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Measurements and estimation of flow velocity in mobile bed rills

International Journal of Sediment Research 2023年第1期38卷 97-104页

作者： yunyun ban China Agricultural University Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Rills are primary sediment sources and hillslope water/sediment runoff transport channels. Water flow velocities in rills are easily affected by bed condition over eroding and non-eroding slopes, which is an important hydrodynamic process in soil erosion research. This research is done to demonstrate the poorly understood “feedback mechanism” related to slope independence of flow velocity to slope gradient. A series of experiments were done on silt loam soil slopes to measure water flow velocity in rills under nine unit width flow rates(q)(0.17 × 10-3, 0.33 × 10-3, 0.67 × 10-3, 1.33 × 10-3, 2.67 × 10-3,5.33 × 10-3, 10.67 × 10-3, 21.33 × 10-3, and 42.67 × 10-3m3/(s·m)) combined with four slope gradients(8.7%, 17.6%, 26.8%, and 36.4%), in which mobile bed rills were monitored. For unit flow velocity under q ≤ 1.33 × 10-3m2/s, independence of flow velocity to slope was obtained. However, the results indicated that slope gradient combined with a higher unit flow rate contributed to better velocity prediction and fitted with a segmented equation well(R2= 0.95). A feedback mechanism was able to verify that the increase in roughness directly dissipated flow energy to reduce flow velocity, but cannot completely counterbalances steep slope effect. The experimental results showed that erosion-caused morphological changes on soil slopes reduce flow velocity by half due to an increase in bed roughness. Therefore, the current experimental measurements considering a wide range of flow rate and slope gradient conditions is useful to reveal the steep slope effect in mobile bed rills. The analysis showed that, for the investigated conditions, the flow velocity is a slope gradient-and flow ratedependent parameter.

关键词： Flow velocity Flow rate Slope gradient Model fitting Slope morphology

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Measuring flow velocity on frozen and non-frozen slopes of black soil through leading edge method

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International Soil and Water Conservation Research 2017年第3期5卷 180-189页

作者： Chao Chen yunyun ban Xuefeng Wang Tingwu Lei College of Water Resources and Civil Engineering China Agricultural UniversityQinghua DongluBeijing100083PR China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Science and Ministry of Water ResourcesYanglingShaanxi Province 712100PR China

Flow velocity is a major parameter related to hillslope hydrodynamics *** study aims to measure flow velocity over frozen and non-frozen slopes through leading edge method before being calibrated with accurate flow velocity to determine the correct coefficient for convenience of flow velocity *** experiments were conducted on frozen and non-frozen soil slopes with flumes involving four slope gradients of 5°,10°,15°,and 20°and three flow rates of 1,2,and 4 L/min with a flume of 6 m long and 0.1 m *** measurements were made with a stopwatch to record the time duration that the water flow ran over the rill segments of 2,4 and 6 m *** flow velocity was measured with electrolyte trace method,under pulse boundary *** leading edge and accurate flow velocities were used to determine the correction coefficient to convert the former to the *** showed that the correction coefficient on frozen soil slope was 0.81 with a coefficient of determination(R2)of *** correction coefficient on non-frozen soil slope was 0.79 with R2 of 0.98.A coefficient of 0.8 was applicable to both soil surface *** accurate velocities on the four frozen black soil slopes were approximately 30%,54%,71%,and 91%higher than those on non-frozen soil *** contrast,the leading edge flow velocities on the frozen soil slopes were 23%,54%,67%,and 84%higher than those on non-frozen soil *** flow velocities on frozen soil slopes increased with flow rate at all four slopes,but they increased from 5 to 15°before getting ***,rill flow velocity can be effectively measured with leading edge method by multiplying the leading edge velocity with a correction coefficient of *** study provides a strategy to measure rill flow velocity for studies on soil erosion mechanisms.

关键词： Flow velocity Leading edge method Frozen/non-frozen soil

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Divergent shift of normal alpine meadow exacerbated soil loss of hillslope alpine meadows based on field experiments

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International Soil and Water Conservation Research 2024年第3期12卷 565-577页

作者： Yulei Ma Yifan Liu yunyun ban Jingxue Zhao Zhihua Shi Gaolin Wu State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau College of Soil and Water Conservation Science and Engineering(Institute of Soil and Water Conservation)Northwest A&F UniversityYanglingShaanxi712100China Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water ResourceYanglingShanxi712100China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China State Key Laboratory of Herbage Imrovement and Grassland AgroEosystem and Colegeof EoogyLanzhou UniversyLanzhou730000Chin College of Resources and Environment Huazhong Agricultural UniversityWuhan430070China CAs Center for Excellence in Quaternary Science and Global Change Xi'an710061China

Global climate change and overgrazing are driving shifts in the plant composition of grassland com-munities,which may profoundly affect the function of grassland ecosystems in regulating runoff and soil ***,we examined the shift effects of normal hillslope alpine meadow to shrub and severely degraded meadow states on runoff and sediment generation under natural rainfall conditions,and determined the contributions of plant and soil properties changes to soil erodibility,runoff and sediment generation by in situ rainfall experiment and monitoring on the hillslope of Qinghai-Tibetan *** results showed that normal meadow shift into severely degraded meadow state,mean weight diameter,soil saturated hydraulic conductivity,soil cohesion and soil erodibility K-factor at the topsoil decreased by 70.3%,73.1%,80.3%and-13.1%,respectively,and when normal meadows shift into shrub meadow state,they reduced by 49.1%,-1.3%,49.4%,and-8.3%,*** and soil loss significantly changed by-40.0%and 177.8%when normal meadow shifted into a severely degraded meadow state,while runoff and soil loss significantly changed by+65.0%and+77.8%when normal meadow shifted into a shrub meadow *** findings highlight that the two divergent shifts both increased soil loss compared to the normal hillslope alpine ***,our results indicate that the divergent shifts of normal alpine meadows exacerbated soil erodibility and soil loss of hillslope alpine *** results obtained here offer a novel perspective on the regulation of runoff and soil erosion in the alpine meadow ecosystem.

关键词： Alpine meadow Divergent shifts RunoffSoil erodibility Soil loss

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Study on the facilities and procedures for meltwater erosion of thawed soil

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International Soil and Water Conservation Research 2016年第2期4卷 142-147页

作者： yunyun ban Tingwu Lei Chao Chen Zhiqiang Liu China Agricultural University Beijing 100083PR China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationCAS and MWRYangling 712100PR China

High erosion rate of seasonal thawed soils by snow-and ice-melting runoff in the high altitude and latitude cold regions has great impacts on ecological systems,industries,agriculture and various manmade infrastructures as well as people's *** facilities and procedures are of great importance for the studies on simulating erosion processes of melt-frozen *** study focuses on the method and facility for simulating the thawing process of frozen *** facility includes soil freezing system,meltwater supply system and experimental flume system for thawed soil *** soil freezing system provides enough space to freeze soil columns in *** water supply system deliveries snow-or icemelting water flow of constant-rate at 0℃.The soil flumes of 200 or 300 cm long,10 cm wide and 12 cm high are designed to be assemble and convenient for soil freezing before they are thawed in one-dimensional manner from top to *** one-dimensional thawing process is realized as *** frozen soil flume is put on ice boxes and thermally insulated with heat-insulating materials all around to prevent frozen soil from being thawed from sidewalls and *** soil thaws with this system shows that it can meet the requirements of simulating the process of soil thawing from top to *** thawed soil flumes are connected from end to end to form rills of 6–8 m long to run the erosion experiments under different designed hydraulic *** equipment provides facility,method and operation process for simulating one-dimensional soil thawing to serve research on the effect of thawed soil depth on erosion process.

关键词： Melt-frozen Soil erosion Method Facilities Procedures

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东北黑土坡耕地不同水力条件下坡长对土壤细沟侵蚀的影响（英文）

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农业工程学报 2019年第5期35卷 155-162页

作者：陈超雷廷武班云云高晓锋中国农业大学水利与土木工程学院北京100083 中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室杨凌712100

集中水流条件下细沟土壤侵蚀过程对研究细沟侵蚀机理与土壤侵蚀预报有着重要的意义,并且为土壤侵蚀模型其他重要参数比如剥蚀率、可蚀性参数提供基础数据。为了研究东北黑土坡耕地不同水动力条件下坡长对土壤细沟侵蚀的影响,该文采用室... 详细信息

集中水流条件下细沟土壤侵蚀过程对研究细沟侵蚀机理与土壤侵蚀预报有着重要的意义,并且为土壤侵蚀模型其他重要参数比如剥蚀率、可蚀性参数提供基础数据。为了研究东北黑土坡耕地不同水动力条件下坡长对土壤细沟侵蚀的影响,该文采用室内模拟试验方法,测量含沙量随坡长的分布。试验设计包括4个坡度(5?、10?、15?、20?)与3个流量(1、2、4 L/min),在不同水力条件下,测量不同坡长(0.5、1、2、3、4、5、6、7、8m)含沙量。结果表明含沙量在各种水力条件下均随坡长增加,且其增加的速率随坡长减小。对坡长与含沙量系列数据用幂指数函数拟合,其决定系数R2在0.85到0.99之间。因此,黑土坡耕地细沟侵蚀产生的含沙量随坡长呈幂指数增加,且含沙量在一定坡长之后将达到最大值。随坡度和流量的增大,水流在更短的坡长上侵蚀并携带更大的最大含沙量。该文对进一步理解与研究细沟侵蚀过程有着重要的意义,且为深入研究细沟侵蚀提供了数据支撑,为土壤侵蚀模型剥蚀率、可蚀性参数等提供依据。

关键词：土壤侵蚀径流坡长含沙量

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土壤冻结对黄土细沟水流流速的影响

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农业机械学报 2018年第4期49卷 282-289,191页

作者：陈丽燕雷廷武班云云高源中国农业大学水利与土木工程学院北京100083

细沟水流流速是冻土和未冻土坡面水文过程的重要参数,与冻融坡面土壤侵蚀和泥沙输移密切相关。试验在长8 m、宽0.1 m、深0.12 m的土槽内填装深度为0.05 m的陕西安塞黄绵土坡面进行。设定坡度为5°、10°、15°、20°,流量为1、2、4、8 L... 详细信息

细沟水流流速是冻土和未冻土坡面水文过程的重要参数,与冻融坡面土壤侵蚀和泥沙输移密切相关。试验在长8 m、宽0.1 m、深0.12 m的土槽内填装深度为0.05 m的陕西安塞黄绵土坡面进行。设定坡度为5°、10°、15°、20°,流量为1、2、4、8 L/min,通过测量冻土与未冻土坡面细沟水流前锋流经整个土槽所用时间,计算水流的前沿流速,对比2种坡面上水流前沿流速的关系,研究冻结对水流流速的影响,同时采用电解质示踪法计算水流的优势流速,分析优势流速与前沿流速的关系。不同工况下,冻土坡面前沿流速在0.260~0.843 m/s之间,未冻土坡面水流前沿流速在0.175~0.552 m/s之间;冻土和未冻土坡面上,随坡度、流量的增大,前沿流速增大,增大率在缓坡(5°~10°、10°~15°)时逐渐减小,流量较小(1、2、4 L/min)时,流量增大,坡度对前沿流速增大率的影响也逐渐减小;坡度和流量对冻土坡面水流前沿流速的影响大于对未冻土坡面水流前沿流速的影响;冻土和未冻土坡面前沿流速均随坡度和流量的增大近似呈幂函数增大;在试验条件下,冻土坡面前沿流速和优势流速比未冻土坡面大43%和40%;冻土和未冻土坡面上优势流速和前沿流速的比值分别为0.61和0.63,表明该系数可以用于标定前沿流速。试验结果可为冻土坡面与未冻土坡面水流动力过程研究提供参考。

关键词：黄绵土冻土坡面坡面径流前沿流速电解质示踪法

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推广胡蜂蜜蜂混合养殖技术确保生物多样性与乡村振兴双赢

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德宏师范高等专科学校学报 2021年第2期30卷 89-92页

作者：党菱婧板芸云梁建平马艳粉德宏职业学院医学技术学院德宏芒市检察院德宏州工信局德宏师专云南芒市678400

昆虫纲膜翅目胡蜂科和蜜蜂科蜂类,分布很广,资源丰富。胡蜂是重要的天敌昆虫,捕食所有森林害虫,可持续控制虫害数量,避免了打农药对生物多样性的影响,同时胡蜂科蜂类和蜜蜂是山区重要的经济昆虫和森林传粉昆虫。但由于胡蜂的捕食特性,... 详细信息

昆虫纲膜翅目胡蜂科和蜜蜂科蜂类,分布很广,资源丰富。胡蜂是重要的天敌昆虫,捕食所有森林害虫,可持续控制虫害数量,避免了打农药对生物多样性的影响,同时胡蜂科蜂类和蜜蜂是山区重要的经济昆虫和森林传粉昆虫。但由于胡蜂的捕食特性,养殖胡蜂和蜜蜂纠纷不断,两败俱伤,所以推广胡蜂蜜蜂混合养殖技术,达到生物多样性保护与乡村振兴双赢的效果势在必行。经过多年的试验研究,我们发明了相关装置,解决了胡蜂、蜜蜂混合养殖的关键技术,促成了胡蜂、蜜蜂混合养殖产业的和谐发展,发挥了人工养殖的天敌昆虫胡蜂科蜂类在生物多样性保护中的绿色防控生态效益和特色经济效益。

关键词：胡蜂蜜蜂混合养殖生态效益

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AWorldVision

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ChinAfrica 2016年第8期8卷 24-25页

作者： ban Ki-moon Li Yafang Liu yunyun UN Beijing Review 不详

UN Secretary General ban Ki-moon visited China from July 6-10. his lOth trip to the country since assuming office on January 1. 2007. Known for his unwavering determination to bring nations together, ban has always ta... 详细信息

关键词： A World Vision World UN

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Debunking Lies Scientists from pharmaceutical companies prove ***’accusations false

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Beijing Review 2020年第19期63卷 30-30页

作者： Liu yunyun Liang Xiao 不详

"Don’t defend Trump,other than the China Travel ban-attack China."This was what the *** Party directed its senatorial candidates to do in a 57-page memo,according to the *** company *** Corona Big Book detailed advic... 详细信息

关键词： Lies racism Book

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CEPC Technical Design Report

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Radiation Detection Technology and Methods 2024年第1期8卷 I0003-I0016,1-1091页

作者： Waleed Abdallah Tiago Carlos Adorno de Freitas Konstantin Afanaciev Shakeel Ahmad Ijaz Ahmed Xiaocong Ai Abid Aleem Wolfgang Altmannshofer Fabio Alves Weiming An Rui An Daniele Paolo Anderle Stefan Antusch Yasuo Arai Andrej Arbuzov Abdesslam Arhrib Mustafa Ashry Sha Bai Yu Bai Yang Bai Vipul Bairathi Csaba Balazs Philip Bambade Yong ban Tripamo bandyopadhyay Shou-Shan Bao Desmond P.Barber Ayse Bat Varvara Batozskaya Subash Chandra Behera Alexander Belyaev Michele Bertucci Xiao-Jun Bi Yuanjie Bi Tianjian Bian Fabrizio Bianchi Thomas Biekotter Michela Biglietti Shalva Bilanishvili Deng Binglin Denis Bodrov Anton Bogomyagkov Serge Bondarenko Stewart Boogert Maarten Boonekamp Marcello Borri Angelo Bosotti Vincent Boudry Mohammed Boukidi Igor Boyko Ivanka Bozovic Giuseppe Bozzi Jean-Claude Brient Anastasiia Budzinskaya Masroor Bukhari Vladimir Bytev Giacomo Cacciapaglia Hua Cai Wenyong Cai Wujun Cai Yijian Cai Yizhou Cai Yuchen Cai Haiying Cai Huacheng Cai Lorenzo Calibbi Junsong Cang Guofu Cao Jianshe Cao Antoine Chance Xuejun Chang Yue Chang Zhe Chang Xinyuan Chang Wei Chao Auttakit Chatrabhuti Yimin Che Yuzhi Che Bin Chen Danping Chen Fuqing Chen Fusan Chen Gang Chen Guoming Chen Hua-Xing Chen Huirun Chen Jinhui Chen Ji-Yuan Chen Kai Chen Mali Chen Mingjun Chen Mingshui Chen Ning Chen Shanhong Chen Shanzhen Chen Shao-Long Chen Shaomin Chen Shiqiang Chen Tianlu Chen Wei Chen Xiang Chen Xiaoyu Chen Xin Chen Xun Chen Xurong Chen Ye Chen Ying Chen Yukai Chen Zelin Chen Zilin Chen Gang Chen Boping Chen Chunhui Chen Hok Chuen Cheng Huajie Cheng Shan Cheng Tongguang Cheng Yunlong Chi Pietro Chimenti Wen Han Chiu Guk Cho Ming-Chung Chu Xiaotong Chu Ziliang Chu Guglielmo Coloretti Andreas Crivellin Hanhua Cui Xiaohao Cui Zhaoyuan Cui Brunella D'Anzi Ling-Yun Dai Xinchen Dai Xuwen Dai Antonio De Maria Nicola De Filippis Christophe De La Taille Francesca De Mori Chiara De Sio Elisa Del Core Shuangxue Deng Wei-Tian Deng Zhi Deng Ziyan Deng Bhupal Dev Tang Dewen Biagio Di Micco Ran Ding Siqin Dingl Yadong Ding Haiyi Dong Jianin AGH University of Science and Technology Faculty of Physics and Applied Computer ScienceKrakow Anhui University HefeiAnhui Applied Physics Department Federal Urdu University of ArtsScience and TechnologyIslamabad banaras Hindu University Institute of ScienceVaranasi bandirma Onyedi Eylul University Bandirma Beihang University Beijing Beijing Computational Science Research Center Beijing Beijing Conveyi LTD Beijing Beijing Glass Research Institute Co. LtdBeijing Beijing Institute of Technology Beijing Beijing Normal University Beijing Brown University ProvidenceRI Budker Institute of Nuclear Physics Novosibirsk Cadi Ayyad University Laboratory of Fundamental and Applied PhysicsPolydisciplinary FacultyMarrakech Cairo University Giza Center for Theory and Computation National Tsing Hua UniversityHsinchu Central China Normal University WuhanHubei Central South University ChangshaHunan Centro de Fisica Teorica de Particulas Universidade Tecnica de LisboaLisboa Chengdu KaitengSifang Digital Radio&TV Equipment Co. LtdChengduSichuan China academy of engineering physics MianyangSichuan China building materials academy Beijing China Center of Advanced Science and Technology Beijing China Institute of Atomic Energy Beijing China Jiliang University HangzhouZhejiang China Nuclear Instrument CO. LTDBeijing China University of Geosciences Beijing China University of Geosciences WuhanHubei China University of Mining and Technology XuzhouJiangsu China West Normal University NanchongSichuan Chongqing University Department of PhysicsChongqing Chulalongkorn University Bangkok City University of Hong Kong Department of PhysicsHong Kong Cockcroft Institute Daresbury Cornell University IthacaNY CPPM(AMU/IPhU&CNRS/INP) Marseille Dalian Minzu University DalianLiaoning Dalian University of Technology Department of PhysicsDalian Deutsches Elektronen-Synchrotron DESY Hamburg Dzhelepov Laboratory of Nuclear Problems of Joint Institute for Nuclear Research(DLNP JINR) Dubna East China University Of Science And Technol

The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international *** complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs *** its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs *** the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of *** Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering ***,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection *** is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 *** commencement of experiments and data collection could potentially be initiated in the mid-2030s.

关键词： initiated exceeding precise

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