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Metal Transfer of Twin-wire Indirect Arc Argon Welding

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稀有金属材料与工程 2011年第S3期40卷 156-159页

作者： Cao Meiqing1, Zou Zengda2, Zhang Shunshan2, Qu Shiyao2 1shandong University of Science and technology, Qingdao 266510, china 2shandong University, jinan 250061, china shandong Univ Sci & Technol Sch Mat Sci & Engn Qingdao 266510 Peoples R China shandong Univ Jinan 250061 Peoples R China

Metal transfer of twin-wire indirect arc argon welding was investigated with high speed camcorder system based on a xenon lamp source and digital oscillograph, forces on droplet were analyzed in this paper. Results show metal transfer mode that of anodal and cathodal is not completely the same. It was divided into seven types of transfer mode; spray transfer and spray-projected transfer are the important transfer mode. The base-plate was melted by energy that of the arc and drop carrying, the drop transfer direction is different from that of the current flow, anodal and cathodal drop transfer at the same time, only the frequence and size are different.

关键词： indirect arc metal transfer short circuiting transfer transfer mode

Investigation on the Surface Coating of Grinding Balls

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Rare Metals 2001年第4期20卷 259-264页

作者： Chengguo Wang1 Yujun Bai1.2 1) college of Materials Science and Engineering, shandong University, jinan 250061, china 2) Mechanical Department. shandong University of Science and technology. jinan 25003), china shandong Univ Coll Mat Sci & Engn Jinan 250061 Peoples R China Shanghai Univ Sci & Technol Dept Mech Jinan 250031 Peoples R China

The surface coating of grinding balls was investigated experimentally. The results show that a coating may form on the surface of grinding balls when Cr or Al powders are subjected to ball grinding. The plastic deformation of the ball surface plays an important role during the coating formation, and the strong binding force between the powders and the balls is a necessary pre-condition. The thickness of coating increases with the plasticity of the powders and the balls. Annealing the balls with coating will result in an obvious diffusion of the elements in the bonding zone of interface.

关键词： coating ball grinding plastic deformation

Monte Carlo calculation method on low energy electronscattering in polybasic medium

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Chinese Science Bulletin 1998年第2期43卷 171-174页

作者： TAN Zhenyu 1 and HE Yancai 2 1. college of Electric Power, shandong University of technology, jinan 250061, china 2. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, china college of Electric Power Shandong University of Technology Jinan China Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai China

A novel Monte Carlo method of simulating low energy electron (LEE) scattering in polybasic medium is presented. The Mott cross section is adopted to describe the elastic scattering of LEE, and a mean cross section idea is proposed instead of usual determination of the scattering center. The Joy’’s modified Bethe equation is used to calculate energy loss of LEE. The scattering processes of LEE in bulk PMMA have been simulated. And the electron backscattering coefficients, the electron interaction range and energy dissipation distribution of LEE in bulk PMMA have been calculated and compared with those calculated by the method of determining scattering center.

关键词： low_energy electron scattering Monte Carlo method cross_section.

Series-based approximate approach of optimal tracking control for nonlinear systems with time-delay

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Progress in Natural Science:Materials International 2008年第12期18卷 1571-1576页

作者： Gongyou Tang~a Mingqu Fan~(a,b) a college of Information Science and Engineering,Ocean University of china,Qingdao 266100,china b college of Information and Engineering,shandong University of Science and technology,jinan 250031,china [a]college of Information Science and Engineering Ocean University of China Qingdao 266100 China [b]college of Information and Engineering Shandong University of Science and Technology Jinan 250031 China

The optimal output tracking control (OTC) problem for nonlinear systems with time-delay is *** a series-based approx- imate approach,the original OTC problem is transformed into iteration solving linear two-point boundary value problems without time- *** OTC law obtained consists of analytical linear feedback and feedforward terms and a nonlinear compensation term with an infinite series of the adjoint *** truncating a finite sum of the adjoint vector series,an approximate optimal tracking control law is obtained.A reduced-order reference input observer is constructed to make the feedforward term physically *** exam- ples are used to test the validity of the series-based approximate approach.

关键词： Nonlinear systems Time-delay Tracking control Optimal control Observer

Effect of physiological heterogeneity of E. coli population on antibiotic susceptivity test

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Science china(Life Sciences) 2007年第6期50卷 808-813页

作者： LIU YuQing1,3, ZHANG HuaiQiang2, SHEN JianZhong3 & GAO PeiJi2 1 Institute of Animal Science and Veterinary Medicine, shandong Academy of Agricultural Science, jinan 250100, china 2 State Key Laboratory of Microbial technology, shandong University, jinan 250100, china 3 college of Veterinary Medicine, china Agricultural University, Beijing 100094, china 1. Institute of Animal Science and Veterinary Medicine Shandong Academy of Agricultural Science Jinan 250100 China 3. college of Veterinary Medicine China Agricultural University Beijing 100094 China 2. State Key Laboratory of Microbial technology Shandong University Jinan 250100 China

According to the instantaneous growth rate (dN/dt) of E. coli CVCC249 growing in batch culture, the entire growth progress was distinguished into four phases: accelerating growth phase, constant growth phase, decelerating growth phase; declining phase, in each of which obvious variation in physiological; biochemical properties was detected, including total DNA, total protein,; MTT-dehydrogenase activity, etc., that led to difference in their antibiotic susceptivity. Antibiotic susceptivity of the population sampled from each phase was tested by Concentration-killing Curve (CKC) approach following the formula N=N 0/{1+exp[r·(x-BC 50)]}, showing as normal distribution at the individual cell level for an internal population, in which the median bactericidal concentration BC 50 represents the mean level of susceptivity, while the bactericidal span BC 199=(2lnN 0)/r indicates the variation degree of the antibiotic susceptivity. Furthermore, tested by CKC approach, the antibiotic susceptivity of E. coli CVCC249 population in each physiological phase to gentamicin or enoxacin was various: susceptivity of the population in the constant growth phase; declining phase all increased compared with that in the accelerating growth phase for gentamicin but declined for enoxacin. The primary investigations revealed that the physiological phase should be taken into account in the context of antibiotic susceptivity; research into antimicrobial mechanism. However there are few reports concerned with this study. Further research using different kinds of antibiotics with synchronized continuous culture of different bacterial strains is required.

关键词： instantaneous growth rate, batch culture, physiological heterogeneity, concentration-killing curve, antibiotic susceptivity test

Properties of meso-tetrakis (4-n-alkanoyloxyphenyl) porphyrin liquid crystal Co and Ni complexes

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Science china Chemistry 2007年第4期50卷 488-493页

作者： LIU Wei1,2 & SHI TongShun2 1 college of Materials Science and Engineering, shandong University of technology, Zibo 255049, china 2 Department of Chemistry, Jilin University, Changchun 130023, china 1. college of Materials Science and Engineering Shandong University of Technology Zibo 255049 China 2. Department of Chemistry Jilin University Changchun 130023 China

Six series of meso-tetrakis (4-n-alkanoyloxyphenyl) porphyrin Co and Ni complexes (12 kinds) were reported. Nine of the compounds were found to exhibit liquid crystal properties and display a hexagonal columnar discotic columnar (Colh) phase. Molecular structure of all synthesized compounds was confirmed by IR, UV, MS, 1H NIVR, and elemental analysis. These liquid crystalline compounds have been studied by cyclic voltammetry, luminescence, and surface photovoltage spectroscopy.

关键词： porphyrin liquid crystal cyclic voltammetry luminescence surface photovoltage spectroscopy

Diffusion and Oxidation Wear of PCBN Tool based on Thermodynamics

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Journal of Wuhan University of technology(Materials Science) 2010年第2期25卷 265-271页

作者：邵芳 Binzhou Vacational college School of Mechanical Engineering Shandong University

The rules of diffusion wear and oxidation wear for PCBN cutting tools were analyzed based on thermodynamics theory. Dissolution concentrations in typical normal workpice materials of PCBN tool material at different temperature were then calculated. Diffusion reaction rules in high temperature were developed and analyzed using the Gibbs free energy criterion. The machining tests were conducted using the PCBN tools at different cutting speeds of 50, 95,100 and 180 m/min, feed of 0.1, 0.2 and depth of cut of 0.1, 0.8, 1, and 1.5 mm respectively on a PUMA300LM numerically-controlled lathe. It was found that the theoretical results were uniform with the experimental data, and the results will provide useful references for tool material design and selection.

关键词： thermodynamics PCBN tool diffusion wear oxidation wear

Detecting malignant patients via modified boosted tree

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Science china(Information Sciences) 2010年第7期53卷 1369-1378页

作者： DONG CaiLing1, YIN YiLong1 & YANG XiuKun2 1School of Computer Science and technology, shandong University, jinan 250101, china 2college of Information and Communication, Harbin Engineering University, Harbin 150001, china 1. School of Computer Science and technology Shandong University Jinan 250101 China2. College of Information and Communication Harbin Engineering University Harbin 150001 China

As one of the most effective measures to extract useful information from medical database and provide scientific decision-making for diagnosis and treatment of diseases, medical data mining has become an increasingly hot topic in the last few years. Some of the intrinsic characteristics of medical databases, such as the huge volume and imbalanced samples as well as stringent performance standards, make this mining process particularly challenging. By elaborating various challenges existing in Task 1 of KDD Cup 2008 competition, this paper analyzes some potential solutions to these problems and presents a modified boosted tree as the final classification model. This model ranked the fourth among all the solutions to Task 1. We hope that our analysis and solutions to these challenges would contribute to the development of medical data mining applications.

关键词： classification boosted tree multiple instances scoring Real AdaBoost breast cancer detection medical data mining

Comparison of Structure and Properties among Various PAN Fibers for Carbon Fibers

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Journal of Materials Science & technology 2005年第3期21卷 376-380页

作者： Dongxin HE, Chengguo WANG, Yujun BAI and Bo ZHU college of Materials Science and Engineering, shandong University, jinan 250061, china college of Materials Science and Engineering Shandong University Jinan 250061 China

To find out the high-quality polyacrylonitrile (PAN) fibers, some differences are sought by comparing domestic PAN fibers with the foreign ones. X-ray diffractometer (XRD), transmission electron microscope (TEM), Fourier transform infrared (FT-IR) spectrometer, elemental analyzer, tensile-testing machine and high-temperature differential scanning calorimeter (DSC) are used to characterize the individual microstructure, chemical structure, elemental content, mechanical properties and thermal properties. It is found that high-quality PAN fibers have high density, lower titre, higher or adequate tensile strength, and they also have better conglomeration structure, smaller crystal dimension with dispersive distribution, less microvoids and flaws.

关键词： Polyacrylonitrile (PAN) fiber Carbon fiber Structure Properties