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Fabrication of Biomimetic Water Strider Legs Covered with Setae

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Journal of Bionic engineering 2009年第1期6卷 1-6页

作者： Zhi-guo Zhou, Zhi-wen LiuDepartment of Electronic engineering, beijing institute of Technology, beijing 100081, P. R. china [a]Department of Electronic engineering Beijing Institute of Technology Beijing 100081 P. R. China

Water striders have remarkable water-repellent legs that enable them to stand effortlessly and move quickly on *** physics indicates this feature is due to a surface-tension effect caused by the special hierarchical structure of the legs,which are covered with a large number of inclined setae with fine nanogrooves inducing water *** inspires us to fabricate special water-repellent structure on functional surfaces through the cooperation between the surface treatment and the surface micro-and nanostructures,which may bring great advantages in a wide variety of *** this paper we present a procedure for fabricating biomimetic water strider legs covered with setae using Polycarbonate Track-Etched(PCTE)membranes as *** choosing appropriate membrane lengths,diameters,pitches and densities of the setae,the biomimetic legs can be fabricated conveniently and at a low *** we investigated the relationship between stiffness of the molding materials,high aspect ratio and density,which affect the fidelity of fabrication and self adhesion,to optimize the stability of *** knowledge we gained from this study will offer important insights into the biomimetic design and fabrication of water strider setae.

关键词： water strider biomimetic setae PCTE membrane Polydimethylsiloxane (PDMS) nanoparticle adhesion

Phase relationship of complex multi-component system in chromate cleaner production

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Progress in Natural Science:Materials International 2007年第7期17卷 845-850页

作者： Ge Xinlei~1 Wang Xidong~(1,3**) Zheng Shili~2 Zhang Mei~1 Zhang Yi~2 (1.Department of Physical Chemistry,University of Science and Technology beijing,beijing 100083,china 2.institute of Process engineering,Chinese Academy of Sciences,beijing 100080,china 3.College of engineering,Peking University,beijing 100871,china) [a]Department of Physical Chemistry University of Science and Technology Beijing Beijing China [b]College of engineering Peking University Beijing China [c]institute of Process engineering Chinese Academy of Sciences Beijing China

The phase relationships of the complex multi-component systems in the liquid-phase oxidization and separation process related with the chromate cleaner production are investigated theoretically and *** phase diagram of main system Fe- Cr2O4-KOH-O2of oxidization process and the relationship of its standard Gibbs free energy change with temperature are calculated.A se- ries of phase diagrams of the separation process at different temperatures,such as K（Na）OH-K（Na）2CrO4-H2O,KOH-KAlO2-H2O, K（Na）OH-K（Na）2CO3-H2O,K（Na）OH-K（Na）HCO3-H2O and K（Na）HCO3-K（Na）2CrO4-H2O have also been *** ex- periments are carried out to verify the calculated *** results showed that the sub-molten salt media are suitable for the oxidization and separation processes;FeCr2O4can be oxidized across a wide range of temperature;K（Na）2CrO4can be separated from K（Na）AlO2system at appropriate temperature and proper concentration;the crystallization of carbonate is easier than that of K（Na）2CrO4.

关键词： chromite chromate system thermodynamics calculation phase diagram

Microstructure and Frictional Behavior of Fe-based Amorphous Metallic Coatings Prepared by Atmospheric Plasma Spraying

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稀有金属材料与工程 2011年第S3期40卷 160-165页

作者： Zhou Zheng1,2, Wang Lu2, He Dingyong1, Liu Yanbo2, Zhang Guanzhen1 1 beijing University of Technology, beijing 100124, china 2 beijing institute of Technology, beijing 100081, china beijing Univ Technol Beijing 100124 Peoples R China beijing Inst Technol Beijing 100081 Peoples R China

Amorphous metallic coatings with a composition of Fe48Cr15Mo14C15B6Y2 were prepared by means of atmospheric plasma spraying (APS) process under different conditions. The microstructure and frictional behavior were characterized simultaneously in this article. The results show that the as-deposited coatings consist of amorphous matrix and some precipitated nanocrystals, while the amorphous fraction and particle deformation as well as crystallization mechanism are significantly sensitive to the spraying parameters. The amorphous coatings express high microhardness and excellent wear resistance under dry frictional wear condition, which attributes to the inherent characteristic of amorphous phase and the dispersion strengthening of precipitated nanocrystals. The dominant wear mechanism of the amorphous coatings is fatigue wear accompanying with oxidative wear. In addition, the microhardness and wear resistance of the amorphous coatings were improved by optimizing spraying parameters, owing to the effect of both structural character and proper proportional of amorphous and nanocrystals fraction.

关键词： Fe-based amorphous coating APS microstructure friction

Cleaning of Chromate Manufacture Process

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International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 132-134页

作者： Xing Zou Yi Zhang(Applied Science School, University of Science and Technology beijing, beijing 100083, china)(institute of engineering Chemistry and Metallurgy, Chinese Academy of Sciences, beijing 100080, china) Applied Science School University of Science and Technology Beijing Beijing 100083 China institute of engineering Chemistry and Metallurgy Chinese Academy of Sciences Beijing 100080 China

Sodium chromate solubility is determined in the range of NaOH concentrations from 450 to 810 g/L andsolution temperatUres from 30 to 110℃. The optimized conditions to separate sodium chromate from NaOH inleached solution are resolved. It is first found the method to efficiently separate sbdium chromate from NaOH andsodium altuninate in crude sodium chromate. Bench-scale studies on the separating are performed. Finally, goodseparation results are achieved.

关键词： chromate separation clean process

Quasi-equality constrained risk-sensitive filtering for nonlinear discrete-time systems

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控制理论与应用（英文版） 2012年第2期10卷 229-235页

作者： Linfeng SHEN, Yan LIN School of Automation Science and Electrical engineering, beijing University of Aeronautics and astronautics, beijing 100191, china School of Automation Science and Electrical engineering Beijing University of Aeronautics and Astronautics Beijing China

More and more data fusion models contain state constraints with valuable information in the filtering process. In this study, an optimal filter of risk sensitive with quasi-equality constraints is formulated using the reference probability method. Through recursion processes of probability density acquired from the probability measure change, the derived algorithm is optimal in the sense of the risk sensitive parameter. The system and constraint models are Consistent in statistics. Simulation results show that it is more robust and efficient than projection filters for the worst-case of noises and model uncertainty.

关键词： Optimal estimation Risk-sensitive filtering Constraints

Surface recrystallization of a Ni_3Al based single crystal superalloy at different annealing temperatures and blasting pressure

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Rare Metals 2012年第3期31卷 209-214页

作者： WU Yuxiao a, YANG Ruibo a, LI Shusuo a, MA Yue a, GONG Shengkai a, and HAN Yafang a, b a Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and engineering, beijing University of Aeronautics and astronautics, beijing 100191, china b beijing institute of Aeronautical Materials, beijing 100095, china Key Laboratory of Aerospace Materials and Performance (Ministry of Education) School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing China beijing institute of Aeronautical Materials Beijing China

The effects of annealing temperature and grit blasting pressure on the recrystallization behavior of a Ni3Al based single crystal superalloy were studied in this work. The results show that the precipitation of the Y-NiMo phase occurs at 900 and 1000 °C, which precedes recrystallization. The initial recrystallization temperature was between 1000 and 1100 °C. Cellular recrystallization was formed at 1100 and 1200 °C, which consisted of large columnar γ′ and fine γ + γ′. The dendrite arm closed to the interdendritic region may act as nucleation sites during initial recrystallization by a particle simulated nucleation mechanism at 1280 °C. The size of the grains first turned large and then became small upon the pressure while the recrystallization depth increased all the time.

关键词： recrystallization temperature pressure Ni3Al based single crystal superalloy nucleation

Electrochemical studies of nickel deposition from aqueous solution in super-gravity field

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Science china(Technological Sciences) 2007年第1期50卷 39-50页

作者： GUO ZhanCheng1,2, GONG YingPeng2 & LU WeiChang2 1 Metallurgical & Ecological School, University of Science and Technology, beijing 100083, china 2 institute of Process engineering, Chinese Academy of Sciences, beijing 100080, china 1. Metallurgical & Ecological School University of Science and Technology Beijing 100083 China 2. institute of Process engineering Chinese Academy of Sciences Beijing 100080 China

The effect of super-gravity on electrochemical deposition of nickel from aqueous solution was studied. The SEM pictures show that the microstructure of nickel film deposited under the super-gravity condition is finer and more uniform compared with that obtained in normal gravity condition, and the crystal grains diminish with the increase of super-gravity coefficient. The XRD patterns indicate that the arrangement of crystalline grains of nickel film deposited under the super-gravity field is more regular, and the crystalline grain sizes decrease with the increase of super-gravity coefficient. Toughness, tensile stress and hardness of the nickel film are markedly raised with the increase of super-gravity coefficient, and hydrogen content in the nickel film decreases with the increase of super-gravity coefficient. From the polarization curves of hydrogen evolution reaction under the super-gravity condition, a significant reduction of over-potential on electrode was found when current density increased. The process of hydrogen evolution reaction was enhanced under the super-gravity condition. The electro-deposition rate, the microstructure and properties of deposited nickel film under super-gravity condition were still affected by the relative orientation between inertia force and depositing surface. It is favorable to gain the nickel film with better mechanic properties when inertia force orientates vertically towards depositing surface. Keywords super-gravity - electrochemistry - electro-deposition - nickel film Supported by the Notional Natural Science Foundation of china (Grant No. 50674011)

关键词： super-gravity electrochemistry electro-deposition nickel film

Parameter identification theory of a complex model based on global optimization method

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Science china(Physics,Mechanics & Astronomy) 2008年第11期51卷 1722-1732页

作者： QU Jie1, JIN QuanLin2 & XU BingYe3 1 College of Automotive engineering, South china University of Technology, Guangzhou 510640, china 2 beijing Research institute of Mechanical and Electrical Technology, beijing 100083, china 3 Department of engineering Mechanics, Tsinghua University, beijing 100084, china 1. College of Automotive engineering South China University of Technology Guangzhou 510640 China 2. beijing Research institute of Mechanical and Electrical Technology Beijing 100083 China 3. Department of engineering Mechanics Tsinghua University Beijing 100084 China

With the development of computer technology and numerical simulation technology, computer aided engineering (CAE) technology has been widely applied to many fields. One of the main obstacles, which hinder the further application of CAE technology, is how to successfully identify the parameters of the selected model. An elementary framework for parameter identification of a complex model is provided in this paper. The framework includes the construction of objective function, the design of the optimization method and the evaluation of the identified results, etc. The parameter identification process is described in this framework, taking the parameter identification of the superplastic constitutive model considering grain growth for Ti-6Al-4V at 927°C as an example. The objective function is the weighted quadratic sums of the difference between the experimental and computational data for the stress-strain relationship and the grain growth relationship; the designed optimization method is a hybrid global optimization method, which is based on the feature of the objective function and incorporates the strengths of genetic algorithm (GA), the Levenberg-Marquardt algorithm and the augmented Gauss-Newton algorithm. The reliability evaluation of parameter identification result is made through the comparison between the calculated and experimental results and between the theoretical values of the parameters and the identified ones.

关键词： constitutive model parameter identification theory inverse analysis global optimization

Application of output feedback sliding mode control to active flutter suppression of two-dimensional airfoil

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Science china(Technological Sciences) 2010年第5期53卷 1338-1348页

作者： YANG Chao,SONG Chen,WU ZhiGang & XIE ChangChuan School of Aeronautic Science and engineering,beijing University of Aeronautics & astronautics,beijing 100191,china 1. School of Aeronautic Science and engineering Beijing University of Aeronautics & Astronautics Beijing 100191 China

The effectiveness of the sliding mode control(SMC) method for active flutter suppression(AFS) and the issues concerning control system discretization and control input constraints were studied using a typical two-dimensional *** airfoil has a trailing-edge flap for flutter *** aeroelastic system involves a two-degrees-of-freedom motion(pitch and plunge),and the equations were constructed by utilizing quasi-steady aerodynamic *** control system,designed by the output feedback SMC method,was incorporated to suppress the pitch-plunge ***,the system discretization and the flap deflection constraints were ***,a classical Runge-Kutta(RK) algorithm was utilized for numerical *** results indicated that the close-loop system with the SMC system could be stable at a speed above the flutter ***,when the flap deflection limits are reached,the close-loop system with the simple discretized control system loses ***,control compensation developed by theoretical analysis was proposed to make the system stable *** parameter perturbations and the time delay effects were also discussed in this paper.

关键词： aeroelasticity flutter airfoil sliding mode control output feedback control