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A simple solution route to control synthesis of Fe_3O_4 nanomaterials at low temperature and their magnetic properties

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science china Chemistry 2009年第7期52卷 916-923页

作者： LIU Yi1,2, CHEN Yun1, ZENG YuPing2 & WANG ShiLong3 1 department of Chemistry and Chemical engineering, Zaozhuang University, Zaozhuang 277160, china 2 Shanghai institute of Ceramics, Chinese Academy of sciences, Shanghai 200050, china 3 School of Life science and technology, Tongji University, Shanghai 200092, china 1. department of Chemistry and Chemical engineering Zaozhuang University Zaozhuang 277160 China 2. Shanghai institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China 3. School of Life science and technology Tongji University Shanghai 200092 China

A series of nanostructured iron compounds including cubic Fe3O4 and orthorhombic FeOOH were synthesized via a facile low temperature (in the range of 60-100℃) solution method. In the whole process, the interaction between FeCl2·4H2O and methenamine (C6H12N4) was carried out through a reflux device under different reaction conditions such as temperature, solvent, and duration. The samples were detected by XRD, TEM, SAED, physical property measurement system, and Mssbauer spectroscopy, separately. The experiments showed that magnetic mixture nanoparticles had flake and rod morphologies, and cubic Fe3O4 took on grain nanostructure. Magnetism measurements indicated that the saturated magnetization of the as-obtained magnetic mixture was lower than that of the cubic magnetite. Mssbauer spectroscopy testified the sample consisting of cubic magnetite rather than γ-Fe2O3. In addition, a possible growth mechanism of cubic magnetic nanoparticles under different conditions was discussed.

关键词： magnetic nanoparticles cubic Fe3O4 oxidation-coprecipitation method reflux magnetic properties at room temperature Mssbauer spectrum

Microwave Disinfection in a Ventilation and Air-Conditioning System

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湖南大学学报（自然科学版） 2009年第S1期36卷 55-59页

作者： LU Zhen1,2,ZHANG Ji-li1,MA Liang-dong1,HE Juan3(1.School of Civil & Hydraulic engineering,Dalian University of technology,Dalian,Liaoning 116023,china 2.Municipal and Environmental engineering Research Center,Shenyang Jianzhu University,Shenyang,Liaoning 110168,china 3.School of Municipal & Environmental engineering,har.in institute of technology,har.in,heilongjiang 150090,china) School of Civil and Hydraulic engineering Dalian University of Technology Dalian 116023 China Municipal and Environmental engineering Research Center Shenyang Jianzhu University Shenyang 110168 China School of Municipal and Environmental engineering Harbin Institute of Technology Harbin 150090 China

Because of its broad spectrum and high efficiency,the microwave disinfection was used to control the airborne microbial contaminates in VAC *** microwave disinfection devices were developed combined with air filter,the design and calculation method was presented,and the disinfection effects on White staphylococcus,Staphylococcus aureus,Bacillus Subtilis,Escherichi coli were *** results show that the major influence factors on disinfection effect are microwave power,water-content of filter material,disinfecting *** 15 min,the kill ratio is >90%,and the log value is >*** microwave field is uniform and the kill effect of bacteria on each surface of filter is the same,without statistically significant difference.

关键词： VAC system microwave disinfection airborne microbe microwave power kill ratio

Attitude Coordinated Tracking for Formation Spacecraft under a Directed Graph

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Attitude Coordinated Tracking for Formation Spacecraft under...

第三十届中国控制会议

作者： ZHANG Haibo,MEI Jie,MA Guangfu department of control science and engineering,har.in institute of technology,heilongjiang 150001,P.R.china

In this paper we study the attitude coordinated tracking problem for formation spacecraft under a directed graph. We design a distributed coordinated tracking algorithm which guarantees all followers to track the *** is shown that the closed system is asymptotically stable as long as the directed communication topology characterizing the interaction among the followers and the leader contains a directed spanning ***,we extend the distributed control algorithm to guarantee that the spacecraft maintain constant relative orientations with their ***,numeric simulations are provided to demonstrate the effectiveness of the proposed control algorithms.

关键词： Multi-agent systems Formation spacecraft Attitude control Coordinated tracking

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透明弹性薄膜调节可见光透射比的试验研究

太阳能学报 2003年第6期24卷 795-800页

作者：张文赵大庆华北科技学院机电系北京 101601 清华大学机械系北京100084

总结了透明弹性薄膜调节可见光的研究试验。基本原理是当光通过凸凹不平的透明薄膜时,在薄膜表面要发生散射,散射能力大致与薄膜表面粗糙度成正比。当通过外力来改变薄膜表面的粗糙度时,就可以改变薄膜的散射比,也即改变了薄膜的直射透... 详细信息

总结了透明弹性薄膜调节可见光的研究试验。基本原理是当光通过凸凹不平的透明薄膜时,在薄膜表面要发生散射,散射能力大致与薄膜表面粗糙度成正比。当通过外力来改变薄膜表面的粗糙度时,就可以改变薄膜的散射比,也即改变了薄膜的直射透射比,从而对透射光强进行一定的调节。实验表明:采用适当硬度的透明弹性薄膜,在一个大气压条件下,薄膜的直射透射比的调节范围可从最小33%达到最大86 7%,透射比的改变时间不超过1秒。这一效果比目前所报道的电致变色调光的范围要大,速度要快,视觉效果也好的多,有一定的应用前景。

关键词：粗糙度直射透射比透明弹性薄膜

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电容式电压互感器的数字仿真模型

同济大学学报（自然科学版） 2004年第3期32卷 401-406页

作者：臧雯冯志彪同济大学信息与控制工程系

对速饱和电抗器型电容式电压互感器 (CVT)的各种状态 ,即空载状态、正常负载状态、一次侧短路故障状态及二次侧短路故障状态建立了数学模型 ,并由合适的数字积分方法建立了CVT各状态相应的数字仿真模型 ,根据所建立的数字仿真模型可方... 详细信息

对速饱和电抗器型电容式电压互感器 (CVT)的各种状态 ,即空载状态、正常负载状态、一次侧短路故障状态及二次侧短路故障状态建立了数学模型 ,并由合适的数字积分方法建立了CVT各状态相应的数字仿真模型 ,根据所建立的数字仿真模型可方便地在计算机上实现CVT的数字仿真并按国标 (GB470 3 )对CVT的暂态特性进行仿真研究。

关键词：电容式电压互感器铁磁谐振实时数字仿真

Design of multiple anti-windup loops for multiple activations

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science china(Information sciences) 2012年第9期55卷 1925-1934页

作者： WU XiongJun 1,2 & LIN Zongli 3,1 1 department of Automation,Shanghai Jiao Tong University,and Key Laboratory of System control and Information Processing,Ministry of Education of china,Shanghai 200240,china 2 No.802 institute of Shanghai Academy of Space Flight technology,the Eighth Academy of china Aerospace science and technology Corporation,Shanghai 200090,china 3 Charles L.Brown department of Electrical and Computer engineering,University of Virginia,P.O.Box 400743,Charlottesville,VA 22904-4743,USA 1. department of Automation Shanghai Jiao Tong University and Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai 200240 China2. No. 802 Institute of Shanghai Academy of Space Flight Technology the Eighth Academy of China Aerospace Science and Technology Corporation Shanghai 200090 China3. Charles L. Brown Department of Electrical and Computer Engineering University of Virginia P.O. Box 400743 Charlottesville VA 22904-4743 USA

This paper considers anti-windup design for linear systems subject to actuator *** anti-windup gains are designed for activations immediately at the occurrence actuator saturation,after the saturation has reached a certain level and in anticipation of the occurrence of saturation,*** design is based on the minimization of L 2 gain from the disturbance to the controlled output of the resulting closed-loop *** anti-windup scheme involves a single anti-windup loop for immediate activation.A recent innovation is to design a single anti-windup loop for delayed or anticipatory activation,as well as to design two anti-windup gains,one for immediate activation and one for delayed *** design of three anti-windup gains for three different activations is shown through simulation to lead to significant further performance improvement over the previous activation schemes.

关键词： actuator saturation anti-windup anticipatory activation delayed activation L 2 gain nonlinear control

WATER TUNNEL EXPERIMENTAL INVESTIGATION ON THE DRAG REDUCTION CharACTERISTICS OF THE TRAVELING WAVY WALL

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Journal of Hydrodynamics 2011年第1期23卷 65-70页

作者： YAO Yan LU Chuan-jing SI Ting ZHU Kun department of engineering Mechanics Shanghai Jiao Tong University Shanghai 200240 China Beijing Electromechanic engineering institute Beijing 100074 China State Key Laboratory of Ocean engineering Shanghai Jiao Tong University Shanghai 200030 China department of modem Mechanics University of Science and Technology of China Hefei 230027 China

Drag reduction experiment of the traveling wavy wall at high Reynolds number is conducted.A suit of traveling wavy wall device is *** drag forces of the traveling wavy wall with various wave speeds（c）are measured under different water speeds（U）in the K15 cavitation water tunnel and are compared with that of the flat *** results show that the mean drag force of the traveling wavy wall have decreased and then increased with oscillation frequency increasing at the same flow *** different flow speeds,when traveling wave wall reached to the minimum of drag force,the corresponding the ratio of the wall motion phase speed c to flow speed U,c /U is slightly *** the parameters of the experiment,whenc /U reaches a certain value,the drag force of the traveling wavy wall can be less than that of the flat *** drag reduction can be up to 42%.Furthermore,as the value ofc /U increases,the traveling wavy wall can restrain the separation and improve the quality of flow field.

关键词： flow control drag reduction traveling wavy wall water tunnel test

Timeliness evaluation of task-oriented networked space-based information system

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Journal of Systems engineering and Electronics 2011年第4期22卷 621-627页

作者： Chen Chen 1,2,and Jie Chen 2,3 1.department of Automation,Tsinghua University,Beijing 100084,P.R.china 2.School of Automation,Beijing institute of technology,Beijing 100081,P.R.china 3.Complex System Intelligent control and Decision,Ministry of Education,Beijing 100081,P.R.china department of Automation Tsinghua University Beijing 100084 P. R. China School of Automation Beijing Institute of Technology Beijing 100081 P. R. China School of Automation Beijing Institute of Technology Beijing 100081 P. R. China Complex System Intelligent control and Decision Ministry of Education Beijing 100081 P. R. China

Task-oriented networked information system is an integrated information system which builds on multi-satellite networking to accomplish one or more tasks. In the background of emer- gency relief for applications, system working flow and response process are analyzed, and a timeliness effectiveness evaluation index system is constructed at multi-task level. The effectiveness is a measurement of promptness of information return. In evalua- tion process, system performance and tasks are associated, then an evaluation model based on efficacy function is established, and different evaluation criteria are selected for different tasks. A distributed simulation system is constructed, and the execution of task is decomposed. The simulation platform provides a comprehensive data source for evaluation. The results are easy to compare with each other, which reflects system time efficiency in different satellites networks and provides actual systems with basis and reference for design and application.

关键词： timeliness efficacy function space-based informationsystem simulation system.

EXPERIMENTAL INVESTIGATION ON THE DRAG REDUCTION CharACTERISTICS OF TRAVELING WAVY WALL AT HIGH REYNOLDS NUMBER IN WIND TUNNEL

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Journal of Hydrodynamics 2010年第5期22卷 719-724页

作者： YAO Yan LU Chuan-jing SI Ting ZHU Kun department of engineering Mechanics Shanghai Jiao Tong University Shanghai 200240 China Beijing Electromechanic engineering institute Beijing 100074 China State Key Laboratory of Ocean engineering Shanghai Jiao Tong University Shanghai 200030 China department of Modern Mechanics University of Science and Technology of China Hefei 230027 China

Drag reduction experiments of the traveling wavy wall at high Reynolds number, ranging from 1.46×106 to 5.83×106 based on the free-stream velocity and the model length, were conducted. A suit of traveling wavy wall device was developed and its characteristics of drag reduction at high Reynolds number were investigated. The drag forces of the traveling wavy wall with various wave speeds （ c ） were measured at different wind speeds （U ） in the FL-8 low-speed wind tunnel and compared with the drag force of the flat plate. The results show that the mean drag force of the traveling wavy wall decreases as the value of c /U increases, at different wind velocities, the values of c /U corresponding to minimal drag force of the traveling wavy wall are different, when the values of c /U are larger than 0.6, the mean drag forces of the traveling wavy wall are smaller than those of the flat plate, and the drag reduction can be up to 60%. The drag reduction effectiveness of traveling wavy wall is thus achieved. Furthermore, as the value of c /U increases, the traveling wavy wall can restrain the separation and improve the quality of flow field.

关键词： flow control drag reduction traveling wavy wall wind tunnel test