检索结果-内蒙古大学图书馆

A method of line spectrum extraction based on target radiated spectrum feature and its post-processing

Journal of Systems Engineering and Electronics 2021年第6期32卷 1381-1393页

作者： DAI Wenshu ZHENG Enming BAO Kaikai Key Laboratory of Instrumentation Science&Dynamic Measurement North University of ChinaTaiyuan 030006China Institute of Acoustics Chinese Academy of SciencesBeijing 100190China Northern Institute of Automatic Control Technology Taiyuan 030051China

To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum that the high intense and stable line spectrum is superimposed on the wide continuous *** method modifies the traditional beam forming algorithm by calculating and fusing the beam forming results at multi-frequency band and multi-azimuth interval,showing an excellent way to extract the line spectrum when the interference and the target are not in the same azimuth interval *** efficiency of the estimated azimuth variance and corresponding power of the line spectrum band depends on the line spectra ratio(LSR)of the line *** change laws of the output signal to noise ratio(SNR)with the LSR,the input SNR,the integration time and the filtering bandwidth of different algorithms bring the selection principle of the critical *** the basis,the detection gain of wideband energy integration and the narrowband line spectrum algorithm are theoretically *** simulation detection gain demonstrates a good match with the theoretical *** application conditions of all methods are verified by the receiver operating characteristic(ROC)curve and experimental data from Qiandao *** fact,combining the two methods for target detection reduces the missed detection *** proposed post-processing method in2-dimension with the Kalman filter in the time dimension and the background equalization algorithm in the azimuth dimension makes use of the strong correlation between adjacent frames,could further remove background fluctuation and improve the display effect.

关键词： towed linear array sonar target radiated noise spectrum line spectra level ratio(LSR) receiver operating characteristic(ROC)curve post-processing

来源：评论

学校读者我要写书评

暂无评论

High-speed Target Recognition Algorithm and Simulation

High-speed Target Recognition Algorithm and Simulation

引用

International Conference on Industrial technology and Management science(ITMS 2015)

作者： Shuai Duan Jiahao Deng School of Mechatronical Engineering Beijing Institute of Technology Science and Technology on Electromechanical Dynamic Control Laboratory

The purpose of this paper is devoted to finding a method to recognize the high-speed target for missile in a certain distance. Based on the quasi-electrostatic field characteristics of the capacitance detector, this paper analyzed the output voltage of detection circuit from a capacitance detector. It can be found that, when a high-speed target getting close to the detector, the output voltage of detection circuit changes with certain rules. Our research applied a low-speed static test to obtain the static characteristic data of the target, proposed a high-speed target recognition algorithm and set threshold values based on starting voltage, second derivative and signal duration. The result showed that the algorithm is effective to recognize high-speed missile target.

关键词： quasi-electrostatic field high-speed target recognition capacitance detector algorithm

来源：评论

学校读者我要写书评

暂无评论

Sizing design and simulation of An SOFC propulsion system for unmanned aerial vehicles 17

Sizing design and simulation of An SOFC propulsion system fo...

引用

17th International Symposium on Solid Oxide Fuel Cells, SOFC 2021

作者： Tong, X. Wang, Y. Shi, Y. National Key Laboratory on Electromechanical Dynamic Control Beijing Institute of Technology Beijing100081 China Department of Energy and Power Engineering Tsinghua University Beijing100084 China

ISBN: (纸本)9781607685395

The short flight endurance is one of the key obstacles for the application of unmanned aerial vehicles (UAVs). Applying the fuel cells as the propulsion system of UAVs instead of batteries can increase the energy density and further lead to a longer cruise duration. Compared to other kinds of fuel cells, the solid oxide fuel cell (SOFC) is advantageous for its ability to use hydrocarbon fuels with a much higher energy storage density than hydrogen. In this paper, a SOFC propulsion system is sized and designed for UAV applications. The power allocation between the SOFC and energy storage components was further studied. A system model was developed, including an SOFC stack, a catalytic partial oxidation (CPOx) reformer, an after burner, and heat exchangers, etc. The design parameters of the SOFC stack and other components were selected to meet the power and energy demand of the UAV. The model is proved to be a useful tool for the design and simulation of the UAV-SOFC systems. © 2021 Electrochemical Society Inc.. All rights reserved.

关键词： Unmanned aerial vehicles (UAV)

来源：评论

学校读者我要写书评

暂无评论

A New Design Using a Metal Wire Brush as the Current Collector of Micro-Tubular SOFCs 17

A New Design Using a Metal Wire Brush as the Current Collect...

引用

17th International Symposium on Solid Oxide Fuel Cells, SOFC 2021

作者： Shi, J. Fan, J. Wang, Y. Shi, Y. Cai, N. Department of Energy and Power Engineering Tsinghua University Beijing100084 China National Key Laboratory on Electromechanical Dynamic Control Beijing Institute of Technology Beijing100084 China

ISBN: (纸本)9781607685395

In this study, a novel current collecting method was designed and demonstrated by inserting a metal wire brush into the anode supported micro-tubular SOFC. The new design enables a tight and stable contact between the wire and the inner wall of the anode which leads to a fine performance of the SOFC. Different kinds of metal wires were applied, where the copper wire brush (CZWB) shows a better performance than the stainless steel wire brush (SSWB). At a temperature of 700 and a fuel feed of hydrogen, the SOFC using CZWB can achieve a maximum power density of 290 mW/cm2 and an ohmic resistance of 0.66 Ωcm2. And the brush size has been approved to have little effect on the ohmic resistance. A 108 h long-time discharge test was carried on, resulting with a degradation rate of 1.728‰/h and indicating a relative stability. © 2021 Electrochemical Society Inc.. All rights reserved.

关键词： Solid oxide fuel cells (SOFC)

来源：评论

学校读者我要写书评

暂无评论

Design, Simulation and Fabrication of a Time-Delay Device Based on Micro-Channel

Design, Simulation and Fabrication of a Time-Delay Device Ba...

引用

第二届先进电子材料、计算机与材料工程国际学术会议（AEMCME 2019）

作者： Qiaoran Zhao Li Sui Ping Song School of Mechatronical Engineering Beijing Institute of Technology Science and Technology on Electromechanical Dynamic Control Laboratory

With the development of micro-machining technology, the application of microchannel is becoming more and more popular. In this paper, we design a set of time-delay device based on micro-channel and micro-fluidics technology. This paper describes the timedelay device's working principle and analyses the micro-channel's flow characteristics by simulation method based on Coventerware. From studies on the micro-channel's cross section, geometry and dimension parameters, the micro-channel's optimal form and dimension can be obtained. Finally, this paper chooses ultra-machining process to fabricate the time-delay device.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Dual-Band Flexible Terahertz Sensor Based on Rotated Metamaterial Structure

Dual-Band Flexible Terahertz Sensor Based on Rotated Metamat...

引用

2023 IEEE MTT-S International Wireless Symposium, IWS 2023

作者： Wang, Dongxu Xu, Kai-Da School of Information and Communications Engineering Xi'an Jiaotong University Xi'an China Science and Technology on Electromechanical Dynamic Control Laboratory Xi'an China East China Normal University State Key Laboratory of Precision Spectroscopy Shanghai200241 China

ISBN: (纸本)9798350336535

In this article, a terahertz flexible metamaterial sensor with dual-band operating characteristics is introduced. The gold metamaterial array is arranged on the top surface of a polyimide film, while the structure is made up of a rotated structure with spiral-shaped strips. Two resonances occur at 0.37 and 1.13 THz with outstanding polarization insensitivity. The metamaterial sensor also has sensitive refractive index sensing properties, with sensitivities of 0.1 THz/RIU and 0.3 THz/RIU, respectively, at the two operating bands. This work shows potential applications in refractive index and nesticide sensing. © 2023 IEEE.

关键词： Metamaterials

来源：评论

学校读者我要写书评

暂无评论

Numerical model of direct internal reforming SOFC: A Comparison between Anode-support and Metal-support 16

Numerical model of direct internal reforming SOFC: A Compari...

引用

16th International Symposium on Solid Oxide Fuel Cells, SOFC 2019

作者： Wang, Y. Ren, J. Shi, Y. Li, X. National Key Laboratory on Electromechanical Dynamic Control Beijing Institute of Technology Beijing100081 China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power Engineering Tsinghua University Beijing100084 China

ISBN: (纸本)9781607688747

Direct internal reforming (DIR) operation provides many benefits for solid oxide fuel cells (SOFCs) by eliminating the need for an extra reformer. Anode-supported SOFCs (AS-SOFCs) are commonly used for DIR operations. However, the strong endothermic reforming reactions at the cell entrance may result in large thermal stresses and lead to premature failure. In this study, a two-dimensional model was developed to analyze the differences between the AS-SOFC and the new generation metal-supported SOFC (MS-SOFC) in DIR operations. The model considered the coupling effects of the chemical/electrochemical reactions, the mass/charge/heat transport processes and the thermal mechanical stress. The distributions of temperature, species composition, current density and thermal stress were determined and compared for both structures. The failure probability of the cell was estimated by stress distributions. The results showed that the MS-SOFC led to a gentler temperature distribution and a smaller failure probability with slight performance increase compared to the AS-SOFC. © The Electrochemical Society.

关键词： Solid oxide fuel cells (SOFC)

来源：评论

学校读者我要写书评

暂无评论

Refined modeling and experimental verification of a torque motor for an electro-hydraulic servo valve

引用

Chinese Journal of Aeronautics 2023年第6期36卷 302-317页

作者： Zhichuang CHEN Shenghong GE Yulei JIANG Wenhao CHENG Yuchuan ZHU National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing Engineering Institute of Aircraft SystemsNanjing 210061China AVIC Nanjing Servo Control System Co. LtdNanjing 210032China

The Permanent Magnet Torque Motor(PMTM)is the key electro-mechanical conversion device in an Electro-Hydraulic Servo Valve(EHSV).In this work,a refined model of a PMTM is developed,considering the non-working air-gaps between the upper or lower yoke and the armature,the fringing effect at the limiting holes,and the nonlinear permeability of soft magnetic *** on the refined model,the influences of various factors on the calculation accuracy of the magnetic flux at the pole surfaces of the armature and the output torque are *** verifying the validity of the refined model,a Finite Element Analysis(FEA)of the PMTM is conducted,and a test platform is *** with existing models,the refined model can better reveal the intrinsic mechanism of the PMTM,and its calculations are more consistent with the FEA *** experimental results of the armature deflection displacement show that the refined model can accurately describe the output characteristics of the PMTM.

关键词： Calculation accuracy Electro-hydraulic servo valve Experimental verification Finite element analysis Refined model Torque motor

来源：评论

学校读者我要写书评

暂无评论

Radio Fuse Echo CEM Model Based on PO-MoM Algorithm

Radio Fuse Echo CEM Model Based on PO-MoM Algorithm

引用

International Symposium on Antennas Propagation and EM Theory

作者： Bo Tian Dong Cui Yu Yu Tie Li NO.3 R & D department Science and Technology on Electromechanical Dynamic Control Laboratory

ISBN: (纸本)9781467317993

For the difficulty and low efficiency in calculating the radio fuze echo of complex target with traditional method, the PO-MOM Hybrid computation methodology is introduced to the traditional radio near-field fuze echo computing model. The established model can approximately calculate and quickly access target near-field equivalent RCS with the PO-MOM hybrid algorithm. When combined with the radar equation, the engineering CEM model of target terminal ballistics radio fuze echo signal can be achieved. The result of model validation shows that: the model has a high calculating speed, and the error is less than 25%, so this model can be used in quick simulation of radio fuze echo signal.

关键词： Echoes Radio Model checking Fuses

来源：评论

学校读者我要写书评

暂无评论

Elementary reaction kinetic model of an anode-supported syngas fueled solid oxide fuel cell considering the carbon deposition effect 17

Elementary reaction kinetic model of an anode-supported syng...

引用

17th International Symposium on Solid Oxide Fuel Cells, SOFC 2021

作者： Zhang, R. Wang, Y. Shi, Y. Wang, Y. Cao, H. National Key Laboratory on Electromechanical Dynamic Control Beijing Institute of Technology Beijing100081 China Department of Energy and Power Engineering Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Tsinghua University Beijing100084 China

ISBN: (纸本)9781607685395

A one-dimensional transient elementary reaction kinetic model of an anode supported solid oxide fuel cell (SOFC) fueled with syngas is developed considering the carbon deposition effect. This model incorporates the coupling effect of heterogeneous elementary chemical and electrochemical reactions, the electrode microstructure and the charge and mass transport processes. The model is validated by both experimental I-V curves and electrochemical impedance spectra. The simulation results agree reasonably well with the experimental data. The numerical results of carbon deposition simulation indicate that the surface carbon coverage can be decreased by increasing the operating temperature and reducing the carbon dioxide, methane or carbon monoxide in the fuel. © 2021 Electrochemical Society Inc.. All rights reserved.

关键词： Carbon monoxide

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：