Results 41 to 50 of about 8,218 (174)
Research and Design of Multi-Channel Temperature Control System for High Power LEDs Online Accelerated Aging [PDF]
, 2016 半导体照明技术伴随时代的进步，应用愈发广泛，大功率LED照明领域更是逐步走向普及。但实际应用中，LED器件和封装的缺陷及工作时发热极大限制了其性能和实际寿命，可靠性问题日渐显露。为此LED寿命加速测试尤为重要，以实现寿命预测，失效机理分析，使得LED可靠性提升。常用的高温老化测试传统上使用高温试验箱，此方法存在诸多缺点：参数检测不连续、温升慢、体积大、功耗高。本文针对性地研制了一套轻便的LED在线寿命加速多路温控系统（以下简称温控系统）。主要工作内容与研究成果如下： 1.研制了温控系统的硬件部分 ...
周骁炀
core
Finite element simulation of the temperature curve of wire rods during the whole process of rolling [PDF]
, 2016 The temperature distribution of billets in a heating furnace is simulated by Deform software and is verified by the "black box". When the heating time is 70 min the temperature difference between surface and center is about 66℃, but it reduces to 15 ...
DENG Su-huai +5 more
core +1 more source
Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT In this study, a newly developed seeded electromagnetic confinement directional solidification (EMCDS) technique was employed to fabricate large‐scale TiAl single crystal ingots with a diameter of 32 mm, overcoming the long‐standing size limitations that have hindered their industrial application.
Wei Wang +9 more
wiley +1 more source
Gaoya dianqi, 2015 传统交流温升试验电源系统采用电网直接供电,因此只能进行50 Hz温升试验,而无法实施60 Hz温升试验,同时,由于其自动化程度较低,在电网电压波动以及负载随温度变化的情况下,只能通过现场手动调节调压器实现电流的稳定控制,且缺乏有效的远程监控手段,不利于系统运行的综合管理。为解决上述问题,笔者结合温升试验的工艺要求以及试验室的具体试验条件,采用发电机作为温升试验电源,通过调节变频器的输出频率改变拖动电动机的转速,实现了试品对不同试验频率的需求;采用可编程控制器设计了一套温升试验自动控制系统 ...
贾一凡 +6 more
doaj
ImpactsAnalysis of Climate Change on China’s Marine Economy Based on CGE Model [PDF]
, 2015 近10年来，海洋经济已经成为中国国民经济新的增长点，对拉动全国经济发展起着重要的作用。然而海洋经济活动主要分布的海岸带地区却是生态环境最为脆弱的区域，特别是在全球气候变化的背景下，这种脆弱性愈发明显。与此同时，为减缓气候变化而实施的碳减排政策对中国经济增长（包括海洋经济增长）带来严峻的压力。在此双重背景下，综合地评估不同气候变化情景下的主要关键风险、以及实施和不实施减排政策对中国海洋经济的影响，可以为应对气候变化、促进海洋经济发展的战略和政策的制定提供科学依据，因而具有十分重要的现实意义和理论意义 ...
孔昊
core
Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT The rapid advancement of 5G communication technology has intensified electromagnetic pollution, creating an urgent demand for flexible multifunctional fabrics with efficient electromagnetic interference (EMI) shielding performance. This study proposes a novel material‐stacked construction strategy to fabricate multifunctional MXene/cellulose ...
Zong‐Kai Yan +9 more
wiley +1 more source
Nitrogen Transports and Transformations in Mangrove Sediments using Nitrogen Isotope Techniques in China [PDF]
, 2012 人类活动对生态系统的影响日益扩大，过量施肥、化石燃料的燃烧等引发的氮(N)负荷迅速增加。陆地生态系统过剩的N通过流域汇集至河口和海岸，威胁着海洋生态系统的健康。目前，全球N循环正致力于揭示河口和海岸地区N的源汇格局及主导机制。红树林湿地广泛分布于热带、亚热带河口和海岸地区，作为陆源营养盐入海过渡带，在缓解陆源N输入方面扮演着重要角色，成为了研究的热点。 本研究利用N稳定同位素技术，将现场培养与室内模拟培养相结合，揭示了我国东南沿海典型河口和海湾红树林湿地沉积物总氮沉积、固氮作用、反硝化作用 ...
李颖
core
Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT To address the issues of aluminum (Al) powder agglomeration during combustion and low oxidizer decomposition efficiency in composite solid propellants, this study utilized in situ self‐assembly technology to prepare cobalt‐based hybrid‐coated modified Al powder (Al@CZ).
Chong Chen +11 more
wiley +1 more source
Gaoya dianqi, 2018 为综合分析特高压直流输电用干式平波电抗器的损耗与温升,获得其热点位置与热点温升,文中推导了平波电抗器各个包封中直流电流损耗与谐波电流损耗分布的计算方法。针对一台±800 kV/4 000 A特高压干式平波电抗器,分析了加载等效直流电流的温升试验工况下电抗器的损耗分布与实际运行中包含谐波损耗的损耗分布的差异。对温升试验工况下特高压干式平波电抗器的温度场进行了计算,获得其温升分布,通过相应的温升试验,验证了仿真计算结果的可靠性;最后,比较了运行工况与温升试验工况下特高压干式平波电抗器的温升分布的差异 ...
肖彩霞, 李琳, 纪锋, 高冲
doaj
Æ E Æ Å – Reshaping the Role of Træna Fishermen
, 2022 This diploma project aims to strengthen the viability of Træna’s community by proposing an ocean research facility in the archipelago, enabling the next generation of local fishermen to collect oceanographic data while working at sea. The idea of the fisherman as oceanographer is inextricably linked to the architectural program on the island of ...
openaire +1 more source