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Climate change and glacier area variations in China during the past half century

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Journal of Mountain Science 2016年第8期13卷 1345-1357页

作者： TIAN Hong-zhen YANG Tai-bao LV Hui LI Cheng-xiu HE Ying-bin School of Management Tianjin Polytechnic University Institute of Glaciology and Ecogeography College of Earth and Environmental Sciences Lanzhou University Remote Sensing Laboratories Department of Geography University of Zurich Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences

Glacier variations in the Tibetan Plateau and surrounding mountain ranges in China affect the livelihood of over one billion people who depend on water from the Yellow, Yangtze, Brahmaputra, Ganges and Indus rivers originating in these areas. Based on the results of the present study and published literature, we found that the glaciers shrank ：5.7% in area from 1963 to 20：0 with an annual area change of -0.33%. The shrinkage generally decreased from peripheral mountain ranges to the interior of Tibet. The linear trends of annual air temperature and precipitation at 147 stations were 0.36℃（10a）^-1 and 8.96 mm （10a）^-1 respectively from 1961 to 2010. The shrinkage of glaciers was well correlated with the rising temperature and the spatial patterns of the shrinkage were influenced by other factors superimposed on the rising temperature such as glacier size, type, elevation, debris cover and precipitation.

关键词： Glacier area Climate change Air

Chronic stress induces ageing-associated degeneration in rat Leydig cells

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Asian Journal of Andrology 2012年第4期14卷 643-648页

作者： Fei-Fei Wang Qian Wang Yong Chen Qiang Lin Hui-bao Gao Ping Zhang Department of Biochemistry and Molecular Biology School of Medicine Shanghai Jiao Tong UniversityShanghai 200025China

Several studies have suggested that stress and ageing exert inhibitory effects on rat Leydig cells. In a pattern similar to the normal process of Leydig cell ageing, stress-mediated increases in glucocorticoid levels inhibit steroidogenic enzyme expression that then results in decreased testosterone secretion. We hypothesized that chronic stress accelerates the degenerative changes associated with ageing in Leydig cells. To test this hypothesis, we established a model of chronic stress to evaluate stress-induced morphological and functional alterations in Brown Norway rat Leydig cells; additionally, intracellular lipofuscin levels, reactive oxygen species （ROS） levels and DNA damage were assessed. The results showed that chronic stress accelerated ageing-related changes： ultrastructural alterations associated with ageing, cellular lipofuscin accumulation, increased ROS levels and more extensive DNA damage were observed. Additionally, testosterone levels were decreased. This study sheds new light on the idea that chronic stress contributes to the degenerative changes associated with ageing in rat Leydig cells in vivo.

关键词： Ageing chronic stress DNA damage Leydig cells reactive oxygen species

干燥方式对高氯酸铵/石墨烯复合材料的结构和热分解行为的影响

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物理化学学报 2013年第10期29卷 2079-2086页

作者：王学宝李晋庆罗运军北京理工大学材料学院北京100081 中国兵器科学研究院北京100089

通过溶胶-凝胶法制备了石墨烯水凝胶,并将其与高氯酸铵(AP)复合,然后分别采用自然干燥、冷冻干燥和超临界CO_2干燥三种干燥方式制备了AP/石墨烯复合材料,并通过扫描电镜(SEM)、元素分析(EA)、X射线衍射(XRD)、差示扫描量热仪(DSC)和热重... 详细信息

通过溶胶-凝胶法制备了石墨烯水凝胶,并将其与高氯酸铵(AP)复合,然后分别采用自然干燥、冷冻干燥和超临界CO_2干燥三种干燥方式制备了AP/石墨烯复合材料,并通过扫描电镜(SEM)、元素分析(EA)、X射线衍射(XRD)、差示扫描量热仪(DSC)和热重-红外联用技术(TG-FTIR)研究了不同干燥方式对其结构和热分解行为的影响.结果表明,干燥方式对AP/石墨烯复合材料的形貌具有明显影响,其中通过超临界CO_2干燥制备的AP/石墨烯复合材料基本能保持与石墨烯气凝胶相似的外观和多孔结构.通过自然干燥、冷冻干燥和超临界CO_2干燥制备的AP/石墨烯复合材料中AP的质量分数分别为89.97%、92.41%和94.40%,其中通过超临界CO_2干燥制备的复合材料中AP的粒径尺寸为69 ***测试结果表明,石墨烯对AP的热分解过程具有明显的促进作用,能使AP的低温分解过程大大减弱,高温分解峰温明显降低.三种干燥方式相比,通过超临界CO_2干燥制备的AP/石墨烯复合材料中石墨烯的促进作用最明显.与纯AP相比,其高温分解峰温降低了83.7°C,表观分解热提高到2110 J·g^(-1).TG-FTIR分析结果表明,AP/石墨烯复合材料的热分解过程中,AP分解产生的氧化性产物与石墨烯发生了氧化反应,生成了CO_2.

关键词：干燥方式石墨烯高氯酸铵溶胶-凝胶法热分解

Influence of metallurgical processing parameters on defects in cold-rolled steel sheet caused by inclusions

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International Journal of Minerals,Metallurgy and Materials 2019年第4期26卷 440-446页

作者： Rui Wang Yan-ping bao Yi-hong Li Zhi-jie Yan Da-zhao Li Yan Kang School of Materials Science and Engineering North University of China State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of Materials Science and Engineering Taiyuan University of Science and Technology

The cleanliness and defects for cold-rolled steel sheet caused by inclusions are greatly influenced by parameters in the metallurgical processing. Good control of parameters during the processing can lead to a better product. In this paper, data mining was used to explore the influence of parameters on defects in steel sheets. A decision tree model was established and it was found that the oxygen content before deoxidation, the end-point temperature of the converter, and the temperature before deoxidation had a great impact on the defects in the cold-rolled sheet that were caused by inclusions. This finding was confirmed by experiments with infrared absorption, scanning electron microscopy(SEM), energy dispersive X-ray spectroscopy(EDS), and automatic inclusion analysis methods. After optimization according to results from the model and experiments, the defect rate caused by the inclusions was reduced from 0.92% to 0.38%.

关键词： IF steel steel cleanliness data mining inclusions

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高压直流电缆聚丙烯绝缘电场调控

物理学报 2023年第6期72卷 325-334页

作者：俞葆青夏兵杨晓砚万宝全查俊伟北京国电富通科技发展有限责任公司北京100071 南瑞集团有限公司(国网电力科学研究院有限公司) 南京211106 北京科技大学化学与生物工程学院北京100083

高压电缆是决定电力输送质量和容量的关键要素.聚丙烯由于自身优良的耐热性、绝缘性和绿色环保性被广泛关注,并应用于电缆绝缘材料开发.高压电缆聚丙烯绝缘材料需要承受脉冲电压和直流额定电压,容易引起电场畸变从而引发空间电荷积累.此... 详细信息

高压电缆是决定电力输送质量和容量的关键要素.聚丙烯由于自身优良的耐热性、绝缘性和绿色环保性被广泛关注,并应用于电缆绝缘材料开发.高压电缆聚丙烯绝缘材料需要承受脉冲电压和直流额定电压,容易引起电场畸变从而引发空间电荷积累.此外,电缆运行过程中,温度会急剧升高,严重影响电缆的绝缘性能,导致电树枝的引发和生长.因此需要对高压电缆进行电场调控从而抑制电场畸变、局部放电、电树枝化等劣化现象的出现.本文重点介绍了高压直流电缆聚丙烯绝缘材料电场调控的理论与方法,分析了当前电场调控的重点,最后展望了聚丙烯电缆绝缘的应用前景.

关键词：高压电缆聚丙烯电场调控绿色环保

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基于医疗质量管理患者信任度评价指标Delphi构建

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科技管理研究 2011年第24期31卷 48-52页

作者：董恩宏鲍勇上海交通大学安泰经济与管理学院上海200052

在整理文献综述的基础上,挑选具有代表性的65个指标制成专家咨询问卷,用Delphi法对20位专家进行两轮咨询,根据咨询结果筛选和修改指标体系,最终构建基于医疗质量管理的患者信任度评价指标体系,证明Delphi法在构建基于医疗质量管理的患... 详细信息

在整理文献综述的基础上,挑选具有代表性的65个指标制成专家咨询问卷,用Delphi法对20位专家进行两轮咨询,根据咨询结果筛选和修改指标体系,最终构建基于医疗质量管理的患者信任度评价指标体系,证明Delphi法在构建基于医疗质量管理的患者信任度评价指标体系的研究中具有良好效果。

关键词：患者信任评价指标体系 Delphi法医疗质量管理

Intramolecular Charge Transfer Dual Fluorescence pH Sensing using p-Dibutylaminobenzoic Acid-β-cyclodextrin Inclusion Complex

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Chinese Chemical Letters 2003年第5期14卷 495-498页

作者： Li Rong LIN Zhao LI Wen Liang YANG Hong CHEN Yun bao JIANG Department of Chemistry and the MOE Key Laboratory of Analytical Sciences Xiamen UniversityXiamen 361005

The intramolecular charge transfer dual fluorescence of p-dibutylaminobenzoic acid-b-cyclodextrin inclusion complex showed a substantially higher sensitivity toward aqueous solution pH variation when compared with that of p-dibutylaminobenzoic acid alone, which established a new principle for direct CT fluorescence sensing in aqueous solution by using the CT fluorophore-cyclodextrin inclusion complex.

关键词： pH sensing dual fluorescence intramolecular charge transfer cyclodextrin inclusion complex p-dibutylaminobenzoic acid.

Soil nutrients in relation to vertical roots distribution in the riparian zone of Three Gorges Reservoir,China

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Journal of Mountain Science 2018年第7期15卷 1498-1509页

作者： ZHONG Rong-hua HU Jin-ming bao Yu-hai Wang Fei HE Xiu-bin Yunnan Key Laboratory of International Rivers and Transboundary Eeo-security Kunming 650091 China Institute oflnternational Rivers and Eco-security Yunnan University Kunming 650091 China Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China

Since the impoundment of the Three Gorges Reservoir(TGR), the riparian zone has been subjected to numerous environmental changes. This study was conducted to recognize the distribution of grass roots and its impacts on soil nutrients in the water level fluctuation zone of TGR. Roots of four predominant herbaceous plants in the study area, specifically, Cynodon dactylon, Hemarthria altissima, Hemarthria compressa, and Paspalum paspaloides, and their corresponding relation with soil nutrient contents were investigated. Root surface area density was determined with Win RHIZO, and the relationships of root distribution with soil depths and soil nutrient contents were studied. The results indicates that most roots are distributed in the top soil layer of 0-10 cm. Estimated root surface area density for the selected grass species ranges from 0.16 to 13.44 cm^2/cm^3, and decreases exponentially with an increase in soil depth. Soil organic matter and total nitrogen contents are significantly lower on bare control area than the corresponding values on the grasslands. Total nutrient contents on grasslands of C. dactylon and H. compressa are higher than those of other grass areas. Root length density and root surface area density are significantly correlated with soil organic matter and total nitrogen content for the four grasslands. The present results suggests that plant roots have significant effects on the distribution of soil nutrients in soil profiles in the riparian zone along the TGR. Nevertheless, additional investigations are needed to reveal the specific interactions between plant roots distribution, soil nutrients and water level fluctuations.

关键词： Roots distribution Soil nutrients Water level fluctuations Riparian zone Root surface area density Root length density

Stability and Passivity Analysis for Lur'e Singular Systems with Markovian Switching

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International Journal of Automation and computing 2013年第1期10卷 79-84页

作者： Ping-Fang Zhou Yue-Ying Wang Quan-bao Wang Ji-An Chen Deng-Ping Duan School of Aeronautics and Astronautics Shanghai Jiao Tong University

This paper is concerned with the stochastic stability and passivity analysis for a class of Lur’e singular systems with time-varying delay and Markovian switching. By using the free-weighting matrices approach, a delay-dependent stability criterion, which guarantees that the system is stochastically stable and robustly passive, is derived in terms of linear matrix inequality （LMI）. Two numerical examples are provided to illustrate the effectiveness of the proposed method. 更多还原

关键词： Lur’e singular time-delay systems Markovian jump systems delay-dependent passivity linear matrix inequality (LMI)