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Journal of systems science & Complexity 2018年第5期31卷 1146-1163页

作者： LIU jun-jun The College of Mathematics Taiyuan University of Technology

This paper is concerned with the boundary feedback stabilization of a coupled ODE- schrodinger system cascades with the external disturbance flowing the control end. The author uses the sliding mode control （sMC） to deal with the disturbance. By the sMC approach, the disturbance is supposed to be bounded only. The existence and uniqueness of the solution for the closed-loop via sMC are proved, and the monotonicity of the ＂reaching condition＂ is pres.nted without the differentiation of the sliding mode function, for which it may not always exist for the weak solution of the dosed-loop system. some numerical simulations is pres.nted to illustrate the effectiveness of the proposed control.

关键词： Boundary control cascade systems disturbance rejection sliding mode control

TiO_(2)/WO_(3)heterogeneous structures prepared by electrospinning and s.ntering steps:Characterization and analysis of the impedance variation to humidity

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Journal of Advanced Ceramics 2019年第2期8卷 238-246页

作者： Evando s.ARAuJO Victor n.s.LEAO Research Group on Electrospinning and nanotechnology Applications(GPEA-nano) Department of Materials ScienceUniversidade Federal do Vale do Sao Francisco

Relative humidity(RH) is a critical environmental variable for transportation and storage of products and for the quality guarantee of several other production processes and services. Heterogeneous structures prepared from the selective semiconductor oxides may improve the s.nsitivity to humidity due to the better electronic and surface properties, when compared to pristine oxides. This work shows an alternative fabrication route for producing titanium dioxide/tungsten trioxide(TiO2/WO3) heterogeneous structures(by electrospinning and s.ntering) for potential application on the RH detection. The microstructural properties of the materials were analyzed by scanning electron microscopy(sEM), energy dispersive X-ray analysis(EDs), X-ray diffraction, and Raman spectroscopy. The electrical characterization of the structures was performed by electrical impedance spectroscopy in RH range of 10%–100%. Results indicated a p-to n-type conduction transition at around 30%–40% RH for all tested settings. The analysis of the impedance signature to humidity showed that the amount of fiber layers on the electrode and working temperature are important parameters to improve the humidity s.ns.ng of the TiO2/WO3 systems.

关键词： electrospinning heterogeneous structures preparation relative humidity semiconductors

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自主可控平台AGV设计及视觉循线算法研究

计算机科学与探索 2025年第1期19卷 264-276页

作者：徐诗高军孙秋君上海海事大学信息工程学院上海201306 中国电信股份有限公司嘉兴分公司浙江嘉兴314000

设计并实现了一种基于自主可控平台的自动导引车(AGV)。AGV满足核心硬件国产化、软件开源可控的要求,并可兼容多种自主导航算法。对传统纯追踪算法在跟踪精度和安全性上进行了改进:一是载具在直线路段偏离参考轨迹较远的情况下使用Dubin... 详细信息

设计并实现了一种基于自主可控平台的自动导引车(AGV)。AGV满足核心硬件国产化、软件开源可控的要求,并可兼容多种自主导航算法。对传统纯追踪算法在跟踪精度和安全性上进行了改进:一是载具在直线路段偏离参考轨迹较远的情况下使用Dubins路径进行快速回归;二是在大曲率参考轨迹处使用预瞄点偏移算法纠正跟踪轨迹,减小跟踪误差;三是应用动态预瞄距离和动态速度进一步减小大曲率路段的跟踪误差和安全风险。改进的算法在设计的AGV上进行了实现。在完成AGV设计和改进算法实现后,在实际环境中进行了视觉循线实验。改进的算法在0.1 m/s的速度下在曲率较小路段的平均偏差相较改进前的两种纯追踪算法变体分别减少了3.3%、7.3%,在大曲率路段减少了8.34%、23.06%;在0.5 m/s的速度下在曲率较小路段的平均偏差相较改进前的两种纯追踪算法变体分别减少了9.08%、11.33%,在大曲率路段减少了2.97%、24.67%。改进算法实验的整体结果优于使用改进前两种算法变体的结果,且设计并实现的AGV能够满足一般环境下的视觉循线导航需求,可应用于多种实际场合。

关键词：自主可控自动导引车(AGV) 跟踪控制纯追踪算法

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A reliability assessment method based on support vector machines for CnC equipment

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science China(Technological sciences) 2009年第7期52卷 1849-1857页

作者： WU jun DEnG Chao sHAO XinYu XIE s Q school of naval Architecture and Ocean Engineering Huazhong University of Science and TechnologyWuhan 430074China state Key Laboratory of Digital Manufacturing Equipment&Technology Huazhong University of Science and TechnologyWuhan 430074China Department of Mechanical Engineering University of AucklandAucklandNew Zealand

With the applications of high technology,a catastrophic failure of CnC equipment rarely occurs at normal operation *** it is difficult for traditional reliability assessment methods based on time-to-failure distributions to deduce the reliability *** paper pres.nts a novel reliability assessment methodology to estimate the reliability level of equipment with machining performance degradation data when only a few samples are *** least squares support vector machines(Ls-sVM) are introduced to analyze the performance degradation process on the equipment.A two-stage parameter optimization and searching method is proposed to improve the Ls-sVM regression performance and a reliability assessment model based on the Ls-sVM is built.A machining performance degradation experiment has been carried out on an OTM650 machine tool to validate the effectiveness of the proposed reliability assessment methodology.

关键词： reliability assessment least squares support vector machines performance degradation radial basis function parameter optimization

Field Measurements of Influence of s.nd Transport Rate on structure of Wind-s.nd Flow over Coastal Transverse Ridge

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Chinese Geographical science 2008年第3期18卷 255-261页

作者： DOnG Yuxiang s L nAMIKAs P A HEsP MA jun school of Geography and Planning SUN Yat-Sen University Guangzhou 510275 China Department of Geography and 4nthropology Louisiana State University USA

The structure of wind-s.nd flow under different total s.nd transport rates was measured with field vertical anemometer and s.nd trap on the crest of typical coastal transverse ridge in Changli Gold Coast of Hebei Province, which is one of the most typical coastal aeolian distribution regions in China and famous for the tall and typical coastal transverse ridges. The measurement results show that, on the conditions of approximate wind velocities and same surface materials and environments, some changes happen to the structure of wind-s.nd flow with the increase of total s.nd transport rate on the crest of coastal transverse ridge. First, the s.nd transport rates of layers at different heights in the wind-s.nd flow increase, with the maximum increase at the height layer of 4-8cm. second, the ratios of s.nd trans-port rates of layers at different heights to total s.nd transport rate decrease at the low height layer (0-4cm), but increase at the high height layer (4-60cm). Third, the distribution of the s.nd transport rate in the wind-s.nd flow can be expressed by an exponential function at the height layer of 0-40cm, but it changes from power function model to ex-ponential function model in the whole height layer (0-60cm) and changes into polynomial function model at the height layer of 40-60cm with the increase of total s.nd transport rate. Those changes have a close relationship with the limit of s.nd grain size of wind flow transporting and composition of s.nd grain size in the wind-s.nd flow.

关键词： s.nd transport rate coastal transverse ridge structure of wind-s.nd flow field measurement

Effects of induced magnetic field on peristaltic flow of Johns.n-segalman fluid in a vertical symmetric channel

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Applied Mathematics and Mechanics(English Edition) 2010年第8期31卷 969-978页

作者： s.nADEEM n.s.AKBAR Department of Mathematics Quaid-i-Azam University

In this paper, the influence of heat transfer and induced magnetic field on peristaltic flow of a Johns.n-segalman fluid is studied. The purpose of the pres.nt investigation is to study the effects of induced magnetic field on the peristaltic flow of non-newtonian fluid. The two-dimensional equations of a Johns.n-segalman fluid are simplified by assuming a long wavelength and a low Reynolds.number. The obtained equations are solved for the stream function, magnetic force function, and axial pressure gradient by us.ng a regular perturbation method. The expressions for the pressure rise, temperature, induced magnetic field, pressure gradient, and stream function are sketched and interpreted for various embedded parameters.

关键词： induced magnetic field vertical symmetric channel Johns.n-segalman fluid magnetohydrodynamics (MHD)

seismic responses of a hemispherical alluvial valley to sV waves: a three-dimensional analytical approximation

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Acta Mechanica s.nica 2006年第6期22卷 547-557页

作者： Chenggang Zhao jun Dong Fuping Gao D.-s. Jeng school of Civil Engineering and Architecture Beijing Jiaotong University Beijing 100044 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China school of Civil Engineering The University of Sydney Sydney NSW 2006 Australia

Abstract An analytical solution to the three-dimen-sional scattering and diffraction of plane sV-waves by a saturated hemispherical alluvial valley in elastic half-space is obtained by us.ng Fourier-Bessel series expan-sion technique. The hemispherical alluvial valley with saturated soil deposits is simulated with Biot＇s dynamic theory for saturated porous media. The following conclusions based on numerical results can be drawn：（1） there are a significant differences in the seismic response simulation between the previous s.ngle-phase models and the pres.nt two-phase model; （2） the nor-malized displacements on the free surface of the alluvial valley depend mainly on the incident wave angles, the dimensionless frequency of the incident sV waves and the porosity of sediments; （3） with the increase of the incident angle, the displacement distributions become more complicated; and the displacements on the free surface of the alluvial valley increase as the porosity of sediments increases.

关键词： Biot's dynamic theory saturated porous media Three-dimensional scattering Hemispherical alluvial valley

Magnetos.nic shocks in Ultra-Relativistic Dissipative Degenerate Plasmas

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Chinese Physics Letters 2016年第8期33卷 77-80页

作者： s.Hussain n.Akhtar n.Mustafa Theoretical Physics Division PINSTECHP.O.Nilore

Magnetos.nic shock structures in dissipative magnetized degenerate electron ion plasma are studied. The two fluid quantum magnetohydrodynamic equations for non-degenerate ions and ultra-relativistic degenerate electron fluids with the Maxwell equations are pres.nted. Us.ng the reductive perturbation technique the Korteweg de Vries Burgers （KdVB） equation is derived and its solution is pres.nted with the tanh method. Astrophysical plasma parameters are used to study the effects of variation of plasma density, magnetic field intensity and kinematic viscosity on the propagation characteristics of nonlinear shock structures in such plasma systems.

关键词： in on is et de of that

POLYMERIC nAnOPARTICLEs FROM sUPERCRITICAL CO_2 MICROEMULsIOn POLYMERIZATIOn

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Chinese Journal of Polymer science 2006年第1期24卷 95-101页

作者： Wei-jun Ye Jas.n s. Keiper Joseph M. Desimone nsF science and Technology Center for Environmentally Responsible solvents and Processes Department of Chemistry University of North Carolina at Chapel Hill CB# 3290 Venable Hall Chapel Hill NC 27599-3290 USA Department of Chemical Engineering North Carolina State University P. O. Box 7905 Raleigh NC 27695-7905 USA

Herein, we reported the microemulsion polymerization in supercritical carbon dioxide. With the aid of an anionic phosphate fluorosurfactant （bis-[2-（F-hexyl）ethyl]phosphate sodium）, water-soluble/CO2-insoluble acryloxyethyltrimethyl ammonium chloride monomer and n,n＇-methylene-bisacrylamide cross-linker were solubilized into CO2 continuous phase via the formation of water-in-CO2 （w/c） microemulsion water pools. Initiated by a CO2-soluble initiator, 2,2＇-azo-bisisobutyronitrile （AIBn）, cross-linked poly（acryloxyethyltrimethyl ammonium chloride） particles were produced and stabilized in these w/c internal water pools. nano-sized particles with sizes less than 20 nm in diameter and narrow particle size distributions were obtained.

关键词： supercritical carbon dioxide nanoparticles Microemulsion polymerization.

CFD simulation of helicopter rotor flow based on unsteady actuator disk model

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Chinese Journal of Aeronautics 2020年第9期33卷 2313-2328页

作者： G.n.BARAKOs T.FITZGIBBOn A.n.KUsYUMOV s.A.KUsYUMOV s.A.MIKHAILOV James Watt school of Engineering Glasgow UniversityGlasgow G128QQUnited Kingdom Department of Aerohydrodynamics Kazan National Research Technical University named after A.N.TupolevKazan 420111Russia

Actuator Disks(AD)can provide characterizations of rotor wakes while reducing computational expense associated with modeling the fully resolved *** work pres.nts an unsteady actuator disk method based on surface circulation distribution combined with empirical data,blade element theory and rotor momentum *** nonuniform circulation distribution accounts for 3 D blade load effects,and in particular,tip *** simulations were conducted for the isolated pressure s.nsitive paint model rotor blade in hover and forward flight us.ng the HMB3 CFD solver of Glasgow *** of CFD results in comparis.n with published numerical data was performed in hover,for a range of blade pitch angles us.ng fully turbulent flow and the k-x ssT *** forward flight,the vortex structures predicted us.ng the unsteady actuator disk model showed configurations similar to the ones obtained us.ng fully resolved rotor *** the reduced grid cells.number,the CFD results for AD models captured well the main vortical structures around the rotor disk in comparis.n to the fully resolved cases.

关键词： CFD Fully resolved blades rotor PsP rotor surface circulation distribution Unsteady actuator disk model