Results 51 to 60 of about 11,500 (168)
Gaoya dianqi, 2013 为满足特高压直流输电工程用直流分压器的校准需求,研制了一台±1 200 kV标准直流分压器。在设计制造过程中,通过电场仿真优化了分压器的结构和屏蔽环的设计,分压电阻采用特殊的屏蔽结构减小了泄漏电流和电容电流的影响,然后对标准分压器进行了量值溯源并进行了国内比对,依据不确定度的评定方法分析了测量不确度分量,给出了总测量不确定度。
袁渊 +5 more
doaj
Gaoya dianqi, 2023 随着柔性直流输电技术的不断成熟，直流输电变得越发普及，而高压直流断路器作为直流输电系统的关键部分，其重要性不言而喻。针对现有高压直流断路器存在故障时短路电流大、分断速度慢、避雷器吸收能量过高等问题，提出了一种具有限流能力的新型高压直流断路器拓扑，该拓扑在传统直流断路器换流支路基础上增加了H型桥限流部分，利用平波电抗器与限流部分共同限流，可以显著降低故障时电流的上升速率与峰值。文中详细说明了新型拓扑的基本工作原理，对故障分断过程进行理论分析并给出相关参数的影响关系及选取依据，通过搭建基于Pscad ...
章宝歌, 荣耀, 张振
doaj
New mechanism of cable anti-theft based on impedance discontinuity measurement methods [PDF]
, 2012 为了解决目前低压电力电缆防盗机制的局限性和缺陷,分析对比了目前各种电缆防盗技术的原理及优点,提出了加载直流电压法和采用交流采样的阻抗测量算法相结合的一种新型综合电缆防盗机制。该机制采用模糊逻辑判断阻抗及电流的特性,根据微机电缆保护的整定值,通过对盗割电缆时电流动态分析,快速给出可靠的报警信号。This paper analyzes the principles and advantages of current cable guard alarm technologies.The limitations
余臻
core
Reframing wildlife disease management problems with decision analysis
Conservation Biology, Volume 38, Issue 4, August 2024.Abstract Contemporary wildlife disease management is complex because managers need to respond to a wide range of stakeholders, multiple uncertainties, and difficult trade‐offs that characterize the interconnected challenges of today. Despite general acknowledgment of these complexities, managing wildlife disease tends to be framed as a scientific ...
Margaret C. McEachran +16 more
wiley +1 more source
Ultrasound in Obstetrics &Gynecology, Volume 63, Issue 4, Page 446-456, April 2024.ABSTRACT Objective To determine the diagnostic accuracy of prenatal ultrasound in detecting coarctation of the aorta (CoA). Methods An individual participant data meta‐analysis was performed to report on the strength of association and diagnostic accuracy of different ultrasound signs in detecting CoA prenatally.
C. Villalaín +20 more
wiley +1 more source
Robust video watermarking algorithm for H.264/AVC based on texture feature [PDF]
, 2012 On the basis of analyzing some existing video watermarking al ithms and combining with the new features of the H.264/AVC video coding standard,a new robust video watermarking algorithm based on texture feature was proposed.The proposed algorithm firstly ...
Jian-yi LIU +4 more
core
Coordinate transformation based coefficients estimation algorithm for digital predistortion of RF power amplifiers [PDF]
, 2015 Based on the low-IF digital predistortion (DPD) architecture,a coordinate transformation based low-complex coefficients estimation algorithm is proposed to reduce the hardware implementation cost and numerical calculation complexity significantly.The ...
GHao HUAN +3 more
core +1 more source
短路电流中带有直流分量时的交流高压断路器燃弧时间差的概率分布特性
Gaoya dianqi, 1994 根据三相短路电流中带有直流分量时的开断过程,提出了分析和计算燃弧时间差的方法,据此求出了中性点接地与不接地系统的短路电流中带有直流分量时,燃弧时间差的分布规律.本文也列出了开断电流波形与电弧能量的关系.
曹荣江, 顾霓鸿, 盛勇
doaj
Development of Dual Channel TV Transmitterwith Image and Audio Modulators [PDF]
, 1996 本文介绍用于机场航班彩色动态信息显示系统的小功率双频道电视发送装置的设计，包括系统的方块组成和工作原理及其主要电路。In this paper,the design of small power dual channel TV transmitter For use in colourdynamic inFormation display system of airport marking and clearing is presented in detail.Themain contents ...
黄云鹰
core
Experimental research on a direct-detection optical OFDM system based on cascaded variable coefficient training sequences and pre-emphasis technique [PDF]
, 2013 Frequency selective fading (FF)caused by digital to analog converter and optical fibe dispersion in optical fiber link was analysed,and signal-signal mixing interference (SSMI) when the orthogonal frequency division multiplex-ing (OFDM) signal was ...
Jian-jun YU +4 more
core +1 more source