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Concave Cooling Control Method for Hot-rolled Strip

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稀有金属材料与工程 2011年第S3期40卷 266-268页

作者： Qiu Chunlin, Gao Xiuhua, Qi Kemin, Wen Jinglin northeastern university, shenyang 110004,{2. northeastern Univ State Key Lab Rolling & Automat Shenyang 110004 Peoples R China

Hot rolled strips usually have higher strength and lower plasticity at the ends, and the mechanical properties are distributed unevenly along the length direction. Such phenomena are caused by the different cooling rates between the end and the center. The ends of the coiled strip cool down faster than the center, inducing finer grains in the sections. Furthermore, the center of the coil is kept at high temperature for longer time, which affects the precipitation of the carbides and creates the different mechanical properties from the ends. In this paper, the temperature field of the strip during cooling was simulated to discover the characteristics of the temperature change and the effect on mechanical properties. Based on the analysis, a concept of concave cooling control was introduced and implemented in the production. Results indicated that applying the concave cooling control method could significantly improve the uniformity of the properties and promote the quality of the products.

关键词： concave cooling control hot rolling strip finite difference method

Level Set Based on Signed Pressure Force Function and Its Application in Liver Image Segmentation

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Wuhan university Journal of Natural Sciences 2011年第3期16卷 265-270页

作者： JIANG Huiyan1,2.FENG Ruijie2.3,GAO Xihe1,2.1.Software College,northeastern university,{2. 110819,liaoning,china 2.Key Laboratory of Medical Image Computing of Ministry of Education northeastern university,{2. 110819,liaoning,china 3.Sino-Dutch Biomedical and Information engineering school,northeastern university,{2. 110819,liaoning,china Software College Northeastern University Shenyang Liaoning China Key Laboratory of Medical Image Computing of Ministry of Education northeastern university Shenyang Liaoning China Sino-Dutch Biomedical and Information engineering school Northeastern University Shenyang Liaoning China

The edge-based level set model gives no satisfactory results for images with weak edge, and the region-based model performs poorly for intensity inhomogeneity images. In this paper, we propose an improved region-based level set model that integrates both the gradient information and the region information. The proposed model defines a novel external energy term, which consists of gradient information and signed pressure forces function. In order to eliminate the re-initialization procedure of traditional level set model, an internal energy term is also introduced for the level set function to maintain signed distance function. Compared with traditional models, our model is more robust against images with weak edge and intensity inhomogeneity. Experiments on liver segmentation from abdominal CT images demonstrate the effectiveness and accuracy of the proposed method.

关键词： segmentation level set signed pressure force liver

Ni60-SiC Coating Prepared by Plasma Spraying, Plasma Re-melting and Plasma Spray Welding on Surface of Hot Forging Die

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Journal of Wuhan university of Technology(Materials Science) 2011年第4期26卷 715-718页

作者：王洪福 school of mechanical {2. and automation North University of China

In order to produce the hear-resistant inner layer of hot-forging die, plasma spraying and plasma re-melting and plasma spray welding were adopted. Substrate material was W6Mo5Cr4V2. including 10%, 2.%, 30% SiC ceramic powder used as coating material to obtain different Ni-based SiC alloys coating. Micro-structure and micro-hardness analysis of the coating layer were followed, as well as thermophysical properties for the coating layer were measured. The experimental results show that the coating prepared with 70% Ni60, 30% SiC powder has best properties with plasma spray welding, in which the micro-hardness can achieve 1100 HV, meanwhile can improve the thermal property of hot-forging die dramatically.

关键词： hot forging die plasma spraying plasma re-melting plasma spray welding thermo- physical properties

In situ experiments on width and evolution characteristics of excavation damaged zone in deeply buried tunnels

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Science china(Technological Sciences) 2011年第S1期54卷 167-174页

作者： LI ShaoJun 1,FENG XiaTing 1,LI ZhanHai 3,CHEN BingRui 1,JIANG Quan 1,WU ShiYong 2.HU Bin 2.&XU JinSong 2.1 State Key Laboratory of Geomechanics and Geotechinical engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,china 2.Ertan Hydropower Development Company,Ltd.,Chengdu 610051,china 3 school of Resources and Civil engineering,northeastern university,shenyang 110004,china 1. State Key Laboratory of Geomechanics and Geotechinical engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China3. School of Resources and Civil Engineering Northeastern University Shenyang 110004 China2. Ertan Hydropower Development Company Ltd. Chengdu 610051 China

The seven long tunnels of Jinping II hydropower station are deeply *** width and evolution characteristics of excavation damaged zone(EDZ) are the key problem to the design of tunnels excavation and *** order to study this problem,several specific experimental tunnels with different overburden and geometric sizes were excavated at this *** borehole camera,sliding micrometer,cross-hole acoustic wave equipment and acoustic emission apparatus were *** paper introduced the comprehensive in situ experimental methods through pre-installed facilities and pre-drilled *** properties of the surrounding rock mass,including cracks,deformation,elastic wave and micro fractures,were measured during the whole process of the tunnel *** width and characteristics of formation and evolution of tunnels EDZ were analyzed under different construction methods involving of TBM and drilling and blasting,the test tunnels were excavated by full-face or two *** relationships between EDZ and tunnel geometry sizes,overburden and excavation method were described as *** results will not only contribute a great deal to the analysis of rock mass behavior in deeply buried rock mass,but also provide direct data for support design and rockburst prediction.

关键词： deeply buried tunnel excavation damaged zone evolution characteristics in situ experiments

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 {2. of Technology,Dalian,liaoning 11602.,china 2.Municipal and Environmental engineering Research Center,shenyang Jianzhu {2.,shenyang,liaoning 110168,china 3.school of Municipal & Environmental engineering,Harbin Institute of Technology,Harbin,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

Segregation of Molten Salt on Chromizing in Thermal Diffusion Process

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Journal of Wuhan university of Technology(Materials Science) 2011年第6期26卷 1189-1192页

作者：王洪福 school of mechanical {2. and automation North University of China

The segregation of thermal diffusion salt bath chromizing process was analyzed. The experimental chromizing ingredients were prepared by the four groups A, B, C, and D. In order to study the segregation status of this case, the cooling molten salt in the crucible was removed by drilling from the heart core of molten salt. The core of molten salt was analyzed by X-ray fluorescence spectroscopy and XRD. Through the analysis, we can conclude that the Cr element deposited in the bottom was 4.51 times than the top. Chloride added to the molten salt will reduce segregation. Meantime we proposed some measures to overcome the segregation problem.

关键词： segregation thermal diffusion process chromizing

Selection Model of Optional Parts in Suppliers Involved in New Product Development

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武汉理工大学学报 2006年第S1期28卷 156-161页

作者： MU Lifeng,TANG Jiafu,PAN Zhendong,HAN Yi (school of Information Science & engineering,{2. university,shenyang 110004,china) school of Information Science & engineering Northeastern UniversityShenyang 110004China

Quality function deployment (QFD),which can translate efficiently customer requirement (CRs) into technical attributes (TAs),is widely used in new product development (NPD) as an efficient customer-driven approach. After lots of QFD application is applied in manufacturing fields,it was proved that without considering suppliers involved,it is difficult to get precise and satisfying results in each process of QFD,particularly part deployment. The paper will address the issues of a model of optional parts selection in suppliers involved in part deployment process. Further,it has been applied to an ERP system reconstruction and updating problem as an illustration.

关键词： new product development suppliers involved quality function deployment part deployment customer requ

Boundary conditions for the bending of a piezoelectric beam

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Science china(Physics,Mechanics & Astronomy) 2008年第7期51卷 847-856页

作者： GAO Yang1, XU SiPeng2.& ZHAO BaoSheng3 1 College of Science, china Agricultural university, Beijing 100083, china 2.College of engineering, Ocean university of china, Qingdao 2.6071, china 3 school of mechanical engineering, university of Science and Technology liaoning, Anshan 114044, china 1. College of Science China Agricultural University Beijing 100083 China 2. College of engineering Ocean University of China Qingdao 266071 China 3. school of mechanical {2. University of Science and Technology Liaoning Anshan 114044 China

For beam bending in transversely isotropic piezoelectric media, the reciprocal theorem and the general solution of piezoelasticity are applied in a novel way to obtain the appropriate stress and mixed boundary conditions accurate to all orders for the beam of general edge geometry and loadings. By generalizing the method developed by Gregory and Wan, a set of necessary conditions on the edge-data for the existence of a rapidly decaying solution is established. The prescribed edge-data of the beam must satisfy these conditions in order that they could generate a decaying state within the beam. When stress and mixed conditions are imposed on the beam edge, these decaying state conditions for the case of bending deformation of piezoelectric beam are derived explicitly. They are then used for the correct formulation of boundary conditions for the beam theory solution (or the interior solution). Besides, an analytical solution of elastic beam is formulated to verify validity of our boundary conditions. For the stress data, our boundary conditions coincide with those obtained in conventional forms of beam theories. More importantly, the appropriate boundary conditions with two sets of mixed edge-data are obtained for the first time.

关键词： boundary conditions beam bending piezoelectric media decaying states regular states

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,{2. university of Mining and Technology Xuzhou 2.1116, P. R.{2. 2. school of mechanical and Electrical engineering,{2. university of Mining and Technology, Xuzhou 2.1116, P. R.{2. [a] school of Materials Science engineering China University of Mining Technology Xuzhou 221116 P. R. China [b] School of Mechanical Electrical engineering China University of Mining Technology Xuzhou 221116 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