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ELEcTROchEMIcAL INVESTIGATION ON cARBON NANOTUBE FILM WITh DIFFERENT PRETREATMENTS

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Acta Metallurgica Sinica(English Letters) 2003年第4期16卷 295-301页

作者： c.G.hu W.L.Wang W.zhu DepartmentofAppliedPhysics ChongqingUniversityChongaing400044China KeyLaboftheEducationMinistryforPhotoelectricTechnologyandSystem ChongqingUniversityChongqing400044China Departmentofchemistry ChongqingUniversityChongqing400044ChinaManuscriptreceived25November2002

Wide potential windows were found at carbon nanotube film electrodes in neutral solutions after being treated with nitric acid and mixed acid. Electrochemical reversibility was investigated at carbon nanotube films with different pretreatments for ferri/ferrocyanide and quinone /hydroquinone. carbon nanotube film electrodes presented quasi-reversible electrochemical behavior for both electrolytes. In the range of scan rate, carbon nanotube film electrodes treated with acids showed heterogeneous electron-transfer properties, which was mainly controlled by its electron state density on the surface of the film. On the whole, the carbon nanotube electrode with nitric acid treatment presented the best electrochemical behaviors, so we chose it as an analytical electrode to determine the trace compound in dilute solution. The results demonstrated that this new electrode material exhibits superior performance characteristics for the detection of azide anion.

关键词： carbon nanotubes cyclic voltammetry treatment azide anion

Stem cell differentiation and human liver disease

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World Journal of Gastroenterology 2012年第17期18卷 2018-2025页

作者： Wen-Li Zhou claire N Medine Liang zhu David c hay Department of Gastroenterology Changzheng Hospital Second Military Medical University ofChina Shanghai 200003 China Medical Re-search council centre for Regenerative Medicine University ofEdinburgh Edinburgh EH 16 4UU Scotland United Kingdom

human stem cells are scalable cell populations capable of cellular *** makes them a very attractive in vitro cellular resource and in theory provides unlimited amounts of primary *** an approach has the potential to improve our understanding of human biology and treating *** the future it may be possible to deploy novel stem cell-based approaches to treat human liver *** recent years,eff icient hepatic differentiation from human stem cells has been achieved by several research groups including our *** this review we provide an overview of the f ield and discuss the future potential and limitations of stem cell technology.

关键词： Differentiation Pluripotent stem cells hepatocyte-like cells Liver development Polymer chemistry Regenerative medicine Transplantation Bio-artif icial liver

PREPARATION OF MULTI-WALLED cARBON NANOTUBES USING NiO cATALYST SYNThESIZED BY hYDROThERMAL METhOD

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维普期刊数据库

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Acta Metallurgica Sinica(English Letters) 2003年第5期16卷 416-420页

作者： Y.J.zhu Y.L.chen X.M.Xue Y.M.chen c.Y.Wu T.c.Kuang S.h.Li h.Y.Zhang DepartmentofAppliedPhysics GuangdongUniversityofTechnologyGuangzhou510090China centerofAnalysisTesting GuangdongUniversityofTechnologyGuangzhou510O9OChina FacultyofMaterialandEnergy GuangdongUniversityofTechnologyGuangzhou510090.China

The Ni(Oh)2/SiO2 binary colloid was prepared using Ni(NO3)2.6h2O and (c2h5O)4SiO4 as starting materials and was used to form NiO/SiO2. composite powder by hydrothermal method and desiccant method in open air respectively. Multi-walled carbon nanotubes (MWcNTs) were synthesized respectively by chemical vapor deposition using the NiO/SiO2 catalyst prepared by different methods. The phase and morphology of the catalysts and the morphology, output yield and purity of MWcNTs were compared by XRD, TEM and SEM. The results show that the catalyst powder prepared by hydrothermal method, compared with that by desiccant method, is smaller, better dispersion and has stronger catalytic activity. Pure MWcNTs with smaller tube diameter and narrow range could be obtained at a high yield using that NiO/SiO2 powder prepared by hydrothermal method as catalyst.

关键词： hydrothermal method dry method at atmosphere carbon nan- otube catalytic pyrolysis

Roles of soil-structure interaction and damping in base-isolated structures built on numerous soil layers overlying a half-space

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Earthquake Engineering and Engineering Vibration 2016年第2期15卷 387-400页

作者： c.S.Tsai c.I.hsueh h.c.Su Department of civil Engineering Feng Chia University Graduate Institute of civil & hydraulic Engineering Feng Chia University Department of Water Resources Engineering and conservation Feng Chia University

This study examines the roles of soil-structure interaction （SSI）, higher modes, and damping in a base-isolated structure built on multiple layers of soil overlying a half space. closed-form solutions for the entire system, including a superstructure, seismic isolator, and numerous soil layers overlying a half-space, were obtained. The formulations obtained in this study simply in terms of well-known frequencies and mechanical impedance ratios can explicitly interpret the dynamic behavior of a base-isolated structure interacting with multiple soil layers overlying a half-space. The key factors influencing the performance of the isolation system are the damping ratio of the isolator and the ratio of the natural frequency of the fixed-base structure to that of the isolated structure by assuming that the superstructure moves as a rigid body. This study reveals that higher damping in the base isolator is unfavorable to higher mode responses that usually dominate the responses of the superstructure and that the damping mechanism plays an important role in transmitting energy in addition to absorbing energy. It is also concluded that it is possible to design a soft soil layer as an isolation system for isolating vibration energy.

关键词： base isolation seismic isolation soil-structure interaction closed- form solution higher-mode effects soilstratum passive control damping effects

Equivalent series system to model a multiple friction pendulum system with numerous sliding interfaces for seismic analyses

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Earthquake Engineering and Engineering Vibration 2014年第1期13卷 85-99页

作者： c.S.Tsai h.c.Su T.c.chiang Department of civil Engineering Feng Chia University Department of Water Resources Engineering and conservation Feng Chia University Earthquake Proof Systems Inc.

current structural analysis software programs offer few if any applicable device-specifi c hysteresis rules or nonlinear elements to simulate the precise mechanical behavior of a multiple friction pendulum system(MFPS) with numerous sliding *** on the concept of subsystems,an equivalent series system that adopts existing nonlinear elements with parameters systematically calculated and mathematically proven through rigorous derivations is *** aim is to simulate the characteristics of sliding motions for an MFPS isolation system with numerous concave sliding interfaces without prior knowledge of detailed information on the mobilized forces at various sliding *** MFPS with numerous concave sliding interfaces and one articulated or rigid slider located between these interfaces is divided into two subsystems: the fi rst represents the concave sliding interfaces above the slider,and the second represents those below the *** equivalent series system for the entire system is then obtained by connecting those for each subsystem in *** equivalent series system is validated by comparing numerical results for an MFPS with four sliding interfaces obtained from the proposed method with those from a previous study by Fenz and ***,these numerical results demonstrate that an MFPS isolator with numerous concave sliding interfaces,which may have any number of sliding interfaces,is a good isolation device to protect structures from earthquake damage through appropriate designs with controllable mechanisms.

关键词： seismic isolation base isolation earthquake engineering multiple friction pendulum system structural control mathematical modeling equivalent series system

TENSILE cREEP DEFORMATION AND DAMAGE BEhAVIOR IN A NIcKEL-BASE SUPERALLOY AT 900℃

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 606-611页

作者： h.c.Yu S.S.Xie h.c.Yang Beijing Institute of Aeronautical Materials Beijing 100095 ChinaR & D Center Baosteel Co. Ltd. Shanghai 201900 ChinaCollege of Materials and Metallurgy Northeastern University Shenyang 110004 China

The tensile creep deformation and damage evolution in a Ni-base superalloy at 900℃/170MPa were investigated. At the first creep stage, abnormal creep occured due to the resolution of fine particles, and the deformation initiated from grain boundary areas. It is evident that nearly all of the dislocations were in γ matrix channels in form of dislocation pairs and the dislocations were impeded at γ/γ' interfaces, thus the dislocation networks developed deformation. At the steady creep stage, impeded dislocations atγ/γ' interfaces climbed over γ' phases by diffusion-dominant mechanism. At the last creep stage, voids were formed around carbides at grain boundary which leaded to accumulated damage and caused creep rate accelerated. With the dislocation networks being broken, the voids connected and grew into micro-cracks gradually. Finally the cracks propagated along grain boundary area and resulted in failure.

关键词： creep deformation and damage dislocation microstructure su-peralloy

Effectuate Application of Optimum Methods in Grinding Process

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厦门大学学报（自然科学版） 2002年第S1期41卷 129-130页

作者： zhu Z h Mo K W School of Mechanical and Automobile Engineering Hefei University of TechnologySchool of Mechanical and Automobile Engineering Hefei University of Technology Hefei 230009 ChinaHefei 230009 China

Random error of grinding process is central factor th at give an effect on grinding quality all through. Optimum methods are usually a pplied on grinding process for higher productivity and preferable grinding quali ty. But the grinding quality can’t be reliably controlled now and then while opt imal solution of grinding processing parameters have been applied in production, because of two involved aspects which are availability of established empirical formulas and reliability of setting up optimum mathematical model. That is to s ay, there is particular application of optimum methods in grinding process. This paper discussed that how to confirm conditions of grinding test which be po int to grinding peculiarity when test design and regression analysis are used to setting up some empirical formulas. In order to reduce effect of random errors on precision of the empirical formulas and enable them to be applied widely, a m ethod that a lot of random error can be sufficiently contained in grinding test was suggested. And then, A means to ameliorate restriction formulas of grinding quality is expounded based on marked level of the empirical formulas and improve d reliability of optimum mathematical model is given, which offer an effectual w ay for solving grinding quality out of control as a result of random error and w orkable optimal solution of grinding processing parameters can be applied in the production really. Finally, an example is presented.

关键词： Effectuate Application of Optimum Methods in Grinding Process

Analysis on Autofrettage of cylinders

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chinese Journal of Mechanical Engineering 2012年第3期25卷 615-623页

作者： zhu Ruilin zhu Guolin TANG Feng Polytechnic college Hunan Normal UniversityChangsha 410081China Basic courses Department Jiangxi Police CollegeNanchang 330103China

Autofrettage is an effective technique to improve load-bearing capacity and safety for pressure *** autofrettaged cylinder,the depth of plastic zone,or overstrain is a key factor which affects load-bearing capacity and *** previous research on overstrain was not done in terms of the point of view of raising load-bearing capacity as far as possible and simultaneously avoiding compressive yield for cylinders experiencing autofrettage handling,and there were no analytic solutions of autofrettage in the above view point presented,the 3rd and 4th strength theories were not applied synthetically in the research to compare the results from these two *** this paper,with the aid of the analytic method,based on summing up the authors＇ previous research,results from autofrettage of a cylinder based on the 3rd and 4th strength theories are studied and compared,and the laws contained in the results are looked ***,the essential cause and reason for the obtained laws are analyzed and the inherent and meaning relations between various parameters in autofrettage theory are *** is shown that the maximum radius ratio for equivalent residual stress at inside surface never exceeds the yield strength even for a cylinder experiencing wholly yielded autofrettage,or the critical radius ratio is kc=2.218 457 489 916 7…,irrespective of the 3rd or 4th strength *** equation relating the depth of plastic zone with the thickness of a cylinder is identical for the 3rd and 4th strength *** form,the optimum load-bearing capacity of an autofrettaged cylinder is two times the initial yield pressure of the unautofrettaged cylinder irrespective of the 3rd or 4th strength *** revealed inherent relations between various parameters and varying laws of the parameters as well as the forms of the relations under the 3rd and 4th strength theories not only have theoretical meanings but also have prospects in engineering application.

关键词： pressure vessel autofrettage load-bearing capacity strength theory

Effects of process parameters on mechanical properties of abrasive-assisted electroformed nickel

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chinese Journal of Aeronautics 2016年第4期29卷 1096-1102页

作者： Ren Jianhua zhu Zengwei zhu Di college of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

A cathode mandrel with translational and rotational motion, which was supposed to obtain uniform friction effect on surface, was employed in abrasive-assisted electroforming for revolving parts with complex profile. The effects of current density, translational speed and rotational speed on the deposit properties were studied by orthogonal test. The tensile strength, elongation and micro hardness value were measured to find out how the factors affected the properties. The optimized results show that changes of current density affect the tensile strength of nickel layer most, while translational speed has the most remarkable influences on both elongation and micro hardness. The low rotational speed affects the properties least. In this experiment, a smooth nickel layer with tensile strength 581 MPa, elongation 17% and micro hardness 248hV is obtained by the orthogonal test. (c) 2016 chinese Society of Aeronautics and Astronautics. Production and hosting by Elsevier Ltd.

关键词： Abrasive cathode compound motion Electroforming Mechanical properties Nickel