Results 51 to 60 of about 7,148 (168)

基于BP神经网络的CVT暂态电压传递特性补偿技术

open access: yesGaoya dianqi, 2022
为兼顾操作冲击电压、雷电冲击电压作用下对CVT的补偿效果,针对CVT的操作、雷电冲击响应所含的频率分量相差较大,本文提出了一种基于分类器和双路BP神经网络还原CVT一次侧波形的方法。通过设置频率分点计算高于频率分点的小波能量曲线以区分冲击电压类型,进而将冲击电压响应输入对应的双路BP神经网络神经元。通过多组雷电、操作冲击电压波形对神经网络进行训练,并验证了该方法能够兼顾CVT的非线性,模型具有波形适应性。现场应用表明,该方法可以用来对CVT进行暂态电压传递特性补偿 ...
谢施君   +5 more
doaj  

Wireless Dual-band Bandpass Filter Design Based on Hybrid Parameter Elements [PDF]

open access: yes, 2010
提出一种基于混合参数元件设计双频带通滤波器的方法,并采用该方法进行gSM(890--960 MHz)/dCS(1 710--1 880 MHz)无线双频带通滤波器的设计。经过AdS仿真设计,并制作出测量的样品实物,样品实物的测量结果和仿真结果吻合,说明该方法的可行性;同时分析该方法的优点和适用范围,对实际工程应用具有重要的参考意义。A method of designing a dual-band bandpass filter based on hybrid parameter elements is
冯晶天, 肖芬, 陈松
core  

Distributed Optical Fiber Acoustic Wave Sensing and Its Progress [PDF]

open access: yes
Distributed optical fiber sensing technology uses optical fiber as the sensing transmission medium to obtain sound wave amplitude and phase along the optical fiber and process the corresponding information.
WANG Longsheng   +3 more
core   +1 more source

Social participation challenges and response strategies identified by adults aging with a disability

open access: yesJournal of Elder Policy, Volume 3, Issue 2, Page 95-109, October 2024.
Abstract Social participation is likely to decrease among older adults as disability levels increase. However, it is a modifiable determinant of health that can impact older adults' well‐being and quality of life. Thus, this secondary data analysis aimed to understand what challenges older adults aging with a mobility or vision disability face with ...
Maurita T. Harris, Wendy A. Rogers
wiley   +1 more source

A Study on the Carrier Transmission Characteristics of the Power Lines in Vehicle [PDF]

open access: yes, 2007
利用载波通信技术可通过汽车电力线实现汽车ECU之间数据传输。通过在XML6796E1G金龙大客车上进行实验,在0~10MHz频段用矢量网络分析仪研究客车在静止和运行情况下载波通信信道的传输特性。实验表明,汽车电力线载波信道具有时变性,但在频率高于5MHz时,时变性不明显。By utilizing carrier communication technique,the data transmission between various electronic control units(ECUs) can ...
潘忠, 陈文芗, 陈石东
core  

Demographic and net primary productivity dynamics of primary and secondary tropical forests in Southwest China under a changing climate 气候变化背景下中国西南热带原始林和次生林的群落和净初级生产力动态研究

open access: yesIntegrative Conservation, Volume 3, Issue 3, Page 230-243, September 2024.
Tropical secondary forest at early sucessional stage had higher diamter growth rate and mortality rate, however, these forests also are more risked to droughts and high temperatures. Rising temperatures and more frequent droughts may decrease the carbon sink capacity of tropical forest ecosystems. Abstract Tropical forests are major carbon sinks on the
Sai Tun Tun Oo   +11 more
wiley   +1 more source

Local perceptions of anthropogenic and climate factors affecting the use and the conservation of Detarium microcarpum and Detarium senegalense in Burkina Faso (West Africa) 当地人对影响布基纳法索(西非)Detarium microcarpum(小果甘豆)和Detarium senegalense(甘豆)的使用和保护的人为因素和气候因素的看法

open access: yesIntegrative Conservation, Volume 3, Issue 1, Page 58-75, March 2024.
Local populations are aware of the decline and disappearance of Detarium species in their habitats, attributing this trend to excessive human exploitation and the effects of climate change. Thus, Detarium plant resources may face challenges in forests with different levels of protection status due to habitat fragmentation and the effects of climate ...
Adama Taonda   +4 more
wiley   +1 more source

Endangered beach mouse resistance to a Category 5 hurricane is mediated by elevation and dune habitat 濒危海滩鼠类五级飓风的抵抗力受海拔和沙丘栖息地的调节

open access: yesIntegrative Conservation, Volume 3, Issue 1, Page 36-45, March 2024.
Threatened and endangered species that occur in coastal areas are susceptible to the impacts of hurricanes that can destroy and reorganize their habitats. We used long‐term tracking of endangered beach mice to reveal they survive these impacts by using high elevation dune habitats to stay safe.
Michael V. Cove   +5 more
wiley   +1 more source

基于级联光纤环微波光子滤波器的微波倍频技术 [PDF]

open access: yes, 2014
为了得到高倍频的微波信号,实现获得了一种基于外调制技术与级联光纤环微波光子滤波器(FRMPF,fiber ring microwave photonic filters)的新型倍频微波信号光学产生技术。利用外调制的方法,采用大功率信号驱动马赫曾德尔调制器(MZM)得到了高阶谐波信号,再利用级联的FRMPF进行选频。理论计算与实验测试了FRMPF的滤波特性。通过调节每个FRMPF的环长,利用第1个FRMPF将基频信号与三阶谐波滤除,再通过第2个FRMPF将二阶谐波滤除,最终得到四倍频信号。研究结果表明 ...
付宏燕, 徐作为, 蔡志平
core  

基于CDEGS的接地极不同结构频谱响应特性研究

open access: yesDianci bileiqi, 2019
杆塔接地诊断有着重要作用。杆塔有其独有的特点,开发针对杆塔诊断的新方法有其必要性。运用CDEGS软件仿真分析电源单端注入、中端注入、交叉点注入3种不同方式下接地导体的频谱响应特性,探讨注入方式的不同对频谱响应曲线的影响,为新方法的提出提供思路。研究发现,不同的接地方式有相似的频谱特性;针对不同参数,接地方式的不同会使频谱响应曲线有差异:当半径变化时,不同接地方式的频谱曲线之间的差异几乎不变;当土壤电阻率变化时,土壤电阻率越大,差异越大。
杨琳   +4 more
doaj  

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