检索结果-南通市图书馆

Vibration Serviceability of Large-Span Steel–Concrete Composite Beam with Precast Hollow Core Slabs Under Walking Impact

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2022年第12期19卷 93-104页

作者： Jiepeng Liu Shu Huang Jiang Li y.frank chen School of Civil Engineering&Key Laboratory of New Technology for Construction of Cities in Mountain Area Ministry of EducationChongqing UniversityChongqing 400045China Central-South Architectural Design Institute Co. Ltd.Wuhan 430071China Department of Civil Engineering The Pennsylvania State UniversityPA 17057USA

A large-span steel–concrete composite beam with precast hollow core slabs(CBHCSs)is a relatively new floor structure that can be applied to various long-span ***,human-induced vibrations may present serviceability issues in such *** alleviate vibrations,both the walking forces excited by humans and the associated floor responses must be *** this study,150 load–time histories of walking,excited by 25 test participants,are obtained using a force measuring *** dynamic loading factors and phase angles in the Fourier series functions for one-step walking are ***,walking tests are performed on seven CBHCS specimens to capture the essential dynamic properties of mode shapes,natural frequencies,damping ratios,and acceleration time *** CBHCS floor system generally exhibits a high frequency(>10 Hz)and low damping(damping ratioy studies using the finite element method are conducted to investigate the vibration performance of the CBHCS floor system,where the floor thickness,steel beam type,contact time,and human weight are ***,analytical expressions derived for the fundamental frequency and peak acceleration agree well with the experimental results and are hence proposed for practical use.

关键词： Composite beam Hollow core slab Walking force Floor vibration Mode shape

Predicting roof-surface wind pressure induced by conical vortex using a BP neural network combined with POD

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Building Simulation 2022年第8期15卷 1475-1490页

作者： Fubin chen Wen Kang Zhenru Shu Qiusheng Li yi Li yfrank chen Kang Zhou School of Civil Engineering Changsha University of Science and TechnologyChangsha410082China School of Civil Engineering Central South UniversityChangsha410083China Department of Architecture and Civil Engineering City University of Hong KongKowloonHong KongChina Hunan Provincial Key Laboratory of Structures for Wind Resistance and Vibration Control&School of Civil Engineering Hunan University of Science and TechnologyXiangtan411201China Department of Civil Engineering The Pennsylvania State UniversityMiddletownPA 17057USA

This study aims to examine the feasibility of predicting surface wind pressure induced by conical vortex using a backpropagation neural network(BPNN)combined with proper orthogonal decomposition(POD),in which a 1:150 scaled model with a large-span retractable roof was tested in wind tunnel under both laminar and turbulent flow *** distributions of mean and fluctuating wind pressure coefficients were first described,and the effects of inflow turbulence,wind direction,roof opening were examined *** the prediction of wind pressure,the POD-BPNN model was trained using measurement data from adjacent *** prediction results are overall *** root-mean-square-error(RMSE)between test and predicted data lies mostly within 10%.In particular,the prediction of mean wind pressure is found to be better than that of fluctuating wind *** outcomes in this study highlight that the proposed POD-BPNN model can be well used as a useful tool to predict surface wind pressure.

关键词： wind tunnel test-roof-surface wind pressure conical vortex proper orthogonal decomposition(POD) backpropagation neural network(BPNN)

步行激励下大跨度钢-混凝土空心板组合梁振动舒适度研究（英文）

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2022年第12期 93-104+6页

作者：刘界鹏黄鉥李江 y.frank chen School of Civil Engineering&Key Laboratory of New Technology for Construction of Cities in Mountain Area Ministry of Education Chongqing University Central-South Architectural Design Institute Co. Ltd. Department of Civil Engineering The Pennsylvania State University

大跨度预制钢-混凝土空心板组合梁(CBHCS)是一种新型的楼板结构,可应用于各种大跨度结构。然而,人为引起的振动会对此类结构的使用性产生影响。为了减轻振动,需要探究由人引起的步行力和楼板状态之间的关系。本文首先使用测力板获取了2...

大跨度预制钢-混凝土空心板组合梁(CBHCS)是一种新型的楼板结构,可应用于各种大跨度结构。然而,人为引起的振动会对此类结构的使用性产生影响。为了减轻振动,需要探究由人引起的步行力和楼板状态之间的关系。本文首先使用测力板获取了25名测试者的150个步行力,确定了单步行走的傅里叶级数中的动态载荷系数和相位角。其次,对7个CBHCS试样进行了行走测试,获取了模态振型、固有频率、阻尼比和加速度等基本动态特性。CBHCS楼板系统通常表现出高频(>10 Hz)和低阻尼(阻尼比<2%)的特性。本文还使用有限元方法进行了灵敏度研究,以研究CBHCS楼板系统的振动性能,考虑了楼板厚度、钢梁类型、接触时间和人体重量。最后,本文推导了基频和峰值加速度的解析表达式,与实验结果吻合较好,具有实际应用的价值。

关键词：

重复压应力作用后再生混凝土中氯离子渗透性研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

混凝土 2017年第1期 31-33页

作者：欧阳璋陈幼佳太原理工大学建筑与土木工程学院山西太原030024 美国宾夕法尼亚州立大学工程学院米德尔顿pa17057

再生混凝土对氯离子的渗透率也随荷载反复作用导致的混凝土内部的结构变化而变化,研究了重复荷载作用下对再生混凝土氯离子渗透性的影响。根据再生混凝土本身的承受应力状况,分别测量对普通混凝土和不同替代率的再生混凝土反复加卸载最... 详细信息

再生混凝土对氯离子的渗透率也随荷载反复作用导致的混凝土内部的结构变化而变化,研究了重复荷载作用下对再生混凝土氯离子渗透性的影响。根据再生混凝土本身的承受应力状况,分别测量对普通混凝土和不同替代率的再生混凝土反复加卸载最大压应力为45%fcy、80%fcy五次后的氯离子渗透性情况。研究表明:经5次加卸载后,再生混凝土氯离子渗透率比普通混凝土要高;反复施加5次荷载后,不同水灰比的再生混凝土与普通混凝土的渗透性,都随着水灰比的增大而增大;加卸载5次最大应力为45%fcy后,替代率不同的再生混凝土渗透性均比相应未加载混凝土大,最大荷载从45%fcy提高到80%fcy后,其氯离子渗透性进一步增大。

关键词：再生混凝土替代率重复荷载氯离子渗透性

Control Policy Learning Design for Vehicle Urban Positioning via BeiDou Navigation

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第1期37卷 114-135页

作者： QIN yahang ZHANG chengye chen Ci XIE Shengli LEWIS frank L School of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of IoT Information Technology Guangzhou 510006China. Center for Intelligent Batch Manufacturing Based on IoT Technology Key Laboratory of Intelligent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint Laboratory for Smart Discrete Manufacturing Guangzhou 510006China Key Laboratory of Intelligent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a learning-based control policy design for point-to-point vehicle positioning in the urban environment via BeiDou *** navigating in urban canyons,the multipath effect is a kind of interference that causes the navigation signal to drift and thus imposes severe impacts on vehicle localization due to the reflection and diffraction of the BeiDou ***,the authors formulated the navigation control system with unknown vehicle dynamics into an optimal control-seeking problem through a linear discrete-time system,and the point-to-point localization control is modeled and handled by leveraging off-policy reinforcement learning for feedback *** proposed learning-based design guarantees optimality with prescribed performance and also stabilizes the closed-loop navigation system,without the full knowledge of the vehicle *** is seen that the proposed method can withstand the impact of the multipath effect while satisfying the prescribed convergence rate.A case study demonstrates that the proposed algorithms effectively drive the vehicle to a desired setpoint under the multipath effect introduced by actual experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation multipath effect prescribed convergence rate reinforcement learning urban localization.

Empirically evaluating virtual reality’s effect on reservoir engineering tasks

在线全文

学校读者我要写书评

暂无评论

Visual Informatics 2024年第1期8卷 26-46页

作者： Bryson Lawton Nanjia Wang Steven Samoil Parisa Daeijavad Siqi Xie Zhangxin chen frank Maurer Department of Computer Science University of Calgary2500 University Dr NWCalgaryT2N 1N4AlbertaCanada Department of Chemical&Petroleum Engineering University of Calgary2500 University Dr NWCalgaryT2N 1N4AlbertaCanada

To help determine in what ways virtual reality(VR)technologies may benefit reservoir engineering workflows,we conducted a usability study on a prototype VR tool for performing reservoir model analysis *** leveraging the strengths of VR technologies,this tool’s aim is to help advance reservoir analysis workflows beyond conventional methods by improving how one understands,analyzes,and interacts with reservoir model *** evaluate our tool’s VR approach to this,the study presented herein was conducted with reservoir engineering experts who used the VR tool to perform three common reservoir model analysis tasks:the spatial filtering of model cells using movable planes,the cross-comparison of multiple models,and well path *** study found that accomplishing these tasks with the VR tool was generally regarded as easier,quicker,more effective,and more intuitive than traditional model analysis software while maintaining a feeling of low task workload on ***,participants provided positive feedback regarding their experience with using VR to perform reservoir engineering work tasks,and in general,it was found to improve multi-model cross-analysis and rough object manipulation in *** indicates the potential for VR to be better than conventional means for some work tasks and participants also expressed they could see it best utilized as an addition to current software in their reservoir model analysis *** were,however,some concerns voiced when considering the full adoption of VR into their work that would be best first addressed before this took place.

关键词： Immersive analytics Visual analytics Data visualization Reservoir engineering Virtual reality VR

Application of machine learning in perovskite materials and devices:A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第7期94卷 254-272页

作者： Ming chen Zhenhua yin Zhicheng Shan Xiaokai Zheng Lei Liu Zhonghua Dai Jun Zhang Shengzhong(frank)Liu Zhuo Xu School of Electric Power Civil Engineering and ArchitectureCollege of Physics and Electronics EngineeringState Key Laboratory of Quantum Optics and Quantum Optics DevicesShanxiUniversityTaiyuan030006ShanxiChina Key Laboratory of Applied Surface and Colloid Chemistry National Ministry of EducationShanxi Engineering Lab for Advanced Energy TechnologySchool of Materials Science and EngineeringShaanxi Normal UniversityXi'an 710119ShaanxiChina State Key Laboratory of Catalysis Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina

Metal-halide hybrid perovskite materials are excellent candidates for solar cells and photoelectric *** recent years,machine learning(ML)techniques have developed rapidly in many fields and provided ideas for material discovery and *** can be applied to discover new materials quickly and effectively,with significant savings in resources and time compared with traditional experiments and density functional theory(DFT)*** this review,we present the application of ML in per-ovskites and briefly review the recent works in the field of ML-assisted perovskite ***,the advantages of perovskites in solar cells and the merits of ML applied to perovskites are ***,the workflow of ML in perovskite design and some basic ML algorithms are ***,the applications of ML in predicting various properties of perovskite materials and devices are ***,we propose some prospects for the future development of this *** rapid devel-opment of ML technology will largely promote the process of materials science,and ML will become an increasingly popular method for predicting the target properties of materials and devices.

关键词： Machine learning Perovskite Materials design Bandgap engineering Stability Crystal structure

Construction Activity Analysis of Workers Based on Human Posture Estimation Information

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第2期33卷 225-236页

作者： Xuhong Zhou Shuai Li Jiepeng Liu Zhou Wu yohchia frank chen School of Civil Engineering Chongqing UniversityChongqing 400044China School of Automation Chongqing UniversityChongqing 400044China Department of Civil Engineering The Pennsylvania State UniversityMiddletownPA 17057USA

Identifying workers’construction activities or behaviors can enable managers to better monitor labor efficiency and construction ***,current activity analysis methods for construction workers rely solely on manual observations and recordings,which consumes considerable time and has high labor *** have focused on monitoring on-site construction activities of ***,when multiple workers are working together,current research cannot accu rately and automatically identify the construction *** research proposes a deep learning framework for the automated analysis of the construction activities of multiple *** this framework,multiple deep neural network models are designed and used to complete worker key point extraction,worker tracking,and worker construction activity *** designed framework was tested at an actual construction site,and activity recognition for multiple workers was performed,indicating the feasibility of the framework for the automated monitoring of work efficiency.

关键词： Pose estimation Activity analysis Object tracking Construction workers Automatic systems

Facile Li-Al layered double hydroxide films on Al alloy for enhanced hydrophobicity, anti-biofouling and anti-corrosion performance

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第20期79卷 230-242页

作者： Ji Li Tianci yuan chengliang Zhou Bo chen yi Shuai Dawang Wu Dongchu chen Xiaohu Luo y.frank cheng yali Liu State Key Laboratory for Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha410082China Department of Mechanical and Manufacturing Engineering University of CalgaryCalgaryAlbertaT2N 1N4Canada School of Chemistry and Chemical Engineering Qiannan Normal University for NationalitiesDuyun558000China College of Mechanical Engineering and Applied Electronics Technology Beijing University of TechnologyBeijing100124China School of Material Science and Energy Engineering Foshan UniversityFoshan528000China

In this work,lithium(Li)-aluminum(Al)layered double hydroxide(LDH)films modified by 4-amino-2-((hydrazine methylene)amino)-4-oxobutanoic acid(denoted as AOA acid)and/or 1H,1H,2H,2H-perfluorooctyltriethoxysilane were prepared on 6N01 Al alloy by a facile,in-situ growth method with enhanced hydrophobicity,anti-biofouling and anti-corrosion *** preparation is low energy consumptive and environment friendly,relying on self-assembly at ambient *** structure,molecular weight and functional groups of the synthesized AOA acid were characterized by NMR spectrometer,ESI-MS spectrometer and Fourier transform infrared(FT-IR)*** the compositions,structure and morphology of the films were characterized by Fourier transform infrared(FT-IR)spectroscopy,glancing-angle X-ray diffraction(GA-XRD),X-ray photoelectron spectroscopy(XPS),field emission scanning electron microscopy(FE-SEM)and energy-dispersive x-ray spectrum(EDS).Water contact angle measurements(CA)and atomic force microscopy(AFM)characterization show that the films possess a micro/nanostructure with an improved *** test,neutral salt tests(NSS)and electrochemical impedance spectroscopy(EIS)conducted in 3.5 wt.%NaCl solutions demonstrate the improved corrosion resistance of the films over bare Al ***,the films also possess an excellent anti-bacterial property toEscherichia coli,Bacillus subtilis and sulfate-reducing bacteria.

关键词： Li-Al layered double hydroxides Anti-biofouling Hydrophobicity Anti-bacterial Anti-corrosion