Results 31 to 40 of about 68,199 (213)

岩层倾向对喀斯特槽谷区地表/地下产流过程的影响

open access: yesShuitu Baochi Xuebao, 2020
喀斯特槽谷区在降雨过程中极易发生水土流失,这使得该区生态环境被破坏。以喀斯特槽谷区为研究对象,通过室内模拟其典型顺/逆层坡面特征及地下孔裂隙发育程度,利用人工降雨试验研究不同雨强条件下地表地下产流特征,从而揭示喀斯特槽谷区地表地下产流机制。结果表明:(1)喀斯特槽谷区地表地下产流受雨强影响,小雨强(30 mm/h)条件下地下产流量大于地表产流量,中雨强(60 mm/h)条件下地表产流量增大且裸坡条件下地表产流量大于地下产流量,大雨强(90 mm/h)条件下裸坡与顺层坡的地表产流量均大于地下产流量。(2 ...
覃自阳, 甘凤玲, 何丙辉
doaj  

A Comparative Study on Financial Performance and Financial Policy between China Shipbuilding Industry Group Power Co., Ltd and Camel Group Co., Ltd [PDF]

open access: yes, 2016
2009年,中国汽车销量达到1364万辆,同年美国汽车销量1060万辆,中国首次超越美国成为世界第一汽车销售市场,汽车电池是汽车必不可少的储能配件。本论文基于“利润-现金-价值-风险-成长”的财务管理理念,以财务报表为基础,对中国动力和骆驼股份两家中国最大的起动用铅酸电池厂家的财务绩效和财务政策进行比较研究,为利益相关者的决策提供依据。 本论文共8章,第一章为研究概述。第二章为行业分析。第三章为公司情况。第四章通过财务报表三维分析来分析财务状况的结构和趋势。第五章中运用五大类财务比率指标 ...
陈榴信
core  

Oxygen Vacancy Engineering of Ultrafine ZnAl2O4 Nanoparticles as a Robust Protective Layer for Dendrite‐Free and Long‐Lifespan Aqueous Zn Metal Anodes

open access: yesRare Metals, EarlyView.
ABSTRACT Aqueous zinc‐ion batteries (AZIBs) hold great promise for safe and sustainable energy storage, but their commercialization is impeded by severe Zn dendrite growth and interfacial instability. To address these challenges, we propose a defect engineering strategy employing ultrafine ZnAl2O4 (ZAO) nanoparticles (∼5 nm) with oxygen vacancy defects
Yilun Ren   +9 more
wiley   +1 more source

武汉东湖颗粒有机碎屑碳、氮、磷的沉降速率 [PDF]

open access: yes, 1989
1983—1984年,测定了东湖水柱总沉降颗粒有机物中的碳、氮、磷、叶绿素a含量和浮游动物数量,以及该湖浮游动、植物优势种的干重/湿重、C/N及C/P比值。利用所得数值计算出其颗粒有机碎屑的沉降速率。东湖这两年的颗粒有机碎屑的沉降速率[g/m~2·a),Ⅰ站分别为10.67与10.97(碳),2.15与2.68(氮)及0.29与0.30(磷);Ⅱ站分别为10.35与7.26(碳),2.17与1.12(氮)及0.22与0.16(磷)。与水柱浮游植物净生产量相比 ...
林婉莲,刘鑫洲
core  

Surface‐Embedded Ag@Multilayer Graphene for Photothermal‐Enhanced Superhydrophobic Anti‐Icing Coatings

open access: yesRare Metals, EarlyView.
ABSTRACT Harnessing solar energy for self‐heating presents an effective strategy to suppress surface ice formation. In this paper, we fabricated nano‐silver‐modified multilayer graphene sheets (Ag@MGs) that integrate photothermal and superhydrophobic properties for anti‐icing applications.
Yihan Zhang   +7 more
wiley   +1 more source

小麦秸秆长度、覆盖量对坡面产流产沙的影响

open access: yesShuitu Baochi Xuebao, 2020
为定量研究小麦秸秆覆盖对坡面产沙产流过程及减水减沙效益的影响,采用室内人工模拟降雨试验,研究在降雨强度为90 mm/h时,不同秸秆长度和秸秆覆盖量下的坡面产流产沙特征和产流产沙过程规律,结果表明:(1)在相同秸秆长度下,随秸秆覆盖量增加,产流量产沙量极显著减少 ...
曾建辉   +5 more
doaj  

Multiscale Study of a Synergistic System in Carbon‐Coated Multimetal‐Based Selenides Toward Rapid and Highly Stable Sodium Storage

open access: yesRare Metals, EarlyView.
ABSTRACT The development of sodium‐ion batteries (SIBs) is limited by slow charge transfer kinetics and large material volume changes caused by the large radius of Na+. Leveraging the excellent physicochemical properties and unique heterostructures of metal selenides, ultrafine hetero‐CuFeSe2‐CoSe2 nanoparticles are in situ wrapped by ...
Ying Zhu   +5 more
wiley   +1 more source

模拟降雨下前期含水量对黄绵土坡面产流产沙过程的影响

open access: yesShuitu Baochi Xuebao, 2023
为探究不同前期土壤含水量条件下坡面产流产沙特征及产流产沙关系,以安塞黄绵土为研究对象,通过设置6个前期土壤含水量处理(5%,10%,15%,20%,25%,30%),采用室内人工模拟降雨试验来系统研究前期土壤含水量对坡面产流产沙过程的影响。每个含水量处理设置2个重复,坡面坡度为15°,设计雨强为90 mm/h,降雨历时为1 h。结果表明:(1)随着前期土壤含水量的升高,坡面初始产流时间幂函数减小,产流量线性增大。(2)坡面土壤流失量随前期土壤含水量增大呈幂函数增加,高含水量组(29.3 ...
淡彩虹   +5 more
doaj  

A Molten Salt Strategy to Convert Bulk Nb2O5 Into 2D Nonlayered Niobium Nitride Nanosheets for Superior Pseudocapacitive Storage

open access: yesRare Metals, EarlyView.
ABSTRACT Two‐dimensional (2D) nonlayered niobium nitrides have attracted considerable interest for electrochemical energy storage. However, the synthesis of these materials is hampered by their nonlayered crystal structures, which are characterized by strong three‐dimensional chemical bonding.
Rui Huo   +7 more
wiley   +1 more source

土地利用变化对产流和产沙的影响分析

open access: yesShuitu Baochi Xuebao, 2004
LUCC(土地利用覆盖变化)对径流的影响研究主要集中在对年径流量的影响,选用基于ArcviewGIS的SWAT模型,利用情景模拟来分析土地利用变化对产流量和产沙量的影响,并重点探讨森林对产流的影响。以黄河下游支流洛河上游卢氏水文站以上流域为研究区域,选取了1992~2000年24个雨量站的雨量资料和同期的气象资料,采用土壤类型图(1∶4000000)以及设定的不同土地利用情景,作为模型的输入,进行土地利用变化的产流量和产沙量的情景模拟。模拟表明:森林的存在增加了径流量,减少了产沙量;草地也能减少产沙量 ...
郝芳华 陈利群 刘昌明 戴东
doaj   +2 more sources

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