Results 41 to 50 of about 14,295 (168)

海洋环境对海上风场接地系统雷击暂态特性影响研究

open access: yesDianci bileiqi, 2018
海上风力发电产业的蓬勃发展面临日益严重的雷电灾害威胁,为有效指导海上风电机组的雷电防护研究,需要研究海洋环境对海上风场接地系统雷击特性的影响。利用PSCAD软件搭建简化海上风场模型,讨论海洋土壤分层环境下上层海水深度和下层土壤电阻率对风机接地系统雷击暂态响应的影响,分析增加接地体长度对于降低暂态过电压的效果。仿真结果表明:风机遭受雷击后,浪涌会传播至其他相连风机,距离雷击点越远的风机,塔底暂态电位幅值越低。下层海床土壤电阻率越大,风机塔底暂态电位幅值越高。上层海水深度越大,风机塔底暂态电位幅值越小 ...
付国定
doaj  

Learning Styles, Engagement and Anxiety in AI‐Mediated Writing: A Multimodal Feedback Study

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Artificial intelligence (AI) tools now permeate English academic writing. However, evidence on how feedback modalities align with student differences and with psychological mechanisms remains limited. Prior work often reduced learning styles to simple matches with delivery modes and treated learning engagement and writing anxiety as peripheral.
Yi Ren   +3 more
wiley   +1 more source

The Role of Technology Standards in Strategic Hedging

open access: yesAsian Politics &Policy, Volume 18, Issue 2, April 2026.
ABSTRACT This article argues that technology standards provide Southeast Asian states with a distinct mechanism for hedging amid intensifying US–China technological rivalry. Traditional hedging strategies emphasizing economic engagement without political alignment are increasingly constrained by the weaponization of technological interdependence ...
Darren J. Lim, Anthea Roberts
wiley   +1 more source

贵州山地风力发电机雷击电磁环境研究

open access: yesDianci bileiqi, 2017
贵州省属于我国西南部高原山地,风能资源丰富,目前全省并网型风电场建设已经达到快速增长阶段。由于贵州省特殊的地形地貌和山地气候特征,导致了雷电活动的复杂性和雷灾的易发性。风力发电机因其所处位置海拔高,极易遭受雷击。对风力发电机进行实地数据勘查,采用CDEGS软件建立风力发电机三维数值模型,利用土壤电阻率和土壤分层模型,结合雷电特征参数和风力发电机采用的防雷系统,分析风力发电机遭受雷击时其周边的电磁场变化及对人员、设备和系统的危害,同时提出了减小雷击对山区风力发电机危害的方法 ...
曾勇   +4 more
doaj  

Development of a model-based optimal control strategy of Centrifugal Chiller System [PDF]

open access: yes, 2017
2006-2007 > Academic research: refereed > Publication in refereed journalVersion of ...
Wang, SW, Xu, XH
core  

Multiple pregnancy with complete hydatidiform mole and coexisting normal fetus: systematic review and meta‐analysis of clinical outcomes from non‐randomized studies

open access: yesUltrasound in Obstetrics &Gynecology, Volume 67, Issue 3, Page 272-282, March 2026.
ABSTRACT Objective Complete hydatidiform mole and coexisting normal fetus (CHMCF) is a rare condition for which there is significant heterogeneity in diagnosis, counseling and management of complications. The objective of this study was to summarize the prevalence of clinical outcomes in reported cases of CHMCF.
N. Salmeri   +8 more
wiley   +1 more source

基于聚类分析的风电场多机等效建模方法研究

open access: yesGaoya dianqi, 2019
针对大规模双馈型机组所组成的风电场,提出1种将变桨机构动作情况作为风电场分群聚类指标的等值建模方法。通过将能够表征变桨机构动作状态的特征向量输入到支持向量机中,对风电机组进行动态分群,将同一群内的风机进行等效合并。此外叙述了等效机组参数计算方法,建立风电场多机等效模型。经过对不同建模方法的比较得出,此方法在保证仿真精度的前提下大幅度缩小了仿真时间,且仿真结果更加接近风电场实际运行工况,验证了该方法能够更加准确的表现出风电场并网点的动态特性。
付盼, 胡庆林
doaj  

The systematic simulation and performance analysis of biomass gasification fuel cell-gas turbine and ground source heat pump combined cycle [PDF]

open access: yes, 2015
生物质气化、地源热泵、燃料电池与燃气轮机联合循环等技术以其清洁、高效、环保等特性,近年来得到国内外众多学者和研究机构的广泛关注。目前针对这几类单项技术的研究已经取得了较多成果,但将这些单项技术进行集成耦合后形成联合循环对其进行系统分析的研究还处于起步阶段,系统的结构、循环的设计、不同单元的规模匹配、部件之间的相互耦合等尚未形成完整的理论体系,需要进行详细的分析和论证。 本文由此提出生物质气化燃料电池-燃气轮机与地源热泵(BGFC-GT-GSHP)的一体化联合循环系统 ...
徐仁超
core  

Landscape Composition and Proximity to Water Affect American Badger Occupancy in Shortgrass Prairies 景观组成和与水的距离影响矮草草原中美洲獾的占域率

open access: yesWildlife Letters, Volume 4, Issue 1, Page 23-31, March 2026.
American badgers, a medium‐sized carnivore occurring in much of North America, are important predators in prairie landscapes though our understanding of their habitat use requirements in these areas is unclear. We used a multi‐scale approach to understand American badger habitat use at both local and landscape scales.
Colleen W. Piper   +5 more
wiley   +1 more source

大电网末端风力发电系统故障穿越关键技术

open access: yesGaoya dianqi, 2017
为了了解大电网末端风电机组故障穿越特性,文中分析了高渗透率风力发电大电网末端电网特性及风机运行特性。结合相应的检测标准及要求,探讨了大电网末端风电并网出现的故障特性,研究了直驱及双馈风电机组故障穿越关键技术及控制策略;结合仿真及实际检测,研究了大电网末端直驱风力发电机高电压穿越能力、双馈机组低电压穿越的可行性,提出了风电机组故障穿越的隐患,为大电网稳定运行提供了依据。
李晖   +6 more
doaj  

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