检索结果-南通市图书馆

IEEE/CAA Journal of Automatica Sinica 2022年第10期9卷 1892-1895页

作者： Leyuan Fang Dingshun Zhu Jun Yue Bob Zhang Min He IEEE the College of Electrical and Information engineering Hunan University the Peng Cheng Laboratory the department of geomatics engineering Changsha University of Science and Technology the PAMI Research Group the Department of Computer and Information ScienceUniversity of Macao

Dear editor,This letter presents an open-set classification method of remote sensing images(RSIs)based on geometric-spectral reconstruction *** specifically,in order to improve the ability of RSI classification model to adapt to the open-set environment,an openset classification method based on geometric and spectral feature fusion is proposed.

关键词： editor letter Open

Time series ground subsidence inversion in mining area based on CRInSAR and PSInSAR integration

在线全文

学校读者我要写书评

暂无评论

Journal of Central South university 2013年第9期20卷 2498-2509页

作者：邢学敏朱建军王永哲杨亚夫 School of Info-Physics and geomatics engineering Central South University School of Traffic and Transportation engineering Changsha University of Science and Technology

The subsidence of the mining area was monitored by analyzing the phase of permanent scatters （PS） which maintained high coherence in magnitude of SAR images.A hew method of spatial unwrapping was presented which used the subsidence rates calculated on comer reflector （CR） points as constraints for PS network to perform the spatial unwrapping using the parametric adjustment *** algorithm achieved the integration of CR data and PSInSAR *** colliery dense distributed area around Baisha reservoir was chosen as the study area in the *** time series of subsidence from February in 2007 to February in 2010 is successfully inversed by using the periodic function to simulate the linear and nonlinear components of the *** simulation results show that the accuracy can be ± 2.1 mm with the leveling data being used as the external validation data.

关键词： permanent scatters comer reflector (CR) constraint adjustment mining subsidence nonlinear deformation

Interaction between cracks and effect of microcrack zone on main crack tip

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2010年第1期31卷 67-76页

作者：夏晓舟章青乔丕忠李丽娟 The Faculty of Construction Guangdong University of Technology State Key Laboratory of Hydrology-Water Resources and Hydraulic engineering Hohai University department of engineering Mechanics Hohai University department of Civil and Environmental engineering Washington State University

Mechanism interaction between cracks with different orientation angles is analyzed based on the principle of superposition and a flattening method. It is found that the maximum interaction effect does not occur when the microcrack is along the direction parallel or perpendicular to the principal tensile stress, which is different from the conclusion drawn by Ortiz （1987）. The mechanism of microcrack generation and the effect of the microcrack zone on the main crack tip are studied. It is concluded that the microcrack zone has effect on the main crack tip, which increases with the increase of microcrack density and length.

关键词： principle of superposition stress intensity factor interaction effect microcrack zone

Microstructure evolution of AZ91 alloy processed by a combination method of equal channel angular pressing and rolling

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2020年第1期8卷 192-198页

作者： Qiong Xu Aibin Ma Yuhua Li Jiapeng Sun Yuchun Yuan Jinghua Jiang Chaoying Ni College of Mechanics and Materials Hohai UniversityNanjing 211100China department of Materials science&engineering University of DelawareDE 19716USA Suqian Institute of hohai university Suqian 223800China

In the present work,AZ91 alloy was successfully processed by equal channel angular pressing(ECAP)for up to 16 passes and rolling(R)for multiple passes with a total reduction of 75%in addition to a combination method with ECAP plus rolling(ECAP+R).The effects of various processes(ECAP,R and ECAP+R)on microstructure evolution were analyzed and the influence of ECAP process on the rolling performance was *** result shows that ECAP contributed to a homogenous grain structure and formed a texture with higher Schmidt factors that was easy for rolling.A plate with smoother surface and reduced edge cracks was observed in the ECAP+R process than in the single R *** the microstructure of the alloy was similar after ECAP+R and R process,the sample of ECAP+R was more refined and had stronger second phase precipitation than the sample of R,which resulted in better rolling characteristics,along with the external surfaces.

关键词： AZ91 alloy ECAP and rolling “ECAP-modified”structure Second phase precipitation Texture

Low-cost cloud computing solution for geo-information processing

在线全文

学校读者我要写书评

暂无评论

Journal of Central South university 2016年第12期23卷 3217-3224页

作者：高培超刘钊谢美慧田琨 department of Land Surveying and Geo-Informatics Hong Kong Polytechnic University Institute of geomatics Department of Civil EngineeringTsinghua University

Cloud computing has emerged as a leading computing paradigm,with an increasing number of geographic information(geo-information) processing tasks now running on *** this reason,geographic information system/remote sensing(GIS/RS) researchers rent more public clouds or establish more private ***,a large proportion of these clouds are found to be underutilized,since users do not deal with big data every *** low usage of cloud resources violates the original intention of cloud computing,which is to save resources by improving *** this work,a low-cost cloud computing solution was proposed for geo-information processing,especially for temporary processing *** proposed solution adopted a hosted architecture and can be realized based on ordinary computers in a common GIS/RS *** usefulness and effectiveness of the proposed solution was demonstrated by using big data simplification as a case *** to commercial public clouds and dedicated private clouds,the proposed solution is more low-cost and resource-saving,and is more suitable for GIS/RS applications.

关键词： cloud computing geo-information processing geo-processing

Microstructure Characteristic and Electrochemical Corrosion Behavior of Surface Nano-crystallization Modified Carbon Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2016年第12期23卷 1281-1289页

作者： Zhao-jun CHENG Dan SONG Jin-yang JIANG Jing-hua JIANG Xiao-long MA Kai YOU Ai-bin MA College of Mechanics and Materials Hohai UniversityNanjing 210098JiangsuChina School of Materials science and engineering Southeast UniversityNanjing 211100JiangsuChina Suqian Research Institute of hohai university Suqian 223800JiangsuChina department of Material science and engineering North Carolina State UniversityRaleigh 27606US

The surface nano-crystallization （SNC） of carbon steel was achieved via a high-speed rotating wire-brush- ing process. Microstructure characteristics of SNC steel were systematically studied. The SNC steel surface exhibited marked deformed plastic flows and high surface roughness. Due to the accumulated strains, a deformed gradient lay er with thickness of 40-50 μm was produced, and the grain size of the topmost zone was about 50-100 nm. X-ray photoelectron spectroscopy （XPS） analysis indicated that enhanced Fe oxides and Cr oxides were generated. Electrochemical corrosion tests, including open circuit potential （OCP）, electrochemical impendence spectroscopy （EIS）, potentiodynamic polarization （PDP） and potentiostatic polarization （PP） were conducted to study the corrosion be- havior of SNC steel in 3.5 mass% NaC1 solution, where an improved corrosion resistance was observed. The resulted improvement resulted from the dominated positive effects （the attached Cr alloying element and enhanced oxide film） against the negative effects （the higher roughness and the improved corrosion activity of surface microstructure）.

关键词： surface nano-crystallization carbon steel microstructure electrochemical corrosion behavior

Atmospheric Pressure Plasma Jet in Organic Solution:Spectra,Degradation Effects of Solution Flow Rate and Initial pH Value

在线全文

学校读者我要写书评

暂无评论

Plasma science and Technology 2014年第12期16卷 1126-1134页

作者：陈秉岩朱昌平陈龙威费峻涛高莹文文单鸣雷任兆杏 department of Mathematics and Physics Hohai University College of Energy and Electrical engineering Hohai University Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology Institute of Plasma Physics Chinese Academy of Sciences College of Mechanical and Electrical engineering Hohai University

The organic compounds of p-nitrophenol （PNP） solution was treated by the active species generated in a stirred reactor by an atmospheric pressure plasma jet （APPJ）. The emission intensities of hydroxyl （OH）, oxygen （O）, nitric oxide （NO）, hydrogen （H） and molecular （N2） were measured by optical emission spectroscopy （OES）. The relations between the flow rates of the PNP solution and degradation, the degradation effects and initial pH value of the solution were also investigated. Experimental results show that there exist intense emissions of O （777.1 nm）, N（337.1 nm）, OH （306-310 nm） and NO band （200-290 nm） in the region of plasma. Given the treatment time and gas flow rate, the degradation increased as a function of discharge energy and solution flow rate, respectively. The solution flow rate for the most efficient degradation ranged from 1.414 m/s to 1.702 m/s, and contributed very little when it exceeded 2.199 m/s. This indicates the existence of diffusion-controlled reactions at a low solution flow rate and activation- controlled reactions at a high solution flow rate. Moreover, increasing or decreasing the initial pH value of neutral PNP solution （pH=5.95） could improve the degradation efficiency. Treated by APPJ, the PNP solutions with different initial pH values of 5.95, 7.47 and 2.78 turned more acidic in the end, while the neutral solution had the lowest degradation efficiency. This work clearly demonstrates the close coupling of active species, photolysis of ultraviolet, the organic solution flow rate and the initial pH value, and thus is helpful in the study of the mechanism and application of plasma in wastewater treatment.

关键词： atmospheric pressure plasma jet active species organic solution degradation,optical emission spectroscopy (OES)

Prediction of sedimentation in reservoirs by combining catchment based model and stream based model with limited data

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2019年第1期34卷 27-37页

作者： Abebe Tadesse Wenhong Dai hohai university Department of Water Conservancy and Hydropower Engineering

Estimation of sedimentation in reservoirs helps in the management and design of the reservoir's useful capacity. This research was done on the Awash River basin at the Koka Dam Reservoir in Ethiopia. The method applied was the loose integration of the Soil and Water Assessment Tool(SWAT) model and Hydrologic engineering Center-River Analysis System(HEC-RAS) model for the estimation of the sediment load reaching the reservoir. The SWAT model was used for the estimation of erosion at the catchment level,and the HEC-RAS model was applied to estimate the sediment transport in the river channel. The implemented method allows sedimentation in the floodplains and bed shear stress to be considered in the sediment modeling, which cannot be considered in the SWAT model. In addition, the river cross sectional properties and the hydrodynamic processes in the rivers were considered in the modeling process. The data used in this study are a combination of i) observed data collected by government agencies, ii) data available online in data repositories, and iii) data extracted from remote sensing in the Shuttle Radar Topographic Mission(SRTM) Digital Elevation Model(DEM). The calibration and validation of the SWAT model was done by using Sequential Uncertainty Fitting(SUIF-2) calibration and validation tools. The HEC-RAS model was calibrated by adjusting the roughness factor. The output from the integrated approaches gives better estimates of flow and sediment near the inlet to the reservoir, with coefficients of determination of 0.85 and 0.67, respectively, and Nash Sutcliffe coefficients of model fit efficiency of 0.90 and 0.62, respectively, for daily simulations.

关键词： Reservoir sedimentation Awash River SWAT HEC-RAS Rating curve

Fractal derivative multi-scale model of fluid particle transverse accelerations in fully developed turbulence

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science China(Technological sciences) 2009年第3期52卷 680-683页

作者： HongGuang Sun Wen Chen department of engineering Mechanics Hohai University Nanjing 210098 China

The Tsallis distribution and the stretched exponential distribution were successfully used to fit the experimental data of turbulence particle acceleration published in Nature (2001), which manifested a clear departure from the normal distribution. These studies, however, fall short of a clear physical mechanism behind the statistical phenomenological description. In this study, we propose a multi- scale diffusion model which considers both normal diffusion in molecular-scale and anomalous diffu- sion in vortex-scale, and the latter is described by a novel fractal derivative modeling approach. This multi-scale model gives rise to a new probability density function which fits experimental data very well.

关键词： fully developed homogeneous turbulence probability density function (PDF) anomalous diffusion power-stretched Gaussian distribution (PSGD) fractal derivative

Dynamics of a multiplex neural network with delayed couplings

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2021年第3期42卷 441-456页

作者： Xiaochen MAO Xingyong LI Weijie DING Song WANG Xiangyu ZHOU Lei QIAO department of engineering Mechanics College of Mechanics and MaterialsHohai UniversityNanjing 211100China

Multiplex networks have drawn much attention since they have been observed in many systems,e.g.,brain,transport,and social *** this paper,the nonlinear dynamics of a multiplex network with three neural groups and delayed interactions is *** stability and bifurcation of the network equilibrium are discussed,and interesting neural activities of the network are *** on the neuron circuit,transfer function circuit,and time delay circuit,a circuit platform of the network is *** is shown that delayed couplings play crucial roles in the network dynamics,e.g.,the enhancement and suppression of the stability,the patterns of the synchronization between networks,and the generation of complicated attractors and multi-stability coexistence.

关键词： neural network time delay synchronization coexisting attractor