Results 11 to 20 of about 194,382 (153)

直流故障引发直流外送系统新能源脱网问题研究 [PDF]

open access: yes, 2023
含高比例新能源的直流外送系统由于送端发电设备支撑能力薄弱,在直流故障发生后新能源发电设备面临着过电压脱网风险。为了防止新能源脱网事故的发生,首先建立新能源直流外送系统仿真模型分析新能源机端暂态过电压形成机理,其次根据无功传输规律分析常规机组、调相机、电气距离等因素对新能源脱网的影响,定量分析常规机组的电压调节灵敏度,在此基础上利用新能源短路比指标对新能源脱网情况进行量化分析,最后根据分析结果提出了提高短路容量、提高风机高压穿越能力等预防直流故障后新能源脱网的策略 ...
王雷   +5 more
core   +2 more sources

配电网弧光接地主动转移型消弧技术

open access: yesDianci bileiqi, 2023
我国城市中低压配电网电容电流急剧上升且消弧线圈补偿效果欠佳,单相接地故障电弧难以自熄易产生弧光接地过电压及扩大事故,探究弧光接地故障的快速有效熄弧方法是保障配网稳定安全运行的基础。首先根据主动转移型消弧技术的工作原理,建立熄弧过程的等效电路,利用叠加定理推导熄弧时故障点电流计算公式,分析其与故障点位置、接地点过渡电阻、线路负荷电流等因素的关系;然后采用Matlab/Simulink搭建10 kV小电流接地系统单相接地故障模型,其中采用控制论电弧模型模拟单相弧光接地故障;最后通过设置典型的故障点位置 ...
李景丽, 任俊跃, 赵子敬
doaj  

電路板故障診斷儀器

open access: yes, 2018
[[abstract]]專題是關於學校電信設備--校園電話交換機的類比內線/外線(PCB 介面) 卡--的電路板故障診斷技術研究。這些電話交換機的類比內線/外線(介面) 卡是因為雷擊而故障損毀。利用系上現有的電路板故障診斷檢測設備來檢測這塊板子,以建立 PCB 板故障診斷的技術。系上現有可供作為(PCB)電路板故障診斷的設備。 CircuitMaster4000M(為多功能電路板故障診斷測試器),將各類PCB 故障診斷測試技術應用在上述PCB 電路板故障診斷設備,將故障損壞的電話交換機類比內 ...
姜宏穎, 陳祐清
core   +2 more sources

International clinical practice recommendations on the definition, diagnosis, assessment, intervention, and psychosocial aspects of developmental coordination disorder – Chinese (Mandarin) translation

open access: yesDevelopmental Medicine &Child Neurology, Volume 61, Issue 3, Page E1-E35, March 2019., 2019
目的 本国际临床指南由欧洲残疾儿童学会(the European Academy of Childhood Disability,EACD)牵头制定,旨在解决发育性协调障碍(developmental coordination disorder,DCD)的定义、诊断、评估、干预以及与社会心理方面的临床应用关键问题。 方法 本指南针对五个领域的关键问题,通过文献综述和专家团队的正式讨论达成共识。为保证指南的循证基础,以“机制”、“评估”和“干预”为检索词, 对2012年更新以来提出的最新建议以及新增的“社会心理问题”和“青少年/成人”为检索词进行检索。根据牛津大学循证医学中心证据等级 (证据水平 [level of evidence, LOE]1–4) 将结果进行分类,最终转化为指南建议。并由国际 ...
Jing Hua   +6 more
wiley   +1 more source

Analysis of Misdiagnosis of Bipolar Disorder in An Outpatient Setting

open access: yesGeneral Psychiatry, Volume 30, Issue 2, Page 93-101, July 2018., 2018
Background Bipolar disorder is a mental illness with a high misdiagnosis rate and commonly misdiagnosed as other mental disorders including depression, schizophrenia, anxiety disorders, obsessive‐compulsive disorders, and personality disorders, resulting in the mistreatment of clinical symptoms and increasing of recurrent episodes.
Hui Shen   +5 more
wiley   +1 more source

基于特征气体和比值准则的RAPO植物油变压器故障诊断方法

open access: yesGaoya dianqi, 2023
植物油变压器具有优良的耐火性能、环保性能和电气性能,是未来充油变压器的发展方向。现有的故障诊断方法仅针对其纯电气故障或热故障,少有电热故障诊断方法研究。为此,文中针对植物油变压器,提出一种基于特征气体和比值准则的变压器故障诊断方法。首先,建立了一个用于研究电热故障的实验台;然后,根据植物油的电热故障实验和产气数据,研究了植物油在纯电气故障、纯热故障和复合电热故障下的生成气体特性,得出了产气规律;最后,结合故障气体生成规律,建立了一种新的比值准则,基于此提出了植物油变压器故障诊断方法 ...
李强   +4 more
doaj  

A Review on Cracking in Laser Additive Manufacturing of Nickel‐Based Superalloys: Types, Formation Mechanisms, and Suppression Strategies

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Nickel‐based superalloys (Ni‐based superalloys) have attracted extensive attention in laser additive manufacturing (LAM) due to their capability to directly fabricate complex and high‐performance structural components. However, the rapid melting and solidification inherent to LAM result in intense thermal cycling, which induces high residual ...
Tianxiang Lin   +9 more
wiley   +1 more source

Risks of Time and Chronology as an Underpinning Infrastructure for Critical Systems: Emerging Chronorisks and Chronosecurity Needs

open access: yesJournal of Critical Infrastructure Policy, Volume 7, Issue 1, Spring/Summer 2026.
ABSTRACT Time and chronology form the invisible architecture upon which modern civilization depends, governing synchronization across markets, power grids, communication networks, transportation, and defense. Yet, this shared temporal framework, engineered through atomic clocks, satellites, and digital synchronization, faces growing vulnerabilities ...
Bilal M. Ayyub
wiley   +1 more source

Blockchain and Quantum Technologies for Securing the Global Nuclear Supply Chain: Synergies, Applications, Technical Challenges and Opportunities

open access: yesJournal of Critical Infrastructure Policy, Volume 7, Issue 1, Spring/Summer 2026.
ABSTRACT The infiltration of counterfeit, fraudulent, and suspect items into civil nuclear supply chains, notably within power generation and medical isotope production, poses severe safety and security threats. The ever‐increasing growth in nuclear installations (70 power plants are under construction and another 100 are in the planning stage) and the
Hafiz Ahmed
wiley   +1 more source

The Rhetoric of Disenchantment: Ghost Belief and Secular Critique in Early Twentieth‐Century China

open access: yesCognitive Science, Volume 50, Issue 1, January 2026.
Abstract This study presents the first large‐scale empirical analysis of how ghosts and spirits were debated during China's early twentieth‐century secular transformation. Using a novel dataset of over 2000 digitized texts—including newspapers, periodicals, and essays from 1890 to 1949—we combine close reading, AI‐assisted annotation, and statistical ...
Ze Hong, Yuqi Chen
wiley   +1 more source

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