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Properties of Nanokaolin and Its Rubber Composites

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Journal of China University of Mining and Technology 2005年第4期15卷 317-321页

作者： zhang yu-de LIU qin-fu JI Lei-bo LU Yin-ping School of Resources and Safety Engineering China University of Mining and Technology Beijing 100083 China

A kind of nanokaolin powder with a thickness of 20-50nm and an average diameter of 300nm is produced through combined procedure of purification, delamination, surface modification and pulverization. The application experiments in butadiene rubber (BR), ethylene-propylene diene methylene (EPDM), and natural rubber (NR) indicates that this nano-kaolin powder material is much better than precipitated silica in reinforcement, while in styrene-butadiene rubber (SBR) it is close to precipitated silica. Nanokaolin is of superiority in elasticity, elongation at break, anti-flexure property.

关键词： nanokaolin properties rubber composites

STUDY ON GEOGRAPHIC VARIATION OF DAHURIAN LARCH IN CHINA

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Journal of Northeast Forestry University 1991年第2期2卷 34-41页

作者： Yang Chuanping zhang Wei yu Bingjun qin Sihua Northeast Forestry University 1. Northeast Forestry University China

Based on the main characteristics of growth, phenology and resistance at both seedling stage (one year old) and sampling stage (seven years old) of Dahurian larch (Larix gmelinii (Rupr.) Rupr.) from seventeen provenances in China ranging from 47 ° 10' to 52 ° 25' N and 119 ° 57' to 130 ° 25' E, the rules and patterns of infraspecific geographic variation have been studied by using variance analysis, correlation analysis, partial correlation analysis and regression analysis. The best provenance for local site and its neighborhood was selected according to the growth characteristics of seven years provenance test on Liangshui Experimental Forest Farm of Northeast Forestry University.

关键词： Dahurian larch Geographic variation Variance analysis

Synthesis and Bioactivity of Isosteviol Derivatives: A Facile Method for Preparation of Ent-16α-hydroxy-15β-hydroxymethylbeyeran-19-oic Acid

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Chinese Chemical Letters 2005年第11期16卷 1441-1444页

作者： Jing Chao TAO Guo Qiang TIAN Yan Bing zhang yu qin FU Gui Fu DAI Ya WU Department of Chemistry Zhengzhou University Zhengzhou 450052

In this paper, two new compounds, ent-16α-hydroxy-15β-hydroxymethylbeyeran-19-oic acid 4 and its ethyl ester 5 were synthesized in good yield with a facile method that has never been reported. The mechanism of this reaction was discussed and the mono-hydroxymethylation of carbonyl compound with two α-hydrogens via Tollens＇ reaction was firstly achieved. Compounds 2-5 were tested for activity of inhibition against glycosidases, among which 5 displays good inhibition of β-glucosidase and α-mannase, respectively.

关键词： Isosteviol 1,3-diol hydroxylation.

Key Social Determinants to Narrow the Gap between Health-adjusted Life Expectancy and Life Expectancy in Megacities

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Biomedical and Environmental Sciences 2022年第9期35卷 773-781页

作者： XI Jun Yan CHEN yuan yuan zhang yu qin LUO Ao DU Zhi Cheng LIANG Bo Heng DONG Hang LIN Xiao qin Peng Zhe HAO yuan Tao Department of Medical Statistics School of Public HealthSun Yat-sen UniversityGuangzhou 510080GuangdongChina Department of Chronic Non-communicable Disease Control and Prevention Guangzhou Center for Disease Control and PreventionGuangzhou 510440GuangdongChina Institute for Infectious Disease Control and Prevention Guangdong Provincial Center for Disease Control and PreventionGuangzhou 511430GuangdongChina Peking University Center for Public Health and Epidemic Preparedness&Response Peking UniversityBeijing 100191China Sun Yat-sen Global Health Institute Sun Yat-sen UniversityGuangzhou 510080GuangdongChina Center for Health Information Research Sun Yat-sen UniversityGuangzhou 510080GuangdongChina

Objective Improvement in the quality of life is reflected in the narrowing of the gap between healthadjusted life expectancy(HALE)and life expectancy(LE).The effect of megacity expansion on narrowing the gap is rarely *** study aimed to disclose this potential *** Annual life tables were constructed from identified death records and population counts from multiple administrative sources in Guangzhou,China,from 2010 to *** regression was used to evaluate the temporal *** principal component analysis and multilevel models were applied to examine the county-level association between the gap and social *** Although LE and HALE in megacities are increasing steadily,their gap is *** and health services are guaranteed to narrow this *** personal wealth,a growing number of newborns and healthy immigrants,high urbanization,and healthy aging have helped in narrowing this *** In megacities,parallel LE and HALE growth should be highly considered to narrow their *** social determinants need to be integrated as a whole to formulate public health plans.

关键词： Generalized principal component analysis Health-adjusted life expectancy Megacities Quality of life Social determinants Temporal trend Urban expansion

THE EFFECT OF OIL CAVITY DEPTH ON TEMPERATURE FIELD IN HEAVY HYDROSTATIC THRUST BEARING

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Journal of Hydrodynamics 2011年第5期23卷 676-680页

作者： SHAO Jun-peng DAI Chun-xi zhang Yan-qin yu Xiao-dong XU Xiao-qiu WANG yun-fei College of Mechanical and Power Engineering Harbin UniverSity of Science and Technology Harbin150080 China

For a heavy hydrostatic bearing with a high linear velocity, the results of numerical calculations often differ from practical conditions if the viscosity is considered as constant. In this article, the influence of the oil cavity depth on the temperature field in the heavy hydrostatic bearing is discussed in the context of variable viscosity. The viscosity-temperature relations for the gap oil film are first established by fitting B-Spline curves, then, numerical calculations for the temperature field in the heavy hydrostatic bearing of different oil cavity depths are carried out based on Finite Volume Method （FVM） under the same rotating speed, and the influence of the oil cavity depth on the temperature distribution in the gap oil film of the hydrostatic bearing is discussed. The results of numerical calculations provide the temperature distribution state inside the hydrostatic bearing, which would help the selection and the design of hydrostatic bearings in engineering practice.

关键词： hydrostatic thrust bearing viscosity-temperature characteristic Finite Volume Method (FVM) temperature field

Hydrochemical characteristics and geochemistry evolution of groundwater in the plain area of the Lake Baiyangdian watershed,North China Plain

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Journal of Groundwater Science and Engineering 2018年第3期6卷 220-233页

作者： zhang yu-qin WANG Guang-wei WANG Shi-qin yuAN Rui-qiang TANG Chang-yuan SONG Xian-fang Key Laboratory of Agricultural Water Resources Hebei Laboratory of Agricultural Water-SavingCenter for Agricultural Resources ResearchInstitute of Genetics and Developmental BiologyChinese Academy of SciencesShijiazhuang 050021China University of Chinese Academy of Sciences Beijing 100049China Faculty of Horticulture Chiba UniversityMatsudo-city271-8510Japan School of Environmental Sciences&Resources Shanxi UniversityTaiyuan 030006China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Water cycle and water quality in the Lake Baiyangdian watershed of the North China Plain have undergone great changes due to over-pumping of groundwater and wastewater *** this paper,hydrogeochemical data was collected to analyze the hydrochemical characteristics and geochemistry evolution of *** study area was divided into two typical *** was in the upstream plain area,where over-pumping had resulted in significant decline of groundwater level;the other one was located in the downstream area near the Fu River and Lake Baiyangdian(Lake BYD region).In addition to the natural weathering of minerals,excessive fertilizer was also a main factor of higher ion concentration in *** to studies,due to good permeability,these regions were easy to be polluted even with deep groundwater ***,upstream shallow groundwater and surface water,including lake water,domestic along with industrial wastewater were all sources of present shallow groundwater in the Lake BYD *** indicated that anthropogenic activities rather than minerals much matter to the groundwater in these ***,wastewater largely decided the groundwater quality,which suggested that the management and restoration of surface water quality was crucial to groundwater protection.

关键词： Hydrochemical characteristics Geochemical processes Groundwater The Lake Baiyangdian Watershed North China Plain

CHRONOABSORPTOMETRY FOR THE DETERMINATION OF KINETIC PARAMETERS OF ELECTRON TRANSFER REACTIONS USING LONG-OPTICAL-PATH ELECTROCHEMICAL CELL

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Chinese Chemical Letters 1993年第8期4卷 729-732页

作者： zhang yu yu Mei qin Mao Chun JING Department of Chemistry,Qufu Normal University,Qufu Shandong,273165

A single potential step chronoabsorptometric method for the determination of ki- netic parameters of simple quasi-reversible reactions is *** is verified by determining the kinetic parameters for the electroreduction of ferricyanide.A long-optical-path electro- chemical cell with a plug-in electrode is *** thickness of solution layer is 0.55 mm

关键词： CHRONOABSORPTOMETRY FOR THE DETERMINATION OF KINETIC PARAMETERS OF ELECTRON TRANSFER REACTIONS USING LONG-OPTICAL-PATH ELECTROCHEMICAL CELL SCE

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深空探测通信技术发展趋势及思考

宇航学报 2007年第4期28卷 786-793页

作者：张乃通李晖张钦宇深圳研究生院哈尔滨工业大学深圳518055

阐述了深空探测通信的重要地位和意义,就深空探测通信中的主要问题和特点开展论述,分析了深空探测通信的国内外研究现状。提出了利用地球静止轨道卫星编队的方法构建我国自主的天基连续测控和通信系统的构想,并以月球为中继、利用地月... 详细信息

阐述了深空探测通信的重要地位和意义,就深空探测通信中的主要问题和特点开展论述,分析了深空探测通信的国内外研究现状。提出了利用地球静止轨道卫星编队的方法构建我国自主的天基连续测控和通信系统的构想,并以月球为中继、利用地月系统内的拉格朗日点开展深空探测。建议当前开展深空探测通信中星际互联网络体系结构、高效信道编码技术和空间协议研究的构想。

关键词：深空探测深空通信星际互联网信道编码空间通信协议

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一种基于能量加权检测的UWB测距方法

电子与信息学报 2009年第8期31卷 1946-1951页

作者：张霆廷张钦宇张乃通哈尔滨工业大学电子与信息技术研究院哈尔滨150001 哈尔滨工业大学深圳研究生院深圳518055

针对无线传感器网络节点低成本、低运算能力的特点,该文为基于超宽带(UWB)的无线传感器网络提出了一种基于能量加权的到达时间(TOA)估计方法。这种方法由直达径(DP)能量窗加权检测和DP在能量窗内位置精确估计两部分组成。文中给出了DP... 详细信息

针对无线传感器网络节点低成本、低运算能力的特点,该文为基于超宽带(UWB)的无线传感器网络提出了一种基于能量加权的到达时间(TOA)估计方法。这种方法由直达径(DP)能量窗加权检测和DP在能量窗内位置精确估计两部分组成。文中给出了DP能量块检测概率和估计结果的闭合表达式,通过理论和数值分析了积分长度,子能量块个数等系统参数对于TOA估计性能的影响。通过仿真结果进行了性能比较和误差分析,结果表明,该算法在保持能量检测方法低采样率特点的同时,在性能上相对传统算法有了较大提升。

关键词：脉冲超宽带能量检测测距到达时间估计