电缆在线监测技术对航空电缆故障检测具有重要意义,扩展频谱时域反射法(Spread Spectral Time Domain Reflectometry,SSTDR)是一种能够在线监测电缆故障的有效方法。本文分析了SSTDR的原理,建立了SSTDR的仿真平台并以FPGA为核心搭建了...电缆在线监测技术对航空电缆故障检测具有重要意义,扩展频谱时域反射法(Spread Spectral Time Domain Reflectometry,SSTDR)是一种能够在线监测电缆故障的有效方法。本文分析了SSTDR的原理,建立了SSTDR的仿真平台并以FPGA为核心搭建了其实验系统。仿真和实验结果表明,该方法对携带通信信号的电缆能够实时监测。最后,根据理论和实验,得出了该方法的定位精度,分析了其适用范围。展开更多
There has existed a great deal of theory researches in term of chip production and chip breaking characteristics under conventional cutting and high speed cutting conditions,however,there isn＇t sufficient research on...There has existed a great deal of theory researches in term of chip production and chip breaking characteristics under conventional cutting and high speed cutting conditions,however,there isn＇t sufficient research on chip formation mechanism as well as its influence on cutting state regarding large workpieces under extreme load cutting.This paper presents a model of large saw-tooth chip through applying finite element simulation method,which gives a profound analysis about the characteristics of the extreme load cutting as well as morphology and removal of the large chip.In the meantime,a calculation formula that gives a quantitative description of the saw-tooth level regarding the large chip is established on the basis of cutting experiments on high temperature and high strength steel2.25Cr-lMo-0.25V.The cutting experiments are carried out by using the scanning electron microscope and super depth of field electron microscope to measure and calculate the large chip produced under different cutting parameters,which can verify the validity of the established model.The calculating results show that the large saw-toothed chip is produced under the squeezing action between workpiece and cutting tools.In the meanwhile,the chip develops a hardened layer where contacts the cutting tool and the saw-tooth of the chip tend to form in transverse direction.This research creates the theoretical model for large chip and performs the cutting experiments under the extreme load cutting condition,as well as analyzes the production mechanism of the large chip in the macro and micro conditions.Therefore,the proposed research could provide theoretical guidance and technical support in improving productivity and cutting technology research.展开更多
Y2002-63306-489 0307190InP 集成电路工艺与集成技术:Process and integrationtechnologies for InP ICs[会,英]/Stanchina,W.E.&Sokolich,M.//2001 IEEE International Conference onIndium Phosphide and Related Materials.—48...Y2002-63306-489 0307190InP 集成电路工艺与集成技术:Process and integrationtechnologies for InP ICs[会,英]/Stanchina,W.E.&Sokolich,M.//2001 IEEE International Conference onIndium Phosphide and Related Materials.—489～492(E)0307191基于 ADV611的质量窗提高监控视频图像压缩率的方法[刊]/马大玮//中国有线电视.—2003,(2).—16～19(E)展开更多
文摘电缆在线监测技术对航空电缆故障检测具有重要意义,扩展频谱时域反射法(Spread Spectral Time Domain Reflectometry,SSTDR)是一种能够在线监测电缆故障的有效方法。本文分析了SSTDR的原理,建立了SSTDR的仿真平台并以FPGA为核心搭建了其实验系统。仿真和实验结果表明,该方法对携带通信信号的电缆能够实时监测。最后,根据理论和实验,得出了该方法的定位精度,分析了其适用范围。
基金Supported by National Natural Science Foundation of China(Grant No.51175131)
文摘There has existed a great deal of theory researches in term of chip production and chip breaking characteristics under conventional cutting and high speed cutting conditions,however,there isn＇t sufficient research on chip formation mechanism as well as its influence on cutting state regarding large workpieces under extreme load cutting.This paper presents a model of large saw-tooth chip through applying finite element simulation method,which gives a profound analysis about the characteristics of the extreme load cutting as well as morphology and removal of the large chip.In the meantime,a calculation formula that gives a quantitative description of the saw-tooth level regarding the large chip is established on the basis of cutting experiments on high temperature and high strength steel2.25Cr-lMo-0.25V.The cutting experiments are carried out by using the scanning electron microscope and super depth of field electron microscope to measure and calculate the large chip produced under different cutting parameters,which can verify the validity of the established model.The calculating results show that the large saw-toothed chip is produced under the squeezing action between workpiece and cutting tools.In the meanwhile,the chip develops a hardened layer where contacts the cutting tool and the saw-tooth of the chip tend to form in transverse direction.This research creates the theoretical model for large chip and performs the cutting experiments under the extreme load cutting condition,as well as analyzes the production mechanism of the large chip in the macro and micro conditions.Therefore,the proposed research could provide theoretical guidance and technical support in improving productivity and cutting technology research.
文摘Y2002-63306-489 0307190InP 集成电路工艺与集成技术:Process and integrationtechnologies for InP ICs[会,英]/Stanchina,W.E.&Sokolich,M.//2001 IEEE International Conference onIndium Phosphide and Related Materials.—489～492(E)0307191基于 ADV611的质量窗提高监控视频图像压缩率的方法[刊]/马大玮//中国有线电视.—2003,(2).—16～19(E)
