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Neural Network-based Adaptive State-feedback Control for High-order Stochastic Nonlinear Systems

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自动化学报 2014年第12期40卷 2968-2972页

作者： MIN hui-Fang duan Na School of Electrical Engineering & Automation Jiangsu Normal University

This paper focuses on investigating the issue of adaptive state-feedback control based on neural networks(NNs)for a class of high-order stochastic uncertain systems with unknown nonlinearities. By introducing the radial basis function neural network(RBFNN) approximation method, utilizing the backstepping method and choosing an approximate Lyapunov function, we construct an adaptive state-feedback controller which assures the closed-loop system to be mean square semi-global-uniformly ultimately bounded(M-SGUUB). A simulation example is shown to illustrate the effectiveness of the design scheme.

关键词：径向基函数神经网络状态反馈控制器随机非线性系统自适应高阶 Lyapunov函数非线性问题不确定系统

Preparation of highly dispersed superfine W-20 wt% Cu composite powder with excellent sintering property by highly concentrated wet ball-milled process

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Rare Metals 2018年第11期37卷 961-967页

作者： Bo-Hua duan Zhen Fu Cheng-Kang Qi hui-Jiang Liu Ao-Kui Sun De-zhi Wang School of Materials Science and Engineering Central South University Key Laboratory of Ministry of Education for Nonferrous Materials Science and Engineering

The ball milling process and the CuWO-WOprecursors were investigated, and a new highly concentrated wet ball-milled process(HWM) was designed. W-20 wt% Cu composite powders with excellent sintering property were synthesized by highly concentrated wet ballmilled process and co-reduction. The powders were characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), field electron transmission electron microscopy(FESEM) and laser-diffraction diameter *** results indicate that particle size of W03-CuO powder mixtures decreases to 390 nm rapidly with the milling time increasing to 5 h. The CuWOprecursors promote the microstructural homogeneity of W and Cu. W-Cu composite powders have a highly dispersed and well sintering property. The particle size of W-Cu powders milled by HWM for 5 h is about 680 nm. High-resolution transmission electron microscopy(HRTEM) result suggests that W phase and Cu phase are mixed at nanometer scale. The above W-Cu composite powders reach the relative density of about 99.3%.

关键词： W-Cu composite powder Ultrafine powder Wet ball-milled Co-reduction Calcination

Direct numerical simulation of hypersonic transition induced by an isolated cylindrical roughness element

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Science China(Physics,Mechanics & Astronomy) 2014年第12期57卷 2330-2345页

作者： duan zhi Wei XIAO zhi Xiang FU Song School of Aerospace Tsinghua University

Hypersonic boundary layer transition induced by an isolated cylindrical roughness element is investigated using direct numerical simulation method based on a finite volume *** simulate the transition procedure by resolving the generation and evolvement of small-scale coherent structures,and capture the shock wave at the same time,high-order minimum dispersion and controllable dissipation scheme is validated and then *** results are compared with the available measurements in the quiet wind tunnel,such as the dominated frequency and root mean square of *** computational dominated frequency of 19.23 k Hz is very close to the experimental one,21 k ***,the disturbances of the roughness are mostly generated by the"jet"just before the roughness,and then they travel and develop downstream with the shear layer and vortex *** transition is mainly dominated by the instabilities of both the horseshoe vortex and the shear layer.

关键词： hypersonic boundarry layer transtion roughness

Generating colorful carrot germplasm through metabolic engineering of betalains pigments

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Horticulture Research 2023年第4期10卷 63-70页

作者： Yuan-Jie Deng Ao-Qi duan hui Liu Ya-hui Wang Rong-Rong Zhang zhi-Sheng Xu Ai-Sheng Xiong National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization Ministry of Agriculture and Rural Affairs Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in East ChinaCollege of HorticultureNanjing Agricultural University1 WeigangNanjing 210095China

Betalains are tyrosine-derived plant pigments exclusively found in the Caryophyllales order and some higher fungi and generally classified into two groups:red-violet betacyanins and yellow-orange *** attract great scientific and economic interest because of their relatively simple biosynthesis pathway,attractive colors and health-promoting ***-expressing two core genes BvCYP76AD1 and BvDODA1 with or without a glycosyltransferase gene MjcDOPA5GT allowed the engineering of carrot(an important taproot vegetable)to produce a palette of unique *** highest total betalains content,943.2μg·g^(−1) DW,was obtained in carrot taproot transformed with p35S:RUBY which produces all of the necessary enzymes for betalains ***-specific production of betalains slightly relieved tyrosine consumption revealing the possible bottleneck in betalains ***,a unique volcano-like phenotype in carrot taproot cross-section was created by vascular cambium-specific production of *** betalains-fortified carrot in this study is thus anticipated to be used as functional vegetable and colorful carrot germplasm in breeding to promote health.

关键词： germplasm breeding orange

Development of a test strip based on DNA-functionalized gold nanoparticles for rapid detection of mercury(II) ions

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Chinese Chemical Letters 2012年第2期23卷 225-228页

作者： Jing duan zhi Yong Guo Faculty of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China

A rapid,sensitive,selective and reliable strip assay based on DNA-functionalized gold nanoparticles for Hg^（2＋） detection has been developed,with a detection limit 5 nmol/*** measurement principle was based on thymine-Hg^（2＋）-thymine（T-Hg^（2＋）-T） coordination chemistry and streptavidin-biotin *** major advantages of this assay are that results can be read visually without any instrument in less than 10 min and that it does not require any sample pretreatment.

关键词： Mercury(Ⅱ) ion Test strip Gold nanoparticles DNA

NN-based Output Tracking for More General Stochastic Nonlinear Systems with Unknown Control Coefficients

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International Journal of Automation and computing 2017年第3期14卷 350-359页

作者： Na duan hui-Fang Min School of Electrical Engineering & Automation Jiangsu Normal UniversityXuzhou 221116 China

This paper considers the output tracking problem for more general classes of stochastic nonlinear systems with unknown control coefficients and driven by noise of unknown covariance. By utilizing the radial basis function neural network approximation method and backstepping technique, we successfully construct a controller to guarantee the solution process to be bounded in *** tracking error signal is 4th-moment semi-globally uniformly ultimately bounded（SGUUB） and can be regulated into a small neighborhood of the origin in probability. A simulation example is given to demonstrate the effectiveness of the control scheme.

关键词： Stochastic nonlinear systems unknown control coefficients output tracking neural networks backstepping

Porous nickel–titanium alloy prepared by gel-casting

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Rare Metals 2014年第4期33卷 394-399页

作者： Bo-Hua duan Hai-Xia Hong De-zhi Wang hui-Jiang Liu Xiao-Jia Dong Dan-Dan Liang School of Materials Science and Engineering Central South University State Key Laboratory of Powder Metallurgy Central South University

To explore the preparation of porous nickel- titanium alloy with excellent properties, larger size and complex shape, the premixed powder of Ni and Ti with atomic ratio of 1：1 was shaped by gel-casting. The effects of solids loading and the content of dispersant on flow ability of nickel-titanium slurry and the mechanical properties of nickel-titanium sintered body were studied. The drying models under different solids loading were also discussed. The results show that the viscosity of slurries significantly increases with an increase in solids loading. After a proper process of drying, the green body with complex shape is obtained. The sintered body with porosity rate reaching up to 49.5 % and compression strength reaching to 364.74 MPa could meet the basic demands of implant materials.

关键词： Gel-casting Porous nickel-titanium alloy Solids loading Drying

Multiplicity of closed geodesics on Finsler spheres with irrationally elliptic closed geodesics

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Science China Mathematics 2016年第3期59卷 531-538页

作者： duan Hua Gui LIU hui School of Mathematical Sciences and LPMC Nankai University Tianjin 300071 China Key Laboratory of Wu Wen-Tsun Mathematics Chinese Academy of SciencesSchool of Mathematical Sciences University of Science and Technology of China Hefei 230026 China

If all prime closed geodesics on(S^n, F) with an irreversible Finsler metric F are irrationally elliptic,there exist either exactly 2 [(n+1)/2] or infinitely many distinct closed geodesics. As an application, we show the existence of three distinct closed geodesics on bumpy Finsler(S^3, F) if any prime closed geodesic has non-zero Morse index.

关键词： closed geodesics multiplicity bumpy Finsler spheres irrationally elliptic

Efficient hydrolysis of hemicellulose to furfural by novel superacid SO_4H-functionalized ionic liquids

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Green Energy & Environment 2019年第1期4卷 49-55页

作者： Wei hui Yan Zhou Yan Dong zhi-Jun Cao Fei-Qiang He Min-Zhong Cai duan-Jian Tao College of Chemistry and Chemical Engineering Institute of Advanced Materials Jiangxi Normal University

Novel superacid SO_4H-functionalized ionic liquids(SFILs) were designed and prepared in this work. The catalytic activities of SFILs were evaluated in xylan hydrolysis and xylose dehydration to produce furfural. Combined with the results of acid strength of SFILs characterized by solid-state ^(31)P MAS NMR, it was found that the catalytic performance of SFILs was positively correlated to their acid strength. The superacid SFIL [Ch-SO_4H][CF_3SO_3] displayed the best catalytic performance with more than 80% yield of furfural, and it was also obviously superior to usual SO_3H-functionalized acidic ILs, mineral liquid acids, and acidic resin Amberlyst-15 catalysts in catalytic activity under optimized conditions. In addition, the superacid SFIL [Ch-SO_4H][CF_3SO_3] could be easily separated from reaction system and reused at least five times without obvious decrease.

关键词： Superacid Ionic liquids Hemicellulose Hydrolysis Furfural