Results 61 to 70 of about 14,849 (205)

Pattern to Process in Land Use and Cover Change and Its Water Quality Response across Multiple Scales in the Jiulong River Basin [PDF]

open access: yes, 2011
河流水质受到自然与人为因素的综合作用,而土地利用/覆被变化(LUCC)是人类活动作用于自然资源与环境的一种最为显著的表现形式。了解LUCC的模式、过程及其水质效应将有助于从人为扰动、非点源污染等角度认识流域水体退化的发生过程和影响机制,进而有利于流域水质的预测、控制与管理。在人口增长与经济发展的压力下,我国水环境问题日渐凸显,研究流域LUCC过程及其水质效应在我国具有现势性和紧迫性。本研究选取土地利用/覆被变化较为剧烈的亚热带中尺度流域—九龙江流域为代表性流域,探讨九龙江流域土地利用 ...
李青生
core  

Acid‐Etched Co‐Vacancy‐Tunable CoFeP/N,P‐Codoped Carbon Nanocages for Highly Efficient Alkaline Water Electrolysis

open access: yesRare Metals, EarlyView.
ABSTRACT Efficient and durable bifunctional electrocatalysts are vital for scalable water electrolysis. Here, we realize cobalt‐vacancy (Covac) engineering in CoFeP supported on N,P‐codoped carbon nanocages (Co1‐vacFeP/NPC) through a simple route comprising a CoFe Prussian blue analog precursor, phosphidation–pyrolysis, tannic‐acid etching, and a ...
Yuan‐Liang Yuan   +6 more
wiley   +1 more source

Analysis on linkage between farm landscape and water quality in Jiulong River watershed [PDF]

open access: yes, 2011
基于lAndSAT遥感影像进行九龙江流域不同坡度类型的农业用地景观与水质指标(COdMn、nH4+-n、TP)的相关性分析,并分别对丰水期、枯水期、平水期的农业用地类型百分比与各水质指标进行线性回归。结果显示,坡度小于15°和大于25°的农业用地占总农业用地的面积比例与各水质指标呈较强的正相关。景观聚集度指数(COnTAg)与水体中TP浓度呈显著正相关,决定系数为0.565;香农多样性指数(SHdI)与水体中TP浓度呈显著负相关,相关系数为-0.527。丰水期和枯水期是九龙江流域水质变化较大的时期 ...
冯媛   +5 more
core  

海绵城市建设中若干水文学问题的研讨

open access: yes水电水利, 2019
伴随着城市化建设进程的逐步深入,城市水体黑臭、内涝等情况受到人们的关注。这些情况均属于水文学问题,原因为污染物排放量过多引起水循环改变,加之原生态系统受城市建设破坏,湖泊、湿地退化所致。为了应对不良水文学问题,海绵城市建设应时而生。尽管目前建设海绵城市已获得一定进展,但仍存在很多不足之处。本文简要针对海绵城市建设水文学问题相关内容进行探讨,目的在于改善城市水温效应,推进城市建设发展。
桥峰 陈, 腾 胡
semanticscholar   +1 more source

Bottom‐Up Strategy Toward 3D Porous MXene/MoS2 Nanosheets/Graphene Nanoarchitectures as Highly‐Efficient Hydrogen Evolution Electrocatalysts

open access: yesRare Metals, EarlyView.
ABSTRACT As a core component in the electrochemical water splitting system, the cathode catalyst is capable of boosting the kinetics of the hydrogen evolution reaction (HER), while the scarcity and expenditure of current noble metal‐based electrocatalysts seriously restrict the large‐scale commercial development of hydrogen manufacturing devices. Here,
Haiyan He   +8 more
wiley   +1 more source

Nanofiltration Membranes for High‐Selectivity Separation of Li+ and Mg2+ From Salt Lake Brines: Strategies, Challenges, and Perspectives

open access: yesRare Metals, EarlyView.
ABSTRACT Against the backdrop of global clean energy transition and surging demand for lithium resources, lithium extraction from salt lakes presents unprecedented development opportunities. Nanofiltration (NF) membrane technology, recognized for its efficiency, energy savings, and environmental benefits, demonstrates significant application potential ...
Wen‐Feng Li   +5 more
wiley   +1 more source

青藏高原东北边缘云杉属-冷杉属林火烧迹地枯落物持水特征

open access: yesShuitu Baochi Xuebao, 2023
以青藏高原东北边缘云杉属-冷杉属林火烧迹地为研究对象,基于典型抽样法于2020年8月和2021年7—8月在火烧迹地和未过火天然林采集枯落物样品,采用室内浸泡法测定分析枯落的蓄积量、持水量、有效拦蓄量等指标,探究林火干扰下不同坡位枯落物的水文效应,为更好地促进森林水源涵养以及水土保持功能提供依据。结果表明:(1)在植被恢复过程中,枯落物的厚度和蓄积量随着恢复年限的增加而增加,且厚度为3.75~8.31 cm,蓄积量为6.16~8.13 t/hm2。恢复5,15年火烧迹地上、中 ...
贺万鹏   +6 more
doaj  

新时期小型农田水利工程管理的问题及对策探究

open access: yes工程技术与管理, 2019
水利工程的建设有利于中国发电、灌溉和防洪等工作的实施,为加快现代化进程奠定了基础。其中,小型农田水利工程是最为关键的组成部分之一,对于农业发展具有重大意义。在新时期社会的发展当中,对于小型农田水利工程管理也提出了更高的要求,应该转变传统管理理念与方法,促进工程建设质量与效率的提升,提升农业经济发展水平。然而,当前管理工作中也会存在诸多问题,限制了工程建设的步伐。本文将通过分析小型农田水利工程管理的问题与原因 ...
璐璐 李
semanticscholar   +1 more source

Effects of parachute science on local research capacity 降落伞科学对当地研究能力的影响

open access: yesConservation Biology, EarlyView.
Abstract Strengthening research capacity is essential to address the global biodiversity crisis. Yet, parachute science often undermines this goal, and its prevalence, costs, and benefits are unclear. We analyzed 13,502 publications on primate research that we extracted from Scopus (1960–2022) to evaluate the effects of parachute science on local ...
Li Yang   +11 more
wiley   +1 more source

水锤效应分析数值模拟方法研究

open access: yesHe jishu
水锤效应一直是核电厂热工安全所关注的重要问题之一。准确获得水锤效应下压力波的传播数据对结构载荷分析和评价至关重要。目前,常见水锤分析程序多采用的是特征线法(Method Of Characteristics,MOC),但其在处理多管道复杂系统和捕捉不连续性方面存在一定的计算误差。而有限体积法(Finite Volume Method,FVM)在计算复杂系统水锤问题上存在优势,典型程序为RELAP5。对此,本文基于FVM初步开发了一款水锤压力波传播分析程序。针对具体的单相水锤问题,发展了一种“汽-液 ...
余 光辉   +4 more
doaj   +1 more source

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