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Synthesis and Lubrication of Phosphorylcholine Derivative

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Journal of Bionic engineering 2010年第3期7卷 254-258页

作者： Zhenliang Qiao~1, Dangsheng Xiong~1, Lude Lu~2, Pengju Jiang~2 1. department of materials science and engineering, nanjing university of science and Technology, nanjing 210094, P.R. china 2. School of Chemical engineering, nanjing university of science and Technology, nanjing 210094, P. R. china [a] department of materials science engineering Nanjing University of Science Technology Nanjing 210094 P.R. China [b] School of Chemical Engineering Nanjing University of Science Technology Nanjing 210094 P. R. China

The monomer of phosphorylcholine derivative, O-(5-（2-methacryloxy）-3, 3-dimethyl-3-azapentyl)-O’-（ω-hydroxy-octyl）-phosphatequaternary ammonium salt, was designed and synthesized successfully. It was characterized by the spectra ofHNMR and Mass spectra （ESI+）, and every signal was assigned. Then the lubricating characteristics of the phosphorylcholinederivative were investigated on the tribological setup of ball-oh-flat. The Ultra-High Molecular Weight Polyethylene（UHMWPE） flat was rotated against a stainless steel ball with 6 mm diameter. The load was 2.3 N, which corresponded to amaximal Hertz contact pressure of 29 MPa. Water, phosphorylcholine derivative, and Acrylic Acid （AA） solution were used aslubricants, respectively. Compared with AA, the phosphorylcholine derivative shows significant lubrication. It can be stronglyhydrated under water due to the charged segment in chemical structure. The thick water layers within the chains serves asboundary lubricants, and this is thought to be the molecular origins of lubricating behavior.

关键词： artificial joint articular cartilage molecular lubrication mechanism phosphorylcholine synthesis UHMWPE

The Microstructure and Mechanical Properties of the Low Carbon Microalloy Steel by High Voltage Electropulse Heating

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材料热处理学报 2004年第5期25卷 635-637页

作者： FANXin-min HuiJing Yinsheng departmentofmaterialsscienceandengineering NanfingUniversityofScienceandTechnologyNanjingChina

The low carbon microalloy steel samples were heated to different temperatures by high voltage electropulse discharge heating method. The temperature of sample increases with the discharge current density. Microstructures were observed by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results show that coexist microstructure of ultrafine ferrite grain and martensite can be obtained by proper high voltage electropulse discharge heating process parameter. The tensile testing indicate that better mechanical properties were obtained, including 758MPa yield strength, 796MPa ultimate strength and 12% total elongation.

关键词：显微结构机械性质晶粒细化低碳微量合金高压电脉冲加热

EFFECT OF ELONGATED GRAIN STRUCTURE ON THEMECHANICAL PROPERTIES OF AN Fe_3Al-BASEDALLOY

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Acta Metallurgica Sinica(English Letters) 1997年第4期10卷 358-362页

作者： X.Q. Yu and Y.S. Sun (department of materials science and engineering, Southeast university, nanjing 210096, china) Southeast Univ Nanjing China

The effect of hot-rolling processing on microstructure as well as the relationship between the elongated grain structure and tensile properties are investigated. The results indicate that the elongated grain structure influences the tensile properties and creep rupture life of Fe3Al alloy significantly. For the better strength and ductility at RT,a thinner elongated grain structure is desirable. When the elongated grain size is increased, the tensile properties will be decreased. On the other hand, the creeP rupture life at 600℃ is increased with the increase of elongated grain size.

关键词： Fe_3Al-based alloy microstructure tensile property

Effects　of　copper，manganese　and　pH　on　the　growth　and　several　enzyme　activities　of　mycorrhizal　fungus　Cenococcum　geophilum　Fr．

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Journal of Environmental sciences 1996年第4期8卷 419-425页

作者： Kong Fanxiang Zhang Min(department of Environmental science and engineering, nanjing university,nanjing 2.0093.china) department of Environmental science Nanjing University Nanjing 210093 China

he effects of various concentrations of copper,manganese and ph on the growth,protein content and several enzyme activities of mycorrhizal fungus Cenococcum geophilum Fr. Were *** results showed that high concentration of copper (20 mg/L)and low ph (3.0-4.0) inhibited the mycelial growth (dry weight), however, the protein content increased or not significantly reduced in mycelia after copper or manganese was applied. The activities of acid phosphatase and α-mannosidase were induced by high concentration of Mn (200-400 mg/L);but the activities of G6PDH, MTLDH and trehalase were inhibited by high content of copper(10-20 mg/L),both of the responses of these enzymes and mycelial growth under the presence of copper were correlative each other. Measurement of these enzyme activities might therefore provide a useful criterion for the evaluation of the fungitoxicity of soil contaminated by copper.

关键词： copper manganese ph mycorrhizal fungus enzyme activity.

Extraction of the spectral information of terahertz signals using superconducting Josephson junction

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science china(Technological sciences) 2010年第5期53卷 1247-1251页

作者： XU WeiWei,CHEN Jian,KANG Lin & WU PeiHeng department of Electronic science & engineering,nanjing university,nanjing 2.0093.china 1. department of Electronic science & engineering Nanjing University Nanjing 210093 China

Using YBa2Cu3O7-δ/MgO bicrystal Josephson junction,we have developed a setup for spectrum analyses of terahertz signals,up to 2.5 THz,with a frequency resolution of 3 *** junction works at liquid nitrogen temperature when the signal frequencies are low while for signals at 1.6 THz and 2.5 THz the junction is cooled to 6 *** signal processing(DSP) chips are made use of to build a data acquisition and processing system so that it can be compact,fast,and *** the completion of the relevant hardwares and softwares,the measurements are now automated.

关键词： Josephson junction THz wave spectrum detection DSP technology

Analysis of variance for testing method of cement in determination of strength

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Progress in Natural science:materials International 2011年第4期21卷 341-346页

作者： Hong HUANG,Xiao-dong SHEN State Key Laboratory of materials-Oriented Chemical engineering,College of Material science and engineering, nanjing university of Technology,nanjing 210009,china State Key Laboratory of materials-Oriented Chemical engineering College of Material Science and Engineering Nanjing University of Technology Nanjing 210009 China

The statistical tools such as descriptive statistics,full factorial design and analysis of source of variation were used to identify the potential factors that impact the validity of testing method for determining the strength of *** results showed that personal error impacted both accuracy and precision of test *** time associated with temperature fluctuation resulted in strength variation but did not impact the precision of test in all curing *** compactions did not impact the precision of test but resulted in the strength variation on 3 d and 28 d *** methods for the initial moist air curing significantly impacted the precision of testing method and resulted in the strength variation of cement on 1 d.

关键词： testing method of cement analysis of variance strength accuracy precision

Microstructures and Properties of Copper-steel Welded Joint by Twin Wire Welding

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稀有金属材料与工程 2011年第S4期40卷 302-305页

作者： Yu Jin,Wu Bowen,Zheng Shubao,Wang Kehong,Zhou QiSchool of materials science and engineering,nanjing university of science and Technology,nanjing 210094,china nanjing Univ Sci & Technol Sch Mat Sci & Engn Nanjing 210094 Jiangsu Peoples R China

The paper studies the twin wire butt welding of 6mm-thick T2 copper and Q235 steel plate by using the twin wire consisting of one copper-plated welding wire and one steel welding *** to the appearance detection,the weld joint gained is sound in shape without crackles,pores,incomplete fusion and other *** shown by the mechanical property,SEM and EDAX and in the metallographic analysis and test,the rupture position of copper-steel welded joint is located in the copper-part HAZ when the tensile strength reaches above 210MPa and Fe content of the welded joint involved in 1# test specimen reaches around 22.78%-26.75%,with the hardness achieving between 102～107HB and the weld structure being (α+ε) duplex solid solution.

关键词： copper-steel welded joint twin-wire welding mechanical property metallurgical structure

Statistical study of cement additives with and without chloride on performance modification of Portland cement

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Progress in Natural science:materials International 2011年第3期21卷 246-253页

The effectiveness of cement additives with and without chloride on the fluidity and the strength development of Portland cement was compared by using statistical full factorial *** experimental results show that the cement additive containing CaCl2and Ca(NO3)2can enhance early strength of cement ***,Ca(NO3)2is less effective than CaCl2even if it is combined with other organic chemicals such as alkanolamine and *** significant difference is found between CaCl2and Ca(NO3)2influencing the fluidity and 28 d strength of *** fluidity is determined by saccharide and its interaction with *** 28 d strength enhancement is determined by *** fluidity as well as the mechanical performance of treated cement can be significantly improved by combining Ca(NO3)2with TIPA and saccharide.

关键词： Portland cement cement additive accelerator type fluidity strength development full factorial design

3D mathematical model for suspended load transport by turbulent flows and its applications

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science china(Technological sciences) 2004年第2期47卷 237-256页

作者： LU Yongjun1,DOU Guoren1,HAN Longxi2,SHAO Xuejun3 & YANG Xianghua1,3 1.nanjing Hydraulic Research Institute,nanjing 210029,china 2.College of Environmental engineering of Hohai university,nanjing 210098,china 3.department of Hydraulic engineering,Tsinghua university,Beijing 100084,china 1. nanjing Hydraulic Research Institute 210029 Nanjing China 2. College of Environmental engineering of Hohai university 210098 Nanjing China 3. department of Hydraulic engineering Tsinghua University 100084 Beijing China

This paper presents a 3D mathematical model for suspended load transport in turbulent flows. Based on Dous stochastic theory of turbulent flow, numerical schemes of Reynolds stresses for anisotropic turbulent flows were obtained. A refined wall function was employed to treat solid wall boundaries. The equations for 2D suspended load motion and sorting of bed material have been expanded into 3D cases. Numerical results are validated by the measured data of the Gezhouba Project, and proved to be in good agreement with the experimental. The present method has been employed to simulate sediment erosion and deposition in the dam area of Three Gorges Project, and for the operation of the project, siltation process and deposition pattern in the near-dam area of the reservoir, size distribution of the deposits and bed material, and flow fields and sediment concentration fields at different time and elevations are predicted. The predicted results are close to the experimental observations in physical model studies. Thus, a new method is established for 3D simulation of sediment motion in dam areas of multi-purpose water projects.

关键词： turbulent flows, Dou's stochastic theory, nonuniform suspended load, riverbed erosion and deposition, 3D mathematical model, Three Gorges Project.