检索结果-内蒙古大学图书馆

Band Alignment and Band Gap Characterization of La2O3 Films on Si Substrates Grown by Radio Frequency Magnetron Sputtering

引用

Chinese Physics Letters 2014年第2期31卷 122-125页

作者：刘其娅方泽波冀婷刘士彦谭永胜谌家军朱燕艳 College of Physics and Electronic Information China West Normal University Nanchong 637002 Department of Physics Shaoxing University Shaoxing 312000 Key Laboratory of Advanced Transducers and Intelligent Control System College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan 030024

La2O3 films are grown on Si （100） substrates by the radio-frequency magnetron sputtering technique. The band alignment of the La203/Si heterojunction is analyzed by the x-ray photoelectron spectroscopy. The valence- band and the conduction-band offsets of La2 Oa films to Si substrates are found to be 2.40±0.1 and 1.66±0.3 eV, respectively. Based on 0 ls energy loss spectrum analysis, it can be noted that the energy gap of La203 films is 5.18±0.2eV, which is confirmed by the ultra-violet visible spectrum. According to the suitable band offset and large band gap, it can be concluded that La2O3 could be a promising candidate to act as high-k gate dielectrics.

关键词： LANTHANUM oxide ENERGY gaps (Physics) MAGNETRON sputtering METALLIC films SILICON SUBSTRATES (Materials science)

来源：评论

学校读者我要写书评

暂无评论

Optimal Design of High Power LED Lamp Heat Dissipation Based on Equivalent Thermal Circuit Method

Optimal Design of High Power LED Lamp Heat Dissipation Based...

引用

2015 5th International Conference on Computer Sciences and Automation Engineering(ICCSAE 2015)

作者： Feng Liang Lianyu Zhao Youjun Yue Zhuoyin Tong Lizhu Wang School of mechanical engineering Tianjin University of Technology Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System School of automation Tianjin University of Technology

Since the heat dissipation problemis harsh in high power LED lamp, in our studywe suggest an optimal design method of high-power LED lamps radiator based on the equivalent thermal circuit method, we abstract mathematical model of the heat dissipation system of the lamps, then chose several key parameters of radiator--spacing of fins S, height of fins H, thickness of fins t and number of Micro Heat Pipe ArrayN Has design parameters, and set minimum temperature of the chips as optimization objective. Based on the optimization algorithm we have mentioned, we designed a new radiator for high power LED lamps, through steady-heat-thermal analysis in ANSYS software, the junction temperature is far below the requirement. Therefore, the optimization algorithm can be effectively applied to radiator design of high power LED devices with the advantage of accuracy and swiftness.

关键词： optimal design micro heat pipe array high power LED lamp dissipation equivalent thermal circuit method

来源：评论

学校读者我要写书评

暂无评论

Dynamic analysis of a 3-DOF 3-PUU parallel manipulator based on the principle of virtual work

Dynamic analysis of a 3-DOF 3-PUU parallel manipulator based...

引用

IEEE/ASME (AIM) International Conference on advanced intelligent Mechatronics

作者： Song Lu Yangmin Li Department of Electromechanical Engineering University of Macau Macao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China

ISBN: (纸本)9781467391085

This paper presents a straightforward and systematical methodology for conducting the inverse dynamic analysis of a 3-prismatic-universal-universal (PUU) parallel kinematic manipulator (PKM) through employing the principle of virtual work. The proposed 3-PUU PKM possesses three translational degree-of-freedom (DOF). The position, velocity and acceleration of joints are solved via the inverse kinematic analysis, the link Jacobian matrices which map the velocity of the moving platform into the velocity and angular velocity of struts are derived in the fixed coordinate system. Based on the d'Alembert's form of the principle of virtual work, the applied generalized forces of the whole mechanical system are divided into the applied forces of moving platform, struts, sliders, and motor-coupling-leadscrew, respectively. The joint actuated torques are obtained through eliminating the virtual displacement in the dynamic equations. Furthermore, the inertial term, centrifugal and Coriolis term, and gravitational term of the total joint torque are determined. Simulation for a conical spiral trajectory demonstrates that the total torque is dominated by the inertial term.

关键词： Manipulator dynamics Joints Acceleration Dynamics Kinematics Mathematical model

来源：评论

学校读者我要写书评

暂无评论

Widely tunable chaotic fiber laser for WDM-PON detection

引用

Optoelectronics Letters 2014年第3期10卷 232-236页

作者：张娟杨玲珍徐乃军王娟芬张朝霞刘香莲 Institute of Optoelectronic Engineering College of Physics and OptoelectronicsTaiyuan University of Technology Key Lab of Advanced Transducers and Intelligent Control System Ministry of EducationTaiyuan University of Technology

A widely tunable high precision chaotic fiber laser is proposed and experimentally demonstrated.A tunable fiber Bragg grating(TFBG) filter is used as a tuning element to determine the turning range from 1533 nm to 1558 nm with a linewidth of 0.5 nm at any *** wide tuning range is capable of supporting 32 wavelength-division multiplexing(WDM) channels with 100 GHz channel *** single wavelengths are found to be chaotic with 10 GHz *** full width at half maximum(FWHM) of the chaotic correlation curve of the different wavelengths is on a picosecond time scale,thereby offering millimeter spatial resolution in WDM detection.

关键词： WDM-PON 光纤激光器可调谐检测光纤布喇格光栅混沌空间分辨率单波长

来源：评论

学校读者我要写书评

暂无评论

Design and analysis of a novel 3-D micromanipulator with large range of motion

Design and analysis of a novel 3-D micromanipulator with lar...

引用

IEEE/ASME (AIM) International Conference on advanced intelligent Mechatronics

作者： Zhigang Wu Yangmin Li Faculty of Science and Technology University of Macau Taipa Macao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China

ISBN: (纸本)9781467391085

A novel parallel micromanipulator with large range of motion based on flexible hinges is designed and analyzed in this paper, which has three degrees of freedom motions along x, y and z axes. The Pseudo-Rigid-Body (PRB) model method is applied to obtain the kinetic performance and inputting stiffness. To calculate the natural frequency of the mechanism, the Lagrange method is used to achieve the dynamic and frequency equations. In addition, the working range of the architecture is also calculated, analyzed and compared with other similar structures by using ANSYS software, our designed micromanipulator has larger workspace than other existed stages.

关键词： Mathematical model Micromanipulators Force Fasteners Springs Kinetic energy Computer architecture

来源：评论

学校读者我要写书评

暂无评论

synchronization of coupled reaction-diffusion neural networks with mixed delays

引用

Complexity 2016年第S2期21卷

作者： Ping He Yangmin Li Department of Electromechanical Engineering Faculty of Science and Technology University of Macau Taipa Macao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China

The reaction-diffusion neural network is often described by semilinear diffusion partial differential equation (PDE). This article focuses on the asymptotical synchronization and synchronization for coupled reaction-diffusion neural networks with mixed delays (that is, discrete and infinite distributed delays) and Dirichlet boundary condition. First, using the Lyapunov–Krasoviskii functional scheme, the sufficient condition is obtained for the asymptotical synchronization of coupled semilinear diffusion PDEs with mixed time-delays and this condition is represented by linear matrix inequalities (LMIs), which is easy to be solved. Then the robust synchronization is considered in temporal-spatial domain for the coupled semilinear diffusion PDEs with mixed delays and external disturbances. In terms of the technique of completing squares, the sufficient condition is obtained for the robust synchronization. Finally, a numerical example of coupled semilinear diffusion PDEs with mixed time-delays is given to illustrate the correctness of the obtained results. © 2016 Wiley Periodicals, Inc. Complexity 21: 42–53, 2016

关键词： asymptotical synchronization synchronization coupled reaction-diffusion neural networks linear matrix inequality (LMI) partial differential systems (PDSs) mixed delays

来源：评论

学校读者我要写书评

暂无评论

Passivity-based synchronization of a new hyperchaotic Lorenz system

Passivity-based synchronization of a new hyperchaotic Lorenz...

引用

IEEE Conference on Cybernetics and intelligent systems

作者： Ping He Yangmin Li Department of Electromechanical Engineering Avenida da Universidade Taipa Macao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China

ISBN: (纸本)9781467373395

In this paper, a passivity-based synchronization method is proposed for a new hyperchaotic Lorenz system based on Lyapunov stability theory and linear matrix inequality (LMI) approach. On the basis of the property of the passive system, the passive controller is designed and synchronization of two identical new hyperchaotic Lorenz systems with different initial conditions is realized. Finally, numerical simulations are presented to demonstrate the effectiveness of the proposed chaos control and synchronization schemes.

关键词： Synchronization control systems Lyapunov methods Complex networks Chaotic communication

来源：评论

学校读者我要写书评

暂无评论

Research of the crack propagation control in a nonlinear rotor

Research of the crack propagation control in a nonlinear rot...

引用

IEEE International Conference on Mechatronics and Automation

作者： Jun Liu Yong Fan Jianen Chen Xiaofeng Wang Hongbiao Xiang School of Mechanical Engineering Tianjin University of Technology Tianjin China Tianjin key laboratory of the Design and Intelligent control of the Advanced Mechanical system Tianjin University of Technology Tianjin China

ISBN: (纸本)9781479970995

Due to the continuing action of alternating loads, the micro defects of rotor's materials and the micro traumas in the mechanic processing will easily cause the crack propagation and even the catastrophic accidents. The vibration characteristics of the rotor system, the crack breathing states and the crack breathing periods are investigated with different parameters of the synchronous state through the numerical simulation, which are all based on the dynamic model of the nonlinear cracked rotor and the describing function of the breathing crack. The crack breathing states are also studied under the asynchronous state. The paper proposes a novel method of the delaying crack propagation using an Electro-Magnetic Actuator (EMA) in order to realize the vibration control and the delaying crack propagation. By comparing influences of the crack breathing state caused by changes of different parameters (rotational speed, crack angle, crack depth and nonlinear parameters, etc.), the paper summarizes the mutation regulations of the crack breathing state in the synchronous and verifies the feasibility of delaying the crack propagation mechanism. The result of the research shows that the EMA can control the vibration of the nonlinear cracked rotor and delay the crack propagation in the running process of the nonlinear cracked rotor.

关键词： Rotors Vibrations Mathematical model Numerical simulation Numerical models Vibration control Finite element analysis

来源：评论

学校读者我要写书评

暂无评论

Dynamic modeling for high-performance controller design of a UAV quadrotor

Dynamic modeling for high-performance controller design of a...

引用

International Conference on Information and Automation (ICIA)

作者： Yi-Rui Tang Yangmin Li Department of Electromechanical Engineering University of Macau Macao SAR China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China

ISBN: (纸本)9781467391054

This paper presents a systematic and comprehensive modeling approach for the derivation of a nonlinear dynamic model of a unmanned aerial vehicle (UAV) quadrotor. The model incorporates a couple of significant aerodynamic effects impacting on the quadrotor flight in different regimes. The controller is accordingly designed to accommodate both specific and uncertain dynamics of the quadrotor. The control laws of linear quadratic regulator (LQR) coupled with sliding mode control (SMC) are applied to the controller design so as to perform the optimal and robust control of the vehicle. The experimental results demonstrate the designed control algorithms are capable of delivering an remarkable performance on tracking of the reference input signals.

关键词： Rotors Blades Aerodynamics Mathematical model Vehicle dynamics Force Nonlinear dynamical systems

来源：评论

学校读者我要写书评

暂无评论

Characteristics of a piloted digital flow valve based on flow amplifier

Characteristics of a piloted digital flow valve based on flo...

引用

International Conference on Fluid Power and Mechatronics (FPM)

作者： Taotao Li Jiahai Huang Yanhong Bai Long Quan Shengguo Wang Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan Technology Center of Taiyuan Heavy Machinery Group Yuci Hydraulic Industry Shanxi China Taiyuan University of Technology Taiyuan Shanxi CN University of Technology Shanxi China

ISBN: (纸本)9781479987719

Hydraulic switching techniques which have less throttling losses, good repeatability and can be controlled intelligently have been largely developed. The biggest challenge is the hydraulic fluctuation. It is generated in the process of opening and closing the valve. A two-stage digital flow valve operated by Pulse Width Modulation (PWM) signal is studied in this paper. The main stage is cartridge valve based on flow amplifying principle; the pilot stage is high-speed on/off valve. The fluctuation characteristic of the digital flow valve is investigated using theoretical derivation and simulation analysis. The results show that the outlet flow fluctuation is influenced by many parameters such as the frequency and duty ratio of PWM signal, the volume of control chamber, etc. It can be weakened through the proper design of these parameters. Although the fluctuation exists, the mean outlet flow can be proportionally controlled by adjustment of the duty ratio of the control signal.

关键词： Valves Fluctuations Switches Frequency control Pulse width modulation Fluids

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：