Results 1 to 10 of about 15,529 (196)

Study & Realization of EMC for the Multimedia Mobile Handset [PDF]

open access: yes, 2005
高速电子器件工作时会产生很强的电磁干扰,这不仅可能使产品无法通过有关的电磁兼容性标准测试,甚至可能连其自身的稳定性也无法保证。特别是手机,电磁兼容一直是手机硬件设计的一个难点,并且不是依靠理论完全能够解决的,只能从实践设计中总结经验。在手机产品研发过程中,由于产品可靠性不高、工作不稳定而浪费大量的时间进行调试,甚至失去市场时机而造成重大损失的事例时有发生。所以手机的电磁兼容性预测和设计非常重要,在原理设计和PCB设计阶段就应该引起足够的重视。本文首先从理论上阐述手机电磁兼容问题 ...
雷德聪
core  

接地变兼站用变短路阻抗基准侧的选取与保护

open access: yes, 2020
从本质上介绍了不接地系统到电阻或消弧线圈接地系统的演变过程;引出了接地变和接地变兼站用变的概念,解释了接地变、接地变兼站用变的构造和原理;遵照国家标准,并借鉴项目经验,总结了通过接地变兼站用变铭牌参数确定短路阻抗选取基准侧的方法,并且结合实例给出了详细的解释推导,奠定了接地变兼站用变的短路电流计算,继电保护整定计算的计算基础;基于确定基准侧后的短路电流计算,分析了接地变兼站用变与普通接地变的速断保护整定计算的差异,分别从躲过变压器低压侧出口三相短路 ...
志磊 辛
core   +1 more source

Quality Infrastructure for Resilient Pharmaceutical Manufacturing in Ethiopia: A Comparative Archival Review

open access: yesJournal of Critical Infrastructure Policy, Volume 7, Issue 1, Spring/Summer 2026.
ABSTRACT The National Quality Infrastructure (NQI) in a given country provides the essential framework for quality assurance integrating standardization, metrology, accreditation, and conformity assessment to create the technical backbone for industry and trade. Hence, building a resilient NQI is fundamental to securing medicine quality, enabling local
Addisu Afrassa Tegegne   +3 more
wiley   +1 more source

A Study of MR Plaza Project Investment [PDF]

open access: yes, 2003
投资活动是促进生产力发展,提高社会物质文明程度,改善人民生活水平的主要经济动力。一个国家的经济增长和社会发展需要项目投资的充分支持,但是项目投资需要消耗大量的资源,而在一定时期内社会可供利用的资源却是十分有限。因此,为了实现项目投资的预期目标,我们必须采用切实有效的分析方法和分析工具,对投资项目进行科学合理的规划﹑评价和论证,从而有效地利用有限的资源。在这个意义上,本文主要针对MR广场投资项目的经营策划以及经济效益和投资风险等问题进行研究,从而论证该项目投资的经济价值 ...
陈振隆
core  

Fault location method for island and reef distributed power supply system based on immune model and improved immune algorithm [PDF]

open access: yes
Objective In order to improve the rapidity and accuracy of fault location for island and reef power supply systems composed of multiple distributed power sources, a fault location method based on an immune model and improved immune algorithm is proposed.
Chenghu XU   +4 more
core   +1 more source

Securing Bangladesh's Nuclear Future: Is the Regulated Asset Base Model the Answer to Address Project Corruption?

open access: yesJournal of Critical Infrastructure Policy, Volume 7, Issue 1, Spring/Summer 2026.
ABSTRACT Bangladesh's goal of achieving high‐income status by 2041 requires dependable, low‐emission, and affordable energy. With near‐universal grid coverage and increasing demand, nuclear energy is a strategic asset for long‐term baseload supply. However, the existing financing model, typified by the country's most expensive $12.65 billion Rooppur ...
Hafiz Ahmed
wiley   +1 more source

The Study of EMC Overall Design for Mobile [PDF]

open access: yes, 2010
随着移动终端系统的不断发展,其功能日益多样化,线路却越来越复杂,集成度也越来越高。由于手机工作频率较高,使用范围较广,涉及环境因素复杂,对EMC设计提出了较高的要求。如何让手机系统在满足自身功能的前提下,又不干扰其它电子设备,显得尤为重要。 电磁兼容(EMC,ElectromagneticCompatibility)是当今电子科技领域非常重要的一项技术。各国对手机EMC都提出一系列的标准。在中国,参照国际规范,目前国家无委和泰尔实验室的高昂的测试费用给测试和设计工作带来了很大的不便 ...
叶菁菁
core  

分析变电站内直流系统的接地与处理

open access: yes, 2020
电力电网对人们的日常生活、学习、工作非常重要,所以,应做好运维管理,对变电站内的直流系统接地问题进行严格监督与管理,及时找出直流接地系统出现故障的原因,而后在通过问题的实质,找出直流系统中潜存的不足之处,按照实际情况及时做出正确的决策,以此保证我国变电站能够长久维持电力输送。基于此,本文主要对变电站内直流系统的接地与处理进行分析,以供参考。
旸 李
core   +2 more sources

Citizens Turning Into Scientists: A Calling to Boost the Knowledge of the Public to Address the Environmental Crisis in the Brazilian Semiarid 从公众到科学家:助力提升公众知识以应对巴西半干旱地区环境危机

open access: yesIntegrative Conservation, Volume 4, Issue 4, Page 546-554, December 2025.
Desertification is increasing in the Brazilian Semiarid, leading to loss of species and ecosystem services, while precise data on biodiversity distribution and trends are lacking. Public engagement in scientific projects can improve ecosystem protection.
Lucas Rodriguez Forti   +3 more
wiley   +1 more source

电网接地方式变化对避雷器参数的影响

open access: yesDianci bileiqi, 2004
110kV和220kV中性点直接接地系统因异常临时变成不接地系统使无间隙金属氧化物避雷器将面临新的考验,笔者对接地方式变化后电网再发生单相接地情况下应如何确定电网过电压和避雷器参数进行了研究,建议110kV系统采用Y5W-110/260型的避雷器。
刘卫东
doaj  

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