检索结果-南通市图书馆

Image analyses for video-based remote structure vibration monitoring system

Frontiers of Structural and Civil Engineering 2016年第1期10卷 12-21页

作者： Yang YANG xiong (Bill) yu Department of Electrical Engineering and Computer Science Case Western Reserve University 10900 Euclid Avenue Bingham203d Cleveland OH 44106-7201 USA Department of Civil Engineering Case Western Reserve University 10900 Euclid Avenue Bingham 210 Cleveland OH 44106-7201 USA

Video-based vibration measurement is a cost-effective way for remote monitoring the health conditions of transportation and other civil structures, especially for situations where accessibility is restricted and does not allow installation of conventional monitoring devices. Besides, video-based system is global measurement. The technical basis of video-based remote vibration measurement system is digital image analysis. Comparison of the images allow the field of motion to be accurately delineated. Such information is important to understand the structure behaviors including the motion and strain distribution. This paper presents system and analyses to monitor the vibration velocity and displacement field. The performance is demonstrated on a testbed of model building. Three different methods （i.e., frame difference method, particle image velocimetry, and optical Flow Method） are utilized to analyze the image sequences to extract the feature of motion. The Performance is validated using accelerometer data. The results indicate that all three methods can estimate the velocity field of the model building, although the results can be affected by factors such as background noise and environmental interference. Optical flow method achieved the best performance among these three methods studied. With further refinement of system hardware and image processing software, it will be developed into a remote video based monitoring system for structural health monitoring of transportation infrastructure to assist the diagnoses of its health conditions.

关键词： structure health monitoring velocity estimation frame difference PIV optical-flow method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Design and analyses of open-ended pipe piles in cohesionless soils

引用

Frontiers of Structural and Civil Engineering 2016年第1期10卷 22-29页

作者： yuan GUO xiong (Bill) yu Department of Civil Engineering Case Western Reserve University 2104 Adelbert Road Bingham 260 Cleveland OH 44106-7201USA

Large open-ended pipe pile has been found to be advantageous for use in transportation projects. The current design method, however, is not adequately developed. To close this practice gap, this paper first summarized different design methods for open-ended pipe piles in sandy soils. A major factor for all the design codes is to properly account for the formation and effects of soil plug. The comparison indicates that there is a large variation in the base capacity evaluation among different methods due to the complex behaviors of soil plug. To close the knowledge gap, discrete element method （DEM） was used to simulate the soil plugging process and provide insight on the plugging mechanism. The simulation results show that the arching effect significantly increases the internal unit shear resistance along pipe piles. The porosity distribution and particle contact force distribution from DEM model indicate a large stress concentration occurs at the bottom of the soil plug. Besides, nearly 90% of the plug resistance is provided by the bottom half portion of the soil column. The soil-pile friction coefficient has a significant effect on the magnitude of plug resistance, with the major transition occurred for friction coefficient between 0.3 and 0.4.

关键词： open-ended pipe pile soil plug DEM base capacity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimization of cavitation venturi tube design for pico and nano bubbles generation

引用

International Journal of Mining Science and Technology 2015年第4期25卷 523-529页

作者： xiong yu Peng Felicia Department of Mining Engineering West Virginia University

Hydrodynamic cavitaion venturi tube technique is used for pico and nano bubble generations in coal column flotation. In order to determine the optimal design of hydrodynamic cavitation venture tube for pico and nano bubble generation, a four-factor three-level Central Composite Design of Experimental was conducted for investigating four important design parameters of cavitation venturi tube governing the median size and the volume of pico and nano bubbles. The test results showed that maximum volume of pico and nano bubbles, 65–75%, and minimum mean pico and nano bubble size,150–240 nm, were achieved at the medium ratio of the diameter of outlet of the venturi-tube and diameter of throat(3–4), medium outlet angle(11–13°), high inlet angle(26–27°) and high ratio of the length of the throat and the diameter of throat(2.3–3). Study the effects of the producing pico and nano bubbles on fine coal flotation was performed in a 5 cm diameter 260 cm height flotation column. The optimal percentage of pico and nano bubbles was about 70%, which produced maximum combustible material recovery of 86% with clean coal ash content of 11.7%.

关键词： Hydrodynamic cavitation venture tub edesign Pico and nano bubbles Bubble volume and mean size distributions Coal Column Froth flotation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Gender difference in the neuroprotective effect of rat bone marrow mesenchymal cells against hypoxiainduced apoptosis of retinal ganglion cells

引用

Neural Regeneration Research 2016年第5期11卷 846-853页

作者： Jing yuan Jian-xiong yu Eye Center Renmin Hospital of Wuhan University Wuhan Hubei Province China Department of Gastrointestinal Surgery Renmin Hospital of Wuhan University Wuhan Hubei Province China

Bone marrow mesenchymal stem cells can reduce retinal ganglion cell death and effectively prevent vision loss. Previously, we found that during differentiation, female rhesus monkey bone marrow mesenchymal stem cells acquire a higher neurogenic potential compared with male rhesus monkey bone marrow mesenchymal stem cells. This suggests that female bone marrow mesenchymal stem cells have a stronger neuroprotective effect than male bone marrow mesenchymal stem cells. Here, we first isolated and cultured bone marrow mesenchymal stem cells from female and male rats by density gradient centrifugation. Retinal tissue from newborn rats was prepared by enzymatic digestion to obtain primary retinal ganglion cells. Using the transwell system, retinal ganglion cells were co-cultured with bone marrow mesenchymal stem cells under hypoxia. Cell apoptosis was detected by flow cytometry and caspase-3 activity assay. We found a marked increase in apoptotic rate and caspase-3 activity of retinal ganglion cells after 24 hours of hypoxia compared with normoxia. Moreover, apoptotic rate and caspase-3 activity of retinal ganglion cells significantly decreased with both female and male bone marrow mesenchymal stem cell co-culture under hypoxia compared with culture alone, with more significant effects from female bone marrow mesenchymal stem cells. Our results indicate that bone marrow mesenchymal stem cells exert a neuroprotective effect against hypoxia-induced apoptosis of retinal ganglion cells, and also that female cells have greater neuroprotective ability compared with male cells.

关键词： nerve regeneration optic nerve injury bone marrow mesenchymal stem cells retinal ganglion cells neuroprotection hypoxic injury gender difference transwell system co-culture cell apoptosis flow cytometry caspase-3 neural regeneration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of particle shape on the erodibility of non-cohesive soil： Insights from coupled CFD-DEM simulations

引用

Particuology 2018年第4期16卷 12-24页

作者： yuan Guo Yang Yang xiong (Bill) yu Department of Civil Engineering Case Western Reserve University 2104 Adelbert Road Bingharn 269 Cleveland OH 44106-7201 USA Department of Electrical Engineering and Computer Science Case Western Reserve University 2104 Adelbert Road Bingharn 203D Cleveland OH 44106-7201 USA Departrnent of Civil Engineering Case Western Reserve University 2104 Adelbert Road Bingharn 206 Cleveland OH 44106- 7201 USA

Soil erosion is a critical process that is being studied in soil science, hydraulic engineering, and geotech- nical engineering. Among many societal and environmental impacts, soil erosion is a major cause for the failures of bridges. The erodibility of soil is determined by its physical and geochemical properties and is also affected by surrounding biological activities. In most of the current models for soil erosion, erodibility of non-cohesive soil is characterized by its median grain size （Dso）, density, and porosity. The contribution to erodibility of the irregular shape of soil grains, which plays an important role in the mechanical and hydraulic properties of coarse-grained soils, is generally ignored. In this paper, a coupled computational fluid dynamics and discrete element method model is developed to analyze the influence of the shape of sand grain on soil erodibility. A numerical model for the drag force on spherical and non-spherical particles is verified by using the results from physical free settling experiments. Erosion of sand grains of different shapes is simulated in a virtual erosion function apparatus, a laboratory device used to mea- sure soil erodibility. The simulation results indicate that the grain shape has major effects on erodibility. Spherical particles do not show a critical velocity because of their low rolling resistance, but a critical velocity does exist for angular particles owing to grain interlocking. The erosion rate is proportional to the flow velocity for both spherical and non-spherical particles. The simulation result for angular particle erosion is fairly consistent with the experimental observations, implying that grain shape is an important factor affecting the erodibility of non-cohesive soils.

关键词： CFD-DEM Soil erosion Grain shape Erodibility of coarse-grained soil Erosion function apparatus mode

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Towards overcoming data scarcity in materials science:unifying models and datasets with a mixture of experts framework

引用

npj Computational Materials 2022年第1期8卷 2322-2330页

作者： Rees Chang yu-xiong Wang Elif Ertekin Department of Materials Science and Engineering University of Illinois at Urbana-Champaign1304 West Green StreetUrbana61801ILUSA Department of Computer Science University of Illinois at Urbana-Champaign201 North Goodwin AvenueUrbana61801ILUSA Materials Research Laboratory University of Illinois at Urbana-Champaign104 South Goodwin AvenueUrbana61801ILUSA Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign1206 West Green StreetUrbana61801ILUSA

While machine learning has emerged in recent years as a useful tool for the rapid prediction of materials properties,generating sufficient data to reliably train models without overfitting is often *** overcoming this limitation,we present a general framework for leveraging complementary information across different models and datasets for accurate prediction of data-scarce materials *** approach,based on a machine learning paradigm called mixture of experts,outperforms pairwise transfer learning on 14 of 19 materials property regression tasks,performing comparably on four of the remaining *** approach is interpretable,model-agnostic,and scalable to combining an arbitrary number of pre-trained models and datasets to any downstream property prediction *** anticipate the performance of our framework will further improve as better model architectures,new pre-training tasks,and larger materials datasets are developed by the community.

关键词： prediction mixture property

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pico–nano bubble column flotation using static mixer-venturi tube for Pittsburgh No.8 coal seam

引用

International Journal of Mining Science and Technology 2015年第3期25卷 347-354页

作者： Peng Felicia F. yu xiong The Department of Mining Engineering West Virginia University

The flotation process is a particle-hydrophobic surface-based separation technique. To improve the essential flotation steps of collision and attachment probabilities, and reduce the step of detachment probabilities between air bubbles and hydrophobic particles, a selectively designed cavitation venturi tube combined with a static mixer can be used to generate very high numbers of pico and nano bubbles in a flotation column. Fully embraced by those high numbers of tiny bubbles, hydrophobic particles readily attract the tiny bubbles to their surfaces. The results of column flotation of Pittsburgh No. 8 seam coal are obtained in a 5.08 cm ID and 162 cm height flotation column equipped with a static mixer and cavitation venturi tube, using kerosene as collector and MIBC as frother. Design of the experimental procedure is combined with a statistical two-stepwise analysis to determine the optimal operating conditions for maximum recovery at a specified grade. The effect of independent variables on the responses has been explained. Combustible material recovery of 85–90% at clean coal product of 10–11% ash is obtained from feed of 29.6% ash, with a much-reduced amount of frother and collector than that used in conventional column flotation. The column flotation process utilizing pico and nano bubbles can also be extended to the lower limit and upper limit of particle size ranges, minus 75 lm and 300–600 lm, respectively, for better recovery.

关键词： Pico-nano bubble generation Cavitation venturi tube Fine coal flotation Statistical analysis method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A holistic computational model for prediction of clay suspension structure

引用

International Journal of Sediment Research 2019年第4期34卷 345-354页

作者： yuan Guo xiong (Bill) yu Department of Civil Engineering Case Western Reserve University

The formation of clay suspensions involves complex interactions among clay particles subjected to the geochemical environment during the sedimentation process. The structural characteristics have a major influence on the physical and mechanical behavior of the suspension. A modeling framework involving a Discrete Element Method(DEM) model with customized particle mechanical interactions is proposed in this paper for the holistic prediction of the physical structure of clay suspensions. The particle interaction force model is based on the Derjaguin, Landau, Verwey, and Overbeek(DLVO) theory that accounts for electrostatic repulsion, van der Waals attraction, contact repulsion, etc. Kaolinite is used as the model clay to demonstrate the model performance. The surface charge density of kaolinite is obtained through Atomic Force Microscope(AFM) force measurement and is implemented in the particle interaction force model in the subsequent simulations. Influencing factors, such as centrifugal acceleration, ionic concentration, platy structure of particles, and particle size, on the formation of kaolinite suspensions are studied with the numerical model and compare favorably well with the experimental data. This work lays down a unique framework consisting of computational modeling and microscale characterization of clay particles to holistically predict the characteristics of clay suspensions, which paves the basis to model and predict their bulk physical and mechanical behavior.

关键词： Clay suspension Discrete element method DLVO theory Atomic force microscope Kaolinite Surface potential

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Review on modification routes for SnO_(x)-based anodes for Li storage:morphological structure tuning and phase structure design

引用

Rare Metals 2023年第9期42卷 2840-2867页

作者： yu Zheng Xue-Xia Lan Xing-yu xiong Bin yuan Ren-Zong Hu School of Materials Science and Engineering Guangdong Provincial Key Laboratory of Advanced Energy Storage MaterialsSouth China University of TechnologyGuangzhou510640China

Fascinating with high specific capacity and moderate lithiation potential,SnO_(x)-based materials have been intensively investigated as one of the most promising anodes for lithium-ion ***,due to poor cycling stability,sluggish reaction kinetics,and limited electrochemical reaction reversibility,the development of SnO_(x)-based anodes has been *** the current preparation and modification routes for SnO_(x)-based anodes lack direct and specific ***,modification routes for SnO_(x)-based anodes have been ***,to provide more direct instructions,the tuning routes of morphological structure for SnO_(x)-based electrodes(including slurry-based and self-supported)have been thoroughly discussed from the preparation ***,according to the properties of SnO_(x)-based anodes,the phase structure design ideas have also been properly classified and organized for addressing chemical reaction kinetics or thermodynamic ***,for future-oriented studies,new insights into the development and commercialization prospects of SnO_(x)-based anodes are also *** review,with comprehensive information on SnO_(x)-based anodes,aims to bring more specific guidance and valuable inspiration for peer researchers who are promoting the application of SnO_(x)-based materials for energy conversion and storage devices.

关键词： Lithium-ion battery(LIB) SnO_(x)-based anodes Reaction kinetics Morphological structure tuning Phase structure design

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Divergence-Free Virtual Element Method for the Stokes Equations with Damping on Polygonal Meshes

引用

Numerical Mathematics(Theory,Methods and Applications) 2024年第1期17卷 210-242页

作者： yu xiong Yanping Chen Jianwei Zhou Qin Liang School of Mathematics and Computational Science Hunan Key Laboratory for Computation and Simulation in Science and EngineeringXiangtan UniversityXiangtan 411105P.R.China School of Mathematics and Statistics Linyi University Linyi 276005P.R.China School of Mathematical Sciences South China Normal UniversityGuangzhou 510631P.R.China

In this paper,we construct,analyze,and numerically validate a family of divergence-free virtual elements for Stokes equations with nonlinear damping on polygonal *** virtual element method is H1-conforming and exact *** virtue of these properties and the topological degree argument,we rigorously prove the well-posedness of the proposed discrete *** con-vergence analysis is carried out,which imply that the error estimate for the velocity in energy norm does not explicitly depend on the *** experiments on various polygonal meshes validate the accuracy of the theoretical analysis and the asymptotic pressure robustness of the proposed scheme.

关键词： Optimal error estimates divergence-free virtual element nonlinear damping term.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：