Results 1 to 10 of about 1,665 (109)

间歇性与连续性降雨对黄土坡面细沟侵蚀影响的比较

open access: yesShuitu Baochi Xuebao, 2020
采用室内模拟降雨试验,对比了间歇性降雨与连续性降雨对黄土坡面细沟侵蚀的影响差异,量化了间歇性降雨相对于连续性降雨条件的试验误差,并评估该试验方法在坡面侵蚀模拟中的适宜性。结果表明:(1)低雨强(≤60 mm/h)时,对于间歇性降雨试验,坡面细沟产沙大幅降低,误差达-40.8%,伴随着沟宽、沟深和割裂度等形态指标的减小,误差介于-33%~-45%;产流误差较小,为0.4%。(2)高雨强(≥90 mm/h)时,产流产沙、细沟形态的各项指标误差均不大,为3%~12%,对试验结果影响相对较小。(3 ...
何育聪, 郑浩杰, 韩剑桥
doaj   +1 more source

Slope Rill Erosion and Morphological Evolution Based on UAV Nap-of-the-object Photogrammetry [PDF]

open access: yes, 2023
[Objective] This study was conducted to determine a rill erosion technology having high efficiency, high accuracy and strong adaptability, and overcome deficiencies associated with traditional measurement methods (low efficiency, high cost, poor ...
Gao Zhaoliang   +7 more
core   +1 more source

Effects of Breccias and Round Gravels on Steep Cut Slope Runoff and Sediment Yield Under Simulated Rainfall [PDF]

open access: yes, 2023
[Objective] The effects of breccias and round gravels on steep cut slope infiltration, runoff, sediment yield, and hydrodynamic characteristics were analyzed in order to provide a theoretical basis for a soil erosion prediction model and soil ...
Cao Longxi   +5 more
core   +1 more source

Understanding Service Providers’ Competency in Knowledge‐Intensive Crowdsourcing Platforms: An LDA Approach

open access: yesComplexity, Volume 2021, Issue 1, 2021., 2021
Knowledge‐intensive crowdsourcing (KIC) is becoming one of the most promising domains of crowdsourcing by leveraging human intelligence and building a large labor‐intensive service network. In this network, the service providers (SPs) constitute the backbone of the KIC platform and play an important role in connecting the platform and service ...
Biyu Yang   +3 more
wiley   +1 more source

土体构型对花岗岩红壤细沟发育形态的影响

open access: yesShuitu Baochi Xuebao, 2023
为探究花岗岩红壤细沟形态特殊变化的原因,解释土体构型影响细沟形态发育的机理。设计单一红土层(H)、单一砂土层(S)、上红下砂层状土层(HS)3种土体构型、不同径流量(低径流量3 L/min、高径流量6 L/min)和不同坡度(中坡20°、陡坡40°)的室内模拟细沟冲刷试验。结果表明:H处理下,细沟形态更多向"V"形和"U"形发育;S处理下,细沟沟道发育过程中短暂形成上窄下宽的深宽梯形断面后,完全崩塌;HS处理下,细沟形态能发育为梯形断面,且能继续扩大发育。与H和S相比,HS陡坡(40 ...
刘子轩   +4 more
doaj   +2 more sources

International clinical practice recommendations on the definition, diagnosis, assessment, intervention, and psychosocial aspects of developmental coordination disorder – Chinese (Mandarin) translation

open access: yesDevelopmental Medicine &Child Neurology, Volume 61, Issue 3, Page E1-E35, March 2019., 2019
目的 本国际临床指南由欧洲残疾儿童学会(the European Academy of Childhood Disability,EACD)牵头制定,旨在解决发育性协调障碍(developmental coordination disorder,DCD)的定义、诊断、评估、干预以及与社会心理方面的临床应用关键问题。 方法 本指南针对五个领域的关键问题,通过文献综述和专家团队的正式讨论达成共识。为保证指南的循证基础,以“机制”、“评估”和“干预”为检索词, 对2012年更新以来提出的最新建议以及新增的“社会心理问题”和“青少年/成人”为检索词进行检索。根据牛津大学循证医学中心证据等级 (证据水平 [level of evidence, LOE]1–4) 将结果进行分类,最终转化为指南建议。并由国际 ...
Jing Hua   +6 more
wiley   +1 more source

黄土坡面细沟侵蚀强度的空间分布及形态分异特征

open access: yesShuitu Baochi Xuebao, 2022
为探索细沟侵蚀的空间分异特性, 通过人工模拟降雨试验的方法, 分析不同降雨强度和坡度下的坡面细沟侵蚀过程, 探讨细沟侵蚀强度及形态在坡面尺度的沿程变化特征。结果表明: 随着坡度和雨强增加, 细沟侵蚀量不断增大; 在特定处理下, 细沟侵蚀强度沿坡长方向均呈现出先增后减的规律; 沟宽、沟深和细沟割裂度等细沟形态参数也表现为先增加后减小, 峰值出现在坡面中部。沟宽和沟深与细沟侵蚀量呈极显著的正相关关系, 细沟侵蚀强度与形态之间的演变具有一致性; 径流汇集导致坡面中部径流侵蚀动力增强, 沟壁崩塌和下切侵蚀严重,
龙琪   +4 more
doaj  

冲刷条件下裸露砒砂岩区坡面细沟微形态变化及其侵蚀特征

open access: yesShuitu Baochi Xuebao, 2021
选择裸露砒砂岩坡面为研究对象,基于野外径流小区冲刷试验结合三维激光扫描技术,研究3种流量(60,100,200 L/h)与4个坡度(5°,10°,20°,30°)组合冲刷下砒砂岩区坡面细沟形态演变特征及径流侵蚀产沙机制。结果表明:坡面细沟在坡下最先发育,随着冲刷流量和坡面坡度的增大而向上延伸;细沟出现的时间随着坡度的增加而缩短;20°坡面细沟的形态为"深窄型",最小宽深比为0.017;随着冲刷强度和坡度的增加,细沟宽深比变小,而细沟数量、细沟密度、细沟复杂度、细沟割裂度等指标均增大 ...
李龙   +4 more
doaj  

不同降雨强度及坡度条件下饱和紫色土坡面细沟形态特征

open access: yesShuitu Baochi Xuebao, 2023
坡面细沟形态特征的定量分析是研究细沟侵蚀的基础。通过设计3种降雨强度(30,60,90 mm/h)和5种坡度(2°,5°,10°,15°,20°)组合条件下的人工降雨模拟试验,定量研究饱和紫色土坡面降雨强度及坡度对细沟形态及其空间变化特征的影响。结果表明:饱和紫色土坡面细沟平均宽度、深度和细沟宽深比分别为3.44~9.64 cm、1.01~8.14 cm和1.18~3.87,细沟宽度和深度沿坡面从上至下整体均表现出先增大后减小的趋势,细沟宽深比沿坡面表现为上坡<中坡<下坡的变化特征。整体来看 ...
麻力文   +5 more
doaj  

重庆饱和紫色土坡面片流与细沟流水力学特性及临界条件试验研究

open access: yesShuitu Baochi Xuebao, 2023
为比较饱和紫色土坡面片流与细沟流水力学特征并明确其临界水力学特性,进行5个坡度(2°,5°,10°,15°,20°)和3个雨强(30,60,90 mm/h)组合 条件下的室内人工模拟降雨试验,在测得坡面片流、细沟流及其转变的临界流速的基础上,计算得到片流、细沟流及其转变的临界水力学参数,包括水深、雷诺数、弗劳德数和达西阻力系数。结果表明:在不同侵蚀阶段,片流流速为0.064~0.151 m/s,细沟流流速为0.175~0.350 m/s,雨强和坡度在不同侵蚀阶段对流速和水深的影响程度存在差异 ...
谭文浩   +5 more
doaj  

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