Results 21 to 30 of about 20,721 (119)
为实现永定河北京段沙质河道生态修复,通过野外径流小区放水冲刷试验,在3种放水流量(0.5,1.0,1.5 m3/h)、坡度10°、5种护岸材料(生态袋、椰丝植生毯、三维土工网、松木桩、卵石)下分析不同生态护岸坡面的水动力学特性、产流产沙状况。结果表明:(1)3种放水流量下5种护岸材料布设坡面的平均流速均小于裸坡,5种护岸材料平均径流流速均表现为卵石 > 松木桩 > 三维土工网 > 生态袋 > 椰丝植生毯。5种生态护岸材料弗劳德数均小于1,雷诺数均小于500。(2)生态护岸措施有效减少产流 ...
郑雪慧 +4 more
doaj
ABSTRACT The commercialization of lithium–sulfur batteries (Li–S batteries) has been hindered by the shuttle effect of lithium polysulfides (LiPSs) and sluggish redox kinetics. In this study, we constructed a three‐dimensional hollow conductive network host material for sulfur with synergistic enhancement effects.
Jie Yang +6 more
wiley +1 more source
根据相关水文气象台站的降水、蒸发、气温和流量观测资料,分析了石羊河流域年平均流量的变化特征及原因.研究表明:45 a来,石羊河流域年平均流量总体呈略减少趋势,流域东、中部年平均流量呈减少趋势,流域东部减少幅度最大,流域西部年平均流量呈略增加趋势.石羊河流域年平均流量的年内分配因受补给条件的影响四季分明,四季流量大小依次为夏季、秋季、春季、冬季.流域四季年平均流量都呈减少趋势,变幅最大的是夏季,冬季最小.石羊河流域在不同时段不同区域年平均流量都存在6~7 a和9~10a的长周期和2~3 a的短周期 ...
李玲萍, 刘明春
doaj
均压电极是高压直流输电工程换流阀内冷水系统的重要部件,起到钳制电势和减小泄漏电流的关键作用,但是在运行过程中,均压电极发生腐蚀或者断裂,将导致换流阀阀塔上与内冷水管道接触的金属器件发生腐蚀,内冷水系统发生渗漏、堵塞等,从而使得换流站因设备过热、水管漏水等问题造成的停运事件屡有发生,严重影响直流工程的安全稳定运行。因此,研究均压电极断裂相关机理和原因能够有效减小内冷水系统事故。文中通过分析均压电极在水管内的受力情况,结合铂金材料的特性,首次从剪切强度的角度开展了均压电极断裂分析。文中从材料成分、力学性能 ...
肖凯 +5 more
doaj
Glycerophosphocholine‐Mediated Dual Regulation for Highly Stable Aqueous Iron‐Ion Batteries
ABSTRACT Iron‐ion batteries (FeIB) offer the advantages of low cost and high capacity, demonstrating potential for large‐scale energy storage. However, severe hydrogen evolution reaction (HER) occurs during cycling, which significantly impacts battery lifespan.
Tian Yang +6 more
wiley +1 more source
准确测量坡面薄层水流流速是分析和计算水动力学参数的前提,也是建立土壤侵蚀模型的基础。设置5个坡度(5°,10°,15°,20°,25°)和4个放水流量(2,4,8,16 L/min),采用长12 m、宽0.1 m、高0.3 m的水槽对坡面薄层水流流速进行了测量。通过记录水流前锋(前沿)流过水槽的时间计算水流的前沿流速,并采用染色剂示踪法和电解质脉冲法测量水流的平均表层流速和平均流速,与前沿流速进行对比。结果表明:试验的前沿流速为0.237~1.290 m/s,且随着坡度和流量的增大呈增大趋势 ...
杨大明 +4 more
doaj
Dual‐Layer Solid Electrolyte Interphase Enables Effective Suppression of Lithium Dendrites
ABSTRACT The heterogeneous solid electrolyte interphase (SEI) at the Li metal anode often leads to slow and uneven Li+ flux, causing severe Li dendrite growth. Herein, we combine X‐ray photoelectron spectroscopy and cryogenic transmission electron microscopy to demonstrate that a dual‐layer SEI, consisting of an inorganic inner layer and an organic ...
Huaping Wang +4 more
wiley +1 more source
ABSTRACT Groundwater depletion is a major challenge in semiarid, hard‐rock regions where irrigation demands often exceed natural recharge. This study evaluates the effectiveness of farm‐scale recharge pits as a local, supplementary, and community‐managed groundwater recharge solution in the Dharta catchment of Rajasthan, India. Alongside check dams and
Prahlad Soni +4 more
wiley +1 more source
根据城轨供电系统的特点分析了雷击城轨整流变电站附近杆塔时对整流变电站的影响方式,认为与铁轨并联的均流线和接触网末端的绝缘配置会引起雷击杆塔时过电压入侵到整流变电站,而整流变电站避雷器接地散流效果和均压效果不好是引起整流变电站事故的主要原因。针对避雷器接地和均流线接地散流和均压不良设计了新的接地装置,并用ANSYS软件对比分析了新的接地装置和原有接地装置的接地性能,分析结果表明:新型接地装置的均压效果相对于原有接地装置的均压效果其最大地电位减小了28 ...
张东, 陶凤源, 董新胜
doaj
ABSTRACT This study developed a metal–modified fluoroethylene vinyl ether (FEVE) organic coating on 6061 aluminum alloy, supported by a micro‐arc oxidation (MAO) pretreatment layer, to enhance corrosion resistance and antifouling performance in marine environments.
Chang Liu +5 more
wiley +1 more source

