基于红外复合光学原理的SF6气体分解产物现场检测方法

为最大化屏蔽光学信号对气体浓度的影响，获得高浓度的SF₆气体分解产物，提出基于红外复合光学原理的SF₆气体分解产物现场检测方法。选择适宜的复合性光学材料，在初始应用结构的作用下，求取具体的红外成像参数，完成对红外复合光学原理作用方法的初步分析。按需设置微流红外气体传感器，根据SF₆分子谱线的分布形式实施对异常峰值的剔除处理，实现基于红外复合光学原理的SF₆气体分解产物现场检测方法的设计。对比实验结果表明，在满足红外复合光学原理作用条件的情况下，光学信号不会对气体浓度产生明显影响，这对于获取高浓度的SF₆气体分解产物能够起到促进性影响作用。     

集中式红外SF6气体检测装置及其测量模型

本文提出了一种集中式红外SF6气体检测装置,该装置采用定时循环轮流选通的方式实现2路以上的变电站现场监测点气体采样检测,并采用了单光源双波长光路结构的红外SF6气体采样检测气室。因此有效地降低了制造、安装、调试、维护成本。通过求取每路红外探测信号在光源周期性开关两种状态下的差值和求取这两个差值的比值,降低了温度信号、背景光信号、光源波动等因素的影响。然后在朗伯-比尔定律的基础上,用求取的比值推导求得该检测装置的线性测量模型,最后采用最小二乘法对测量模型进行了标定,从而提高了SF6气体浓度测量的准确性和稳定性。     

SF6气体泄漏红外成像检测的技术分析和应用探讨

本文阐述了SF₆气体泄漏红外成像技术原理,总结了检测工作相关的技术标准,结合技术原理对检测工作中的影响因素进行了重点分析,并提出了相应对策,通过技术比较分析了SF₆气体泄漏红外成像的技术特点,据此提出了技术应用的策略,以更好地开展SF₆气体泄漏红外成像检测,提高开关、互感器、套管、变压器等SF₆气体绝缘设备缺陷巡检质量。     

2250kV半柔软型SF6绝缘高压脉冲传输线的研制

为了传输高压脉冲,设计了半柔软型SF6压缩气体绝缘高压脉冲传输线。根据使用要求,该传输线采用了SF6压缩气体作为绝缘,聚苯醚(PPO)绝缘垫片作为内外导体之间的支撑结构,同时内外导体均采用轧纹结构大大提高了传输线的柔软性。为实际工程使用安全性考虑,传输线外层设计了不锈钢丝铠装结构作为抗拉元件。试验结果表明,该传输线可承受的峰值电压高达到2 250kV,衰减系数为0.016dB/m,截止频率为625MHz,各项性能指标均满足要求,可用于传输高压纳秒脉冲信号。     

基于三直方图均衡的SF6红外图像对比度增强方法

电力设备SF₆泄漏气体红外图像容易淹没在背景中，肉眼难以辨识低对比度图像中泄漏气体情况，给电力设备检修带来了困扰。提出了基于三直方图均衡的SF₆红外图像对比度增强方法。首先，利用三样条插值拟合图像直方图得到二阶连续曲线，计算每个灰度级对应的一阶导数绝对值。其次，根据一阶导数绝对值和直方图分布划分直方图为两个波峰和一个相对平坦的波谷区域；最后，根据波峰和波谷将直方图分为3个子图，对3个子图分别进行直方图均衡后合并为增强图像。为了验证算法有效性，对现场拍摄的电力设备SF₆泄漏低对比度红外视频流进行增强，并与CLAHE和双直方图均衡算法进行对比。实验结果表明：本文方法在提升图像的整体对比度同时增强了泄漏气体与周围图像的对比度，提升泄漏气体红外图像视觉效果，相比于CLAHE和双直方图均衡方法，本文获得的峰值信噪比和均方根对比度值更高，增强后的图像质量更好。     

高压变电站室内SF6浓度的红外激光吸收检测方法研究

为了实现高压变电站室内SF6气体浓度的精确实时检测,对红外激光吸收方法用于SF6检测进行了研究和分析.根据SF6气体在红外波段(10.55 μm)的强吸收特性,研究了在该波段下SF6吸收特性和其浓度之间的关系,并得出了二者之间的关系曲线.该方法为高压变电站室内SF6气体的定量检测提供了理论基础.     

利用仿真技术从红外光谱中反演污染气体浓度的研究

;作为一种有效的大气污染气体遥感探测识别手段,傅里叶变换红外光谱仪已经得到越来越广泛的应用.当污染气体与背景存在温差时,红外光谱就能反映出污染气体的吸收或发射特征.目前,已有越来越多的人利用被动式傅里叶变换红外光谱仪进行大气污染气体的探测识别研究,而且也发展了许多由光谱提取目标信号的算法,但是这些方法大多是仅针对污染气体的定性研究的.利用仿真方法可以快速简便地计算出污染气体的浓度程长积,并可实现对遥感红外光谱的定量分析,且误差较小.     

氦离子检测器在微量SF6分解产物浓度检测中的应用分析

在SF6电气设备发生故障时,会导致SF6分解,产生气体分解产物,可以利用对SF6分解产物浓度的检测,来诊断SF6电气设备故障。虽然检测SF6分解产物浓度的方法有多种,但要实现对微量SF6分解产物准确检测非常困难,本文阐述氦离子检测器在微量SF6分解产物检测方面的应用。     

SF6气体泄露的激光成像检测技术

SF6设备发生气体泄露时,与传统离线或其他在线检测技术相比,激光成像技术无需设备停运即可远程检测,并能使操作者看到泄露气体的清晰图像,为泄漏源的快速定位提供了一种有效方法,确保了人员及设备安全.     

红外光谱技术在气体检测中的应用

根据气体在红外光谱区的吸收,可以采用红外光谱来检测气体的浓度.本文介绍了红外光谱技术在气体浓度检测方面的应用情况以及国外的研究进展.以甲烷和一氧化碳气体为例,描述了用红外半导体激光器或发光二极管结合红外光谱技术实现的气体探测系统.最后介绍了几种气体传感系统的实例.     

Effects of Ar and O2 additives on photopatternable sol-gel etching in an SF6-based plasma for planar lightwave circuit fabrication

We present a novel study of the interaction of SF₆-based plasmas with sol-gel materials in a parallel plate reactive ion etching (RIE) system. The purpose of these experiments was to obtain quantitative measures and optimisation of the RIE parameters, which can be used in the microfabrication of planar lightwave circuit (PLC) devices. The sulfur hexafluoride chemistry is chosen due to its excellent etching properties of SiO₂, which is one of the components of the photopatternable sol-gel materials and is not present in typical photoresist materials. Fast process etching rate and good selectivity is achieved by varying SF₆ flow and power delivered to the electrodes. The study also reveals a marginal influence of oxygen and argon flow on the character of the sol-gel etching. The experimental data obtained can be used as a reference for any sol-gel devices fabricated using widely available RIE reactors.     

二氧化碳气体高温红外辐射的测量与研究

在高频等离子体风洞中建立了高温二氧化碳流场,通过测量和计算获得了温度和摩尔比数分布,同时进行了红外光谱测量实验。给出了测量实验装置、原理及方法,并在1500 K～3000 K范围内四个不同的温度环境下进行实验,获得了二氧化碳在不同温度下4.3 μm附近v₃振动带的红外光谱数据。发现随着温度的升高,光谱曲线的最高峰位置向长波方向移动。通过理论分析得到了高温下二氧化碳气体红外辐射实验测量中出现“红移”现象的理论原因,以及与天体物理中红移现象的区别。该理论可应用于高温气体温度测量。     

一种用于CO2气体传感器的新型MEMS红外光源

基于CO2红外气体传感器微型化、智能化、低功耗的发展要求,创新性地提出一种中心温度为407℃的CO2检测用微电子机械系统(MEMS)红外光源芯片.采用X型悬空桥式微热板结构,内部发热区域以环形走线的钨(W)电极为加热丝,以SiO2和Si3N4双层薄膜作为机械支撑保护层,可防止钨电阻丝氧化并提高寿命.电热耦合有限元仿真分析显示,该光源芯片具有发热区温度分布均匀、热响应时间短、功耗低的优点.采用10.16 cm(4 inch)MEMS工艺完成了芯片的流片制造.测试结果表明,该光源芯片在24 ms内即可快速升温至工作温度407℃,功耗低至46 mW,工作电压为2.85V,工作电流为16.2 mA,具有热响应时间快、功耗低、集成度高的特点.     

用于红外激光防护的VO2薄膜的研究进展

二氧化钒（VO2）薄膜由于具有优异的热致变色性能已成为激光防护材料领域的研究热点.本文综述了国内外VO2薄膜的研究进展,对VO2薄膜的主要制备方法、用于红外激光防护的原理及防护波段进行了探讨,并总结了用VO2薄膜实现激光防护所面临的问题.     

SOI planar photonic crystal fabrication: Etching through SiO2/Si/SiO2 layer systems using fluorocarbon plasmas

Dry plasma etching of sub-micron structures in a SiO₂/Si/SiO₂ layer system using Cr as a mask was performed in a fluorocarbon plasma. It was determined that the best anisotropy could be achieved in the most electropositive plasma. A gas composition yielding the desired SOI planar photonic crystal structures was optimized from the available process gases, Ar, He, O₂, SF₆, CF₄, c-C₄F₈, CHF₃, using DC bias data sets. Application of the c-C₄F₈/(noble gas) chemistry allowed fabrication of the desired SOI planar photonic crystal. The average etching rates for the pores and ridge waveguide regions were about 71 and 97 nm/min, respectively, while the average SiO₂/Si/SiO₂ to Cr etching selectivity for the ridge waveguide region was about 33:1 in case of the c-C₄F₈/90%Ar plasma with optimized parameters.     

New TIT capacitor with ZrO2/Al2O3/ZrO2 dielectrics for 60 nm and below DRAMs

New ZrO₂/Al₂O₃/ZrO₂ (ZAZ) dielectric film was successfully developed for DRAM capacitor dielectrics of 60 nm and below technologies. ZAZ dielectric film grown by ALD has a mixture structure of crystalline phase ZrO₂ and amorphous phase Al₂O₃ in order to optimize dielectric properties. ZAZ TIT capacitor showed small Tox.eq of 8.5 Å and a low leakage current density of 0.35 fA/cell, which meet leakage current criteria of 0.5 fA/cell for mass production. ZAZ TIT capacitor showed a smaller cap leak fail bit than HAH capacitor and stable leakage current up to 550 °C anneal. TDDB (time dependent dielectric breakdown) behavior reliably satisfied the 10-year lifetime criteria within operation voltage range.     

Effect of Ge-GeO2 co-doping on non-ohmic behaviour of TiO2-V2O5-Y2O3 varistor ceramics

An investigation was made into the effect of doping with the elemental crystal Ge or/and GeO₂ on the TiO₂-V₂O₅-Y₂O₃ varistor ceramics. The result shows that as the doping contents of V₂O₅ and Y₂O₃ are 0.5 mol%, respectively, co-doping with 0.3 mol% Ge and 0.9 mol% GeO₂ makes the highest α value (α = 12.8), the lowest breakdown voltage V_1mA (V_1mA = 15.8 V/mm) and the highest grain boundary barrier Φ_B (Φ_B = 1.48 eV), which is remarkably superior to the TiO₂-V₂O₅-Y₂O₃ varistor ceramics undoped with Ge and GeO₂ and mono-doped with Ge or GeO₂. The TiO₂-V₂O₅-Y₂O₃-Ge-GeO₂ ceramic has the prospect of becoming a novel varistor ceramic with excellent electrical properties.     

Excellent performance of gas sensor based on In2O3-Fe2O3 nanotubes

In₂O₃-Fe₂O₃ nanotubes are synthesized by an electrospinning method. The as-synthesized materials are characterized by scanning electron microscope and X-ray powder diffraction. The gas sensing results show that In₂O₃-Fe₂O₃ nanotubes exhibit excellent sensing properties to acetone and formaldehyde at different operating temperatures. The responses of gas sensors based on In₂O₃-Fe₂O₃ nanotubes to 100 ppm acetone and 100 ppm formaldehyde are 25 (240℃) and 15 (260℃), and the response/recovery times are 3/7 s and 4/7 s, respectively. The responses of In₂O₃-Fe₂O₃ nanotubes to 1 ppm acetone (240℃) and formaldehyde (260℃) are 3.5 and 1.8, respectively. Moreover, the gas sensor based on In₂O₃-Fe₂O₃ nanotubes also possesses an excellent selectivity to acetone and formaldehyde.     

退火Mn1.95Co0.77Ni0.28O4薄膜在近红外和中红外波段的光学机理

采用双洛伦兹模型和有效介质近似(Efficient Medium Approximation, EMA)色散模型对退火的Mn_1.95Co_0.77Ni_0.28O₄薄膜在近红外和中红外波段的椭偏数据进行了拟合。通过比较直流电压下测试的电导率与低频下计算的电导率(ω→0)发现,A谐振子主要产生传导电流,B谐振子主要产生位移电流。对于Mn_1.95Co_0.77Ni_0.28O₄薄膜,随着退火温度的升高,晶格共振吸收逐渐被电子共振吸收所取代。退火样品的折射率n和消光系数k均由退火过程决定。     

Preparation and physical properties of lanthanum-modified Srl-xBaxNb2O6, ferroelectric crystals

The growth parameters and some physical properties of lanthanum-modified strontium barium niobate crystals, grown by the Czochralski method, have been investigated. Crystals were grown from melts having lanthana, La₂O₃ concentrations ranging from 0.01 to 1.50% (by weight;, the Sr to Ba ratio was one. Knoop microhardness was measured as a function of La content and the hardness was found to decrease with increasing La content. Room temperature compressive strength measurements were also made. None of the samples tested exhibited yielding. Fracture stresses did not change in a sensible manner as a function of La content. Lattice parameter measurements were made using x-ray diffraction and showed that the ‘c’ parameter decreased while the ‘a’ parameter increased slightly with increasing La content.