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The assessment of soil loss by water erosion in China

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International Soil and Water Conservation Research 2020年第4期8卷 430-439页

作者： Baoyuan Liu Yun Xie Zhiguang Li Yin Liang Wenbo zhang Suhua Fu Shuiqing Yin Xin Wei keli zhang Zhiqiang Wang Yingna Liu Ying Zhao Qiankun Guo Faculty of Geographical Science Beijing Normal UniversityBeijing100875China Soil Conservation Monitoring Centre Ministry of Water Resources of People's Republic of ChinaBeijing100053China Institute of Soil Science Chinese Academy of SciencesNanjing210008China China Institute of Water Resources and Hydropower Research Ministry of Water Resources of People's Republic of ChinaBeijing100038China

Soil erosion is a major environmental problem in *** for soil erosion control requires accurate soil erosion rate and spatial distribution *** aim of this article is to present the methods and results of the national soil erosion survey of China completed in 2011.A multi-stage,unequal probability,systematic area sampling method was employed.A total of 32,948 sample units,which were either 0.2-3 km2 small catchments or 1 km2 grids,were investigated on *** erosion rates were calculated with the Chinese Soil Loss Equation in 10 m by 10 m grids for each sample unit,along with the area of soil loss exceeding the soil loss tolerance and the proportion of area in excess of soil loss tolerance relative to the total land area of the sample *** were created by using a spatial interpolation method at national,river basin,and provincial *** showed that the calculated average soil erosion rate was 5 t ha-1 yr-1 in China,and was 18.2 t ha-1 yr-1 for sloped,cultivated *** soil erosion occurred on cropland,overgrazing grassland,and sparsely forested *** proportions of soil loss tolerance exceedance areas of sample units were interpolated through the country in 250 m *** national average ratio was 13.5%,which represents the area of land in China that requires the implementation of soil conservation *** survey results and the maps provide the basic information for national conservation planning and policymaking.

关键词： National soil erosion survey CSLE Sample units Chinese soil loss map Soil erosion rate Ratio of soil erosion area

Triblock copolymer-assisted construction of 20 nm-sized ytterbium-doped TiO_2 hollow nanostructures for enhanced solar energy utilization efficiency

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Science China Chemistry 2015年第5期58卷 850-857页

作者： Lin Cheng Xuefeng Xu Yuyan Fang Yan Li Jiaxi Wang Guojia Wan Xueying Ge Liangjie Yuan keli zhang Lei Liao Quan Yuan Key Laboratory of Analytical Chemistry for Biology and Medicine Ministry of Education College of Chemistry and Molecular Sciences Wuhan University Key Laboratory of Artificial Micro- and Nano-structures Ministry of Education Department of Physics Wuhan University

Rare-earth doped titania single-crystalline hollow nanoparticles of 20 nm are constructed via a simple sol-gel process. Amphiphilic ABA tri-block copolymers played a key role in assisting the formation of hollow structure, for which a hollow nanostructure growth mechanism is proposed. By introducing rare earth into the synthesis process, the as-prepared nanoparticles exhibit near-infrared light absorption properties. Photo-decomposition efficiency of Orange II azo dye can be successfully evaluated when using Yb3+-doped Ti O2 hollow nanoparticles as photocatalysts; it is more than two times higher than the pure Ti O2 hollow nanoparticles. The hollow nanostructured Yb3+-doped Ti O2 samples are exploited as photoanodes in N719- sensitized solar cells and prove able to improve the photoelectric conversion efficiency by measuring the solar cell parameters of dye-sensitized solar cells(DSSCs) under simulative sunlight.

关键词： rare earth hollow nanostructure titania single-crystalline copolymer

Critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau

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Chinese Science Bulletin 1998年第5期43卷 409-412页

作者： TANG keli+1, zhang keli 1,2 and LEI Aling 1,3 1. Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling 712100, China 2. Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China 3. Water Resources C Institute of Soil and Water Conservation Chinese Academy of Sciences Yangling China Department of Hydraulic Engineering Tsinghua University Beijing China Water Resources Conservation Bureau of Yangtze River Ministry of Water Resources Wuhan China

Scientific evidence for the upper limit of farmland is proposed. Shallow gully erosion is one of erosion types distributed extensively on sloping farmland in the hilly regions of the Loess Plateau. Field observation and aerial photos interpretation, as well as laboratory experiments show that the shallow gully erosion occurring on the steeper farmland in the hilly regions of the Loess Plateau is an important factor leading to intensive erosion on slope, because of its extensive distribution and intensive runoff collection. The data on the formation, development and distribution of shallow gullies on sloping farmland indicate that critical slope gradient for shallow gully initiation ranges from 15 to 20 degrees with an average of 18.2 degrees. Therefore, it is suggested that critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau should be kept within the critical slope gradient for shallow gully initiation to prevent shallow gully formation in order to control soil loss more effectively. But as the first step, the cultivation on the slopes with slope larger than 25 degrees where the maximum erosion occurs should be strictly forbidden.

关键词： hilly region of Loess Plateau upper limitation for farmland shallow gully erosion erosion dynamic.

RELATIONSHIP OF ECO-ENVIONMENTAL CHANGE WITH NATURAL EROSION AND ARTIFICIALLY ACCELERATED EROSION

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Journal of Geographical Sciences 1997年第2期7卷 75-84页

作者： Zheng Feili Tang keli zhang keli Cha Xuan Bai Hongying Northwest Institute of Soil and Water Conservation, CAS and Ministry of Water Resources, Yangling, Shaanxi 712100 People’s Republic of China

The natural landscape of the Loess Plateau was changed by severe soil erosion. The Ziwuling forest area provides research base for tracing back eco environmental change related to natural erosion and artificially accelerated erosion. Using methods of typical region investigations, in situ experimental study and chemical analysis of samples, impact of vegetation destruction and rehabilitation on soil erosion, characteristics of natutal erosion under conditions of natural ecological balance and artificially accelerated erosion resulting from vegetation destruction in forest area, and the processes of artificially accelerated erosion and soil degradation have been analyzed and discussed.

关键词： vegetation destruction rehabilitation natural erosion artificially accelerated erosion eco environmental change Ziwuling forest area.

Post-Marketing Surveillance of Adverse Events Following Immunization with Haemophilus Influenzae Type b Conjugate Vaccine—China,2010–2021

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China CDC weekly 2024年第33期6卷 834-840页

作者： Minrui Ren keli Li Yan Li Chunxiang Fan Yuyang Xu Lina zhang Yuan Li Lei Cao Wenzhou Yu Zundong Yin National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases(NITFID) National Immunization ProgrammeChinese Center for Disease Control and PreventionBeijingChina Department of Expanded Programme on Immunization Hangzhou Center for Disease Control and PreventionHangzhou CityZhejiang ProvinceChina

Introduction The Haemophilus influenzae type b(Hib)conjugate vaccine is widely administered in *** We extracted data on Hib vaccine doses administered and adverse events following immunization(AEFI)reported between 2010 and 2021 from the Chinese National Immunization Information System(CNIIS).A descriptive analysis was conducted to examine the characteristics and incidence rates of AEFI with the Hib *** In China,between 2010 and 2021,a total of 52,910 AEFIs with the Hib vaccine were reported,resulting in an overall AEFI reporting rate of 38.10 per 100,000 ***(typically minor)and rare(potentially serious)vaccine reactions occurred at rates of 34.71 and 2.78 per 100,000 doses,*** the common vaccine reactions,the incidences of fever(axillary temperature≥38.6℃),injection site redness and swelling(>2.5 cm in diameter),and injection site induration(>2.5 cm in diameter)were 11.93,9.69,and 3.38 per 100,000 doses,*** vaccine reactions included anaphylactic rash,angioedema,and febrile convulsion with reported incidences of 2.42,0.10,and 0.05 per 100,000 doses,*** incidence of serious rare vaccine reactions was 0.16 per 100,000 *** The reported incidence of AEFI with the Hib vaccine was low,with the occurrence of serious rare adverse reactions also being markedly low throughout the period 2010–2021 in China.

关键词： doses markedly injection

发挥学生主体作用的高职院校个性化教学管理研究

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职教论坛 2020年第9期36卷 19-24页

作者：张科丽浙江建设职业技术学院浙江大学教育学院

新发展形势下实施个性化教学管理是当前高职院校需要切实思考和解决的课题,其对于实现育人价值回归、提升高职院校内部治理水平具有重要价值意义。根据权变理论中环境变量与管理变量的权变关系,高职院校教学管理应遵循适切性、动态性和... 详细信息

新发展形势下实施个性化教学管理是当前高职院校需要切实思考和解决的课题,其对于实现育人价值回归、提升高职院校内部治理水平具有重要价值意义。根据权变理论中环境变量与管理变量的权变关系,高职院校教学管理应遵循适切性、动态性和多样性原则,并在专业选择、课程选择、教学实施及学习成果管理四个环节中充分发挥学生主体作用,从而促进高职院校个性化教学管理的实施。

关键词：学生主体高职院校个性化教学管理

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基于动理学理论的坡面水流土壤分离能力研究

应用基础与工程科学学报 2021年第3期29卷 591-605页

作者：贾宝真钟德钰张科利清华大学水利水电工程系水沙科学与水利水电工程国家重点实验室北京100084 青海大学省部共建三江源生态与高原农牧业国家重点实验室青海西宁810016 北京师范大学地理科学学部地表过程与资源生态国家重点实验室北京100875

土壤分离能力是反映土壤侵蚀强弱的重要参数,但目前研究中多采用基于实验数据建立的经验公式来计算,在反映水流作用下土壤分离过程的物理机制时存在不少困难.本文基于泥沙运动的动理学理论建立了新的土壤分离函数,将分离能力表示为单位... 详细信息

土壤分离能力是反映土壤侵蚀强弱的重要参数,但目前研究中多采用基于实验数据建立的经验公式来计算,在反映水流作用下土壤分离过程的物理机制时存在不少困难.本文基于泥沙运动的动理学理论建立了新的土壤分离函数,将分离能力表示为单位时间内在外力作用下,单位面积床面上脱离土体的物质通量.分离函数的核心为颗粒速度分布函数,反映了土壤分离过程中颗粒微观受力状态的分布规律,而颗粒脱离床面的速度在状态空间上的积分则反映了分离过程的宏观统计规律.文中采用共计12组实验数据对分离函数进行了验证,并与其他3家代表性分离函数进行了对比.结果表明,本文分离函数的计算值与实验数据较为一致,相对误差在[-0.5,0.5]之间的数据占所有数据的78%,具有良好的计算精度.由于基于泥沙运动的动理学理论得到的分离函数具有较强的理论基础,本文的研究结果也为揭示土壤分离过程的力学机制提供了新的理论方法.

关键词：坡面流分离能力动理学理论速度分布函数水动力学机制

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我国人工降雨侵蚀相关试验的研究进展回顾

中国水土保持科学 2018年第2期16卷 134-143页

作者：柯奇画张科利北京师范大学地理科学学部地理学院北京100875

人工降雨试验是土壤侵蚀过程机理研究的重要手段,自20世纪60年代开始,在世界各国得到普遍应用。笔者运用文献法,从时间历程、空间分布、研究主题、试验平台、降雨机类型、试验方法、研究机构及其地区分布等方面,对我国运用人工降雨试验... 详细信息

人工降雨试验是土壤侵蚀过程机理研究的重要手段,自20世纪60年代开始,在世界各国得到普遍应用。笔者运用文献法,从时间历程、空间分布、研究主题、试验平台、降雨机类型、试验方法、研究机构及其地区分布等方面,对我国运用人工降雨试验进行侵蚀相关研究的文献资料进行统计分析。结果表明:1)在我国,人工降雨应用于侵蚀相关研究的发展过程可分为3个阶段:20世纪60—70年代的起步阶段、80—90年代的缓慢发展阶段和进入21世纪以后的快速发展阶段。2)我国人工降雨侵蚀相关试验研究集中在黄土高原,主要受试土壤为黄土、红壤、紫色土、黑土和石灰土,热点研究主题是细沟与细沟间侵蚀,主要试验平台是直型坡,主要降雨机类型是静止喷嘴式中的侧喷式和下喷式。3)相关研究机构和文献发表分别集中于北京和陕西;以中科院水保所为首的研究院所和以西北农林科技大学为首的高校是我国人工降雨侵蚀相关试验研究的主导力量,相关试验站和行政管理单位也参与进来。最后分别从降雨装置和模拟方法方面提出人工降雨试验方法存在的问题和今后的前进方向。本研究可为准确把握我国土壤侵蚀模拟试验研究方法提供基础数据,对进一步认识我国的水土保持研究和工作具有重要意义。

关键词：人工降雨试验侵蚀相关研究国内进展

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北方池塘无公害养殖罗非鱼高产试验

科学养鱼 2006年第5期28卷 18-19页

作者：张克利河北唐山市陡河水库管理处

唐山是北方地区的水产大市,近几年养殖鲤鱼效益滑坡,为提高养殖效益,探索罗非鱼出口的可行性,受上级水产部门的委托,我场于2004年和2005年进行无公害养殖试验.在两年试验中,最高亩产1650千克,罗非鱼的质量和规格均能达到出口标准.

关键词：无公害养殖高产试验北方地区罗非鱼池塘养殖效益出口标准养殖试验水产鲤鱼