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NUMERICAL SIMULATON OF IMPROVED BOUSSINESQ EQUATIONS BY A FINITE ELEMENT METHOD

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Journal of Hydrodynamics 2003年第4期15卷 31-40页

作者： Zhao Ming, Teng Bin, Liu Shu-xue state key {2. of Coastal and Offshore Engineering, Dalian university of technology, Dalian 11602., china Lab. of Coastal and Offshore Eng. Dalian Univ. of Technol. Dalian 116024 China

The improved Boussinesq equations for varying depth derived by Beji andNadaoka significantly improved the linear dispersive properties of wave models in intermediate waterdepths. In this study, a finite element method was developed to solve the improved Boussinesqequations. A spongy layer was applied at the open boundary of the computational domain to absorb thewave energy. The fourth-order predictor-corrector method was employed in the time *** test cases were illustrated. The numerical results of this model were compared withlaboratory data and those from other numerical models. It turns out that the present numerical modelis capable of giving satisactory prediction for wave propagation.

关键词： boussinesq equations finite element method numerical simulation

Eliminate indeterminacies of independent component analysis for chemometrics

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Progress in Natural Science:Materials International 2008年第8期18卷 1009-1014页

作者： Zhixiang Yao a,b, Kai Zhang c,*, Huanbin Liu b, Hui Su a a Department of Biological and Chemical Engineering, Guangxi university of technology, Liuzhou 545006, {2. b state key laboratory of Pulp and Paper-making Engineering, South {2. university of technology, Guangzhou 510640, {2. c state key laboratory of Heavy Oil Processing, {2. university of Petroleum, Beijing 102.49, {2. Department of Biological and Chemical Engineering Guangxi University of Technology Liuzhou 545006 China state key {2. of Pulp and Paper-making Engineering South China University of Technology Guangzhou 510640 China state key {2. of Heavy Oil Processing China University of Petroleum Beijing 102249 China

An improved method has been proposed to eliminate the indeterminacies of independent component analysis (ICA) for chemometrics. Following the arrangement of principal components analysis (PCA), the ICA mixing matrix is selected as signal content indexes, and ICA output are sorted and directed. After many times reputations, independent components (ICs) are paired according to the maximum correlation coefficient, and then the mean values of each IC substitutes the original ICs. This indicates that the ICA indeterminacies are eliminated. A simulation example is tested to validate this improvement. Finally, a set of experimental LC-MS data is processed without any prior knowledge or specific limitation and the results show that the improved ICA can directly separate the mixed signals in chemometrics, and it is simpler and more reasonable than the simple to use interactive self-modeling mixture analysis (SIMPLISMA).

关键词： Independent component analysis Indeterminacy in ICA Chemometrics

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低刚度铣削工艺系统的弹性铣削力建模方法

天津大学学报 2010年第2期43卷 143-148页

作者：戚厚军张大卫蔡玉俊沈煜天津大学机械工程学院天津300072 天津工程师范学院天津市高速切削与精密加工重点实验室天津300222

为了提高高速加工过程中薄壁结构件的加工精度,针对低刚度工艺系统的形变特点,建立了低刚度铣削工艺系统的弹性铣削力模型.该模型中基于弯扭剪耦合弹性力学理论,推导出了工件弹性铣削形变的解析式;并考虑到工件和铣刀的弹性形变共同引... 详细信息

为了提高高速加工过程中薄壁结构件的加工精度,针对低刚度工艺系统的形变特点,建立了低刚度铣削工艺系统的弹性铣削力模型.该模型中基于弯扭剪耦合弹性力学理论,推导出了工件弹性铣削形变的解析式;并考虑到工件和铣刀的弹性形变共同引起铣削啮合角的变化,推导出啮合角的表达式.通过铣削力和铣削变形仿真以及铣削试验验证得知:铣削力与工件的铣削形变密切相关,工件的法向铣削分力是引起工件形变的主要因素.最后,经铣削力试验验证了实测结果和仿真结果具有较好的一致性.

关键词：弹性铣削力低刚度工件形变预测弯扭耦合铣削加工

Networked Kalman filtering with combined constraints of bandwidth and random delay

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Science china(Information Sciences) 2012年第10期55卷 2343-2357页

作者： GE QuanBo 1,2.WEN ChengLin 1 & XU TingLiang 1 1 School of Automation,Hangzhou Dianzi university,Hangzhou 310018,china 2.{2. key laboratory of Industrial Control technology,Zhejiang university,Hangzhou 31002.,china 1. School of Automation Hangzhou Dianzi University Hangzhou 310018 China2. State Key Laboratory of Industrial Control Technology Zhejiang University Hangzhou 310027 China

Kalman filter is a powerful tool in target tracking and self-localization across wireless sensor networks with many *** paper considers the filters design for networked systems with combined constraints of bandwidth and random delay,and proposes a kind of universal networked Kalman estimator for given linear time invariant(LTI) or determinate parameters(DP) systems,which are also called linear and determinate parameters(LDP) systems ***,two modeling ways to treat bit quantization error vector are given and the corresponding LDP systems taken after bit quantization are ***,we introduce an equivalent weighted summation form of the conventional linear Kalman filter,which fully uses two essential characteristics,namely offline computation property from the LDP systems and linear weighted summation property from the linear minimum mean square error ***,by adopting the replacement and innovation compensation operations,a kind of integrated networked estimator,involving two estimation algorithms with different modeling ways to bit quantization error actually,is presented based on the weighted summation filter for random delay *** proposed universal networked estimation algorithms have some outstanding advantages such as extensive application,concise algorithm structure,high estimate accuracy,and good running *** examples are demonstrated to validate the proposed networked estimation algorithms.

关键词： Kalman filter LDP systems LMMSE limited bandwidth random delay

DIELECTRIC PROPERTIES OF ZNTIO_3 MICROWAVE CERAMICS CONSOLIDATED WITH MGTIO_3

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Transactions of tianjin university 2006年第1期12卷 28-32页

作者：吴霞宛王玉梅肖谧 key laboratory OF ADVANCED CERAMICS AND MACHINING {2. OF EDUCATION MINISTRY SCHOOL OF ELECTRONIC INFORMATION ENGINEERING TIANJIN UNIVERSITYTIANJIN 300072CHINA

Stabilized ZnTiO4 was prepared by doping magnesium oxide through traditional solid state reaction. The experimental results indicate that zinc titanate crystals doped with magnesium oxide grow well and the decomposition into Zn2.iO4 and TiO2.is restrained through traditional solid state reaction, By adjusting molar ratio of MgO, better properties can be obtained The dielectric properties of the ceramics doped with 30% MgO（ molar percentage） sintered at 1060℃ are as follows：the value of quality factor is greater than 2.000（6.5 GHz ）, the temperature coefficient of resonance frequency is about 2.± 10^-6 /℃,the dielectric constant ranges from 180 to ***,it is proved that heat treatment can optimize microstructure and the value of quality factor, which increases from 2.833.93 to 47584.00 after 2. of heat treatment at 1040℃.

关键词： microwave ceramics magnesium titanate heat treatment quality factor

Performance Optimization of Dispersion-Managed WDM Systems Based on Four-Wave Mixing

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光学学报 2003年第S1期23卷 39-40页

作者： Shiming Gao Changxi Yang Guofan Jinstate key {2. of precision Measurement technology and instruments, Tsinghua university, Beijing 100084, P. R. china, state key {2. of precision Measurement technology and instruments Tsinghua University Beijing 100084 P. R. China

We systemically investigate the interchannel four-wave mixing (FWM) in dispersion-managed WDM systems with arbitrary launch position. We optimize the number of fiber sections, and the dispersion ratio for the system p... 详细信息

关键词： WDM as FWM Performance Optimization of Dispersion-Managed WDM Systems Based on Four-Wave Mixing of Four Wave on

A Novel Uniplanar Multi-Electrode Capacitive Sensor for In-Situ Weathering Damage Detection of Nonmetallic Materials

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稀有金属材料与工程 2006年第S3期 630-633页

作者： Ensheng Dong~(1,2. Yonggui Dong~1 Wener Lv~1 Huibo Jia~1 Jun Li~2.(1.state key {2. of precision Measurement technology and instruments,Dept.of precision instruments and Mechanology,Tsinghua university,Beijing 100084,china) (2.Dept.of Aviation Control and Engineering,Aviation university of Air Force,Changchun 13002.,china)

A uniplanar capacitive sensor with 5-electrodes on one plane substrate and a large reflector electrode,was designed to get the corresponding capacitance information for weathering damage detection of non-metallic materials exposed to a service environment.A 2.D finite-element method was employed to simulate the electric potential distribution and capacitance measurements for the sensor.2.marble slabs,one was healthy and the other was notched,were experimentally *** the simulation and the preliminary experimental results show that the measured capacitances decrease after weathering damage occurs in nonmetallic *** reflector can enlarge the sensitive *** weathering assessment of nonmetallic materials can be done by processing the measured *** proposed approach can effectively detect the weathering damage of nonmetallic material and can be practically used for in-situ weathering damage evaluation.

关键词： capacitive sensor weathering damage detection reflector electrode non-metallic materials

Investigation of Al-based Alloys for Brazing SiC_p/Al Composites

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稀有金属材料与工程 2011年第S3期40卷 132-135页

作者： Wu Mao1,2. Chang Lingling2. Peng Zirong2. Feng Zelong2. Yong Weina2. Wang Wei2. He Xinbo1,2. Qu Xuanhui1,2.1state key {2. for Advanced Metals and Materials, university of Science and technology Beijing 100083, china 2.Beijing key {2. for Powder Metallurgy and Particulate Materials, university of Science and technology Beijing, Beijing 100083, china Univ Sci & Technol Beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China Univ Sci & Technol Beijing Beijing Key Lab Powder Met & Particulate Mat Beijing 100083 Peoples R China

The brazing of SiCp/Al composites is limited owing to the unavailability of suitable commercial intermediate temperature brazes. Adding a third constituent of copper to aluminum-silicon brazing alloy can depress the melting point sharply. While, it generates a large volume fraction of the hard Al2.u intermetallic compounds (IMCs), which makes the alloy brittle and reduces its corrosion resistance. A quaternary addition of nickel that partly substitute for copper can refine grain size significantly, improve the mechanical properties, and without altering the melting range of aluminum-silicon-copper alloy. Al-Cu-Ni-Si braze alloy has been prepared and a fluxless process has been employed to braze SiCp/Al composites that leads to a good bonding strength of brazing joint.

关键词： SiCp/Al composites Al-based brazes brazing intermetallic compounds (IMCs)

Statistics and Its Applications in Identification of Irregular Particles

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Semiconductor Photonics and technology 2001年第3期7卷 183-188页

作者： ZENG Zhou mo, ZHANG Zhi rong, LU Hong bo, PAN Yin sheng (state key Lab. of {2. Measurement technology and instruments, tianjin university, tianjin 300072, CHN) 天津大学精密测试技术及仪器国家重点实验室天津 300072

Phase Doppler anemometry(PDA) is very sensitive to the shape of testing particles, which is based on sphericity assumption and Mie’s theory. In practice, there exists effectiveness of non sphericity and the response of PDA system deviates from the theoretical prediction. In this paper, the statistic characteristics of PDA signal are analyzed and a method of identifying and quantifying irregular particles is proposed. It is concluded that phase difference of PDA signal for irregular particles is an unbiased estimation for spherical particles.

关键词： Statistic analysis Fuzzy pattern recognition Particle measurement Phase Doppler anemometry