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Research on dual-stator winding multi-phase high-speed induction generator with rectifier load

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Science china(Technological Sciences) 2008年第6期51卷 683-692页

作者： WANG XiangHeng1 & WU XinZhen2 1 Department of electrical engineering, Tsinghua University, Beijing 100084, china 2 Department of electrical engineering, Qingdao University, Qingdao 266071, china Department of electrical engineering Tsinghua University Beijing China Department of electrical engineering Qingdao University Qingdao China

Based on analysis and calculation of the relation between current harmonics and MMF harmonics in the dual-stator winding multi-phase high-speed induction gen-erator with a rectifier load, a new idea, which divides the generator system into two sub-systems to be analyzed individually, is presented. For the sub-system of the 12-phase power winding with a rectifier load, the loop current method is used to establish network equation set in terms of the network graph theory. The numerical stability problem is solved by alternating use of fixed time-step and varied time-step, and the voltage and current with their fundamental components of the power winding are obtained. For the other sub-system of the induction generator with dual-stator winding and solid cage rotor, the electromagnetic field analysis method and the multi-variable optimization approach are combined to get the con-trol winding current and stator frequency. Calculated results well match experiment results, indicating that the new proposed method is of effectiveness and high ac-curacy.

关键词： dual-stator winding induction generator rectifier load MMF analysis loop current method finite element method optimization approach

Design,analysis and control of hybrid excited doubly salient stator-permanent-magnet motor

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Science china(Technological Sciences) 2010年第1期53卷 188-199页

作者： ZHU XiaoYong1,2 & CHENG Ming1 1 engineering Research Center for Motion Control of MOE,School of electrical engineering,Southeast University,Nanjing 210096,china 2 School of electrical and Information engineering,Jiangsu University,Zhenjiang 212013,china engineering Research Center for Motion Control of MOE School of Electrical Engineering Southeast University Nanjing China School of electrical and Information engineering Jiangsu University Zhenjiang China

In this paper,a new hybrid excited doubly salient stator-permanent-magnet motor is proposed,where both permanent magnets and DC field windings are located in the *** theory,the mathematical model and design method of the motor are *** corresponding output power equation and the relationship between the flux control capability and the extended speed range are deduced in *** using an efficient "one-step" three-dimensional(3D) finite element method,the electromagnetic performances are analyzed,in which the leakage flux outside the stator circumference and end-effect are taken into *** on the operation principle of the motor,the control strategy and scheme are developed and implemented *** experimental results and finite element analysis show that the proposed motor not only maintains the advantages of doubly salient permanent magnet motors,but also offers high energy efficiency over a wide speed range,which makes the motor an interesting candidate for electric vehicles.

关键词： stator permanent magnet motor hybrid excitation doubly salient finite element method flux weakening control

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湘湖未来学校,杭州,浙江,中国

世界建筑 2024年第4期 10-15页

作者： china United engineering Corporation Limited 中国联合工程有限公司

湘湖未来学校是一个30班的九年一贯制学校。位于杭州湘湖景区,用地面积27,644.5m^(2),总建筑面积66,786.7m^(2),其中地下建筑面积30,504m^(2)。湘湖未来学校是一个学生快乐成长大本营。模式化的学校显然已经无法承载培养学生的重任,未... 详细信息

湘湖未来学校是一个30班的九年一贯制学校。位于杭州湘湖景区,用地面积27,644.5m^(2),总建筑面积66,786.7m^(2),其中地下建筑面积30,504m^(2)。湘湖未来学校是一个学生快乐成长大本营。模式化的学校显然已经无法承载培养学生的重任,未来学校应该让学生快乐生活、健康成长、高效学习。建筑设计根植于湘湖历史文脉,总体布局由多重院落空间构成;造型提炼自江南民居形态,塑造了一座现代、典雅的江南书院。

关键词：九年一贯制学校地下建筑面积用地面积高效学习建筑设计湘湖总体布局历史文脉

Stability of impulsive stochastic functional differential systems in terms of two measures via comparison approach

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Science china(Information Sciences) 2012年第6期55卷 1313-1322页

作者： YAO FengQi 1,2 & DENG FeiQi 1 1 Institute of System engineering,South china University of Technology,Guangzhou 510640,china 2 School of electrical engineering and Information,Anhui University of Technology,Maanshan 243032,china Institute of System engineering South China University of Technology Guangzhou China School of electrical engineering and Information Anhui University of Technology Maanshan China

Comparison principles for general impulsive stochastic functional differential systems are *** the comparison principles and the theory of differential inequalities,stability and instability,involving two measures,of impulsive stochastic functional differential systems are *** stability and instability criteria are obtained,and two examples are also given to illustrate our results.

关键词： stochastic systems impulsive functional differential systems comparison principle stability in terms of two measures instability

Description to wear debris boundaries by radar graph fractal method

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Chinese Science Bulletin 2007年第16期52卷 2285-2290页

作者： LIU HongTao1,2 & GE ShiRong1 1 Institute of Tribology and Reliability engineering,china University of Mining & Technology,Xuzhou 221008,china 2 College of Mechanical and electrical engineering,china University of Mining & Technology,Xuzhou 221116,china Institute of Tribology and Reliability engineering China University of Mining & Technology Xuzhou China College of Mechanical and electrical engineering China University of Mining & Technology Xuzhou China

In this paper,radar graph fractal method is introduced to describe wear debris boundaries. Research results show that it is a nice way to describe wear debris boundaries. Since the longest axis is selected as the first coordinate axis,its center point selected as the center point of the radar graph,and the co-ordinate value of wear debris boundary selected as the measure parameter,the limitations existing in Yard fractal measure method can be avoided. For any wear debris,its radar graph fractal dimension value is one and only,and as the wear debris shape changes from round to strip,the radar graph fractal dimension value also changes from low to high,showing strong uniqueness and independence. Due to the fact that the researched wear debris is gotten in different wear states,the results also prove that radar graph fractal dimension value is correlated with frictional pairs work condition and wear state. Radar graph fractal method is compared with Yard fractal measure methods,and results show that ra-dar graph fractal dimension values gotten from different wear debris have enough value grads to avoid effect of errors,and provide higher sensitivity for wear debris shape. This paper also discusses the influencing factors for radar graph fractal method. With the increase of the decomposing degree value,the radar graph fractal dimension tends to keep stable at one certain value,showing the typical characteristic of the fractal theory. All this proves that radar graph fractal method is an effective description method for wear debris boundaries.

关键词：磨粒边界雷达图表分形法

Effect of Preparation Methods on Mechanical Properties of PVA/HA Composite Hydrogel

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Journal of Bionic engineering 2010年第3期7卷 235-243页

作者： Dekun Zhang~1, Junjie Duan~1, Dagang Wang~2, Shirong Ge~2 1. School of Materials Science and engineering, china University of Mining and Technology Xuzhou 221116, P. R. china 2. School of Mechanical and electrical engineering, china University of Mining and Technology, Xuzhou 221116, P. R. china School of Materials Science and engineering China University of Mining and Technology Xuzhou P. R. China School of Mechanical and electrical engineering China University of Mining and Technology Xuzhou P. R. China

Poly(vinyl alcohol) (PVA)/hydroxyapatite (HA) composite hydrogel specimens were prepared with 15% PVA and 1%,2%, 3%, 4% and 5% HA by repeated freezing-thawing. The tests of static and dynamic mechanical properties were carried out todiscuss the influence of different contents of HA and freezing-thawing cycles on the mechanical properties of PVA/HA compositehydrogel. The results of static mechanical tests showed that the PVA/HA composite hydrogel with 3% HA and ninefreezing-thawing cycles had excellent stress relaxation properties, higher relaxation ratio, lower stress equilibrium value andpresented better properties of creep and recovery. The results of dynamic mechanical test showed that the PVA/HA compositehydrogel with nine freezing-thawing cycles had higher storage modulus and loss modulus, so was the PVA/HA compositehydrogel with 3% HA.

关键词： composite hydrogel HA contents freezing-thawing cycles static properties dynamic properties

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北京朝阳医院常营院区

建筑实践 2024年第5期 126-133页

作者： china IPPR International engineering Co., Ltd. 中国中元国际工程有限公司

北京朝阳医院是—所拥有3个院区的大型综合医院,其中的常营院区是2023年建成并投入使用的全新院区。项目南北两侧为居住小区,东侧为城市体育公园,西侧为体育设施用地。基地处于开发成熟的城市街区,四面环路,地铁、公交车站等公共交通发...

北京朝阳医院是—所拥有3个院区的大型综合医院,其中的常营院区是2023年建成并投入使用的全新院区。项目南北两侧为居住小区,东侧为城市体育公园,西侧为体育设施用地。基地处于开发成熟的城市街区,四面环路,地铁、公交车站等公共交通发达。由于基地面积和容积率的限制,项目的建筑面积共20万m2,其中8.3万m2需被埋在地下。设计方案围绕改善地下建筑的自然采光和通风条件展开,通过在基地东西走向引入生态绿谷,实现了与东西体育公园的视线贯通。

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Theoretical analysis and experiment of micromechanics and mechanics-optics coupling of distributed optic-fiber crack sensing

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中国科学：技术科学英文版 2011年第S1期54卷 185-191页

作者： LIU HaoWu 1,2,CHEN Jiang 2,SUN Man 3 & DING Rui 2 1 State Key Laboratory of Hydraulics and Mountain River engineering,Sichuan University,Chengdu 610065,china 2 School of Water Resource Hydropower,Sichuan University,Chengdu 610065,china 3 School electrical engineering and Information,Sichuan University,Chengdu 610065,china State Key Laboratory of Hydraulics and Mountain River engineering Sichuan University Chengdu China School of Water Resource Hydropower Sichuan University Chengdu China School electrical engineering and Information Sichuan University Chengdu China

The micromechanical behaviors and mechanics-optics coupling effects of optic-fiber-concrete complex in the distributed optic-fiber sensing concrete-crack technology,which was used in health monitoring of Wu Gorge Bridge on Yangtze River and a large dam successfully,have been investigated.A micromechanical theoretical analysis method and micromechanical frictional contact bi-interface model,as well as a modified optical theoretical analysis method of the mechanics-optics coupling effects are presented.A series of verification experiments,including mechanical experiments and mechanics-optics coupling experiments,have been *** results of micromechanical theoretical analysis and the analysis of the modified theory of mechanics-optics coupling along with mechanical and optical experimental data are shown to be in close *** the micromechanical theory and the modified theory of mechanics-optics coupling with their analysis methods can not only enhance credibility of this novel distributed sensing technology but also provide a way to understand its sensing mechanism and optimize its technical details and system.

关键词： optic-fiber sensing mechanics-optics coupling micromechanics health monitoring concrete structure crack detection

Nanostructured Sulfide Composite Coating Prepared by Atmospheric Plasma Spraying

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材料工程 2006年第Z1期34卷 281-284页

作者： GUAN Yao-hui~1,XU Yang~1,ZHENG Zhong-yu~2,TONG Xiao-hui~2(1 engineering College of china Agricultural University,Beijing 100083,china 2 Beijing Research Institute of Mechanical & electrical Technology,Beijing 100083,china) engineering College China Agricultural University Beijing 100083 China Beijing Research Institute of Mechanical and electrical Technology Beijing 100083 China

Nanostructured FeS-SiC coating was deposited by atmospheric plasma spraying（APS）.The microstructure and phase composition of the coating were characterized with SEM and XRD,*** addition,the size distribution of the reconstituted powders and the porosity of the coating have been *** was found that the reconstitiuted powers with sizes in the range of 20 to 80 μm had excellent flowability and were suitable for plasma spraying *** as-sprayed FeS-SiC composite coating exhibited a bimodal distribution with small grains（30～80nm） and large grains（100～200nm）.The coating was mainly composed of FeS and SiC,a small quantity of Fe1-xS and oxide were also *** porosity of the coating was approximately 19%.

关键词： plasma spraying nanostructured FeS-SiC composite coating