Results 1 to 10 of about 311 (61)

对流——辐射边界对变压器温度场影响的解耦研究

open access: yesGaoya dianqi, 2022
对流—辐射边界是油浸式变压器最重要的散热方式,对变压器内部温度分布具有决定性作用。文中结合传热学基本理论以及变压器实际结构对变压器对流边界和辐射边界进行研究,针对目前直接以材料辐射率表征辐射换热强度的方法进行修正,结合变压器结构提出了有效辐射率的概念,使得辐射边界计算更加准确。并通过建立110 kV油浸式变压器三维流体—温度场模型分析了不同环境条件(风速、环境温度)对变压器对流边界和辐射边界的影响,为有限元分析计算中边界条件的确定提供了指导。
鲁非   +6 more
doaj  

低气压下多通道等离子体点火器性能研究

open access: yesGaoya dianqi, 2022
为提升现有航空发动机点火电嘴的点火性能,解决高空极端条件下发动机点火边界窄的问题,基于多通道放电技术和等离子体合成射流技术,设计研制了一种嵌入式多通道等离子体点火器(multi-channel plasma igniter,MCPI)。在不同气压条件下开展了多通道等离子体点火器与传统半导体火花点火器(spark igniter,SI)的放电特性实验,基于高速图像摄像系统,利用数值图像处理方法分析获得的点火器放电图像,分析了两种点火器的火花射流穿透深度、平均射流速度和最大影响区域。结果表明 ...
何羊羊   +4 more
doaj  

供气式气液双喷嘴射流器的充氧性能研究

open access: yesGongye shui chuli, 2007
以供气式气液双喷嘴射流器为研究对象,采用不稳定状态下的清水充氧性能试验,考察了射流水量(Q水)、气量(Q气)、射流器喷嘴口径(D)和安装高度(H)等因素对其性能的影响,得出了影响该射流器工作性能的主次因素顺序为:H→Q水→D→Q气。在较佳工作条件下(即射流器安装高度为5m、喷嘴直径为25mm、气水比为1.4),理论动力效率可达3.23kg/(kW·h)。
陈文召, 李光明, 董有, 宋珏容
doaj   +2 more sources

ASO-S卫星HXI调制定标装置设计与验证

open access: yesKongjian kexue xuebao, 2023
先进天基太阳天文台卫星(ASO-S)是中国首颗综合性太阳观测任务,太阳硬X射线成像仪(HXI)是ASO-S卫星三大载荷之一,主要负责太阳耀斑观测。HXI采用阵列空间调制间接成像方法,包含91个子准直器单元。发射前,在地面对HXI进行调制参数定标非常必要,但由于没有平行的X射线源而十分困难。本文根据HXI的基本原理与设计方案,提出了基于地面调制功能定标的设备与HXI调制定标的需求。根据所述需求,介绍了研制的X射线束流调制定标装置;利用该装置对HXI飞行件上所有子准直器完成地面调制功能定标 ...
陈 灯意   +3 more
doaj   +1 more source

与射流曝气器充氧性能相关的一些因素

open access: yesGongye shui chuli, 2004
从测定曝气器充氧性能的实验方法、射流曝气器的结构和工作条件三方面分析了与射流曝气器充氧性能相关的因素。着重论述了对研发射流曝气器比较重要的结构类型和供气方式。
姚萌, 贺延龄
doaj   +2 more sources

Hyperspectral outcrop models for palaeoseismic studies

open access: yesThe Photogrammetric Record, Volume 34, Issue 168, Page 385-407, December 2019., 2019
To overcome the limitations of the traditional study of palaeoseismic trenches, a new workflow is presented that integrates infrared hyperspectral and photogrammetric data. This method was applied on two palaeoseismic trenches excavated across a post‐glacial fault scarp in northern Finnish Lapland.
Moritz Kirsch   +19 more
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

High‐Performance Self‐Powered Ultraviolet Photodetector Based on NiO/La‐Doped SrSnO3/Nb‐Doped SrTiO3 Dual‐Heterojunction

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT The development of high‐performance photodetectors critically relies on innovative interfacial band engineering, a strategy that enables the synergistic enhancement of photocurrent and drastic suppression of dark current. Herein, a self‐powered ultraviolet (UV) photodetector is demonstrated based on a NiO/La‐doped SrSnO3 (LSSO)/Nb‐doped SrTiO3
Wentian Zhang   +7 more
wiley   +1 more source

Full‐Spectrum Solar Light–Activated Chemiresistive Sensors Based on W18O49/Ag2S S‐Scheme Heterostructure for Highly Sensitive Room‐Temperature NO2 Detection

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT Light‐activated gas sensors hold significant potential in environmental monitoring and smart Internet of Things (IoT) owing to their advantage in room temperature operation. Nevertheless, due to a narrow light absorption range, high photocarrier recombination rate, and weak redox activity of the sensing material, the performance enhancement of
Jinyong Hu   +5 more
wiley   +1 more source

Symbiotic Germination Technique of an Endangered Epiphytic Orchid Dendrobium sinominutiflorum: A Promising Conservation Application 濒危附生兰科植物勐海石斛 (Dendrobium sinominutiflorum) 的共生萌发技术:一种具有应用前景的保护策略

open access: yesIntegrative Conservation, Volume 5, Issue 2, Page 192-204, June 2026.
We developed an effective ex‐situ conservation approach for an endangered orchid species, Dendrobium sinominutiflorum. A compatible fungal strain Tulasnella sp. was obtained by using in‐situ seed baiting technique. The Symbiotic germination with Tulasnella sp. significantly promotes seed germination and seedling growth.
Han‐Xiao Huang   +6 more
wiley   +1 more source

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