Results 11 to 20 of about 1,437,568 (165)

1000kV避雷器电流分布试验方法及特性的研究

open access: yesDianci bileiqi, 2011
介绍了1 000 kV交流系统用避雷器的电流分布试验方法及研究结果。在操作冲击电流和雷电冲击下多柱并联电阻片的电流分布试验结果表明,冲击电流的波形对电流分布系数的影响不大,但在同一波形下随着冲击电流幅值减小,电流分布系数增大;同时分析了电阻片配组参数,当按照每层每片电阻片的直流2 mA参考电压值和500 A操作冲击残压值之间的偏差同时小于0.5%的原则进行配组,电流分布系数小于10%;不同串联片数的4柱并联电阻片组进行试验,结果表明,随着串联电阻片的数量增加,电流分布系数减小。
祝嘉喜   +3 more
doaj  

Structure–Property Relationship‐Guided Mechanisms for Electromagnetic Wave Absorption, Triboelectric Generation, and Negative Permittivity in Magnetic Metacomposites

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT The composition and structural characteristics of metacomposites are crucial for tuning their negative electromagnetic parameters; however, the lack of a clear structure–property relationship severely limits their application in dielectric and magnetic fields.
Chunyuan Deng   +9 more
wiley   +1 more source

雨滴击溅对薄层水流水力摩阻系数的影响

open access: yesShuitu Baochi Xuebao, 1994
采用模拟降雨的试验方法,在分析计算有无雨滴击溅作用坡面薄层水流水力摩阻系数的基础上,进一步分析了雨滴击溅作用对薄层水流水力摩阻系数的影响。结果表明,雨滴击溅作用可减少薄层水流的水力摩阻系数,从而减少水流摩擦阻力,使水流侵蚀力相对增大;有雨滴击溅作用时其水力摩阻系数平均为无雨滴击溅时的66.14%。这说明雨滴的击溅除了本身的分散和破坏土壤结构等侵蚀作用外,还可降低水流的水力摩阻系数 ...
吴普特 周佩华
doaj   +2 more sources

Simultaneous Generation of Topographic Models and Manning Roughness Coefficient Maps From Tri‐Stereoscopic Satellite Images: Application to the Huarmey River, Peru

open access: yesThe Photogrammetric Record, Volume 41, Issue 195, July/September 2026.
Tri‐stereoscopic PeruSat‐1 imagery enables the simultaneous generation of 0.70 m‐resolution topography and spatially distributed Manning roughness maps, achieving 0.434 m vertical accuracy. Integrated into HEC‐RAS, these products provide consistent, high‐resolution inputs that improve hydraulic modelling and flood risk assessment in data‐scarce river ...
Jorge L. Miranda‐Pita   +3 more
wiley   +1 more source

Symbiotic Germination Technique of an Endangered Epiphytic Orchid Dendrobium sinominutiflorum: A Promising Conservation Application 濒危附生兰科植物勐海石斛 (Dendrobium sinominutiflorum) 的共生萌发技术:一种具有应用前景的保护策略

open access: yesIntegrative Conservation, Volume 5, Issue 2, Page 192-204, June 2026.
We developed an effective ex‐situ conservation approach for an endangered orchid species, Dendrobium sinominutiflorum. A compatible fungal strain Tulasnella sp. was obtained by using in‐situ seed baiting technique. The Symbiotic germination with Tulasnella sp. significantly promotes seed germination and seedling growth.
Han‐Xiao Huang   +6 more
wiley   +1 more source

Laws, Enforcement, and Strategy: A Multi‐Layered Qualitative Study of Multinational Enterprise Compliance Under European Union and Chinese Data Protection Regimes

open access: yesPolicy &Internet, Volume 18, Issue 2, June 2026.
ABSTRACT In an era of proliferating but divergent data protection regimes, the European Union's rights‐based approach and China's sovereignty‐centric model have become two dominant poles of global data governance. This article examines how multinational enterprises navigate compliance under these dual systems and how that compliance is shaped through ...
Yiping Cao
wiley   +1 more source

Too Difficult to Report? User Experiences With DSA and Community Guideline Reporting on Social Media

open access: yesPolicy &Internet, Volume 18, Issue 2, June 2026.
ABSTRACT User reporting of norm‐violating content on social media is a crucial component of platform governance. While prior research has explored the motivations behind reporting—often drawing on the Bystander Intervention Model—less attention has been paid to how users navigate the processes involved.
Ursula K. Schmid   +2 more
wiley   +1 more source

发/变电站站外短路避雷线分流系数计算方法研究

open access: yesDianci bileiqi, 2016
避雷线分流系数是接地网设计、避雷线选型和热效应分析以及评价输电线路电磁环境的基础,因此合理的避雷线分流系数计算方法有着重要的意义。基于避雷线的等效阻抗模型,提出了计算站外短路情况下避雷线分流系数的分流阻抗模型计算方法,并利用MATLAB程序实现了计算过程。针对某发电厂站外短路的情况,分别利用ATPDraw软件和分流阻抗模型计算了避雷线分流系数,两者计算结果的相对误差小于10%,满足工程计算要求,验证了本文站外短路分流阻抗模型的正确性。最后,本文利用分流阻抗模型分析了电站接地电阻 ...
杨琪   +5 more
doaj  

Changing trends in prenatal screening and treatment of cytomegalovirus infection in France: 7‐year national cohort study (2017–2023)

open access: yesUltrasound in Obstetrics &Gynecology, Volume 67, Issue 6, Page 756-763, June 2026.
ABSTRACT Objectives Cytomegalovirus (CMV) is the leading cause of congenital infectious neurosensory impairment. We aimed to present national epidemiological data on maternal CMV infection during pregnancy in France, focusing in particular on primary infection in the periconceptional period or first trimester, and to assess the impact of changes in ...
P. Coste‐Mazeau   +176 more
wiley   +1 more source

坡面流水动力学特性研究

open access: yesShuitu Baochi Xuebao, 2001
采用变坡水槽研究了坡面流水动力学参数 (流态、流速、水深及阻力系数 )随流量和坡度的变化规律。结果表明 ,坡面流流态与水深密切相关 ,当水流深度小于 0 .316 cm时 ,坡面流呈过渡流 ,水深大于 0 .316 cm时呈紊流流态 ;当坡度为 5~ 2 5°、单宽流量为 0 .6 2 5~ 12 .5× 10 - 3m3/(s· m)时 ,坡面流平均流速和平均水深主要受流量控制 ,坡度的影响并不显著 ,可用简单的线性函数来模拟平均流速、水深与流量和坡度间的关系 (r2分别为 0 .89,0 .78) ;
张光辉 张光辉 卫海燕 刘宝元
doaj   +2 more sources

Home - About - Disclaimer - Privacy