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THEORY AND APPLICATION OF WAVELET ANALYSIS INSTRUMENT LIBRARY

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Chinese Journal of Mechanical Engineering 2006年第3期19卷 464-467页

作者： BO Lin qin Shuren LIU xiaofeng College of Mechanical Engineenng Chongqing University Chongqing 400044 China

Some new theory and algorithms on wavelet analysis are proposed, including continuous wavelet transform （CWT）, discrete wavelet transform （DWT）, wavelet package transform （WPT）, wavelet denosing and mother wavelet selection, etc. Using the component-based hierarchy mode, the platform for virtual instrument （VI） is constructed, and the functions such as data sampling, data analysis and data present, etc are provided. Subsequently, the wavelet analysis library is designed and developed. The library consists of expert system, experienced database, development platform and abundant wavelet analysis functional module, which together implement general and special wavelet analysis in the field of mechanical engineering, energy source, transportation and biomedicine, etc. Finally, the wavelet analysis virtual instrument library is applied to detect fault called engine knock. Experimental result indicates that the wavelet analysis virtual instrument library can efficiently solve the engineering problem such as detecting engine knock.

关键词： Wavelet analysis Virtual instrument library Engine knock

HYBRID WAVELET PACKET-TEAGER ENERGY OPERATOR ANALYSIS AND ITS APPLICATION FOR GEARBOX FAULT DIAGNOSIS

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Chinese Journal of Mechanical Engineering 2007年第3期20卷 79-83页

作者： LIU xiaofeng qin Shuren BO Lin College of Mechanical Engineering Chongqing University Chongqing 400044 China

Based on wavelet packet decomposition （WPD） algorithm and Teager energy operator （TEO）, a novel gearbox fault detection and diagnosis method is proposed. Its process is expatiated after the principles of WPD and TEO modulation are introduced respectively. The preprocessed sigaaal is interpolated with the cubic spline function, then expanded over the selected basis wavelets. Grouping its wavelet packet components of the signal based on the minimum entropy criterion, the interpolated signal can be decomposed into its dominant components with nearly distinct fault frequency contents. To extract the demodulation information of each dominant component, TEO is used. The performance of the proposed method is assessed by means of several tests on vibration signals collected from the gearbox mounted on a heavy truck. It is proved that hybrid WPD-TEO method is effective and robust for detecting and diagnosing localized gearbox faults.

关键词： Wavelet packet Teager energy operator Fault diagnosis Demodulation analysis

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Effects of atmospheric pressure fluctuations on hill-side coal fires and surface anomalies

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International Journal of Mining Science and Technology 2015年第6期25卷 1037-1044页

作者： Song Zeyang Zhu Hongqing Xu Jiyuan qin xiaofeng Jiangsu Key Laboratory of Hazardous Chemicals Safety and Control College of Safety Science and Engineering Nanjing Tech University Faculty of Resources and Safety Engineering China University of Mining and Technology

This paper presents numerical studies on the effects of atmospheric pressure fluctuations on hill-side coal fires and their surface anomalies. Based on the single-particle reaction–diffusion model, a formula to estimate oxygen consumption rate at high temperature controlled by oxygen transport is *** fluctuant atmospheric pressure was imposed on boundaries, including the abandoned gallery and cracks. Simulated results show that the effects of atmospheric pressure fluctuations on coal fires and surface anomalies depend on two factors: the fluctuant amplitude and the pressure difference between inlet(s) and outlet(s) of the air ventilation system. If the pressure difference is close to the fluctuant amplitude, atmospheric pressure fluctuations greatly enhance gas flow motion and temperatures of the combustion zone and outtake(s). If the pressure difference is much larger than the fluctuant amplitude, atmospheric pressure fluctuations exert no impact on underground coal fires and surface anomalies.

关键词： Coal firesOxygen consumpdon rateAir leakageVentilation

A new technology for hard-rock tunneling based on drilling and hydraulic impact breaking

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International Journal of Mining Science and Technology 2015年第6期25卷 1053-1058页

作者： Long Risheng Sun Shaoni Lian Zisheng Liao Yaoyao qin xiaofeng College of Mechanical Engineering Taiyuan University of Technology Shanxi Key Laboratory of Fully Mechanized Coal Mining Equipment Shenyang Puyue Group School of Mechanical Engineering & Automation Northeastern University

In order to realize the safety, high efficiency and rapidity of hard rock tunneling, we propose the drilling &hydraulic impact hard-rock tunneling(DHIHT) technology and method. Based on the LS-DYNA explicit module and APDL programming, the key parameters of DHIHT, including drilling spacing and drilling radius, were investigated. The simulation results show that: the drilling spacing should not exceed0.20 m-larger distances weaken the actual breaking effect; the best drilling radius is about 0.035 m, larger or smaller distances would both decrease the effect of drilling-hole free surfaces. The field impact breaking experiments were conducted in Baitaizi township granite quarry, Jinzhou, Liaoning province,China. The experiment results indicate that DHIHT is a feasible method for hard-rock tunneling, but its efficiency still needs to be further optimized and improved.

关键词： Hydraulic impact breakingHard rock tunnelingBreaking mechanismNumerical simulationTechnology research

Preparation of Undoped LaCl3 Crystal and Its Luminescence Properties

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Journal of Rare Earths 2004年第z1期22卷 12-14页

作者： Pei Yu Ren Guohao Chen xiaofeng qin Laishun Li Zhongbo Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 201800 China Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 201800 China Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 201800 China Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 201800 China Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 201800 China

In this paper, undoped LaCl3 crystal growth was reported by modified Bridgman *** starting materials used as charge for crystal growth was found to contain seven to three crystallized water molecules, and dehydration will take place when heating the raw materials at about 230 ℃ for several *** oxidization of LaCl3 during dehydration and growth can be avoided by adding a special scanvenger into the growing *** grown LaCl3 crystals are colorless and transparent, but very *** optical cut-off edge was confirmed to be 220 *** excited and X-ray induced emission spectra were measured at room temperature, whose peak is at 405 nm.

关键词： rare-earth trihalide crystal growth optical properties

NON-STATIONARY SIGNAL DENOISING USING TIME-FREQUENCY CURVE SURFACE FITTING

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Journal of Electronics(China) 2007年第6期24卷 776-781页

作者： Liu xiaofeng qin Shuren Bo Lin Test Center of Mechanical Engineering Chongqing University Chongqing 400044 China

Based on the theory of adaptive time-frequency decomposition and Time-Frequency Dis- tribution Series (TFDS), this paper presents a novel denoising method for non-stationary signal. Ac- cording to the input signal features, an appropriate kind of elementary functions with great concen- tration in the Time-Frequency (TF) plane is selected. Then the input signal is decomposed into a linear combination of these functions. The elementary function parameters are determined by using ele- mentary function TF curve surface to fit the input signal’s TFDS. The process of curved surface fitting corresponds to the signal structure matching process. The input signal’s dominating component whose structure has the resemblance with elementary function is fitted out firstly. Repeating the fitting process, the residue can be regarded as noises, which are greatly different from the function. Selecting the functions fitted out initially for reconstruction, the denoised signal is obtained. The performance of the proposed method is assessed by means of several tests on an emulated signal and a gearbox vi- brating signal.

关键词： Time-frequency decomposition Elementary function Time-Frequency Distribution Series (TFDS) Curve surface fitting Noise suppressing

New Solution for the Earth’s Free Wobble and Its Geophysical Implications

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Geo-Spatial Information Science 2010年第1期13卷 49-55页

作者： CHEN Wei SHEN Wenbin qin xiaofeng School of Geodesy and Geomatics Wuhan University 129 Luoyu Road Wuhan 430079China State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University 129 Luoyu Road Wuhan 430079 China Key Laboratory of Geospaee Environment and Geodesy Ministry of Education Wuhan University 129 Luoyu Road Wu- han 430079China

In this paper, the theory of the free wobble of the triaxial Earth is developed and new conclusions are drawn: the Euler period should be actually expressed by the first kind of complete elliptic integral; the trace of the free polar motion is elliptic and the orientations of its semi-minor and major axes are approximately parallel to the Earth's principal axes A and B, respectively. In addition, the present theory shows that there is a mechanism of frequency-amplitude modulation in the Chandler wobble, which might be a candidate for explaining the correlation between the amplitude and period of the Chandler wobble.

关键词： triaxial Earth elliptic free polar motion variation of Chandler period frequency-amplitude modulation

Geochemistry of Permian Mafic Igneous Rocks from the Napo-qinzhou Tectonic Belt in Southwest Guangxi, Southwest China: Implications for Arc-Back Arc Basin Magmatic Evolution

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Acta Geologica Sinica(English Edition) 2012年第5期86卷 1182-1199页

作者： qin xiaofeng WANG Zongqi ZHANG Yingli PAN Luozhong HU Guiang ZHOU Fusheng College of Earth Science Guilin University of TechnologyGuilinGuangxi 541004China Institute of Mineral Resources Chinese Academy of Geological SciencesBeijing 100037China Guangxi Institute of Regional Geological Survey GuilinGuangxi 541003China

The Napo-qinzhou Tectonic Belt （NQTB） lies at the junction of the Yangtze, Cathaysia and Indochina （North Vietnam） Blocks, which is composed of five major lithotectonic subunits： the qinzhou-Fangcheng Suture Zone （QFSZ）, the Shiwandashan Basin （SB）, the Pingxiang-Nanning Suture Zone （PNSZ）, the Damingshan Block （DB） and the Babu-Lingma Suture Zone （BLSZ）. On the basis of geochemical compositions, the Permian mafic igneous rocks can be divided into three distinct groups：（1） mafic igneous rocks （Group 1） from the Longjing region in the PNSZ and Hurun region in the BLSZ, which are characterized by intermediate Ti, P and Zr with low Ni and Cr contents; （2） mafic igneous rocks （Group 2） from the Naxiao and Chongzuo region in the DB, characterized by low-intermediate Ti, P and Zr with high Ni and Cr concentrations; and （3） mafic igneous rocks （Group 3） from the Siming region in the Jingxi carbonate platform of the northwestern margin of the NQTB, with intermediate-high Ti, P and Zr and low Ni and Cr contents. The Group 1 rocks yield a weighted mean 206 Pb/ 238 U age of 250.5±2.8 Ma and are geochemically similar to basalts occurring in back-arc basin settings. The Group 2 rocks exhibit geochemical features to those basalts in island arcs, whereas the Group 3 rocks show geochemical similarity to that of ocean island basalts. All three groups are characterized by relatively low ε Nd （t） values （-2.61 to ＋1.10） and high initial 87 Sr/ 86 Sr isotopic ratios （0.705309-0.707434）, indicating that they were derived from a subduction-modified lithospheric mantle and experienced assimilation, fractional crystallization, and crustal contamination or mixing during magmatic evolution. Accordingly, we propose the existence of an arc-back arc basin system that developed along the NQTB at the border of SW Guangxi Province （SW China） and northern Vietnam, and it was formed by continued northwestward subduction of the Cathaysian （or Yunkai） Block under the Yangtze Block, and northeastward

关键词： Permian mafic igneous rocks geochemistry petrogenesis arc-back arc basin the Napo- qinzhou tectonic belt northwest China

Radio-ligand receptor binding assav in vitro and animal biodistribution in vivo of ^(99)Tc^m-N-ethyl-N_2S_2-memantine as a potential NMDA receptor imaging agent

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Nuclear Science and Techniques 2010年第3期21卷 171-176页

作者： LIU Yingtao ZHOU Xingqin CAO Guoxian ZHANG Jiankang qin xiaofeng XU Xijie ZOU Meifen Jiangnan University School of Medicine and Pharmaceutics Wuxi 214122 China Key Laboratory of Nuclear Medicine Ministry of Health Jiangsu Institute of Nuclear Medicine Wuxi 214063 China

The pharmacologic characteristics of ^(99)Tc^m-N-ethyl-N_2S_2-memantine,an NMDA receptor imaging agent,was *** was prepared by a one-step reaction from N-ethyl-N_2S_*** affinity and specificity were determined by radio-ligand receptor binding assay(RRA).Biodistribution in vivo in mice was *** results showed that ^(99)Tc^m-N-ethyl-N_2S_2-memantine bound to a single site on NMDA receptor with a K_d of 584.32 nmol/L and a B_(max)of 267.05 nmol/mg.A competitive analysis showed that such specific binding could be inhibited by specific inhibitors of NMDA receptor,such as ketamine and(+)-*** biodistribution exhibited rapid uptake and favorable retention in mice *** major radioactivity was metabolized by the hepatic system.A two-compartment model of C=4.49e^(-0.083t)+ 1.42e^(-0.0016t)was established,and the half life was 8.35 min in *** conclusion,the new radio-ligand ^(99)Tc^m-N-ethyl-N_2S_2-Memantine has a moderate affinity and specific binding to NMDA receptor,and can easily cross the blood-brain barrier(BBB).Therefore,it may be a potential NMDA receptor imaging agent.

关键词： NMDA受体体内分布受体结合无线电显像剂乙基配体特异性结合