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Carbonation Resistance of Sulphoaluminate Cement-based High Performance Concrete

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Journal of Wuhan University of technology(materials {2.) 2009年第4期24卷 663-666页

作者：张德成 school of materials {2. and engineering Wuhan University of Technology school of materials {2. and engineering University of Jinan

The influences of water/cement ratio and admixtures on carbonation resistance of sulphoaluminate cement-based high performance concrete （HPC） were investigated. The experimental results show that with the decreasing water/cement ratio, the carbonation depth of sulphoaluminate cement-based HPC is decreased remarkably, and the carbonation resistance capability is also improved with the adding admixtures. The morphologies and structure characteristics of sulphoaluminate cement hydration products before and after carbonation were analyzed using SEM and XRD. The analysis results reveal that the main hydration product of sulphoaluminate cement, that is ettringite （AFt）, decomposes after carbonation.

关键词： sulphoaluminate cement carbonation high performance concrete (HPC) admixture ettringite

A mathematical model for solid liquid and mass transfer coupling and numerical simulation for hydraulic fracture in rock salt

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Progress in Natural science:materials International 2005年第8期15卷 742-748页

作者： LIANG Weiguo 1,2. and ZHAO Yangsheng1(1. Mining technology Institute, taiyuan University of technology, taiyuan 03002., china 2. Rock and Soil Mechanics Institute, Chinese Academy of sciences, Wuhan 430071, china) Mining technology Institute Taiyuan University of Technology Taiyuan 030024 China Rock and Soil Mechanics Institute Chinese Academy of Sciences Wuhan 430071 China

The hydraulic fracture in rock salt is a complicated solid fluid and mass transfer coupling process. Through theoretical analysis, a solid fluid and mass transfer coupling mathematical model of hydraulic fracture in rock salt is established in this work, and numerical simulations are carried out with the model. The simulation results indicate that rock salt cracks in the typical way of wing-crack(or tensile crack) during the fracture, and the relation of fracture aperture (w) with expanding distance (x) and fracture time (t) is w=(0.0034+0.0006t)e (0.0007+0.0018t)x. Furthermore, it has been found that both the water pressure in the crack and the expanding velocity of the crack decrease gradually as a result of the influence of salt dissolving during fracturing. These numerical simulations well illustrate the process of hydraulic fracture in rock salt and are significantly meaningful in engineering practice.

关键词： rock salt hydraulic fracture solid liquid and mass transfer coupling mathematical model numerical simulation.

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 {2. and College of materials science and engineering, Yanshan University, Qinhuangdao 066004, china 2. Institute of Physics, Chinese Academy of sciences, Beijing 100080, china Key Laboratory of Metastable materials science and {2. and College of materials science and engineering Yanshan University Qinhuangdao China Institute of Physics Chinese Academy of Sciences 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.

Effects of lanthanum on calcium-activated K^+ currents and its kinetics in MC3T3 cells

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science china Chemistry 2010年第6期53卷 1281-1286页

作者： ZHANG LiPing1,2.& YANG Pin1 1Key Laboratory of Chemical Biology and Molecular engineering of Ministry of Education Institute of Molecular science,Shanxi University,{2. 030006,china 2.ollege of Environment and Safety,{2. University of science and technology,{2. 03002.,china Key Laboratory of Chemical Biology and Molecular engineering of Ministry of Education Institute of Molecular science Shanxi University Taiyuan China College of Environment and Safety Taiyuan University of Science and Technology Taiyuan China

Using the whole cell patch-clamp technique,we studied the effects of La3+ on calcium-activated K+ currents and its kinetics of activation and inactivation in non-excitable MC3T3 *** results showed that the calcium-activated outward K+ currents were promoted with increasing concentration of Ca2. in the pipette solution and a voltage- and Ca2.-dependent ***3+ in the bath solution inhibited the currents in a concentration-dependent manner and the inhibition EC50 was 8.2. ± 1.45 μmol/*** the concentration of 50 μmol/L,La3+ significantly changed the Vh of the activation curve and shifted the activation curve to more positive potentials,but shifted the inactivation curve to more negative *** had no effect on the slope factor k of the activation and inactivation *** currents inhibition could induce a series of physiological and molecular biological functions,presumably because of its ability to depolarize the plasma membrane and enhance cell excitability,resulting in increasing Ca2. influx and cytoplast Ca2. *** process may be one of the molecular mechanisms by which La3+ affects the cell growth and function of MC3T3 cells.

关键词： MC3T3 cell potassium ion channel La3+ patch-clamp technique

Effects of Al on Microstructure and High-Temperature Wear Properties of Austenitic Heat-Resistant Steel

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Journal of Iron and Steel Research International 2012年第3期19卷 62-66页

作者： ZHANG Yan1, SUN Yu-fu2. ZHAO Jing-yu2. GUAN Shao-kang2.(1. school of materials {2., Nanjing Institute of technology, Nanjing 2.1167, Jiangsu, china 2. school of materials science and engineering, Zhengzhou University, Zhengzhou 450002. Henan, china) school of materials {2. Nanjing Institute of Technology Nanjing Jiangsu China school of materials {2. and engineering Zhengzhou University Zhengzhou Henan China

Microstructure and high-temperature dry sliding wear at 600 ~C in ambient air of austenitic heat-resistant steel ZG40Cr2.Ni2. with different contents （mass percent） of AI （0 to 7.10~） have been investigated. The results show that microstructures of 4.68% and 7.10% A1 addition content consist of the matrix and reinforcement of inter- metallic compound y＇ and carbide, while microstructures of ZG40Cr2.Ni2. without A1 and with A1 of 1.68% are ab- sent of y＇. Higher wear resistance than the original ZG40Cr2.Ni2. alloy is achieved in alloys with higher content of A1 under the same high-temperature wear test condition. The wear rates of Fe-2.Cr-2.Ni-7.10A1 and Fe-2.Cr-2.Ni- 4.68A1 are only 2..83% and 45.83% of that of Fe-2.Cr-2.Ni, respectively. Heat-resistant steels with higher con- tents of AI （4.72. and 7.10%） have higher hardness than those with lower contents of AI （1.68% and 0）. Wear mechanisms of ZG40Cr2.Ni2. are considered as severe plough plastic deformation and slight adhesive. However, wear mechanisms of Fe-2.Cr-2.Ni 4.68A1 are light micro-cutting and oxidation-wear, while that of Fe-2.Cr-2.Ni- 7. 10A1 are severe adhesive transfer and oxidation-wear_

关键词： austenitic heat resistant steel Al microstructure high-temperature sliding wear mechanism

Spinning Deformation Criteria of Thin-walled Tubular Part with Longitudinal Inner Ribs

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Journal of Wuhan University of technology(materials {2.) 2006年第4期21卷 169-172页

作者：江树勇 engineering Training Center Harbin Engineering University Harbin 150001China

As a successive and local plastic deformation process, backward ball spinning was applied for the purpose of prodacing thin-walled tubular parts with longitudinal inner ribs. According to the local plastic deformation theoo,, the application of yield criterion to the spinning process and the influence of the radial spinning force component on the formability of inner ribs were analyzed. Based on yield criterion and plastic mechanics, the stable flow rule of metal material and forming criteria of the inner ribs were obtained aad conformed to the experimental results so as to contribute greatly to improving the ball spinning process and optimizing the process variables, such as the diameter of ball, the reduction in a pass and the wall thickness of tubular blank, which have a significant influenee on the formability of the inner ribs. The knowledge of the influence of the process variables such as the diameter of ball, the reduction in a pass and the wall thickness of tubular blank on the spinning process is essential to preventing the quality defects of the spun parts and obtaining the desired spun parts.

关键词： ball spinning power spinning spinning force criterion

Sensitization and Intra-molecular Energy Transfer of Eu^(3+) by Tb^(3+) in Eu-Tb Binuclear Complexes/PMMA

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Journal of Wuhan University of technology(materials {2.) 2011年第3期26卷 398-402页

作者：韩晶 College of Mechatronic engineering North University of China

A series of Eu0.5Tb0.5（TTA）3Phen/PMMA （TTA=thenoyltrifluoroacetone,Phen=phenanthroline） and Eu0.5Tb0.5（TTA）3Dipy/PMMA （Dipy=2.2.-dipyridyl） were prepared by in-situ *** structures of the composites were characterized by IR spectra and electron *** properties were investigated by UV-Vis spectra and fluorescence ***,the energy transfer models were set *** results indicated that polymer parts were attached with the rare-earth molecular parts in the composite luminescent ***0.5Tb0.5（TTA）3Phen/PMMA and Eu0.5Tb0.5（TTA）3Dipy/PMMA emitted mostly characteristic fluorescence of europium ion and intense red fluorescence with peak wavelength at 611.8 nm and bandwidth of 10.4 nm under UV excitation at 365 *** intensity of Eu0.5Tb0.5（TTA）3Phen/PMMA was found to be influenced with the content of *** fluorescence emission of europium ions was greatly sensitized by terbium ions and the enhancement of red emission was most likely due to the energy transfer enhancement from Tb3＋ to Eu3＋.

关键词： sensitization energy transfer rare-earth polymer in-situ polymerization

Structure and Mechanical Properties of Ni-based Porous Superalloy

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Journal of Wuhan University of technology(materials {2.) 2010年第1期25卷 73-77页

作者：米国发 school of materials {2. and engineering Henan Polytechnic University

The porous superalloy materials with hollow spherical and oriented linear pores were fabricated by means of powder metallurgy using Ni-based superalloy powders. Structure observation revealed that the pores of the porous material exhibited uniform distribution and the pores were of the same size in principle. The sintering necks created between adjacent particles on metal skeleton after sintering. The porosity of the porous material increased with increasing the addition of pore forming agent, and the hollow spherical porous material with a porosity of 81.62. were obtained when the addition of pore forming agent was 40%. The compression test indicated that this kind of materials possesses excellent energy absorption capability, and the compression resistance decreased with the increasing of porosity and pore size.

关键词： porous superalloy powder metallurgy hollow spherical pores oriented linear pores

Structure and kinematic analysis of a novel 2.DOF translational parallel robot

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Progress in Natural science:materials International 2007年第10期17卷 1213-1219页

作者： Chen Tao1, Wu Chao2.and Liu Xinjun2.1. school of Application science and {2., Harbin University of science and {2., Harbin 150080, china 2. Department of Precision Instruments, Tsinghua University, Beijing 100084, china) school of Application science and {2. Harbin University of Science and Technology Harbin 150080 China Department of Precision Instruments Tsinghua University Beijing 100084 China

This paper addresses the analysis of a novel parallel robot with 2.translational degrees of freedom (DOFs). The robot can position a rigid body in a plane with constant orientation. The kinematic structure of the robot is first described in detail. Some kinematic problems, such as the inverse and forward kinematics, velocity, and singularity are then analyzed. The working and assembly modes are discussed. Since it is the most important index to design a robot, the workspace of the robot is studied systematically in this paper. Based on the analysis of reachable workspace and singularity, a kind of workspace concept characterizing the region that the end-effector of the robot can reach in practice is defined. The results of this paper will be very useful for the design and application of the robot.

关键词： parallel robot degree of freedom kinematics workspace.