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Fracture analysis of magnetoelectroelastic bimaterials with imperfect interfaces by symplectic expansion

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Applied Mathematics and mechanics(English Edition) 2017年第8期38卷 1043-1058页

作者： Xinsheng XU Zhenzhen TONG Dalun RONG Xianhe CHENG Chenghui XU Zhenhuan ZHOU State Key Laboratory of Structural Analysis for Industrial Equipment Department ofEngineering MechanicsInternational Center for Computational MechanicsDalian University of TechnologyDalian 116024Liaoning ProvinceChina The Forty-First institute of China Aerospace Science and Industry Corporation Hohhot 010010China

A Hamiltonian-based analytical method is used to study the mode Ⅲ interface cracks in magnetoelectroelastic bimaterials with an imperfect interface. By introducing an unknown vector, the governing equations are reformulated in sets of first-order ordinary differential equations. Using separation of variables, eigensolutions in the symplectic space are obtained. An exact solution of the unknown vector is obtained and expressed in terms of symplectic eigensolutions. Singularities of mechanical, electric, and magnetic fields are evaluated with the generalized intensity factors. Comparisons are made to verify accuracy and stability of the proposed method. Numerical examples including mixed boundary conditions are given.

关键词： symplectic Fracture imperfect Hamiltonian ordinary singularity interfaces exact brittle verify

Generation of 17-TW 23-fs Pulses with a Two-Stage Ti：Sapphire Amplifier at Repetition Rate 10 Hz

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Chinese Physics Letters 2007年第5期24卷 1276-1278页

作者：李闯陆效明王乘冷雨欣梁晓燕李儒新徐至展 State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800

We have developed a two-stage Ti：sapphire amplifier system which can produce 17- TW/23-fs pulses at a repetition rate 10Hz. A birefringent plate is used in the regenerative amplifier to alleviate gain narrowing, while an all- reflective cylindrical-mirror-based pulse stretcher and an acousto-optic programmable dispersive filter （AOPDF） are used to compensate for the higher order dispersion of the system.

关键词： OPTICAL PULSES LASER SYSTEM AMPLIFICATION COMPRESSION FILTER

Glass homogeneity effect on wavefront aberration in lithography projection lens

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Chinese Optics Letters 2013年第9期11卷 25-27页

作者：尚红波黄纬刘春来许伟才杨旺 State Key Laboratory of Applied Optics Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun 130033 China

Analysis of glass homogeneity To improve analysis accuracy, using the attaching interferometric we establish the three-dimensional data model neglects body distribution. gradient index （GRIN） model of glass index by analyzing fused silica homogeneity distribution in two perpendicular measurement directions. Using the GRIN model, a lithography projection lens with a numerical aperture of 0.75 is analyzed. Root mean square wavefront aberration deteriorates from 0.9 to 9.65 nm and then improves to 5.9 nm after clocking.

关键词： 080.3095 Inhomogeneous elements in optical systems 220.3740 Lithography 220.1000 Aberration compensation

Monitoring the Heavy Element of Cr in Agricultural Soils Using a Mobile Laser-Induced Breakdown Spectroscopy System with Support Vector Machine

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Chinese Physics Letters 2016年第8期33卷 64-68页

作者：谷艳红赵南京马明俊孟德硕余洋贾尧方丽刘建国刘文清 Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsChinese Academy of Sciences University of Science and Technology of China

Due to its complicated matrix effects, rapid quantitative analysis of chromium in agricultural soils is difficult without the concentration gradient samples by laser-induced breakdown spectroscopy. To improve the analysis speed and accuracy, two calibration models are built with the support vector machine method： one considering the whole spectra and the other based on the segmental spectra input. Considering the results of the multiple linear regression analysis, three segmental spectra are chosen as the input variables of the support vector regression （SVR） model. Compared with the results of the SVR model with the whole spectra input, the relative standard error of prediction is reduced from 3.18% to 2.61% and the running time is saved due to the decrease in the number of input variables, showing the robustness in rapid soil analysis without the concentration gradient samples.

关键词： of is on LIBS in Monitoring the Heavy Element of Cr in Agricultural Soils Using a Mobile Laser-Induced Breakdown Spectroscopy System with Support Vector Machine SVR Cr with

Detection of void and metallic inclusion in 2D piezoelectric cantilever beam using impedance measurements

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Frontiers of Structural and Civil Engineering 2019年第3期13卷 542-556页

作者： S.SAMANTA S.S.S.NANTHAKUMAR R.K.ANNABATTULA X.ZHUANG institute of Continuum mechanics Leibniz University Hannover30167 HannoverGermany Indian institute of Technology Madras Chennai 600036India College of Civil Engineering Tongji UniversityShanghai 200092China

The aim of current work is to improve the existing inverse methodology of void-detection based on a target impedance curve,leading to quick-prediction of the parameters of single circular *** this work,mode-shape dependent shifting phenomenon of peaks of impedance curve with change in void location has been analyzed.A number of initial guesses followed by an iterative optimization algorithm based on univariate method has been used to solve the *** each iteration starting from each initial guess,the difference between the computationally obtained impedance curve and the target impedance curve has been *** methodology has been extended to detect single circular metallic inclusion in 2D piezoelectric cantilever beam.A good accuracy level was observed for detection of flaw radius and flaw-location along beam-length,but not the precise location along beam-width.

关键词： piezoelectricity impedance curve mode shapes inverse problem flaw detection curve shifting

Laser Doppler vibrometer for real-time speech-signal acquirement

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Chinese Optics Letters 2009年第8期7卷 732-733页

作者：尚建华贺岩刘丹臧华国陈卫标 Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

Laser Doppler vibrometer （LDV） has a potential application prospect in remote sensing. Based on the correlation theories of heterodyne detection, a LDV system with a configuration of all fiber and heterodyne techniques is developed to detect the sound signal through the vibration of glass. Experimental results show that the LDV system has an ability to acquire the real-time speech signal 25 m away through glass. While, the system signal-to-noise ratio （SNR） value decreases with the increase of the glass thickness and the detection distance.

关键词： Acoustic intensity Classifiers Correlation theory Doppler effect Glass Heterodyning Laser Doppler velocimeters Remote sensing Signal to noise ratio

Influence of Different Substrates on Laser Induced Damage Thresholds at 1064 nm of Ta2O5 Films

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Chinese Physics Letters 2008年第4期25卷 1321-1324页

作者：许程麻健勇晋云霞贺洪波邵建达范正修 Shanghai institute of Optics and Fine mechanics Chinese Academy of Sciences Shanghai 201800 Graduate School of Chinese Academy of Sciences Beijing 100049

Ta2O5 films are prepared on Si, BK7, fused silica, antireflection （AR） and high reflector （HR） substrates by electron beam evaporation method, respectively. Both the optical property and laser induced damage thresholds （LIDTs） at 1064 nm of Ta2O5 films on different substrates are investigated before and after annealing at 673 K for 12 h. It is shown that annealing increases the refractive index and decreases the extinction index, and improves the O/Ta ratio of the Ta2O5 films from 2.42 to 2.50. Moreover, the results show that the LIDTs of the Ta2O5 films are mainly correlated with three parameters： substrate property, substoichiometry defect in the films and impurity defect at the interface between the substrate and the films. Details of the laser induced damage models in different cases are discussed.

关键词： OPTICAL-PROPERTIES THIN-FILMS COATINGS

An Ultra-Broadband Spatially Dispersed Regenerative Amplifier Free from Spatial Chirp

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Chinese Physics Letters 2008年第6期25卷 2048-2050页

作者：李闯冷雨欣张春梅梁晓燕李儒新徐至展 State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800

An ultra-broadband Ti：sapphire regenerative amplifier based on spatially dispersed amplification is demonstrated experimentally. Departing from previous reports, a new design of the cavity gets the amplified pulse free from spatial chirp. Utilizing this new regenerative amplifier, chirped pulses with bandwidth （FWHM） of about 80 nm are obtained, and the bandwidth is limited only by that of the incident seed pulses.

关键词： supernova explosion proto-neutron star shock wave

On the optimization problem of model-based monitoring

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Science China(Technological Sciences) 2011年第5期54卷 1095-1106页

作者： L. GINZINGER M. N. SAHINKAYA B. HECKMANN P. KEOGH H. ULBRICH Department of Mechanical Engineering Faculty of Engineering and Design University of Bath institute of Applied mechanics Technische Universitt München

Today there is a big interest in reducing the maintenance costs and in increasing the reliability of machines in continuous operation. Therefore, maintenance on condition is used. State-of-the-art is a trend analysis and a fault prediction made only based on sensor signals and stochastic methods. The identification possibilities of this technique are limited. A new concept for model-based monitoring has been developed for more detailed fault identification. The developed concept determines the condition of a machine after the occurrence of a fault. The concept is based on a simulation including various faults and an optimization tool. The development of a cost function and the optimization is one of the challenges of such a concept. Using an AMB rotor system with an auxiliary bearing, the new concept of model-based monitoring is investigated using experiments and the optimization is discussed in this paper.

关键词：基于模型优化问题监测电磁轴承转子系统基础故障预报故障识别传感器信号