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Application of Improved PSO Algorithm in Hydraulic Pressing System Identification

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Journal of Iron and Steel Research International 2012年第9期19卷 29-35页

作者： YU Yu-zhen 1 , 2., REN Xin-yi 2., DU Feng-shan 2., SHI Jun-jie 2.( 1.institute of Mechanical engineering , Hebei United University , Tangshan 063009 , Hebei ,{2. 2.institute of Mechanical engineering , yanshan University , qinhuangdao 066004 , Hebei ,{2. ) [a] institute of Mechanical engineering Hebei United University Tangshan 063009 Hebei China [b] institute of Mechanical engineering Yanshan University Qinhuangdao 066004 Hebei China

In view of characteristics of particle swarm optimization ( PSO ) algorithm of fast convergence but easily falling into local optimum value , a novel improved particle swarm optimization algorithm is put forward , and it is applicable to identify parameters of hydraulic pressure system model in strip rolling *** order to maintain population diversity and enhance global optimization capability , the algorithm is firstly improved by means of decreasing its inertia weight linearly from the maximum to the minimum and then combined with chaotic characteristics of ergodicity , randomness and sensitivity to initial *** the improved algorithm is used to identify parameters of hydraulic pressure system , the comparison of simulation curves and measured curves indicates that the identification results are reliable and close to actual situation.A new method was provided for hydraulic AGC system model identification.

关键词： hydraulic pressing system PSO algorithm chaos self-adaptive parameter identification

Magnetron sputtering synthesis of large area well-ordered boron nanowire arrays

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Science china(Physics,Mechanics & Astronomy) 2004年第4期47卷 403-415页

作者： CAO Limin1,2. ZHANG Ze2.& WANG Wenkui1,2.1. Key Laboratory of Metastable Materials Science and Technology and College of Materials Science and engineering, yanshan University,{2., china 2. institute of Physics, Chinese Academy of Sciences, Beijing 100080, china 1. Key Laboratory of Metastable Materials Science and Technology and College of Materials Science and engineering Yanshan University 066004 Qinhuangdao China 2. institute of Physics Chinese Academy of Sciences 100080 Beijing China

One-dimensionally nanostructured materials, such as nanowires and nanotubes, are the smallest dimensional structures for efficient transport of electrons and excitons, and are therefore critical building blocks for nanoscale electronic and mechanical devices. In this paper, boron nanowires with uniform diameters from 2. to 80 nm were synthesized by radio-frequency magnetron sputtering of pure boron powder and B2.3 powder mixtures in argon atmosphere. The boron nanowires produced stand vertically on the substrate surface to form well-ordered arrays over large areas with self- organized arrangements without involvement of any template and patterned catalyst. The high-density boron nanowires are parallel to each other and well distributed, forming highly ordered and uniform arrays. A more interesting and unique feature of the boron nanowires is that most of their tips are flat rather than hemispherical in morphologies. Detailed studies on its structure and composition indicate that boron nanowires are amorphous. Boron nanowire appears as a new member in the family of one-dimensional nanostructures. Considering the unique properties of boron-rich solids and other nanostructures, it is reasonable to expect that the boron nanowires will display some exceptional and interesting properties. A vapor-cluster-solid (VCS) mechanism was proposed to explain the growth of boron nanowires based on our experimental observations.

关键词： boron nanowires, magnetron sputtering, arrays, self-assembly.

Large-scale boron nanowire nanojunctions and their highly-oriented arrays

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Science china(Physics,Mechanics & Astronomy) 2004年第5期47卷 621-632页

作者： CAO Limin1,2. ZHANG Ze2.& WANG Wenkui1,2.1. Key Laboratory of Metastable Materials Science and Technology, yanshan University, qinhuangdao 066004,{2. 2. institute of Physics, Chinese Academy of Sciences, Beijing 100080,{2. 1. Key Laboratory of Metastable Materials Science and Technology Yanshan University 066004 Qinhuangdao China 2. institute of Physics Chinese Academy of Sciences 100080 Beijing China

Highly oriented multiple boron nanowire nanojunctions with unilateral feather- like morphology were first successfully prepared using a radio-frequency magnetron sputtering method. The branched boron nano-feathers always nucleate and grow on the same sidewall of the stems, and align in parallel to form multiple T- and/or Y-type nanojunctions. The diameters of the branches and the stems are in the range of 2.—40 and 60—80 nm, respectively. The thinner branches and thicker stems of the boron nanowires self-assembled into large-scale, highly ordered arrays on various substrates. During the formation and self-assembly of the arrays, no template or catalyst was needed. We believe that the approach presented here can be used to fabricate heterostructures with bottom-up assembly of a wide variety of one-dimensional nanostructures via the rational design of targets and the proper control of the experimental conditions.

关键词： boron nanowires, nanojunctions, self-assembly, magnetron sputtering.

CRYSTALLIZATION OF METALLIC GLASS Zr_70Cu_30 UNDER HIGH PRESSURE

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Acta Metallurgica Sinica(English Letters) 1993年第8期6卷 137-140页

作者： SHEN Dejiu WU Haoquan yanshan University,qinhuangdao,{2. SHEN Zhongyi CHEN Guiyu YIN Xiujun institute of Physics,Academia Sinica,Beijing,{2. Iectrurer,Department of Materials engineering,yanshan University,qinhuangdao 066004,{2. yanshan Univ Qinghuangdao China

Crystallization temperature of the metallic glass Zr_(70)Cu_(30),observed by X-ray diffraction analysis,may be increased about 2.℃,the superior limit of increase range of the temperature is about 30℃,under high pres... 详细信息

关键词： metallic glass Zr_(70)CU_(30) crystallization high pressure

Sliding Mode Control for Nonlinear System Based on T-S Model

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Systems Science and Systems engineering 2002年第4期11卷 425-430页

作者： WU Zhong-qiangCollege of electrical engineering, {2. University, qinhuangdao 066004, china College of electrical engineering Yanshan University Qinhuangdao 066004 China

Using T-S model as an approximation for nonlinear system, the nonlinear system has been fuzzy into local linear model. The variable structure controller designed by using Lyapunov theory insures the stability of system. The sliding mode controller is designed by using unit vector style, and it suit the uncertain elements satisfying matching condition or do not satisfy matching condition. The effect of the scheme has been tasted with a simulation of an inverted pendulum.

关键词： nonlinear T-S model sliding model control

Grain evolution of nano-crystals ZnO under HP and HT

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Science china(Physics,Mechanics & Astronomy) 2006年第3期49卷 281-290页

作者： SHAO Guangjie1, QIN Xiujuan1, LIU Riping1, WANG Wenkui1,2.& YAO Yushu2.1. Key Laboratory of Metastable Materials Science and Technology, yanshan University, qinhuangdao 066004,{2. 2. institute of Physics, Chinese Academy of Sciences, Beijing 100080,{2. 1. Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 China 2. institute of Physics Chinese Academy of Sciences Beijing 100080 China

Grain evolution of nano-crystals ZnO under high temperature and pressure is studied using a cubic high pressure apparatus. The structure, grain sizes and morphology of the samples are characterized by X-ray diffraction and field emission scanning electron microscopy. The results show that the grain sizes of ZnO grow rapidly at temperature 2.0℃ under pressure. At temperature lower than 300 ℃ (including 300 ℃), the grain sizes of the samples first increase with the pressure increasing from 1 to 3 GPa and later de- crease from 4 to 6 GPa. The activation volume from 1 to 3 GPa and from 4 to 6 GPa is calculated respectively using the phenomenological kinetic grain growth equation at temperature 300 ℃. At temperature higher than 400℃ (including 400 ℃), the grain sizes of the samples increase with the pressure increasing from 1 to 6 GPa. ZnO nano-bulks with good quality can be obtained under the specific conditions.

关键词： nano-crystals ZnO,high temperature and pressure,grain evolution

Tensile and compression properties of Zr-based bulk amorphous alloy at different temperatures

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Science china(Technological Sciences) 2005年第5期48卷 489-495页

作者： WANG Xu1,3, LOU Decheng1, GAO Zhanjun4, LIU Lei1, LIANG Hongmei1, WANG Qingfeng1, LI Qiang1,3 & MA Mingzhen1,2.1. Key Laboratory of Metastable Materials Science & Technology of Hebei, yanshan University, qinhuangdao 066004,{2. 2. National Key Laboratory for Precision Hot Processing of Metals, Harbin institute of Technology, Harbin 150001,{2. 3. College of Mechanical engineering, yanshan University, qinhuangdao 066004,{2. 4. Chinese Academy of engineering, Beijing 100038,{2. 1. Key Laboratory of Metastable Materials Science & Technology of Hebei Yanshan University 066004 Qinhuangdao China 2. College of Mechanical engineering Yanshan University 066004 Qinhuangdao China 3. Chinese Academy of engineering 100038 Beijing China 4. National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology 150001 Harbin China

Mechanical properties of the Zr41Ti14Cu12.5Ni10Be2..5 bulk amorphous alloy at different temperatures were investigated. The compression test was carried out on a Gleebe-32.0 machine at 345 and 375°C, respectively, in the supercooled liquid region. It is shown that decreasing the compressive rate and increasing temperature have a similar influence trend on the compressive behavior of the bulk amorphous alloy. Room and low temperature tensile strengths were tested on the Instron materials testing system. At low temperature, the tensile strength decreased with decreasing of the testing temperature. Hardness measurement indicated that below the glass transition temperature, the hardness decreased with increasing of the annealing temperature and duration time. It, however, increased when the annealing treatment was performed above the glass transition temperature.

关键词： Zr41Ti14Cu12.5Ni10Be2..5 bulk amorphous alloy, mechanical properties, compressive deformation.

Morphologies of Fe-66.7 at.%Si alloy solidified in a drop tube

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Science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 658-666页

作者： WANG Haiyan1,2. LIU Riping1, MA Mingzhen1, JING Qin1, LI Gong1, SUN Liling2.& WANG Wenkui1,2.1. Key Laboratory of Metastable Materials Science & Technology, yanshan University, qinhuangdao 066004,{2. 2. institute of Physics, Chinese Academy of Sciences, Beijing 100080,{2. 1. Key Laboratory of Metastable Materials Science & Technology Yanshan University 066004 Qinhuangdao China 2. institute of Physics Chinese Academy of Sciences 100080 Beijing China

Solidification of 0.1―1.0 mm diameter droplets of Fe-66.7 at.%Si alloy was achieved in a 3 m drop tube. The XRD, EDS, and SEM measurements reveal that all the droplets are composed of the primary phase α and the α+ε eutectic. With decreasing droplet diameter, the growth mode of the primary phase α changes from faceted to nonfaceted growth and the eutectic changes from needle-like to anomalous eutectic. In addition, the width of the primary phase α decreases with decreasing droplet size. The different cooling rates and undercooling levels corresponding to the samples with different sizes are responsible for the morphology changes. The cooling rates of the samples with different diameters during free fall were calculated and their effects on the microstructure formation were discussed. This kind of transition is also found inside the same sample, which is due to the larger cooling rate on the surface than at the center.

关键词： Fe-Si alloy, solidification, drop tube, undercooling.

Compression behavior of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(2..5) bulk metallic glass up to 2. GPa

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Science china(Physics,Mechanics & Astronomy) 2005年第3期48卷 319-324页

作者： LI Gong 1, 2., ZHAN Zaiji 2., LIU Jing 3 , YUN Jinku 1 , SUN Liling 2., LIU Riping 1 , ZHANG Jun 2.& WANG Wenkui 1, 2.1. Key Laboratory of Metastable Materials Science and Technology, yanshan University, qinhuangdao 066004,{2. 2. Center for Condensed Matter Physics, institute of Physics, Chinese Academy of Sciences, Beijing 100080,{2. 3. BSRF, institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039,{2. 1. Key Laboratory of Metastable Materials Science and Technology Yanshan University 066004 Qinhuangdao China 2. Center for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 3. BSRF Institute of High Energy Physics Chinese Academy of Sciences 100039 Beijing China

The compression of a Zr41Ti14Cu12.5Ni10Be2..5 bulk metallic glass (BMG) is investigated at room temperature up to 2. GPa using in-situ high pressure energy dispersive X-ray diffraction with a synchrotron radiation source. The pressure-induced structural relaxation is exhibited. It is found that below about 8 GPa, the existence of excess free volume contributes to the rapid structural relaxation, which gives rise to the rapid volumetric change, and the structural relaxation results in the structural stiffness under higher pressure.

关键词： bulk metallic glass, high pressure, structural relaxation, synchrotron radiation.