Results 21 to 30 of about 14,739 (111)

复杂土壤结构对流入变压器直流电流的影响分析

open access: yesDianci bileiqi, 2020
直流输电系统以单极大地方式运行时,地中流散的直流电流流入极址附近交流变压器中性点,导致变压器产生直流偏磁现象。研究土壤结构对流入变压器的直流电流的影响是分析变压器直流偏磁现象的基础。建立考虑山川、海洋、湖泊等复杂土壤结构的直流接地极特性电磁场有限元模型,计算直流接地极散流产生的地中电位;结合变电站电路模型计算流入相应变压器的直流电流;在此模型基础上分析极址附近交流变电站接地网位置对流入变压器直流电流的影响。结果表明:当两交流变电站之间连线与山川、海洋平行时,流入变压器的直流电流量最小 ...
李景丽, 栗超超, 冯鹏
doaj  

Spatial segregation and bycatch risk as potential drivers of population trends of wandering albatrosses at South Georgia

open access: yesConservation Biology, Volume 40, Issue 1, February 2026.
Abstract Spatial segregation in at‐sea distribution is frequently observed in seabirds and can have important implications for conservation and management. Globally, many albatross and petrel populations are declining due to bycatch in fisheries. In South Georgia, the decrease in wandering albatrosses (Diomedea exulans) differs among breeding sites ...
V. Warwick‐Evans   +3 more
wiley   +1 more source

双极柔性直流电网短路电流暂态特性分析 [PDF]

open access: yes全球能源互联网, 2018
架空线柔性直流电网是实现大规模可再生能源广域协调互补和可靠送出的有效解决方案,是未来高压大容量柔性直流输电的重要应用方向。直流线路短路电流是柔性直流电网中换流阀、直流断路器及电抗器等关键主设备参数选取的重要依据之一。通过建立双极柔性直流电网单个换流站在直流线路不同短路故障类型下的等效电路数学模型,构建了故障时刻双极柔性直流电网等效电路网络模型,提出了一种适用于双极柔性直流电网的单极接地、单极接中性线及双极短路的暂态短路电流定量分析方法,实现了双极柔性直流电网直流线路任意故障类型 ...
裴翔羽   +5 more
doaj   +1 more source

Volatile Energy, Stunted Investment: How Energy Price Inflation Shapes Foreign Direct Investment Into Africa

open access: yesWorld Affairs, Volume 189, Issue 1, Spring 2026.
ABSTRACT In the study, we investigate the roles energy price inflation and its volatility play in shaping foreign direct investment (FDI) inflow into Sub‐Saharan Africa (SSA). Applying data from 37 SSA economies between 2002 and 2023 and the system generalized method of moments (GMM) as the estimation strategy to account for endogeneity, the results ...
Chimere O. Iheonu   +2 more
wiley   +1 more source

直流偏磁下变压器的振动噪音分析

open access: yesGaoya dianqi, 2021
分析直流偏磁对变压器造成的异常振动噪音规律是预防变压器故障的前提。为此,针对E型电力变压器,根据"铁心—绕组"模型分析了直流偏磁下变压器的振动噪音机理并利用Comsol搭建了电磁—振动—声场多物理场耦合模型,研究直流量大小、直流量从初级绕组流入和直流量从次级绕组流入两种情况下,直流偏磁对不同运行状况变压器的振动噪音规律和对绕组电压电流波形的影响。研究表明:直流量从初级绕组流入对空载变压器的影响最大,随直流量的增加铁心绕组上的振动噪音加剧且振动噪音最大值分布在铁心上 ...
吴静   +6 more
doaj  

Strain in Ni-Mo Alloys Pulse-Plated From An Acidic Citrate Bath [PDF]

open access: yes, 1996
The effect of the pulsing current on the composition and strain of Ni-Mo alloys pulse-plated from acidic citrate bath was investigated. The molybdenum content increased with increasing molybdate ion concentration in the bath, and the increasing tendency ...
中村 優子   +3 more
core   +1 more source

Participation Disenchants: How Online Political Participation Decreases Online Political Efficacy in China

open access: yesRegulation &Governance, Volume 20, Issue 1, Page 35-63, January 2026.
ABSTRACT Existing literature largely agrees that authoritarian regimes establish channels for political participation to gather valuable information on citizens' anti‐regime sentiments and policy preferences and to supervise lower‐level bureaucrats and firms.
Anton Bogs
wiley   +1 more source

Basic experiments on electric quenching of fog II [PDF]

open access: yes, 1996
In the present motorization life, the dense fogs on the highways bring the heavy traffic obstacle. It is important and urgent to solve this fog problem. The basic experiments on electric quenching of fog are carried on.
北村 岩雄   +3 more
core   +1 more source

Video Assistant Referee(ndums): A Populist Weapon or Effective Tool to Stop Autocrats in Competitive Authoritarian Regimes in Latin America?

open access: yesLatin American Policy, Volume 16, Issue 4, December 2025.
ABSTRACT In recent years, video assistant referee systems have been increasingly used to correct unfair decisions in sports. Similarly, I argue that constitutional referendums play a corrective role in hybrid or competitive authoritarian regimes, where the electoral referee is biased and the government enjoys unfair advantages.
Muhammet Derviş Mete
wiley   +1 more source

Driving of the Squirrel-cage Three Phase Induction Motor with Mc Murray-type Three-phase Inverter [PDF]

open access: yes, 1968
The output wave form of Mc Murray type three phase inverter is rectangular and it involves many harmonics. The squirrel-cage three phase induction motor (750W, 200V, 50/60 c/s, 4 poles) was drived by the inverter, then efficiendes and temperature rises ...
岡田 粂ニ
core   +1 more source

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