Results 31 to 40 of about 18,080 (163)

冲击接地电阻模型对输电线路耐雷水平的比较研究

open access: yesDianci bileiqi, 2015
对规程法冲击接地电阻模型、火花效应接地电阻模型以及暂态接地电阻模型等三种不同的接地模型进行了分析。结合220 kV双回输电线路,在ATP/EMTP中建立了相应的输电线路耐雷水平模型。在该耐雷模型中,使用无损多波阻抗模拟输电线路杆塔,同时考虑了工频电压对耐雷水平的影响。分别在工频电压初相角为0°、60°、120°、180°、240°以及300°等6种情况下计算了模型的反击和绕击耐雷水平。仿真结果表明:在相同的条件下,反击耐雷水平从高到低依次为火花效应模型、规程法模型、暂态电阻特性模型 ...
刘杰   +4 more
doaj  

Emerging applications of large language models in ecology and conservation science

open access: yesConservation Biology, EarlyView.
Abstract Large language models (LLMs) mark a major development in artificial intelligence, with potentially transformative implications for ecology and conservation science. Built on advanced deep‐learning architectures, these models can support a wide range of tasks. We reviewed emerging applications of LLMs, drawing on the wider scientific literature
Christos Mammides   +5 more
wiley   +1 more source

小流域水沙调控正态整体模型模拟实验

open access: yesShuitu Baochi Xuebao, 1994
在小流域正态整体模型上,分散配置水土保持措施,采用人工降雨方法,研究水沙变化规律。结果表明,流域产水产沙与水土流失的治理程度呈对数关系。文中还探讨了模型比例尺选择,模型制作和下垫面模拟技术等问题。
蒋定生 周清
doaj   +2 more sources

坡面土壤水蚀建模历程

open access: yesShuitu Baochi Xuebao, 2002
阐述国内外坡面土壤水蚀建模发展历程,然后分别论述经验模型、概念模型、物理模型以及水蚀遥感信息模型的发展历程,最后比较各类模型优缺点。
沈大勇 马蔼乃 毛善君 杨萍
doaj  

基于经典机器学习模型的河流重点水质预测

open access: yesJingshui jishu
近年来,水体污染问题日益突出,给河道环境造成巨大压力,故河道水环境破坏问题亟待解决。机器学习是一种基于大量监测数据的水质预测预警方法,是河道治理的新途径。【目的】本文旨在对比不同模型对不同水质指标的预测能力。【方法】本文以长江中下游平原某河流断面为例,首先通过显著性分析和主成分分析筛选出主要水质影响因子,随后根据自动监测站点数据选用支持向量机(SVM)和长短期记忆网络(LSTM)、门控循环单元(GRU)、时间卷积网络(TCN)神经网络模型对水质水平进行模拟。【结果】氨氮和溶解氧 ...
LÜ Ting   +3 more
doaj   +1 more source

Motivation, Self‐Regulated R2W Strategy Use, and Their Relationship Patterns Among Different Writing Performance Groups

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT The study investigated how writing motivation and self‐regulated read‐to‐write (SRL‐R2W) strategy use was related to writing performance and how the relationship between motivation and SRL‐R2W strategy use varied among different writing performance groups.
Huixuan Zhou   +3 more
wiley   +1 more source

The Development and Validation of the Chinese Vocabulary Levels Test

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT In response to the increasing need for effective Chinese vocabulary assessments, this study developed the Chinese Vocabulary Levels Test (CVLT), a test designed for intermediate‐level Chinese as a second or foreign language (CSL/FL) learners, based on the vocabulary lists (levels 4–6) from the Chinese Proficiency Grading Standards for ...
Shiwei Qi, Ailan Fu
wiley   +1 more source

湖泊水环境承载力研究

open access: yesShuitu Baochi Xuebao, 2004
以博斯腾湖为实例研究湖泊的水环境承载力,从湖泊水环境承载力的承载媒介(水资源量和水体质量)入手,以湖泊水环境承载力的承载对象(人口、污染物质、人类活动等等)为基础,建立湖泊水环境承载力研究概念模型和量化模型,通过建立湖泊生态需水量模型、湖泊环境需水量模型,结合系统动力学法计算了博斯腾湖的水资源量承载力,结合二维水流——水质模型模拟了湖泊中的污染物质(BOD、TN、矿化度)浓度分布,通过各点浓度分布经过聚合得到整个湖泊不同水位、不同来水频率下的水环境容量、富营养化水平、矿化度水平,而博湖的有机污染加剧 ...
王玉敏 周孝德 冯成洪 李家科
doaj   +2 more sources

水质模型的中间件实现技术及其在WebGIS上的应用

open access: yesShuitu Baochi Xuebao, 2005
水质模型是水体污染物迁移转化模拟的主要工具,在水环境保护、水污染防治等领域得到了广泛的应用。按照J2EE标准,在提高软件的可扩展性、可维护性和代码复用率指导思想下,以中间件技术的表现形式的应用框架为基础,以零维水质模型为代表,采用MVC软件设计模式,实现了水质预测中间件,建立了面向Web的水质预测系统,并使用WebGIS技术可视化水质模拟结果,该系统缩短了模型建模周期,提高了模型的使用效率。
王晓辉 解建仓 马斌 司毅铭 汪妮
doaj  

Complementary Capacities and Shared Challenges: Lessons From a Brazil‐Australia Water Management Consortium

open access: yesWorld Water Policy, Volume 12, Issue 2, May 2026.
ABSTRACT Transnational collaboration is critical for water‐security innovation, yet actor configurations and thematic priorities remain poorly characterized. We surveyed 92 Australian and Brazilian researchers from the Tropical Water Research Alliance (TWRA), analyzing 11 sets of binary variables on collaboration modes, stakeholders, implementation ...
A. P. Matei   +7 more
wiley   +1 more source

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