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Study on wave dispersion characteristics of piezoelectric sandwich nanoplates considering surface effects

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Applied Mathematics and Mechanics(English Edition) 2022年第9期43卷 1339-1354页

作者： Biao HU Juan LIU Yuxing wang Bo ZHANG Jing wang Huoming SHEN Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace EngineeringSouthwest Jiaotong UniversityChengdu 610031China School of Mechanical and Electrical Engineering Southwest Petroleum UniversityChengdu 610500China

In this study,the wave propagation properties of piezoelectric sandwich nanoplates deposited on an orthotropic viscoelastic foundation are analyzed by considering the surface effects(SEs).The nanoplates are composed of a composite layer reinforced by graphene and two piezoelectric surface layers.Utilizing the modified Halpin-Tsai model,the material parameters of composite layers are obtained.The displacement field is determined by the sinusoidal shear deformation theory(SSDT).The Euler-Lagrange equation is derived by employing Hamilton’s principle and the constitutive equations of piezoelectric layers considering the SEs.Subsequently,the nonlocal strain gradient theory(NSGT)is used to obtain the equations of motion.Next,the effects of scale parameters,graphene distribution,orthotropic viscoelastic foundation,and SEs on the propagation behavior are numerically examined.The results reveal that the wave frequency is a periodic function of the orthotropic angle.Furthermore,the wave frequency increases with the increase in the SEs.

关键词： surface effect(SE) scale parameters orthotropic foundation functional gradient graphene piezoelectric sandwich nanoplate

A Triangulation-Based Visual Localization for Field Robots

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IEEE/CAA Journal of Automatica Sinica 2022年第6期9卷 1083-1086页

作者： James Liang Yuxing wang Yingjie Chen Baijian Yang Dongfang Liu Department of Computer Engineering Rochester Institute of TechnologyRochesterNY 14623 USA IEEE Department of Computer and Information Technology Purdue UniversityWest LafayetteIN 47907 USA

Dear Editor,Visual localization relies on local features and searches a prestored GPS-tagged image database to retrieve the reference image with the highest similarity in feature spaces to predict the current location[1]-[3].For the conventional methods[4]-[6],local features are generally explored by multiple-stage feature extraction whichfirst detects and then describes key-point features[4],[7].

关键词： Visual database image

Numerical Study of Heat Transfer Characteristic for Subcooled Falling Film outside the Shaped Tubes under Rolling Motion

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Journal of Thermal Science 2023年第3期32卷 922-932页

作者： HAN Hui wang Junqi wang Shaowei LI yuxing Provincial Key Laboratory of Oil and Gas Storage and Transportation Safety in Shandong Province China University of Petroleum(Huadong)Qingdao 266580China

The heat transfer performance of spiral wound heat exchanger used in the floating liquefied natural gas(FLNG)may be significantly affected by the sloshing conditions.In this paper,a three-dimensional numerical model combined with the dynamic mesh technology is conducted to study subcooled falling film heat transfer under static and sloshing conditions.The three-dimensional velocity distribution of the liquid film on the shell side is observed.The effects of cross-section shape of heat exchange tubes,Reynolds numbers and sloshing parameters on heat transfer characteristics are analyzed.The results indicate that the heat transfer performance of the egg-shaped tube is superior to that of the elliptical and circular tube under both static and sloshing conditions due to significant heat transfer improvement in the lower half of the tube.The heat transfer coefficients of three different kinds of tubes decrease under sloshing conditions.When the rolling amplitude is 6°,the average heat transfer coefficients of the circular tube,elliptical tube and egg-shaped tube are reduced by 2.1%,3.7%and 4.9%respectively.Under the current sloshing parameters,increasing the rolling amplitude,the heat transfer coefficients of three different tubes are slightly increased,while the sloshing period has little effect on heat transfer.The egg-shaped tube and elliptical tube are greatly affected by sloshing motion at the low Reynolds number,while the effect is relatively small at the high Reynolds number.

关键词： falling film flow sloshing condition spiral wound heat exchanger floating liquefied natural gas

Photodegradable polar-functionalized polyethylenes

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National Science Review 2023年第7期10卷 124-133页

作者： Chaoqun wang Jian Xia yuxing Zhang Xiaoqiang Hu Zhongbao Jian State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences School of Applied Chemistry and Engineering University of Science and Technology of China

The degradation of plastics has attracted much attention from the global community.Polyethylenes(PEs),as the most abundant synthetic plastics,are most frequently studied.PE is non-degradable and non-polar because of the sole presence of the pure hydrocarbon components.Concurrent incorporation of both in-chain cleavable and functional groups into the PE chain is an effective pathway to overcome the non-degradable and non-polar issue;however,the method for achieving this pathway remains elusive.Here,we report a strictly non-alternating(>99%) terpolymerization of ethylene with CO and fundamental polar monomers via a coordination-insertion mechanism using late transition metal catalysts,which effectively prevents the formation of undesired chelates originating from both co-monomers under a low CO concentration.High-molecular-weight linear PEs with both in-chain isolated keto(>99%) and main-chain functional groups are prepared.The incorporation of key low-content isolated keto groups makes PEs photodegradable while retaining their desirable bulk material properties,and the introduction of polar functional groups considerably improves their surface properties.

关键词： degradable plastic homogeneous catalysis C1 chemistry non-alternating copolymerization polyolefin

Investigation on hydrate growth at the oil–water interface:In the presence of asphaltene

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Chinese Journal of Chemical Engineering 2022年第5期35卷 211-218页

作者： Guangchun Song Yuanxing Ning yuxing Li Wuchang wang Shandong Key Laboratory of Oil-Gas Storage and Transportation Safety College of Pipeline and Civil EngineeringChina University of PetroleumQingdao 266580China State Key Laboratory of Natural Gas Hydrates Beijing 100028China

Natural gas hydrates can readily form in deep-water oil production processes and pose a great threat to the oil industry.Moreover,the coexistence of hydrate and asphaltene can result in more severe challenges to subsea flow assurance.In order to study the effects of asphaltene on hydrate growth at the oil-water interface,a series of micro-experiments were conducted in a self-made reactor,where hydrates nucleated and grew on the surface of a water droplet immersed in asphaltene-containing oil.Based on the micro-observations,the shape and growth rate of the hydrate shell formed at the oil-water interface were mainly investigated and the effects of asphaltene on hydrate growth were analyzed.According to the experimental results,the shape of the water droplet and the interfacial area changed significantly after the formation of the hydrate shell when the asphaltene concentration was higher than a certain value.A mechanism related to the reduction of the interfacial tension caused by the absorption of asphaltenes on the interface was proposed for illustration.Moreover,the growth rate of the hydrate shell decreased significantly with the increasing asphaltene concentration under experimental conditions.The conclusions of this paper could provide preliminary insight how asphaltene affect hydrate growth at the oil-water interface.

关键词： Hydrate Asphaltene Interface Growth Shape

Wave propagation in graphene reinforced piezoelectric sandwich nanoplates via high-order nonlocal strain gradient theory

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Acta Mechanica Sinica 2021年第9期37卷 1446-1456,I0003页

作者： Biao Hu Juan Liu Yuxing wang Bo Zhang Huoming Shen Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and EngineeringSouthwest Jiao Tong UniversityChengdu610031China

Αn analytical method is developed to explore the wave propagation characteristics of piezoelectric sandwich nanoplates in the present work.The sandwich nanoplates are composed of a graphene reinforced composite core layer with two piezoelectric surface layers exposed to electric field.The material properties of the nanocomposite layer are given by the Halpin–Tsai model and mixture’s rule.The Euler–Lagrange equation of the nanoplates is obtained by Hamilton's principle and first-order shear deformation theory.Then,combining the high-order nonlocal strain gradient theory with the hygrothermal constitutive relationship of composite nanoplates,the nonlocal governing equations are presented.Finally,numerical studies are conducted to demonstrate the influences of scale parameters,applied external voltage,temperature variation,moisture variation,graphene size,and weight fraction on wave frequency.The results reveal that low-order and high-order nonlocal parameters and length scale parameters have different effects on wave frequency.The wave frequency can be reduced by increasing temperature and the thickness of graphene.This could facilitate the investigation of the dynamic properties of graphene nanocomposite structures.

关键词： Wave propagation High-order nonlocal strain gradient theory Piezoelectric sandwich nanoplates Graphene platelets Hygrothermal environment

Assembling Fe_(2)O_(3)/BiOCl Composite for Highly Effective Degradation of Water Pollutants under Visible-Light Irradiation

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China Petroleum Processing & Petrochemical Technology 2022年第1期24卷 59-67页

作者： Liu Xiaoqing wang Zisha Hu yuxing wang Haifang School of Environment and Safety Engineering North University of ChinaTaiyuan 030051 Beijing Aerospace Institute for Metrology and Measurement Technology Beijing 100076

Fe_(2)O_(3)was synthesized by the solvothermal method,and the synthesized Fe_(2)O_(3)was added in the process of preparing BiOCl by hydrolysis,and then Fe_(2)O_(3)/BiOCl photocatalytic materials with different composite ratios were prepared.The optimal Fe_(2)O_(3)/BiOCl(1Fe/50Bi)sample showed a highest photocatalytic efficiency for cationic dyes(Rhodamine B)and anionic dye(methyl orange)degradation irradiated with visible light,as compared with that of a bare BiOCl catalyst.Meanwhile,radical capturing experiments indicated that the photo-induced holes(h^(+)) is the main active species.X-ray powder diffraction and ultraviolet-visible diffuse reflectance spectroscopy were used to characterize the structural and optical properties,which proved that Fe_(2)O_(3)was successfully composited to the BiOCl surface and effectively reduced the bandgap of BiOCl.More importantly,the optimal 1Fe/50Bi sample shows the highest photocatalytic efficiency for tetracycline(TC)degradation(98%)irradiated with visible light,as compared with that of a bare BiOCl catalyst.Consequently,the Fe_(2)O_(3)/BiOCl photocatalyst have potential applications in environmental purification.

关键词： Fe_(2)O_(3) BiOCl composite photocatalytic

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王玉兴谈治痿者独取阳明之易水方案

中国中医药现代远程教育 2022年第24期20卷 63-66页

作者：曾粤睿王玉兴天津中医药大学中医学院天津301617

痿证是临床常见的以肢体痿软无力,不能随意运动,甚或肌肉萎缩为特征的一类疾病,属于现代医学的重症肌无力、肌萎缩侧索硬化、运动神经元病等范畴。《黄帝内经》所述“治痿者独取阳明”是公认的治疗原则,后世医家对此各有发挥,其中张元... 详细信息

痿证是临床常见的以肢体痿软无力,不能随意运动,甚或肌肉萎缩为特征的一类疾病,属于现代医学的重症肌无力、肌萎缩侧索硬化、运动神经元病等范畴。《黄帝内经》所述“治痿者独取阳明”是公认的治疗原则,后世医家对此各有发挥,其中张元素所创的易水学派在痿证治疗方案上亦有独到之处,王玉兴教授从事临床与文献研究多年,作者有幸跟师学习,受益匪浅,现将王玉兴教授所谈《黄帝内经》之痿证与“治痿者独取阳明”之易水方案记录如下。

关键词：痿证治痿者独取阳明易水学派补中益气汤王玉兴

Progressive Failure Analysis of Composite/Aluminum Riveted Joints Subjected to Pull-Through Loading

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Chinese Journal of Mechanical Engineering 2023年第1期36卷 129-138页

作者： yuxing Yang Yongjie Bao Xueshu Liu Jinlong wang Fengming Du Marine Engineering College Dalian Maritime UniversityDalian116026China School of Automotive Engineering Dalian University of TechnologyDalian116024China

Out-of-plane mechanical properties of the riveted joints restrict the performance of the wing box assembly of airplane.It is necessary to investigate the pull-through performance of the composite/metal riveted joints in order to guide the riveting design and ensure the safety of the wing box assembly.The progressive failure mechanism of composite/aluminum riveted joint subjected to pull-through loading was investigated by experiments and finite element method.A progressive damage model based on the Hashin-type criteria and zero-thickness cohesive zone method was developed by VUMAT subroutine,which was validated by both open-hole tensile test and three-point bending test.Predicted load-displacement response,failure modes and damage propagation were analysed and compared with the results of the pull-through tests.There are 4 obvious characteristic stages on the load-displacement curve of the pull-through test and that of the finite element model:first load take-up stage,damage stage,second load take-up stage and failure stage.Relative error of stiffness,first load peak and second load peak between finite element method and experiments were 8.1%,-3.3%and 10.6%,respectively.It was found that the specimen was mainly broken by rivet-penetration fracture and delamination of plies of the composite laminate.And the material within the scope of the rivet head is more dangerous with more serious tensile damages than other regions,especially for 90°plies.This study proposes a numerical method for damage prediction and reveals the progressive failure mechanism of the hybrid material riveted joints subjected to the pull-through loading.

关键词： Composite/metal joints Riveted joints Pull-through test Progressive damage model