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相关法高抗干扰超声波距离测量中的信号处理 被引量:12
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作者 葛万成 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2002年第1期71-76,共6页
提出了一种建立在信号模型基础上的高抗干扰超声波距离测量相关法 .通过对超声波传感器频率特性的分析而求得一个十分简单的超声波匹配电路 .为了降低所处理的信号频率采用了调制与解调技术 .由于伪随机二进制信号PRBS和超声波传感器的... 提出了一种建立在信号模型基础上的高抗干扰超声波距离测量相关法 .通过对超声波传感器频率特性的分析而求得一个十分简单的超声波匹配电路 .为了降低所处理的信号频率采用了调制与解调技术 .由于伪随机二进制信号PRBS和超声波传感器的特性 ,可用方波载波信号来有效地代替正弦波载波信号 .还描述了用于提高采样频率的线形内插法和用于抑制分散回声的均值法 . 展开更多
关键词 相关声波距离测量技术 声波传感器 调制解调 信号处理 声波匹配电路 平均值 内插
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基于围岩松动圈现场测量的巷道支护优化 被引量:14
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作者 钱振宇 任奋华 +2 位作者 苗胜军 李楷 冀东 《金属矿山》 CAS 北大核心 2013年第10期16-20,共5页
为研究三山岛金矿深部-600 m水平巷道围岩的松动圈范围与应力状态,使用RSM-SY6型声波检测仪进行围岩松动圈现场测量,运用FLAC3D数值模拟方法分析围岩应力,验证测量结果。基于现场测量的结果和应力分布情况,采用围岩松动圈支护理论,对三... 为研究三山岛金矿深部-600 m水平巷道围岩的松动圈范围与应力状态,使用RSM-SY6型声波检测仪进行围岩松动圈现场测量,运用FLAC3D数值模拟方法分析围岩应力,验证测量结果。基于现场测量的结果和应力分布情况,采用围岩松动圈支护理论,对三山岛金矿的巷道支护形式和参数进行优化。结果表明,经过参数优化后的支护方案,可以在保障安全生产的同时创造经济效益,并为矿山今后的支护设计提供技术参考。 展开更多
关键词 松动圈 声波现场测量支护设计
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基于定量分析的气固两相流声速模型综述
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作者 宋志江 胡尚锋 李言钦 《应用声学》 CSCD 北大核心 2023年第1期182-192,共11页
声波法是多相流测量的一种有效方法,可靠的声速模型是其中时差法等测量的理论基础。该文系统总结了国内外不同学者所建立的气固两相声速模型。为直观地呈现其差异、发展与局限,该文以颗粒相浓度的影响为例,采用模拟计算和实验测量相结... 声波法是多相流测量的一种有效方法,可靠的声速模型是其中时差法等测量的理论基础。该文系统总结了国内外不同学者所建立的气固两相声速模型。为直观地呈现其差异、发展与局限,该文以颗粒相浓度的影响为例,采用模拟计算和实验测量相结合的方法对其中不同典型声速模型进行了定量分析与比较。结果表明,传统的拟均相介质模型声速随颗粒浓度变化,与在其基础上考虑声波特性的改进模型,以及分别基于相间耦合和颗粒散射的声速模型差异均较大,且显著偏离实验测量值。其主要源于传统的拟均相介质模型未考虑两相间相对运动的影响;而考虑相间相互作用的声速模型间虽有不同差异,但均与实验测量值较为接近,根据稀相区实验研究,所得声速值均较实验值偏小。 展开更多
关键词 声速模型 声波法测量 气固两相流 颗粒浓度 综述
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炉内温度速度耦合场声线弯曲特性研究 被引量:5
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作者 贾韶琦 宋志江 +2 位作者 李言钦 关雪丰 刘治港 《动力工程学报》 CAS CSCD 北大核心 2021年第8期617-623,共7页
为了实现声波法测量热物理量场的可靠重建,弄清介质温度和流速对声速的耦合作用机理,采用三角形前向展开法和Lagrangian法建立追踪模型,针对仿真的不同炉膛典型温度场和流场,研究了声波传播路径的弯曲效应,同时建立一维流场模型以从理... 为了实现声波法测量热物理量场的可靠重建,弄清介质温度和流速对声速的耦合作用机理,采用三角形前向展开法和Lagrangian法建立追踪模型,针对仿真的不同炉膛典型温度场和流场,研究了声波传播路径的弯曲效应,同时建立一维流场模型以从理论角度验证上述方法的可行性和可靠性。结果表明:炉内烟气温度、流速耦合场对声波传播路径影响复杂,若不考虑声线弯曲,必将导致相应声学法温度场和流场测量重建结果的失真;基于上述不同理论方法计算追踪出的对象场声线分布彼此吻合,证明所建声线追踪模型可靠。 展开更多
关键词 温度 流速 多场耦合 声波法测量 声线追踪
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Determination of contents of 10-Hydroxycamptothecin in Camptotheca acuminata by high-performance liquid chromatogram 被引量:5
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作者 马梅芳 于涛 +2 位作者 戴绍军 王洋 阎秀峰 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第2期144-146,165,共3页
The determination method of 10-hydroxycamptothecin in Camptotheca acuminata fruits by high-performance liquid chromatogram (HPLC) was studied. The HPLC analysis was performed on a HIQ sil C18(4.6×250 mm) column w... The determination method of 10-hydroxycamptothecin in Camptotheca acuminata fruits by high-performance liquid chromatogram (HPLC) was studied. The HPLC analysis was performed on a HIQ sil C18(4.6×250 mm) column with mobile phase of acetonitrilewater (3:7, V:V), flow rate 1 mLmin-1 and UV detective wavelength 266 nm. Extracting 10-hydroxycamptothecin by ultrasonic method from fruits of C. acuminata to prepare samples for analysis was systematically discussed. The optimal extraction condition was carried out by 60% alcohol solution at 60℃ for 50 minutes. 展开更多
关键词 HYDROXYCAMPTOTHECIN Camptotheca acuminata HPLC ultrasonic extraction method
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水轮机差压法及超声波法效率试验软件的设计及实现 被引量:6
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作者 赖擎 曹力立 吕云 《水电自动化与大坝监测》 2009年第3期29-31,35,共4页
水轮机效率试验是评价水轮机性能的重要指标。目前,国内效率试验的做法通常是要根据试验使用的方法(如蜗壳差压法和超声波法等),选择特定的数据采集硬件结合自行开发的软件进行。文中设计开发了一套可采用蜗壳差压法或超声波法进行水轮... 水轮机效率试验是评价水轮机性能的重要指标。目前,国内效率试验的做法通常是要根据试验使用的方法(如蜗壳差压法和超声波法等),选择特定的数据采集硬件结合自行开发的软件进行。文中设计开发了一套可采用蜗壳差压法或超声波法进行水轮机效率试验的软件测试系统,数据采集的硬件选用USB-4711数据采集卡,软件采用Delphi语言。文中介绍了该系统的功能特点以及设计思路。 展开更多
关键词 水轮机 差压流量测量 声波流量测量 效率试验软件
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Determination of Hg in soil by ultrasonic slurry sampling hydride generation atomic fluorescence spectrometry
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作者 LIANG Shu-xuan LV Tian-feng ZHOU Wei-jing SUN Han-wen 《Journal of Environmental Science and Engineering》 2008年第5期9-13,共5页
Ultrasonic aided slurry sampling hydride generation atomic fluorescence spectrometry (USS-HG-AFS) was developed for the determination of Hg in soil samples from a sewage-irrigated farm. 500 mg grounded soil was susp... Ultrasonic aided slurry sampling hydride generation atomic fluorescence spectrometry (USS-HG-AFS) was developed for the determination of Hg in soil samples from a sewage-irrigated farm. 500 mg grounded soil was suspended in agar solution by an ultrasound water bath before the HG-AFS determination. The results for the reference material of soil (serial number GBW-07411) agreed satisfactorily with the certified values. Results obtained by the developed procedure compared well with those after traditional acid digestion of samples. The detection limit are 6.7ngL-1 for Hg respectively, with average relative standard deviation values of 6.4% for analysis of a series of soil samples of different origin. The recoveries of the anatytes varied in the range from 95 to 107%. This observation has stimulated interest in fast, accurate and sensitive analytical methods for determination of metals in soil. 展开更多
关键词 hydride generation ultrasonic slurry sampling atomic fluorescence spectrometry SOIL trace element
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INFORMATION FUSION STEADY-STATE WHITE NOISE DECONVOLUTION ESTIMATORS WITH TIME-DELAYED MEASUREMENTS AND COLORED MEASUREMENT NOISES
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作者 Sun Xiaojun Deng Zili 《Journal of Electronics(China)》 2009年第2期161-167,共7页
White noise deconvolution or input white noise estimation problem has important appli-cation backgrounds in oil seismic exploration,communication and signal processing.By the modern time series analysis method,based o... White noise deconvolution or input white noise estimation problem has important appli-cation backgrounds in oil seismic exploration,communication and signal processing.By the modern time series analysis method,based on the Auto-Regressive Moving Average(ARMA) innovation model,under the linear minimum variance optimal fusion rules,three optimal weighted fusion white noise deconvolution estimators are presented for the multisensor systems with time-delayed measurements and colored measurement noises.They can handle the input white noise fused filtering,prediction and smoothing problems.The accuracy of the fusers is higher than that of each local white noise estimator.In order to compute the optimal weights,the formula of computing the local estimation error cross-covariances is given.A Monte Carlo simulation example for the system with 3 sensors and the Bernoulli-Gaussian input white noise shows their effectiveness and performances. 展开更多
关键词 Multisensor information fusion White noise estimator DECONVOLUTION Time-delayed measurement Modern time series analysis method
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Optimal filtering for uncertain systems with stochastic nonlinearities, correlated noises and missing measurements 被引量:3
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作者 Shuo Zhang Yan Zhao +1 位作者 Min Li Jianhui Zhao 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第5期1052-1059,共8页
The globally optimal recursive filtering problem is studied for a class of systems with random parameter matrices,stochastic nonlinearities, correlated noises and missing measurements. The stochastic nonlinearities ar... The globally optimal recursive filtering problem is studied for a class of systems with random parameter matrices,stochastic nonlinearities, correlated noises and missing measurements. The stochastic nonlinearities are presented in the system model to reflect multiplicative random disturbances, and the additive noises, process noise and measurement noise, are assumed to be one-step autocorrelated as well as two-step cross-correlated.A series of random variables is introduced as the missing rates governing the intermittent measurement losses caused by unfavorable network conditions. The aim of the addressed filtering problem is to design an optimal recursive filter for the uncertain systems based on an innovation approach such that the filtering error is globally minimized at each sampling time. A numerical simulation example is provided to illustrate the effectiveness and applicability of the proposed algorithm. 展开更多
关键词 globally optimal recursive filtering random parame- ter matrices stochastic nonlinearities correlated noises missing measurements
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