in the ambient nitrate mass *** addition,the Nfof BC-N decreased from 65.3%to 28.4%as the absorbing Angstrom exponents(AAE)of e BC increased from 0.75 to 1.45,which indicated the reduction of light absorption ability of aged BC particles with the enhanced formation of BC-N *** results of this work indicated a change in the mixing state of BC particles due to the dominance of nitrate in PM_(2.5),which also influenced the optical properties of aged BC particles.

关键词： Single particle Black carbon Mixing state Nitrate Aging process

Impaired autophagy in amyloid-beta pathology:A traditional review of recent Alzheimer's research

在线全文

学校读者我要写书评

暂无评论

The Journal of Biomedical Research 2023年第1期37卷 30-46页

作者： minghao yuan Yangyang Wang Zhenting Huang Feng Jing Peifeng Qiao Qian Zou Jing Li Zhiyou Cai Chongqing Medical University Chongqing 400042China Department of Neurology Chongqing General HospitalUniversity of Chinese Academy of SciencesChongqing 400013China Department of Neurology Chongqing SchoolUniversity of Chinese Academy of SciencesChongqing 400013China Chongqing Key Laboratory of Neurodegenerative Diseases Chongqing 400013China

Alzheimer’s disease(AD) is the most prevalent neurodegenerative disorder. The major pathological changes in AD progression are the generation and accumulation of amyloid-beta(Aβ) peptides as well as the presence of abnormally hyperphosphorylated tau proteins in the brain. Autophagy is a conserved degradation pathway that eliminates abnormal protein aggregates and damaged organelles. Previous studies have suggested that autophagy plays a key role in the production and clearance of Aβ peptides to maintain a steady-state of Aβ peptides ***, a growing body of evidence suggests that autophagy is significantly impaired in the pathogenesis of AD, especially in Aβ metabolism. Therefore, this article reviews the latest studies concerning the mechanisms of autophagy, the metabolism of Aβ peptides, and the defective autophagy in the production and clearance of Aβpeptides. Here, we also summarize the established and new strategies for targeting autophagy in vivo and through clinical AD trials to identify gaps in our knowledge and to generate further questions.

关键词： Alzheimer’s disease autophagy amyloid-beta amyloid precursor protein secretases metabolism

Microglia in brain aging:An overview of recent basic science and clinical research developments

在线全文

学校读者我要写书评

暂无评论

Journal of Biomedical Research 2024年第2期38卷 122-136页

作者： Haixia Fan Minheng Zhang Jie Wen Shengyuan Wang minghao yuan Houchao Sun Liu Shu Xu Yang Yinshuang Pu Zhiyou Cai Chongqing Medical University Chongqing 400042China Department of Neurology Chongqing General HospitalChongqing 400013China Chongqing Key Laboratory of Neurodegenerative Diseases Chongqing 400013China Department of Neurology the First Hospital of Shanxi Medical UniversityTaiyuanShanxi 030001China Department of Gerontology the First People's Hospital of JinzhongJinzhongShanxi 030009China

Aging is characterized by progressive degeneration of tissues and organs,and it is positively associated with an increased mortality *** brain,as one of the most significantly affected organs,experiences age-related changes,including abnormal neuronal activity,dysfunctional calcium homeostasis,dysregulated mitochondrial function,and increased levels of reactive oxygen *** changes collectively contribute to cognitive *** is also a key risk factor for neurodegenerative diseases,such as Alzheimer's disease and Parkinson's *** many years,neurodegenerative disease investigations have primarily focused on neurons,with less attention given to microglial ***,recently,microglial homeostasis has emerged as an important mediator in neurological disease ***,we provide an overview of brain aging from the perspective of the *** doing so,we present the current knowledge on the correlation between brain aging and the microglia,summarize recent progress of investigations about the microglia in normal aging,Alzheimer's disease,Parkinson's disease,Huntington's disease,and amyotrophic lateral sclerosis,and then discuss the correlation between the senescent microglia and the brain,which will culminate with a presentation of the molecular complexity involved in the microglia in brain aging with suggestions for healthy aging.

关键词： microglia brain aging Alzheimer's disease Parkinson's disease Huntington's disease

OSCILLATION OF A CLASS OF HILLE EQUATION

在线全文

学校读者我要写书评

暂无评论

Annals of Differential Equations 2005年第3期21卷 256-259页

作者： Cheng Chonggao yuan minghao Dept. of Math. Huanggang Normal College Huangzhou 438000

This paper studies a class of Hille equation. A formula for solutions of a class of Hille equation is given. Under some suitable conditions the oscillation and nonoscillation of a class of Hille equation are establish... 详细信息

关键词： Hille equation function identity self-conjugate differential equation oscillation property

在线全文

学校读者我要写书评

暂无评论

反应堆内熔融物冷却的三维数值模拟研究

原子能科学技术 2019年第7期53卷 1255-1263页

作者：薛峰袁明豪张建陈秋炀苏州热工研究院有限公司核安全与运行技术中心

目前国际上普遍采用堆芯熔融物压力容器内滞留(IVR)策略来缓解严重事故后果。本文基于日本应用能源研究所开发的核电厂事故分析程序SAMPSON,对其压力容器内熔融物冷却分析(DCA)模块进行改进,增加了熔池内金属和氧化物分层模型,开发了熔... 详细信息

目前国际上普遍采用堆芯熔融物压力容器内滞留(IVR)策略来缓解严重事故后果。本文基于日本应用能源研究所开发的核电厂事故分析程序SAMPSON,对其压力容器内熔融物冷却分析(DCA)模块进行改进,增加了熔池内金属和氧化物分层模型,开发了熔融物三维直角坐标网格与压力容器三维曲面坐标的交界面几何参数前处理程序,改进了压力容器外冷却的传热关系式。通过AP1000核电机组严重事故下的IVR对改进后的程序进行分析验证,并与实验结果进行对比。结果表明,改进后的SAMPSON程序可对核电厂严重事故下下封头内的熔融物冷却滞留开展有效的模拟分析。

关键词：严重事故 SAMPSON程序熔融物压力容器内滞留两层熔池模型