浅谈光缆线路防雷接地技术

通过对光缆线路遭受雷击原因的分析，简要介绍了光缆线路的几种防雷方法。     

地下光缆的防雷措施

地下光缆一般顺延自然地形埋设,在遭受雷击时容易造成光缆设备损坏,导致大通路阻断等现象。而且在一般情况下,雷击往往造成隐蔽性障碍,查修比较困难。因此,地下光缆的防雷问题成为工程设计、施工及线路维护的重点工作之一。     

智慧小区直埋光缆的防雷设计

从光缆的结构入手,分析了直埋光缆遭受雷击的原因,并进行了直埋光缆防雷的安全距离测算,最后提出了智慧小区直埋光缆经济可行的防雷解决方案。工程实践证明该解决方案取得了一定的效果。     

论光缆线路防雷的思路

从光缆线路的固有特殊性以及光缆线路遭受雷击的机理出发,在以往电缆防雷取得理论和技术成果的基础上,论证了光缆线路上防雷及防强电技术,提出了有别于电缆防护技术的新思路,以及在各个环节上确保光缆ＰＥ护套的质量对防雷的有效性。     

光缆设备与避雷技术

光缆设备与避雷技术王听才（宜兴电视台２１４２００）宜兴电视台的电视信号源主要来自邮电部１７３站微波开口，自１９７５年至今，先是电缆传送，后改为光缆传送，期间遭受多次雷击，每经过一次雷击，我们就总结经验教训，改变传送方法，从中掌握了一些有效的避雷方法。...     

地下光缆防雷问题的浅析与思考

1 前言 直埋光缆遭受雷击时常常造成光纤熔断、中继和终端设备损坏,重则引起大通路阻断,轻则引起隐蔽性障碍,查修比较困难,因此地下光缆的防雷问题成为我们工程设计施工及线路维护中的一大工作要点。     

地下光缆防雷问题的浅析与思考

直埋光缆遭受雷击时常常造成光纤熔断、中继和终端设备损坏，重则引起大通路阻断，轻则引起隐蔽性障碍，查修比较困难，因此地下光缆的防雷问题成为我们工程设计施工及线路维护中的一大工作要点。     

农村有线电视网络应及时采取避雷措施

夏季雷雨天气较多 ,农村有线电视网络遭受雷击的情况时有发生 ,轻则光接收机、放大器保险管被打坏 ,重则放大器电源变压器、整流滤波器件被击毁。虽然雷雨过后即能维修和更换器件 ,但不免会影响群众收看电视节目。由于农村有线电视网络 2ｋｍ以上主干线基本上采用架空光缆线路 ,2ｋｍ以内支干线基本上采用架空电缆线路 ,各光接收点的光接收机、放大器都是采用倒馈电方式 ,从村向线路设备馈电。因此在农村有线电视网络中光缆线路遭受雷电损坏的极少 ,而电缆线路中放大器、分配器、分支器遭受雷击损坏的居多。这说明 ,农村有线电视网络遭受雷…     

试论广播电视光缆红路的防雷避雷

光缆以其良好的防护性能和非金属传递材料,形成光传递特有的方式,使其与传统的电缆和明线有质的区别。因此光缆的防雷避雷问题往往被忽视,有相当一部分人错误地认为:光缆是用非金属玻璃纤维来传递广播电视信号的,不会遭受雷击。来自各方面的资料表明,随着光缆被大量使用,光缆线路因雷击遭到严重破坏的事件时有发生,其后果往往比电缆、明线等线路更严重。因此,在当前有线广播电视网发展中,充分认识广播电视光缆线路防雷避雷的重要性和迫切性是一个亟待解决的新课题。1　光缆线路落雷的原因雷电是一种常见的自然现象,经常给人类造成灾害。通常…     

试论广播电视光缆线路的防雷避雷

光缆以其良好的防护性能和非金属传递材料,形成光传递特有的方式,使其与传统的电缆和明线有质的区别。因此光缆的防雷避雷问题往往被忽视,有相当一部分人错误地认为：光缆是用非金属玻璃纤维来传递广播电视信号的,不会遭受雷击。来自各方面的资料表明,随着光缆被大量使用,光缆线路因雷击遭到严重破坏的事件时有发生,其后果往往比电缆、明线等线路更严重。因此,在当前有线广播电视网发展中,充分认识广播电视光缆线路防雷避雷的重要性和迫切性是一个亟待解决的新课题。 1 光缆线路落雷的原因 雷电是一种常见的自然现象,经常给人类造成灾害。通常雷电是通过两种形式损坏电器设施,一种是直接雷击电流损坏电器设施,叫直接雷;另一种是间接雷击电流损坏电器设施,叫感应雷。直接雷由于雷击电流特别强大,防雷避雷很难成功。 感应雷是打雷时产生电磁感应的一种间接雷击现象,即天空的雷雨云发生雷击时会产生频谱极宽、强度极大的电磁波,这时处在影响范围内所有架空天线、有线电视、电信、供电等系统,以及所有金属制成的电线、电缆都会在雷击点一定范围内(大约2～5 km左右,视雷电强度、地形环境而定)感应出相应强度的雷电脉冲、电压和电流。这些电流通过连接在电器设备上的各种电缆、电线进入电器设备内部,当其强度超出该电器设备承受极限时,就会将电器设备击坏,严重时会把整机或部分元器件摧毁,这就是感应雷造成危害的全过程。打雷时任何连接在电器设备上的金属线都有可能把雷电脉冲引入机内,损坏电器设备及自身。那么,雷电又是怎样侵入有线广播电视光缆线路的呢? 我们知道,光纤具有不导电性,可以免受冲击电流,传输损耗极小。为使其免受外力的损坏(如：地埋时,动物、锐石等的损坏;架空时,金属附件的碰撞、鸟枪射击损害及其他自然的人为的影响),光纤必须设有铠装层、加强芯以及业务铜线等。它们都是金属导体,这就给雷电带来了可乘之机,当电力线接近光缆线路或雷击金属构件时,会感应出交流电或浪涌电流,破坏光缆线路及设备。再者,雷电具有寻找阻抗最小路径以泄放雷云电荷与地下异性电荷中和的趋势。当雷击附近大地或建筑物时,落雷点的电位升高,而光缆延伸到很远,这时远端电位可视为零,这样落雷点与光缆之间形成极大的电位差,这一电位差若超过落雷点与光缆外护层间的耐压强度,便会击穿外护层,形成从落雷点到金属构件的电弧通道,使大量的电流涌向光缆,造成光缆严重损坏。还有,光缆线路在施工中,难免会损伤护套,另外鼠咬、外力等均可能造成光缆中金属层暴露,这些暴露点更易将强电或雷电荷引入光缆中,造成损害。光缆线路遭受雷击主要有以下因素,并且随这些因素的增加,遭雷击的机率将指数级增高。     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.