室温甲烷气敏传感器综述

甲烷是一种无色无臭气体,也是天然气的主要成分.天然气的泄露易造成燃烧爆炸,对公民人身和财产安全构成重大威胁.加强天然气泄漏的检测是降低天然气爆炸威胁的重要方法,需要可靠、经济的室温甲烷气敏传感器.本文按类型分类整理了近年来室温甲烷气敏传感器的发展,包括电化学型、半导体金属氧化物型、气相色谱仪、电声型、光学型,同时对各种...     

纳米ZnO气敏传感器研究进展

半导体金属氧化物气敏传感器被广泛应用于有毒性气体、可燃性气体等的检测.ZnO是一种重要的半导体气敏材料,特别是纳米ZnO,由于其粒子尺寸小,比表面积大,成为被广泛研究的气敏响应材料之一.简要介绍了纳米ZnO气敏传感器的气敏机理、主要特性,综述了通过新型纳米形貌、结构制备以及元素掺杂改性提升纳米ZnO气敏性能等方面的研究进展,并进一步指出了纳米ZnO气敏传感器研究中存在的问题和未来的研究方向.     

多孔纳米棒氧化锌的制备及其气敏特性

采用水热法制备表面多孔的纳米棒状氧化锌。利用X射线衍射(XRD)、扫描电子显微镜(SEM)对样品的结构和形貌进行表征。以表面多孔的棒状氧化锌作为敏感材料制成旁热式结构的气体传感器,并对样品在不同温度下对乙醇气体的灵敏度进行了测试。结果表明:在280℃下,样品对100×10-6乙醇气体的灵敏度约为27.9,响应恢复时间分别约为3s和10s,此结果约是表面无孔的纳米棒状氧化锌在相同条件下对乙醇气体灵敏度的4.8倍,并且是相同条件下干扰气体中灵敏度最大的丙酮气体的3.1倍,表明该器件具有良好的选择性。     

氧化锌气敏传感器性能的改善及在民航系统的应用

氧化锌是多功能N型半导体材料,具有优良的气敏性能,在气体传感器方面具有广泛的用途。氧化锌气敏材料及测试方法进一步优化后,传感器具有更高的灵敏度和更广泛的适用性。对纳米氧化锌传感器的气敏机理、改善气敏性能的主要方法以及传感器在民用航空方面的应用做了详细的综述。     

基于无线传感器网络的风光混合发电监测系统的设计

本文分析了风光混合发电系统的现状以及对风光混合发电监测系统的需求,提出了一种基于无线传感器网络的风光混合发电监测系统,并详细介绍了无线传感器网络、传感器的选择,最后给出一套完整的风光混合发电监测系统的设计方案。     

气敏传感器的发展

综合介绍了气敏传感器的种类及其近期的发展以及MEMS技术对气敏传感器的推动，并着重对声表面波（SAW)气敏传感器及石英微天平（QCM)气敏传感器的结构、工作原理和涂层材料作了详细的介绍。     

基于无线传感器网络的社区保健监测系统

以躯域传感网络技术为载体,结合无线传感器网络在社区的合理安置,研究人体生理参数的无创连续监测技术以及穿戴式医疗仪器开发,设计了一个适用于慢性病人(如糖尿病人)的社区无线医疗保健监测网络系统;同时设计出一种新的无线传感器网络低能量数据汇聚模型——集合汇聚模型,把此模型应用于本系统以期达到降低能耗延长网络生命周期目的.最后,提出了在人体生理数据处理过程中需考虑的数据分级处理和安全问题.     

SnO_2复合薄膜甲烷气敏传感器研究进展

甲烷是具有稳定四面体分子结构的碳氢化合物,其键能大、分解困难且活性低,是煤矿安全生产的主要障碍及一种温室气体。SnO2半导体薄膜制备工艺简单、成本低廉、性能稳定,是甲烷传感器研发的主流气敏材料。科技人员进行了很多相关研究以提高传感器的性能,如新气敏材料的研究、催化剂/添加剂的使用、气敏机理的探索、传感器结构改进及气敏膜的表面修饰改性等。本文从气敏膜制备与改性、传感器结构设计及气敏机理研究三个方面,综述了近年来SnO2复合薄膜甲烷传感器的研究进展,结果表明:①应开发复合型金属氧化物半导体及高分子气敏材料,以提高灵敏度、选择性与稳定性;②研发微型智能传感器是未来发展的主要方向,而自组装技术应可用于制备金属氧化物半导体薄膜气体传感器微纳阵列;③气敏机理应与实验测试、材料设计及器件制备进行对照研究。     

基于无线传感器网络的煤矿瓦斯监测系统探析

在我国煤炭行业中,瓦斯爆炸是危机人员安全的首要问题。当前,随着科学技术和煤矿挖掘技术的进步,煤炭开采规模不断地扩大,同时煤矿井下作业的工作强度也在增加,在这样的情况下我们就需要进一步加强煤矿挖掘的安全性。随着煤矿挖掘深度的增加,使得井下存在着更多的瓦斯,瓦斯的含量越高,人们工作的危险系数就在不断增加,给煤炭工作者带来了严重的危害。近几年来,煤矿瓦斯爆炸事故频发,给煤炭工人和煤炭企业带来了严重的损害。当前,为了能够满足煤矿瓦斯监测系统的需要,相关人员结合现代的网络技术研究出了无线传感器网络监测系统,用以进行煤矿瓦斯监测,这种无线传感器具有普通传感器不具备的优点,提高了瓦斯监测的精度,提高了煤矿工人的生命安全保障。本文就煤矿瓦斯的无线传感器网络进行探析。     

ZnO nanomaterials based surface acoustic wave ethanol gas sensor

ZnO nanomaterials based surface acoustic wave (SAW) gas sensor has been investigated in ethanol environment at room temperature. The ZnO nanomaterials have been prepared through thermal evaporation of high-purity zinc powder. The as-prepared ZnO nanomaterials have been characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray Diffraction (XRD) techniques. The results indicate that the obtained ZnO nanomaterials, including many types of nanostructures such as nanobelts, nanorods, nanowires as well as nanosheets, are wurtzite with hexagonal structure and well-crystallized. The SAW sensor coated with the nanostructured ZnO materials has been tested in ethanol gas of various concentrations at room temperature. A network analyzer is used to monitor the change of the insertion loss of the SAW sensor when exposed to ethanol gas. The insertion loss of the SAW sensor varies significantly with the change of ethanol concentration. The experimental results manifest that the ZnO nanomaterials based SAW ethanol gas sensor exhibits excellent sensitivity and good short-term reproducibility at room temperature.     

纳米ZnO气敏元件对H2的测定研究

以采用物理热蒸发法制备的纯ZnO纳米线以及Ag掺杂ZnO纳米线为气敏基料制备成旁热式气敏元件,用静态配气法对不同浓度的H2进行气敏性能测试。利用测试结果,绘制元件灵敏度与所测气体浓度的关系曲线,并对此曲线进行了线性拟合。结果表明,Ag掺杂纳米ZnO元件与纯纳米ZnO元件相比会明显提高对H2的灵敏度,两类元件的气敏性能与所测气体浓度呈现相同的变化规律。用拟合方程计算出的气体浓度值与实际检测值间吻合较好,误差小于10%。因此,可以利用这两类元件及其拟合直线对H2气体浓度进行测定。     

The properties of ethanol gas sensor based on Ti doped ZnO nanotetrapods

An ethanol gas sensor was fabricated based on Ti doped ZnO nanotetrapods which were prepared by chemical vapor deposition (CVD) of ZnO nanotetrapods followed by co-annealing with TiO₂ powder. X-ray diffraction (XRD), Raman spectra and scanning electron microscopy (SEM) were used to characterize the morphology and structure of the as-obtained sample and the ethanol-sensing characteristics of the device were investigated. ZnO:Ti sensors show higher gas response than ZnO counterparts towards 100 ppm ethanol gas at a temperature of 260 °C. The recovery times of the devices are 3.1 min for ZnO:Ti and 10.1 min for ZnO, respectively. The enhancement of sensing properties of ZnO:Ti tetrapods indicates the potential application for fabricating low power and highly sensitive gas sensors.     

ZnO transparent thin films for gas sensor applications

Zinc oxide (ZnO) transparent thin films were deposited onto silicon and Corning glass substrates by dc magnetron sputtering using metallic and ceramic targets. Surface investigations carried out by Atomic Force Microscopy (AFM) and X-ray Diffraction (XRD) have shown a strong influence of deposition technique parameters on film surface topography. Film roughness (RMS), grain shape and dimensions are correlated with the deposition technique parameters as well as with the target material. XRD measurements have proven that the dc sputtered films are polycrystalline with the (002) as preferential crystallographic orientation. AFM analysis of thin films sputtered from a ceramic target has shown a completely different surface behavior compared with that of the films grown from a metallic target. This work demonstrates that the target material and the growth conditions determine the film surface characteristics. The gas sensing characteristics of these films are strongly influenced by surface morphology. Thus correlating the optical and electrical film properties with surface parameters (i.e. RMS and Grain Radius) can lead to an enhancement of the material's potential for gas sensing applications.     

Laser sintering ZnO thick films for gas sensor application

The thick films based on ZnO nanoparticles were prepared by laser sintering with different powers and sintering times for the first time. The microstructure of laser-sintered films was observed by SEM, and their resistance and sensitivity to VOCs as a function of temperature were measured, and compared with the unsintered thick films. The results showed that the laser-sintered ZnO thick films had higher sensitivity than that of the unsintered films. In all the laser-sintered ZnO thick films, the films sintered at shorter sintering time had the higher sensitivity at the same power, and the sensitivity of the films could be further improved with increasing laser power from 60 to 70 W. The differences in resistance and sensitivity were probably due to the fact that the microstructure of the films and stoichiometric proportion of ZnO changed with the laser power and sintering time.     

真空技术在煤炭工业安全生产中的应用

根据煤炭工业的发展现状,分析了瓦斯气体引起的安全问题的几个方面和其利用前景,介绍了真空设备在该行业的成熟应用和潜在应用,提出了在煤炭安全生产上应用真空抽气设备,能够适应安全需求,符合国家的循环经济、节能经济、可持续发展的基本国策。提出了真空抽气设备在煤炭工业中的发展和改进方向建议。     

煤矿瓦斯抽放监控系统数据采集模块的设计

数据采集在煤矿安全生产方面有着举足轻重的作用。在全面分析各种采集模块的基础上,提出了一种基于MSP430瓦斯监控系统数据采集的设计方案。该系统利用传感器采集现场数据,MSP430作为核心器件实时对采集数据进行处理、诊断和传信。它与过去瓦斯抽放监控数据采集模块相比,结构简单、体积小、功耗低,便于观测和处理,为进一步研发瓦斯监控数据采集模块提供新的实现方法。     

Gas concentration monitoring system for small and medium sized coal mines based on gas sensing detection and single chip control

This paper is aimed at the actual conditions of disaster caused by gas in small and medium-sized coal mines. A new gas concentration monitoring system for coal mines is developed on the basis of gas-sensing detection and single-chip control. The monitoring system uses the tin oxide as the main material of N-type semiconductor gas sensors, because it has good sensitive characteristics for the flammable and explosive gas (such as methane, carbon monoxide). The QM-N5-semiconductor gas sensor is adopted to detect the output values of the resistance under the different gas concentrations. The system, designedly, takes the AT89C51 digital chip as the core of the circuit processing hardware structure to analyze and judge the input values of the resistance, and then achieve the control and alarm for going beyond the limit of gas concentration. The gas concentration monitoring system has many advantages including simple in structure, fast response time, stable performance and low cost. Thus, it can be widely used to monitor gas concentration and provide early warnings in small and medium-sized coal mines.