Results 11 to 20 of about 14,739 (111)
Research on Methods of Modeling and Fault Diagnosis for Micro Direct-Current Motors [PDF]
, 2015 直流微电机以体积小、重量轻、便于控制等优点被广泛应用于生产消费领域，在微型精密仪器中尤为重要。为了保证产品出厂品质，生产过程必须对直流微电机进行100%检测。目前检测主要依靠人工的经验来判断电机的好坏，其工作量大，生产效率低，漏检现象严重，导致电机出厂质量不稳定。因此有必要寻找一种简便和可靠的直流微电机在生产线上的故障检测技术。该技术即可以对出厂前的直流微电机进行自动在线检测，以保证直流微电机的出厂合格率；又可以推广应用于其他永磁直流电机的故障检测与诊断。 通过分析空载下直流电机的动态数学模型 ...
谢志平
core
Rare Metals, EarlyView.ABSTRACT Photodetectors, based on GaAs nanowires (NWs), hold significant promise in the fields of high integration micro‐ and nano‐optoelectronics applications because of their outstanding electronic and optical properties. To date, significant efforts have been directed toward enhancing the performance of photodetectors, aiming for high detectivity ...
Yu Hao +11 more
wiley +1 more source
Gaoya dianqi, 2022 为提升柔性直流输电系统稳定性，一般在柔直单元逆变侧设置辅助直压环，当正、负极间直流电压跌落到一定阈值时，直流电压由逆变侧控制，整流侧输送固定有功功率，并为交流系统电压提供无功功率支撑。然而受环境或自身质量影响，高压直流分压器有可能产生故障，进而引发直流电压波动。当整流侧测量异常偏高时，引起逆变侧辅助直压环起动作，导致此时系统的整流侧和逆变测两端均控直流电压，直流系统输送功率失控，甚至发生反转。针对这一风险，文中基于RTDS的异步联网仿真平台，通过对测量值乘一个异常系数k来模拟直流电压电流测量异常 ...
罗炜, 谢超, 陈培龙
doaj
Studies on the Anodic Oxidation of Aluminum (IV) : Anodic Oxidation on Aluminum in Aqueous Solution Containing Sulfuric Acid and Potassium Permanganate Using Direct Current Overlapped with Alternative Current [PDF]
, 1967 Anodic oxidation of aluminum in aqueous solution containing sulfuric acid and p otassium permanganate using d-c overlaped with a-c was examined. Results obtained were as follows: Using an overlap ed current, the oxide layers obtained were stronger and ...
横山 辰雄, 西部 慶一
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Rare Metals, EarlyView.ABSTRACT With the continuous advancement of materials science and technology, the rare metal gallium has increasingly emerged as a promising alternative to the toxic metal mercury. Although existing research has predominantly focused on the high electrical conductivity and excellent deformability of liquid metal (LM), its intrinsic fluidic property ...
Feifan Guo +6 more
wiley +1 more source
Control strategy research for PV DC microgrid with hybrid storage system [PDF]
, 2016 以光伏、风电等可再生能源为主的分布式发电技术因为其随机性、不稳定性，对配电网潮流改变带来的安全性等问题，其发展得到一定的制约。微电网被广泛认为是解决分布式发电技术应用瓶颈的有效解决方案，而直流微电网以直流形式传输电能，控制结构简单，不需考虑频率和相位，系统损耗小，效率高，也更加适合越来越多的直流电器的接入，因此具有很强的推广实用价值。本文在研究了直流微电网的国内外研究发展现状、架构，以及包括控制技术、储能技术、保护技术等关键技术基础上，对包含有蓄电池和超级电容器在内的光伏直流微电网系统进行了研究 ...
杨贇
core
Rare Metals, EarlyView.ABSTRACT This study introduces novel nonequiatomic TiZrCoCrMoCux (x = 0, 5, 10; at%) medium‐entropy alloys (MEAx) tailored for orthopedic implants, synergistically combining the biocompatibility of Ti‐based alloys, the wear resistance of CoCrMo alloys, and the antibacterial/osteogenic attributes of Cu. The alloy's microstructure, mechanical properties,
Hang Yu +9 more
wiley +1 more source
Rare Metals, EarlyView.ABSTRACT Two‐dimensional (2D) nonlayered niobium nitrides have attracted considerable interest for electrochemical energy storage. However, the synthesis of these materials is hampered by their nonlayered crystal structures, which are characterized by strong three‐dimensional chemical bonding.
Rui Huo +7 more
wiley +1 more source
Gaoya dianqi, 2020 为了减小特高压直流接地极入地电流对交流电网直流偏磁的危害,文中从优化直流接地极位置角度出发减小交流电网中直流偏磁危害。研究断裂构造与岩土类型对直流接地极预选选址的影响,并将预选极址采用网格点模式法划分网格区域,以直流偏磁站点数量最少与交流电网中直流电流总量最低为目标,筛选优化预选址区域,并确定最终直流接地极位置。研究表明:直流接地极极址应远离断裂构造,且极址应选择在地表为低阻率土壤以及地下为高阻率岩石区域,合理的直流接地极位置从源头上降低了直流接地极所引起的直流偏磁对交流电网的影响。
曾富, 樊艳芳, 耿山
doaj
Policy &Internet, Volume 18, Issue 1, March 2026.ABSTRACT This article investigates how TikTok Shop reproduces the e‐commerce model of Douyin Shop against a backdrop of divergent regulatory challenges and geopolitical distrust. One of the strategic changes we observe in TikTok Shop is the shift of consumer goods suppliers from local merchants to China‐based sellers.
Shuaishuai Wang, Jing Meng, Yitong Li
wiley +1 more source