Results 11 to 20 of about 5,840 (109)

An Intelligent Algorithm for Aerodynamic Parameters Calibration of Wind Tunnel Experiment at a High Angle of Attack

open access: yesInternational Journal of Aerospace Engineering, Volume 2023, Issue 1, 2023., 2023
In this paper, an intelligent algorithm for the aerodynamic parameter calibration of wind tunnel experiments of advanced layout aircraft at a high angle of attack is proposed. The proposed algorithm is based on a homologous comparison and tuning algorithm, and it can effectively improve the accuracy of the wind tunnel experiment model.
Yeguang Wang   +6 more
wiley   +1 more source

500 kV耦合负压换流型混合式直流断路器原理与研制 [PDF]

open access: yes全球能源互联网, 2018
多端柔性直流系统在分布式能源和直流负荷接入、网络柔性互联、电能质量等方面具有显著优势,成为未来电网的重要发展趋势。为了保证多端柔性直流系统安全稳定可靠运行,需要能够在数毫秒内开断故障电流的直流断路器。本文面向张北±500 kV柔性直流电网示范工程的应用需求,开展了500 kV直流断路器原理研究与样机研制。首先,提出500 kV耦合负压换流型混合式直流断路器系统方案,给出其拓扑结构、工作原理和控制逻辑;进而,设计基于电磁斥力操动机构和电磁缓冲机构的快速机械开关 ...
张翔宇   +7 more
doaj   +1 more source

基于随机生产模拟的火电机组深度调峰提升新能源消纳能力评估方法 [PDF]

open access: yes全球能源互联网, 2019
中国许多地区已经开展火电机组深度调峰辅助可再生能源消纳的试点工作,但基于场景的时序模拟方法在分析其调峰效果时受到各类不确定因素影响,难以覆盖所有的运行场景,导致中长期评估结果准确性不高。因此,时序方法不适用于缺少详细时序数据的电源容量规划。为此基于随机生产模拟方法,面向规划应用提出了一种火电深度调峰提升系统可再生能源消纳效果的评估方法。该方法建立了包括非供热火电机组、热电联产机组和风电等电源在内的供给侧概率模型,分析了在不同火电深度调峰方式下,系统负荷、可再生能源发电的概率特性变化 ...
马彦宏   +4 more
doaj   +1 more source

构建区域能源互联网:理念与实践 [PDF]

open access: yes全球能源互联网, 2018
以智慧能源与互联网技术相结合为特征的能源互联网已成为国家“十三五”能源领域的重大战略性新兴产业。多能源系统是实现能源互联网规划建设的物理基础。文中首先介绍了能源互联网的三层架构与多能源系统的基本概念,在此基础上从能源互联网价值实现的角度阐述了能源互联网的规划优化及商业模式构建的思路。最后,以山西太原区域能源互联网的规划建设为实例,对太原区域能源互联网的建设背景、潜在价值、关键问题和难点几个方面进行了总结和展望。
黄武靖   +4 more
doaj   +1 more source

Unseen Costs: The Direct and Indirect Impact of U.S. Immigration Policies on Child and Adolescent Health and Well‐Being

open access: yesJournal of Traumatic Stress, Volume 33, Issue 6, Page 873-881, December 2020., 2020
Abstract Shifts in migration and border control policies may increase the likelihood of trauma exposure related to child–parent separation and result in costs to the health system and society. In the present study, we estimated direct and indirect costs per child as well as overall cohort costs of border control policies on migrant children and ...
T. Joseph Mattingly II   +6 more
wiley   +1 more source

Bayesian Time‐Series Models in Single Case Experimental Designs: A Tutorial for Trauma Researchers

open access: yesJournal of Traumatic Stress, Volume 33, Issue 6, Page 1144-1153, December 2020., 2020
Abstract Single‐case experimental designs (SCEDs) involve obtaining repeated measures from one or a few participants before, during, and, sometimes, after treatment implementation. Because they are cost‐, time‐, and resource‐efficient and can provide robust causal evidence for more large‐scale research, SCEDs are gaining popularity in trauma treatment ...
Prathiba Natesan Batley   +2 more
wiley   +1 more source

渝鄂柔性直流输电交直流动态特性及控制保护策略研究 [PDF]

open access: yes全球能源互联网, 2018
渝鄂柔性直流背靠背工程是世界首个用于异步大型电网互联的柔性直流工程,工程投运后,能够优化西南与华中电网的系统潮流分布,提高电压和频率稳定水平,但同时会带来系统转动惯量和动态阻尼减小等新的问题。因此分别从系统及设备的角度出发,分析工程接入系统后的交互影响。首先,充分调用柔直自身快速功率调节能力,提高接入后电网的稳定性;其次,基于设备的耐压耐流水平,针对近区严重故障,提出了故障穿越策略,保证了设备的安全可靠运行,减少了对交流系统的冲击。对所提的故障穿越策略进行实时仿真测试,验证了策略的有效性。上述所做分析 ...
朱琳, 寇龙泽, 刘栋
doaj   +1 more source

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

Bifunctional Competitive Structure of Biomass Carbon‐Derived Metacomposites for Tunable ε′‐Near‐Zero and ε′‐Negative Responses

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Regulating negative parameters of metacomposites is mainly limited by their unclear mechanisms, which affects their practical applications in new sensing, communication, electromagnetic (EM) protection and other fields. This work proposes a dual‐functional competitive design strategy based on the waste corncob‐derived carbon/polyaniline ...
Qiuyun Yang   +4 more
wiley   +1 more source

基于分步有限元法的110 kV变压器振动与噪声研究

open access: yesGaoya dianqi, 2023
为解决现有的变压器振动噪声仿真方法存在计算量过大、难以求解、对工程实际的参考价值较小的问题,文中提出一种基于Comsol Multiphysics有限元仿真软件的变压器振动噪声分步有限元仿真方法。首先,考虑硅钢片各向异性修正铁心材料参数,计算铁心在磁致伸缩效应影响下的形变仿真结果;其次,根据实际形态及彼此配合关系,考虑辐向油道,构建绕组、油箱、铁心和垫块的二维模型,获得绕组的振动仿真结果;最后,构建变压器整体三维模型,将铁心在磁致伸缩效应影响下的形变仿真结果以及绕组振动的形变结果引入声场仿真中,并将铁心、
谢璐佳   +7 more
doaj  

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