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光纤通信网络中衰减形变故障信号诊断系统设计 被引量:4
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作者 樊强 马贺男 《激光杂志》 北大核心 2018年第5期111-115,共5页
传统的故障信号诊断系统存在故障识别精度低的问题,提出将光纤通信网络中衰减形变故障信号的诊断系统。利用小波包分解,实现光纤通信网络中频带局部故障能量信号的特征识别,来提高故障信号识别精度,并以此实现对通信网络中的故障信... 传统的故障信号诊断系统存在故障识别精度低的问题,提出将光纤通信网络中衰减形变故障信号的诊断系统。利用小波包分解,实现光纤通信网络中频带局部故障能量信号的特征识别,来提高故障信号识别精度,并以此实现对通信网络中的故障信号,为光缆线路的故障,还是光端设备故障的初步判断;设计最优的数字滤波器最小二乘数字信号滤波器,对光纤通信网络信号进行滤波,以实现噪声点的减少和信号毛刺的去除,增强去噪效果;实验表明,本文方法提高了光纤网络中衰减形变故障信号识别精度和诊断准确性,且信号增强效果良好。 展开更多
关键词 光纤通信网络 衰减形变 故障信号 诊断 系统设计
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光纤通信网络故障信号诊断系统的设计与实现 被引量:7
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作者 牛丹丹 李培强 《激光杂志》 北大核心 2018年第10期87-91,共5页
当前故障信号诊断系统诊断精度低,设计了光纤通信网络中衰减形变故障信号的诊断系统。给出设计光纤通信网络中衰减形变故障信号诊断系统结构,其主要包括数据采集层、后台服务器层和客户端。介绍了OTDR工作原理,依据工作原理,在光纤一端... 当前故障信号诊断系统诊断精度低,设计了光纤通信网络中衰减形变故障信号的诊断系统。给出设计光纤通信网络中衰减形变故障信号诊断系统结构,其主要包括数据采集层、后台服务器层和客户端。介绍了OTDR工作原理,依据工作原理,在光纤一端注入窄脉冲,对背向散射信号进行接收,绘制背向散射曲线,实现衰减形变故障信号的诊断。介绍了信号处理机、激光驱动电路和接收机的设计过程,通过信号处理器形成格雷互补码,利用光发射机形成光信号,经光纤耦合器进入被测光纤通信网络,光脉冲在光纤通信网络传输时形成背向回波信号,利用光纤耦合器反馈至光接收机,转换成电信号后进入信号处理器完成处理,从而判断光纤通信网络的传输特性,诊断衰减形变故障信号。实验结果表明,该诊断系统诊断精度高。 展开更多
关键词 光纤通信网络 衰减形变 故障信号 诊断 系统
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Experimental study on sliding shaft lining mechanical mechanisms under ground subsidence conditions 被引量:11
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作者 姚直书 杨俊杰 孙文若 《Journal of Coal Science & Engineering(China)》 2003年第1期95-99,共5页
Aimed at more than 60 shaft linings damaged in Huaibei, Datun, Xuzhou and Yanzhou mine areas, this paper presents a new type of sliding shaft lining with asphalt blocks sliding layer. By model test, it is obtained tha... Aimed at more than 60 shaft linings damaged in Huaibei, Datun, Xuzhou and Yanzhou mine areas, this paper presents a new type of sliding shaft lining with asphalt blocks sliding layer. By model test, it is obtained that the deformation characteristics and the mechanical mechanisms of the sliding shaft lining under the condition of ground subsidence. The research results provide a testing basis for the sliding shaft lining design. By now, this kind of sliding shaft lining had been applied in 9 shafts in China and Bangladesh. 展开更多
关键词 shaft lining asphalt blocks sliding layer constrictive layer model test
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Failure behavior of cellular titanium under dynamic loading 被引量:3
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作者 REN HuiLan WANG Jing +1 位作者 HAO Li SHEN HaiTing 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2017年第4期613-623,共11页
The dynamic compressive deformation of cellular titanium with regularly distributed cylindrical pores is investigated to evaluate the effect of shock attenuation and obtain the shock Hugoniot relationship of the mater... The dynamic compressive deformation of cellular titanium with regularly distributed cylindrical pores is investigated to evaluate the effect of shock attenuation and obtain the shock Hugoniot relationship of the material. Dynamic compression experiments are conducted at room temperature using a single-stage light gas gun. The Hugoniot relations between shock wave velocity and particle velocity for the cellular titanium samples with porosities 20% and 30% are obtained. The shock response of the regular cellular titanium shows a clear wave attenuation effect. Numerical simulations are also conducted to supplement the experimental study.Inelastic deformation is observed in the samples using optical micrographs, indicating that the deformation of pores contributes significantly to the shock wave attenuation of the cellular titanium material. 展开更多
关键词 plate impact cellular titanium Hugoniot relation dynamic compression
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Switchable dual-wavelength erbium-doped fiber laser with tunable wavelength 被引量:1
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作者 童峥嵘 刘梦颖 +2 位作者 曹晔 张卫华 郝霞 《Optoelectronics Letters》 EI 2015年第5期325-328,共4页
A switchable dual-wavelength erbium-doped fiber laser(EDFL) with tunable wavelength is demonstrated. The ring cavity consists of two branches with a fiber Bragg grating(FBG) and a spherical-shape structure as fiber fi... A switchable dual-wavelength erbium-doped fiber laser(EDFL) with tunable wavelength is demonstrated. The ring cavity consists of two branches with a fiber Bragg grating(FBG) and a spherical-shape structure as fiber filters, respectively. By adjusting the variable optical attenuator(VOA), the laser can be switched between the single-wavelength mode and the dual-wavelength mode. The spherical-shape structure has good sensitivity to the temperature. When the temperature changes from 30 °C to 190 °C, the central wavelength of the EDFL generated by the branch of spherical-shape structure varies from 1 551.6 nm to 1 561.8 nm, which means that the wavelength interval is tunable. 展开更多
关键词 tunable spherical branches Bragg grating switched lasing adjusting cascaded coupler
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