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Development of a multiprobe electrical resistivity tomography prototype system and robust underground clustering 下载免费PDF全文
This study reports a 24‐probe electrical resistivity tomography (ERT) prototype system and its empirical evaluation in a case study setting. The system was designed using the Wenner soil resistivity measurement method. The performance and outputs of the approach and the developed prototype system were assessed and approved by the General Directorate of Mineral Research and Exploration of Turkey. This study is also supported by the Republic of Turkey Ministry of Science, Industry and Technology through the project “Distinguishing of Metallic Targets (code number is 1064.STZ.2011‐2).” The state of the art of this study is multiprobe ERT, which has a touchscreen for ease of use and improved measurement accuracy for minimizing RMS (root mean square) error using a 16‐bit ADC. Similar to other ERT systems, the prototype system that we have developed allows the user to change the current and probe interval via the touchscreen user interface. In addition to this system, a new fuzzy clustering algorithm named robust colored image fuzzy C‐mean was developed in this study. The robust colored image fuzzy C‐mean performs underground clustering in RGB colors, which provides improved clustering results compared to those of the conventional fuzzy C‐mean clustering algorithm. 相似文献
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熔铝电阻率的测量基于电涡流原理,设计了传感器的结构和标定方法。为了简化测量熔铝电阻率的硬件电路,在信号处理电容中采用了LVDT专用芯片AD598硬软件结合消除了温度影响,在熔铝及铝基合金的凝固研究中得到实用。 相似文献
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随着碳化硅(SiC)材料的MEMS器件在恶劣环境测量中的应用前景和迫切需求,进行了碳化硅的直接键合实验.研究了工艺条件对键合样品力学性能的影响,同时借助激光共聚焦扫描显微镜(CLSM)、扫描电子显微镜(SEM)、能谱仪(EDS)和拉曼光谱仪等对碳化硅键合样品界面的微观结构进行了分析.结果表明:退火温度和加载压力是影响键合效果的关键性因素.当退火温度为1 300℃,加载压力为3 MPa和退火时间为3 h时,此时键合样品的气密性非常好,力学性能达到最佳,键合强度2 MPa.最后通过样品微观界面分析表明碳化硅直接键合的机理为界面氧化硅过渡层的形成及粘性流动与碳化硅和碳化硅的熔融直接键合. 相似文献
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Surface plasmon resonance based fiber optic sensor for the detection of low water content in ethanol
Sachin K. SrivastavaAuthor VitaeRoli VermaAuthor Vitae Banshi D. GuptaAuthor Vitae 《Sensors and actuators. B, Chemical》2011,153(1):194-198
A fiber optic sensor utilizing surface plasmon resonance (SPR) has been fabricated for the detection of low content of water in ethanol. The sensor utilizes spectral interrogation technique for operation. The resonance wavelength has been found to vary linearly with water content in the range 0-10% with sensitivity of 1.149 nm per percentage of water. The results are in agreement with the refractive index variation of ethanol-water mixture. The sensor has a water resolution of 0.145% which is better than the evanescent wave absorption sensor reported for the similar study. The sensor will find application in determining the low water content in ethanol which is used as a bio-fuel and in the field of medicine and organic chemistry. 相似文献
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为减小碳纤维原丝生产工艺中双扩散过程对原液细流进入浴槽凝固成初生纤维的影响,必须保证出丝槽流系统中流场的稳定性.采用时变雷诺方程和标准k-ε湍流模型,模拟计算不同形状和结构尺寸的喷丝孔外罩对碳纤维出丝槽流系统流域中湍流的影响.利用不同长高比二维矩形钝体模型计算高雷诺数下绕流的情形,对比不同尺寸下尾流内湍流的大小,分析得到较优的结构参数.结果表明,外罩长高比是影响湍流大小的主要因素;长高比增大有利于减弱尾流内的湍流;当长高比接近4时,喷丝口处湍流较小,但长高比再增大,湍流减小程度不明显. 相似文献
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Cheng-Shane ChuAuthor Vitae Yu-Lung LoAuthor Vitae 《Sensors and actuators. B, Chemical》2011,155(1):53-57
A simple, low-cost technique for fabrication of high performance optical fiber oxygen sensor is described. An organically modified silicate (ORMOSIL) as a matrix for the fabrication of oxygen sensing film was produced. The technique is based on coating the end of an optical fiber with ORMOSIL composite xerogel films film sequestered with luminophore platinum (II) meso-tetrakis(pentafluorophenyl)porphyrin (PtTFPP) prepared by a sol-gel process. The composite xerogels studied are 3,3,3-trifluoropropyltrimethoxysliane (TFP-TriMOS) or n-propyltrimethoxysilane (n-propyl-TriMOS)/tetraethylorthosilane (TEOS)/n-octyltriethoxysilane (Octyl-triEOS). Results show that, expect for PtTFPP-doped TFP-TriMOS or n-propyl-TriMOS/TEOS/Octyl-triEOS composite xerogels show the high sensitivity and linear Stern-Volmer relationship which indicate the homogenous environment of the luminophore. The sensitivities of the two oxygen sensors are quantified in terms of the ratio IN2/IO2, where IN2 and IO2 represent the detected fluorescence intensities in pure nitrogen and pure oxygen environments, respectively. The experimental results reveal that the PtTFPP-doped TFP-TriMOS/TEOS/Octyl-triEOS and n-propyl-TriMOS/TEOS/Octyl-triEOS oxygen sensors have sensitivities of 101 and 155, respectively. The experimental results confirm that the current oxygen sensors exhibit the linear Stern-Volmer plots and high-sensitive based on the oxygen indicator embedded in TFP-TriMOS or n-propyl-TriMOS/TEOS/Octyl-triEOS composite xerogels. 相似文献
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新能源电力的规模化开发以及传统能源的清洁高效利用已成为当前能源革命的主题.目前,我国新能源电力比例持续增加,但受限于化石能源占主导的电源结构,未来很长一段时间内我国将处于混合能源时代.强随机波动性、间歇性以及不确定性使得规模化新能源电力的消纳问题日益严重,我国弃风弃光现象十分突出.深入认知电源侧、电网侧、负荷侧的基本特性,着重解决其控制与优化难题,是实现新能源电力系统安全高效运行的基本前提.本文围绕电源效应、电网响应、负荷响应,着重从电网友好型发电控制、基于多源互补的火力发电弹性控制、适应高比例新能源电力消纳的电网调度控制、需求侧资源特性与主动适应控制以及基于分布式能源的微电网控制5个方面阐述了新能源电力系统局部与全局控制中存在的关键科学问题. 相似文献
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双光纤光栅可以用于光纤光栅传感器中波长移动的探测与解调,提出了一种新的解调方案并对几种可能的解调方案进行了实验对比。结果表明,在宽带光源光谱全功率较小的前提下,利用双光栅透射谱的相关及双光栅透射谱和反射谱的卷积都能实现波长移动的探测与解调,前者有更好的信噪比。而因为系统损耗过大,利用双光栅反射谱的相关不能探测与解调光栅中心反射波长的移动。双光栅波长探测与解调技术将波长的移动转化为相对光强极值的探测,避免了光纤光栅传感器中使用光谱仪等价格昂贵,体积庞大,使用不方便的光谱探测器件,有利于光纤光栅传感器的实用化。 相似文献
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棉花中的异性纤维比重小,但危害大,针对目前棉花异纤检测中存在效率低、稳定性差等问题,提出了一种改进的Canny检测算子和一种基于区域生长的三基色阈值检测算法,开发了一种基于机器视觉的棉花异纤高速清除系统。系统采用FPGA加DSP构建高速图像采集处理卡进行异纤检测运算,使用双层照明结构和PLC在线监控模式,实验证明了算法在异纤检测中的有效性和先进性,提高了异纤检测速度和检测精度,具有更高的运行稳定性。 相似文献
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XU ShiLang YU WenTing&SONG ShiDe College of Civil Engineering Architecture Zhejiang University Hangzhou China The rd Railway Survey Design Institute Tianjin State Key Laboratory of Coastal Offshore Engineering Dalian University of Technology Dalian 《中国科学:信息科学(英文版)》2011,(9)
Carbon/glass fiber hybrid textile reinforced concrete is a relatively new composite material with good mechanical capacity and excellent electrical conductivity.Both small-scale slab heating experiments and numerical simulation are presented in this paper.Temperature variation curves obtained during heating indicate the effects of environmental temperature,heat-conducting layer thickness and electric heating power.Comparison of temperature rising between the situations with and without thermal isolation lay... 相似文献
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XU Kun YIN Jie NIU Jian SUN XiaoQiang WU Jian & LIN JinTong Key Laboratory of Information Photonics Optical Communications Ministry of Education Beijing University of Posts Telecommunications Beijing China 《中国科学:信息科学(英文版)》2011,(2):236-243
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The absence of tactile force information at the tip of a medical instrument makes precise minimally invasive surgery difficult and is prone to resulting in serious outcomes. In this paper, a fiber optic force sensor is fabricated based on Fabry-Perot interferometry and integrated with a puncture needle. The force sensor is attached to the needle tip, where interactive force arises as it inserts into soft tissue. Needle insertion experiments have been conducted on ex vivo swine liver and belly with the calibrated force sensor. Using wavelet transform method, the acquired force data are analyzed and used to identify layered tissue types and boundaries. We found that the force amplitudes are not always identical, but the patterns of forces are almost the same, which enables us to identify layered tissues and to realize a safe needle insertion procedure under robot control. 相似文献
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Functional electrical stimulation (FES) is used to excite paralyzed muscles that are no longer controlled by patients with spinal cord injuries (SCI). Appropriate stimulation patterns are chosen to stimulate intact muscles, in order to extend their overall performance, postponing thus the muscular fatigue during the daily activities such as standing, standing up, sitting down and walking. This paper presents the modeling and the control of a knee joint actuated by the quadriceps muscles. Appropriate stimulation patterns are computed as a function of the desired lower-limb knee joint movements. Parameters of the biomechanical model are identified based on experimental kinematic data. Model predictive control (MPC) is applied to the input-output feedback linearized (IOFL) system. IOFL allows linearization by inverting the system dynamics through a nonlinear feedback transformation. The described control approach is validated through different simulation scenarios for knee flexion-extension. Internal dynamics stability is mathematically proved and performances are compared to those produced by classical pole placements method. The controller has shown satisfactory results in terms of regulation, stability and robustness with respect to external disturbances. 相似文献