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三维水动力学模型高精度差分格式和解法研究

天津大学学报（自然科学与工程技术版） 2003年第5期36卷 590-594页

作者：谢伟松陶建华天津大学理学院天津300072 天津大学机械工程学院天津300072

采用高精度差分格式对三维水动力学问题的时均化Navier Stokes方程进行了数值模拟,进而采用广义共轭剩余法(GCR方法)求解压力泊松方程,并采用显式三级二阶Runge Kutta格式模拟了时间步进过程.傅立叶分析表明,文中所采用的三阶迎风紧致... 详细信息

采用高精度差分格式对三维水动力学问题的时均化Navier Stokes方程进行了数值模拟,进而采用广义共轭剩余法(GCR方法)求解压力泊松方程,并采用显式三级二阶Runge Kutta格式模拟了时间步进过程.傅立叶分析表明,文中所采用的三阶迎风紧致差分格式具有较高的精度.数值实验进一步验证了上述数值模型的准确性和有效性.

关键词：三维水动力学模型高精度差分格式时均化Navier-Stokes方程数值模拟广义共轭剩余法

Adaptive Neural-Network Tracking Stabilization for Switched Nonlinear Systems with Disturbances

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Adaptive Neural-Network Tracking Stabilization for Switched ...

2011 Chinese Control and Decision Conference（CCDC）

作者： Lei Yu is with the school of mechanical and electrical engineering,Soochow university,Suzhou,215021,china,and with the school of Automation,Southeast university,Nanjing,210096,china.Shumin Fei is with the school of Automation,Southeast university,Nanjing,210096,china.

In this paper,the robust adaptive tracking stabilization problem in the sense of uniformly ultimate boundedness （UUB） for a class of switched nonlinear systems with external disturbances is *** neural networks （NNs） are used to approximate unknown functions for solving the restraints of feedback linearizable *** weights of RBF NNs updated laws and switching signals have been derived to make the closed loop system Lyapunov stable.A robust H∞ controller is designed to enhance robustness due to the existence of the compound disturbance which consists of approximation errors of the neural networks and external *** proposed control scheme can guarantee asymptotical stability and disturbance attenuation performance of tracking error for switched nonlinear systems under all admissible switching ***,we give a simulation example to illustrate the effectiveness of the proposed control scheme.

关键词： RBF neutral networks H∞ control Asymptotical stability Disturbance attenuation

Output-Feedback Stabilization for More General Stochastic High-Order Nonlinear Systems

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Output-Feedback Stabilization for More General Stochastic Hi...

2010 Chinese Control and Decision Conference

作者： Xue-Jun xie~1,Liang Liu~2 1.school of electrical engineering & Automation,xuzhou Normal university,xuzhou,Jiangsu Province,221116,china 2.Institute of Automation,Qufu Normal university,Qufu 273165,china

This paper investigates the problem of output-feedback control for a class of more general stochastic high-order nonlinear systems,which power is a ratio of odd *** extending the adding a power integrator technique,introducing a new rescaling transformation,and choosing an appropriate Lyapunov function,an output-feedback controller is constructed to render the closed-loop system globally asymptotically stable in probability and the output can be regulated to the origin almost surely.A simulation example is provided to show the effectiveness of the design.

关键词： Stochastic high-order nonlinear systems a ratio of odd integers power output-feedback control

THE RESEARCH ON MATERIAL SELECTION AND STRAIN ANALYSIS OF VEHICLE COMPLICATED DEFORMABLE PARTS WITH ASAME

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THE RESEARCH ON MATERIAL SELECTION AND STRAIN ANALYSIS OF VE...

2006年中国机械工程学会年会暨中国工程院机械与运载工程学部首届年会

作者： LI Xincheng*, CAI Shougui, ZHU Weixing, WANG Yun*, ZHAO Liangyi* *school of mechanical engineering, Jiangsu university, Zhenjiang 212013, china school of material engineering, Jiangsu university, Zhenjiang 212013, china school of electrical and information engineering, Jiangsu university, Zhenjing 212013,china

Vehicle complicated deformable parts are formed using stamping. When stamping is applied, the deforming size and selected material of plate affect greatly the up to grade rate of pressing parts. The s

关键词： Complicated deformable part automated strain analysis and measure environment (ASAME) forming limit diagram (FLD) forming performance forecasting of selecting materials.

Finite element analysis of the connecting zone of spherical head and cylinder of a biomass pyrolysis reactor

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Finite element analysis of the connecting zone of spherical ...

第五届中美化学工程学术会议

作者： Qingruo xie~(1,2),Huqi Wang~2,Zhangfa Tong~1 1 school of Chemistry and Chemical engineering,Guangxi university, Nanning,china 2 Department of mechanical engineering,Guangxi university of technology,Liuzhou,china

＜正＞The study on the biomass pyrolysis reactor configuration is of rapidly growing interest in china at *** is important to regard that pyrolysis need an effective device with the stable and safe *** stresses of the connecting zone of head and cylinder are analyzed using finite element method （FEM） based on the safety assessment,and the vessel head and the flange are designed for installing *** important positions are investigated by FEM in the connecting zone including the vessel head,the flange and the screw bolt.

关键词：

Topological Confinement in Reversibly Interlocked Polymer Networks

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Chinese Journal of Polymer Science 2024年第2期42卷 133-140,I0004页

作者： Wan-Ting Dai Zhen-Hua xie Yu-Bin Ke Yang You Min-Zhi Rong Ming-Qiu Zhang Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education GD HPPC LabIGCMESchool of ChemistrySun Yat-sen UniversityGuangzhou510275China Spallation Neutron Source Science Center China Spallation Neutron SourceDongguan523803China Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China College of Materials and Metallurgy Guizhou UniversityGuiyang550025China

Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-networks, although the direct evidence for the deduction is still lacking. Herein, a specially-designed RILNs system, in which the inter-component hydrogen bonds can be shielded as needed, was prepared and used to study the micro-structures of RILNs, aiming to verify the existence of mechanical interlocking in RILNs. By changing the pH of the swelling solvent, the effect exerted by the inter-component non-covalent bonds was eliminated, so detailed information of the networks structure was exposed. The small angle X-ray scattering(SAXS) and small-angle neutron scattering(SANS) results indicated that swelling-induced structural evolution of the two sub-networks mutually affected each other, even when the inter-component hydrogen bonds were absent, proving the presence of topological interlocking. The findings may help to draw a more accurate physical image and reveal the detailed structureproperty relationship of RILNs.

关键词： Reversibly interlocked polymer networks Small angle X-ray scattering Small-angle neutron scattering Topological confinement

A resonant high-pressure microsensor based on a composite pressure-sensitive mechanism of diaphragm bending and volume compression

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Microsystems & Nanoengineering 2024年第2期10卷 57-66页

作者： Pan Qian Zongze Yu Jie Yu Yulan Lu Bo xie Jian Chen Deyong Chen Junbo Wang The State Key Laboratory of Transducer technology Aerospace Information Research InstituteChinese Academy of SciencesBeijing100190China The school of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijing100049China

In this paper,a composite pressure-sensitive mechanism combining diaphragm bending and volume compression was developed for resonant pressure microsensors to achieve high-pressure measurements with excellent *** composite mechanism was explained,and the sensor structure was designed based on theoretical analysis and finite element *** all-silicon resonant high-pressure microsensor with multiple miniaturized cavities and dual resonators was developed,where dual resonators positioned in two resonant cavities with suitably different widths are used to perform opposite characteristics in pressure and the same characteristics at different temperatures,which can improve pressure sensitivities and realize temperature self-compensation by differential frequency *** microsensor was fabricated by microfabrication,and the experimental results showed that the sensor had an accuracy of±0.015%full scale(FS)in a pressure range of 0.1~100 MPa and a temperature range of−10~50℃.The pressure sensitivity of the differential frequency was 261.10 Hz/MPa(~2523 ppm/MPa)at a temperature of 20℃,and the temperature sensitivities of the dual resonators were−1.54 Hz/℃(~−14.5 ppm/℃)and−1.57 Hz/℃(~−15.6 ppm/℃)at a pressure of 2 *** differential output had an outstanding stability within±0.02 Hz under constant temperature and ***,this research provides a convenient solution for high-pressure measurements because of its advantages,namely,large range,excellent accuracy and stability.

关键词： stability resonant bending

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结构声辐射的虚边界元最小二乘法及仿真研究

系统仿真学报 2004年第10期16卷 2169-2171页

作者：崔喆黄协清西安交通大学机械工程学院振动与噪声控制工程研究所西安710049

提出用虚边界元最小二乘法研究结构体声辐射,推导了该方法计算振动结构辐射声场的计算公式,与常规边界元法相比,虚边界元最小二乘法避免了奇异积分的数值处理,且系数矩阵是对称的,通过仿真计算与解析解验证。结果表明,本文方法思想简单... 详细信息

提出用虚边界元最小二乘法研究结构体声辐射,推导了该方法计算振动结构辐射声场的计算公式,与常规边界元法相比,虚边界元最小二乘法避免了奇异积分的数值处理,且系数矩阵是对称的,通过仿真计算与解析解验证。结果表明,本文方法思想简单,程序处理容易,能够有效克服特征频率处解的非唯一问题,在边界附近解的精度较高等优点,便于工程应用。

关键词：虚边界元最小二乘法声辐射边界元

Microstructures and mechanical properties of a commercial Mg-Al-Zn-Mn alloy with various hot-extrusion processes

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Rare Metals 2024年第3期43卷 1329-1336页

作者： He Ma Fan-Zhi Meng Qiang Yang Ze-Feng xie Yuan-Ding Huang Xin Qiu State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China school of Materials Science and engineering Changchun University of Science and TechnologyChangchun130022China MagIC-Magnesium Innovation Center Helmholtz-Zentrum Geesthacht21502GeesthachtGermany engineering Research Center of Optoelectronic Functional Materials Ministry of EducationChangchun University of Science and TechnologyChangchun130022China

Mg-Al-Zn-Mn(AZ)system alloys have become widely used due to their good castability,excellent formability and outstanding corrosion resistance[1-6].However,their strength is still much lower than that of traditional Mg... 详细信息

关键词： alloys alloy corrosion