Results 11 to 20 of about 889,376 (167)

Test technology of longitudinal stage separation for two-stage-to-orbit vehicle in shock tunnel

open access: yes, 2023
高超声速多体分离问题是航天多体飞行器研发中的关键技术问题,基于分离过程中高速流动的复杂性,对高速多体分离的风洞试验研究极具挑战性,特别是激波风洞分离试验。激波风洞具有高速、高焓试验气流特点,更准确评估高超声速分离气动力/热特性,但是其有效试验时间短(ms量级),进行主动式动态级间分离试验极其困难。提出一种应用于激波风洞主动式多体分离试验的高速气动发射系统(High-speed Pneumatic Ejection to Launch Vehicle Model System, HPELS ...
汪运鹏, 姜宗林, 王粤
core   +1 more source

大容量试验系统建模方法及一键顺控方案研究 [PDF]

open access: yes, 2023
大容量试验是检验电力装备性能,保障装备安全可靠运行的重要环节。现有的大容量试验回路主要依靠人工操作,存在流程复杂、效率低且易出错的问题。针对大容量试验回路智能化控制的难题,研究建立了冲击发电机单电机短路模型和双电机并联短路模型,分析了发电机短路特性,结合典型大容量试验回路设计了一键顺控方案,提出试验回路一键顺控操作流程。通过对发电机短路模型和大容量试验回路系统的仿真 ...
戴建卓   +7 more
core   +2 more sources

Vocabulary Strategy Instruction in the Argentine EFL Context: Teachers’ Perspectives and Practices

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Despite extensive research on vocabulary strategy instruction (VSI), little has been known about teachers’ perspectives on how it is understood and implemented in practice. This study investigated Argentinian EFL teachers’ priorities in vocabulary instruction, their perceived knowledge of learner strategies for spoken vocabulary, and factors ...
Isobel Kai‐Hui Wang, Andrew D. Cohen
wiley   +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

Beyond Political Control and Bureaucratic Protection: Public Appointments for the Formation of Programmatic Groups and Representative Bureaucracy

open access: yesReview of Policy Research, Volume 43, Issue 3, May 2026.
ABSTRACT Public appointments shape the top‐level bureaucracy by serving as a gateway for professionals with different profiles, chosen based on different criteria. In general, the literature has been more interested in analyzing appointments based on merit or sponsorship, based on verification of loyalty to the government or technical competence ...
André Vaz Lopes   +1 more
wiley   +1 more source

Effectiveness of a case management model for the comprehensive provision of health services to multi‐pathological people 向多种疾病患者全面提供医疗服务的案例管理模式的有效性

open access: yesJournal of Advanced Nursing, Volume 75, Issue 3, Page 665-675, March 2019., 2019
Abstract Aim To determine the effectiveness of a case management model for approaching multi‐pathological people in a health promoting entity of the contributory healthcare scheme in Bogotá, Colombia between 2018 ‐ . Design Mixed methods research.
Sandra Milena Hernández‐Zambrano   +9 more
wiley   +1 more source

喀斯特山地垭口处直流棒形悬式复合绝缘子运行性能研究

open access: yesDianci bileiqi, 2022
喀斯特山地垭口地区地形特殊,气候复杂,运行于该地区的线路复合绝缘子老化更为严重,有必要开展专门的运行性能测试和状态评估。对4支运行于喀斯特山地垭口处的±500 kV直流棒形悬式复合绝缘子进行了试验研究,主要包括污秽度测量、憎水性测试、伞裙性能测试、水煮及陡波试验、工频电压试验、带护套芯棒水扩散试验、密封性能试验、机械破坏性试验等。研究结果表明,运行8年的直流复合绝缘子的伞裙材料性能、电气性能仍保持良好,但受山地垭口地区高风速的影响,绝缘子存在应力疲劳现象,表现为机械性能出现一定降低,且伞裙老化程度加剧 ...
赵伟   +5 more
doaj  

Using miniaturized laboratory equipment and DNA barcoding to improve conservation genetics training and identify illegally traded species

open access: yesConservation Biology, Volume 40, Issue 2, April 2026.
Abstract Illegal wildlife trade (IWT) is one of the largest global illegal activities, and it negatively affects biodiversity and sustainable development worldwide. DNA barcoding coupled with high‐throughput sequencing (i.e., metabarcoding) is useful in identifying taxa affected by IWT and has been used routinely for decades.
Maria Joana Ferreira da Silva   +9 more
wiley   +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

复现高超声速飞行条件下10°尖锥标模气动力特性试验研究 [PDF]

open access: yes, 2015
综述了应用中科院力学所的JF12长试验时间激波风洞中,在复现40km高度,飞行马赫数7的试验条件下,开展的10 ...
汪运鹏   +4 more
core   +1 more source

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