共查询到20条相似文献,搜索用时 46 毫秒
1.
Mario BoehmeAuthor Vitae Friedemann VoelkleinAuthor VitaeWolfgang EnsingerAuthor Vitae 《Sensors and actuators. B, Chemical》2011,158(1):286-291
Within the last decade there has been a great increase in the need of trace and ultra-trace explosive detection. In this report, we demonstrate a new and versatile type of chemical explosive sensors based on metal oxide nanotubes easily made, even with the need of a low budget. We describe the step-by-step procedure to fabricate a sensing chip device, beginning with the synthesis of the starting materials to the point of supersensitive measurements of PETN explosive. As a result, the whole process actually is one of the most cost-effective methods to produce explosive sensing devices reported until now. The achieved chemical sensor device will be able to detect PETN explosive down to ∼112 ppt. 相似文献
2.
Salim F. BamsaoudAuthor Vitae S.B. RaneAuthor Vitae R.N. KarekarAuthor VitaeR.C. AiyerAuthor Vitae 《Sensors and actuators. B, Chemical》2011,153(2):382-391
SnCl2 (solution) was spin coated on soda lime glass and Al2O3 substrate to obtain nano-particulate tin oxide film, directly by sintering at 550 °C for 40 minutes (min). The surface morphology and crystal structure of the tin oxide films were analyzed using atomic force microscopy (AFM) and X-ray diffraction (XRD). The size of SnO2 nanostructure was determined from UV-vis and found to be ?3 nm. These films were tested for sensing H2 concentration of 0.1-1000 ppm at optimized operating temperature of 265 °C. The results showed that sensitivity (Rair/Rgas per ppm) goes on increasing with decreasing concentration of test gas, giving concentration dependent changes. Special studies carried out at low concentration levels (0.1-1 and 1-10 ppm) of H2, give high sensitivity (200 × 10−3/ppm) for lowest concentration (0.1-1 ppm) of H2. The selectivity for H2 against relative humidity (RH), CO2, CO and LPG gases is also good. The sensor, at operating temperature of 200 °C, is showing nearly zero response to 300 ppm of H2, and offering response to acetone vapour of 11 ppm. Selectivity for acetone against RH% and CO2 was also studied. These sensors can be used as H2 sensor at an operating temperature of 265 °C, and as an acetone sensor at the operating temperature of 200 °C. 相似文献
3.
This paper presents a novel approach and a framework for web-based systems that can be used in distributed manufacturing environments. A prototype is developed to demonstrate its application to remote monitoring and control of a Tripod—one type of parallel kinematic machine. It utilizes the latest Java technologies (Java 3D and Java Servlets) as enabling technologies for system implementation. Instead of using a camera for monitoring, the Tripod is modeled using Java 3D with behavioral control nodes embedded. Once downloaded from its server, the 3D model behaves in the same way of its counterpart at client side. It remains alive by connecting with the Tripod through message passing, e.g., sensor signals and control commands transmissions. The goal of this research is to eliminate network traffic with Java 3D models, while still providing users with intuitive environments. In the near future, open-architecture devices will be web-ready having Java virtual machines embedded. This will make the approach more effective for web-based device monitoring and control. 相似文献
4.
Ulrich WeissAuthor Vitae Peter Biber Author Vitae 《Robotics and Autonomous Systems》2011,59(5):265-273
In this article, we discuss the advantages of MEMS based 3D LIDAR sensors over traditional approaches like vision or stereo vision in the domain of agricultural robotics and compare these kinds of sensors with typical 3D sensors used on mobile robots. Further, we present an application for such sensors. This application deals with the detection and segmentation of plants and ground, which is one important prerequisite to perform localization, mapping and navigation for autonomous agricultural robots. We show the discrimination of ground and plants as well as the mapping of the plants. Experiments conducted using the FX6 LIDAR by Nippon Signal were carried out in the simulation environment Gazebo, with artificial maize plants in the laboratory and on a small maize field. Our results show that the tested plants can be reliably detected and segmented from ground, despite the use of the low resolution FX6 sensor. Further, the plants can be localized with high accuracy. 相似文献
5.
In2O3 nanofibers with diameters of around 60 nm have been fabricated by electrospinning with a solution containing both poly (vinyl pyrrolidone) (PVP) and indium nitrate, followed by calcination in air at 700 °C. Without further adding catalysts or doping other metal oxides, the sensor based on the as-prepared indium oxide (In2O3) nanofibers showed high response and selectivity, fast response and recovery time towards ethanol gas. The simple preparation and excellent properties significantly advance the viability of electrospun gas sensors. 相似文献
6.
Andreas Janshoff Claudia Steinem Axel Michalke Christian Henke Hans-Joachim Galla 《Sensors and actuators. B, Chemical》2000,70(1-3):243-253
β-Cyclodextrins functionalized by different moieties that were tethered to a single 6-deoxyaminoglucose unit were investigated with respect to their suitability for sensor applications. Derivatizing the cyclodextrins with hydrophobic moieties like dipalmitoylglycerol and cholesterol allowed us to study packing density and orientation of the cyclodextrin tori at the air–water interface. From the pressure-area isotherms, it was concluded that the cyclodextrins are positioned towards the water subphase, with their molecular axis predominately parallel to the interface. By introducing a disulfide group, we managed to immobilize cyclodextrins on gold surfaces via self-assembly. MALDI mass spectrometry (MALDI MS) and XPS confirmed that the molecules are chemisorbed on the gold substrate displaying high surface coverage as determined by means of impedance spectroscopy. The inclusion of various charged guest molecules was monitored by changes in the charge transfer resistance of the redox couple [Fe(CN)6]3−/[Fe(CN)6]4−. The charge transfer resistance is sensitive to the surface potential, which leads to either repulsion or attraction of the redox active species. 相似文献
7.
α-Benzoinoxime, a highly selective reagent used for the gravimetric and colorimetric determination of copper, was successfully immobilised on XAD-2 and coupled with optical fibres to investigate a sensor-based approach for determining copper. Reflectance measurements were used to quantify sensor response. Optimum response was obtained at a wavelength of 560 nm and at a solution pH of 7. Using a kinetic approach in which the rate of change of reflectance is measured over a 4-min period, the response was found to be linear in the range 5–127 ppm. After measurement, the sensor can be regenerated for reuse by immersing the probe in 0.1 M HCl. With continuous use, the sensing layer was found to be stable for at least 3 days. The advantages of using α-benzoinoxime in this way are compared with its use in the traditional gravimetric and colorimetric way. 相似文献
8.
9.
Z. AhmadAuthor Vitae M.H. SayyadAuthor VitaeM. YaseenAuthor Vitae K.C. AwAuthor VitaeM. M-TahirAuthor Vitae M. AliAuthor Vitae 《Sensors and actuators. B, Chemical》2011,155(1):81-85
An organic compound 5,10,15,20-Tetrakis(3′,5′-di-tertbutylphenyl)porphyrinatocopper(II) (TDTPPCu) is synthesized and studied as an active material for multifunctional capacitive sensor. The capacitance of the device as a function of illumination, humidity and temperature has been investigated. It is observed that the capacitance increases by 4.7 times from the dark condition under an illumination of 3850 lx. The capacitance is also changed 9.5 times with the increase in relative humidity (RH) from 30% to 95%. No change in capacitance appeared below critical temperature 120 °C. Based on the experimental results for the multifunctional sensor a mathematical model has been developed. The model is mainly based on the assumption that the capacitive response of the sensor is associated with dielectric polarization. The sensors are simulated using this model. The simulated results match well with experimental results. 相似文献
10.
L. Chambon J. P. Germain A. Pauly V. Demarne A. Grisel 《Sensors and actuators. B, Chemical》1999,60(2-3):138-147
An analysis of single gases using non-selective sensor elements is presented. It contains two steps: the identification of an unknown substance and the estimation of its concentration. To prepare the identification step, a calibration procedure is done to associate a class with each definite gas. In order to do this classification, the signals of the sensor array are transformed into quantities independent of the gas concentration but characteristic for its chemical compound. Then, the analysis parameters of an unknown substance allow to identify it with one of the calibration classes. After the identification of the gas, its concentration can be estimated with the model which is specific for each class of a single gas. The accuracy of this estimation is discussed. 相似文献
11.
In this paper, we propose a novel energy-aware and density-based clustering and routing protocol (EA-DB-CRP) for gathering data in wireless sensor networks which basically aims at distributing the load among available sensor nodes which in turn balances the energy consumption in the network and consequently elongates the network lifetime. More precisely, we introduce a network model that ends up of having empirical expressions that describe how to partition the network field efficiently into equal-size layers and sub-layers. In each sub-layer, the role of cluster head is pivoted among all cluster individuals, in a round robin fashion, that are sorted in a list in a descending order based on an extremely effective cluster head weight. Additionally, there are a minimum number of cluster members maintained to guarantee the feasibility of clusters being formed and this is through proposing a cluster merge algorithm. Not only to this extent, but rather, we maintain the consideration of network density over created clusters to balance them and subsequently prolong the network lifetime. Lastly, an effective relaying algorithm is proposed in which cluster heads get aware of those sensor nodes located in a layer ahead toward the base station along with their relay-node weights whereas each cluster head picks the relay node that has the highest weight. Our proposed protocol is evaluated through conducting various MATLAB simulations. Strikingly, results demonstrated that our proposed protocol has a momentous change against other related works regarding network lifetime and energy use. 相似文献
12.
Huijuan Yan Fanhong Shurong Baolin Xianzhi Jun Yanmei Shihua 《Sensors and actuators. B, Chemical》2008,134(1):133-139
Pure and Au-doped WO3 powders for NO2 gas detection were prepared by a colloidal chemical method, and characterized via X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The NO2 sensing properties of the sensors based on pure and Au-doped WO3 powders were investigated by HW-30A gas sensing measurement. The results showed that the gas sensing properties of the doped WO3 sensors were superior to those of the undoped one. Especially, the 1.0 wt% Au-doped WO3 sensor possessed larger response, better selectivity, faster response/recovery and better longer term stability to NO2 than the others at relatively low operating temperature (150 °C). 相似文献
13.
以膜厚为250 μm的Al2O3膜为微结构基板、95#Al2O3瓷板为微壳结构体,设计并采用激光微加工技术制作了具有Φ0.2 mm微孔通道的微结构传感器.阐述了CuCl杂化修饰CuPc的工艺过程,并通过真空镀膜形成气敏膜.实现了主动吸气的检测模式,提高了响应时间和气敏性.通过SEM分析得到了良好的表面形貌和膜尺寸,用做电极和加热器Pt膜厚为500nm,敏感膜厚为150 nm,微壳深度为150~200μm.测试结果表明对Cl2具有较好的敏感响应,灵敏度为0.01%浓度下0.25倍,并呈现P型半导体的变化规律.研究了通气状态和加热电压对传感器响应和气敏性的影响. 相似文献
14.
Fei-Ming LiAuthor VitaeJia-Ming LiuAuthor Vitae Xin-Xing WangAuthor VitaeLi-Ping LinAuthor Vitae Wen-Lian CaiAuthor VitaeXuan LinAuthor Vitae Yi-Na ZengAuthor VitaeZhi-Ming LiAuthor Vitae Shao-Qin LinAuthor Vitae 《Sensors and actuators. B, Chemical》2011,155(2):817-822
Gold nanorods (GNRs) exhibit strong longitudinal surface plasmon resonance absorption (LPA), which is highly dependent on its aspect ratio (length/width). The strong oxidization of Cr (VI) enables it to etch GNRs selectively at tips. The redox etching causes the aspect ratio of GNRs to decrease, resulting in the LPA blue shifts and the color of GNRs distinctly changes. Besides, the blue shift is linear to the concentration of Cr (VI) in the range of 0.1-20 μM. Thus, a non-aggregation based label free colorimetric sensor for the detection of Cr (VI) has been developed based on the selective etching of GNRs. The proposed colorimetric sensor is responsive, simple, sensitive (detection limit is 8.8 × 10−8 M) and selective, and it has been successfully applied to the detection of Cr (VI) in drinking water and sea water. Moreover, the mechanism of colorimetric sensor for the detection of Cr (VI) was also discussed. 相似文献
15.
Pure and Pt-loaded gamma iron oxide as sensor for detection of sub ppm level of acetone 总被引:1,自引:0,他引:1
Ramesh Chandra BiswalAuthor Vitae 《Sensors and actuators. B, Chemical》2011,157(1):183-188
In this study, pure and Pt-loaded nanocrystalline γ-Fe2O3 have been prepared by precipitation using ultrasonic irradiation. The synthesized powders were characterized by X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), differential thermal analysis (DTA), transmission electron micrograph (TEM), selected area electron diffraction (SAED), scanning electron microscope (SEM) and energy dispersive X-ray (EDX). Pure nanocrystallline γ-Fe2O3 sensors were found to show good response towards sub ppm level of acetone at 250 °C, and improves significantly on Pt loading. As an example, 1 wt% Pt loading of nanocrystallline γ-Fe2O3 increased its response towards acetone by 55%. The high response of γ-Fe2O3 holds it as a potentially promising candidate for acetone detection which may lead for the non-invasive testing of diabetics. 相似文献
16.
Nur AksunerAuthor Vitae 《Sensors and actuators. B, Chemical》2011,157(1):162-168
A new sensor membrane based on a novel triazolo-thiadiazin derivative immobilized in polyvinyl chloride has been developed for the determination of Pb(II) ions that displays excellent performance. The parameters involved in the preparation of the optode and determination of Pb(II) were optimized. Under the optimal conditions, the proposed sensor displays a calibration response for Pb(II) over a wide concentration range of 5.0 × 10−8 to 3.8 × 10−4 M with the detection limit of 2.2 × 10−8 M. In addition to high reproducibility and reversibility of the fluorescence signal, the sensor also exhibits good selectivity over common metal ions. The optode membrane developed is easily prepared, stable, rapid, and simple for the determination of Pb(II). The accuracy of the proposed sensor was confirmed by analyzing standard reference materials of natural water and surface water. The sensor was successfully used for the determination of Pb(II) ions in water samples with satisfactory results. 相似文献
17.
程鹏翔 《计算机测量与控制》2020,28(12):238-242
目前提出的弹药检测虚拟训练系统接收检测信号接收率较低,检测虚拟训练成功率较低。基于3D虚拟现实技术设计一种新的弹药检测虚拟训练系统,硬件由主控操作机、检测总线接口以及资源测试器组成,软件部分在3D虚拟现实技术下构建虚拟空间,在开放式软件结构构建的基础上进行检测指标划分,对用户界面的文件进行整改,按照弹药检测的指标数据提升整改的方向正确性,选用自检公式对检测的信息进行系统自检,依据检测到的问题的发生形式判断下一次问题发生的触发机制,由此避免下一次问题的产生,从而实现软件流程。实验结果表明,基于3D虚拟现实技术的弹药检测虚拟训练系统能有效提高信号接收率,增强虚拟训练接收成功率,具有较强的应用性。 相似文献
18.
Tellurium trioxide (TeO3) and tellurium dioxide (TeO2) thin film has been deposited by rf sputtering. The influence of γ-radiation doses (in the range 10–50 Gy) on the optical and electrical properties of as-deposited films were studied. Optical band gap values were found to decrease with increasing radiation dose whereas electrical conductivity was increased by about five orders in magnitude. Monotonic decrease in the values of dielectric constant for the deposited TeO3 films with increase in radiation dose was observed. The γ-ray response behavior of TeO3 and TeO2 thin films are compared, and TeO3 thin film is found to be more suitable in amorphous form for γ-ray detection. 相似文献
19.
R.J. DeokateAuthor VitaeD.S. DhawaleAuthor Vitae C.D. LokhandeAuthor Vitae 《Sensors and actuators. B, Chemical》2011,156(2):954-960
Nanocrystalline cadmium indium oxide (CdIn2O4) thin films of different thicknesses were deposited by chemical spray pyrolysis technique and utilized as a liquefied petroleum gas (LPG) sensors. These CdIn2O4 films were characterized for their structural and morphological properties by means of X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The dependence of the LPG response on the operating temperature, LPG concentration and CdIn2O4 film thickness were investigated. The results showed that the phase structure and the LPG sensing properties changes with the different thicknesses. The maximum LPG response of 46% at the operation temperature of 673 K was achieved for the CdIn2O4 film of thickness of 695 nm. The CdIn2O4 thin films exhibited good response and rapid response/recovery characteristics to LPG. 相似文献