检索结果-南通市图书馆

Thickness-Shear Frequencies of an Infinite Quartz Plate with Graded Material Properties Across the Thickness

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2020年第3期33卷 361-367页

作者： rongxing wu Wenliang Zhang Tingfeng Ma Jianke Du Ji Wang Piezoelectric Device Laboratory School of Mechanical Engineering and MechanicsNingbo University818 Fenghua RoadNingbo 315211ZhejiangChina Department of Architectural Engineering Ningbo Polytechnic1069 Xinda RoadBeilun DistrictNingbo 315800ZhejiangChina

For quartz crystal resonators of thickness-shear type,the vibration frequency and mode shapes reflect the basic material and structural properties of a quartz crystal plate and the variation with time under attack by erosive gases and liquids that can cause surface and internal degradation in a graded *** gradual effects,in turn,will change surface conditions through elastic constants and stiffness and more importantly the gradient of such properties across the thickness with certain *** we study the thickness-shear vibrations of functionally graded material plates with properties of the popular AT-cut quartz crystal varying across the thickness in a general pattern represented by both sine and cosine components of the *** vibration solutions are obtained through the Fourier expansion of the plate deformation.

关键词： Thickness-shear Frequency Vibration Functionally graded materials Resonator

Frequency–Temperature Analysis of Thickness-Shear Vibrations of SC-Cut Quartz Crystal Plates with the First-Order Mindlin Plate Equations

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

Acta Mechanica Solida Sinica 2021年第4期34卷 516-526页

作者： rongxing wu Wenjun Wang Guijia Chen Jianke Du Tingfeng Ma Ji Wang Department of Architectural Engineering Ningbo Polytechnic1069 Xinda RoadBeilun DistrictNingbo315800China Piezoelectric Device Laboratory School of Mechanical Engineering and MechanicsNingbo University818 Fenghua RoadNingbo315211China State Key Laboratory for Strength and Vibration of Mechanical Structures School of AerospaceXi’an Jiaotong University28 Xianning Xilu RoadXi’an710049China TXC-NBU Joint Center of Research School of Mechanical Engineering and MechanicsNingbo University818 Fenghua RoadNingbo315211China

With the incremental thermal field theory by Lee and Yong,the Mindlin plate equations for the analysis of thickness-shear vibrations of SC-cut quartz crystal with the consideration of thermal effect have been *** assuming straight-crested waves in a rectangular plate,the dispersion relations,frequency spectra,mode shapes,and frequency–temperature relations of the thickness-shear mode of SC-cut quartz crystal plates are calculated with plate *** computational results from SC-cut quartz crystal plates are compared with those from AT-cut,which shows that SC-cut resonators have better frequency–temperature relation as a *** practical applications,such results will be useful in the precision design and improvement of SC-cut quartz crystal resonator structures.

关键词： Quartz Anisotropic Plate Resonator Vibration Temperature

A nonlinear analysis of surface acoustic waves in isotropic elastic solids

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

Theoretical & Applied Mechanics Letters 2022年第2期12卷 98-103页

作者： Haoxiang wu rongxing wu Tingfeng Ma Zixiao Lu Honglang Li Ji Wang Piezoelectric Device Laboratory School of Mechanical Engineering&MechanicsNingbo UniversityNingbo 315211China National Center for Nanoscience and Technology Beijing 100190China

With the fast evolution of wireless and networking communication technology,applications of surface acoustic wave(SAW),or Rayleigh wave,resonators are proliferating with fast shrinking sizes and increasing *** is inevitable that the smaller resonators will be under a strong electric field with induced large deformation,which has to be described in wave propagation equations with the consideration of *** this study,the formal nonlinear equations of motion are constructed by introducing the nonlinear constitutive relation and strain components in a standard procedure,and the equations are simplified by the extended Galerkin method through the elimination of *** wave velocity of the nonlinear SAW is obtained from approximated nonlinear equations and boundary conditions through a rigorous solution *** is shown that if the amplitude is small enough,the nonlinear results are consistent with the linear results,demonstrating an alternative procedure for nonlinear analysis of SAW devices working in nonlinear state.

关键词： Surface Wave Nonlinear Galerkin Resonator

The Extended Galerkin Method for Approximate Solutions of Nonlinear Vibration Equations

在线全文

学校读者我要写书评

暂无评论

The Extended Galerkin Method for Approximate Solutions of No...

Interfacial modification using the cross-linkable tannic acid for highly-efficient perovskite solar cells with excellent stability

第十四届全国振动理论及应用学术会议(NVTA2021)

作者： Ji Wang rongxing wu Piezoelectric Device Laboratory Ningbo University

An extension has been made with the popular Galerkin method by integrating the weighted equation of motion over the time of one period of vibrations to eliminate the harmonics from the deformation function. A set of successive equations of coupled higher-order vibration amplitudes is obtained, and a nonlinear eigenvalue problem is presented for the frequency-amplitude dependence of nonlinear vibrations of successive displacements. The subsequent solutions of vibration frequencies and deformation are actually consistent with other successive approximate methods such as the harmonics balance method. This is a novel extension to Galerkin method which has wide applications in approximate solutions particularly for solid mechanics problems. This extended Galerkin method can also be utilized for the analysis of free and forced nonlinear vibrations of structures as a new technique with significant advantages.

关键词： vibration nonlinear frequency approximation Galerkin

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第4期91卷 236-244页

作者： Xing Gao Lirong Rong Fei wu Yen-Hung Lin Ye Zeng Junhong Tan rongxing He Cheng Zhong Linna Zhu Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energy School of Materials&EnergySouthwest UniversityChongqing 400715China Hubei Key Lab on Organic and Polymeric Optoelectronic Materials Department of ChemistryWuhan UniversityWuhan 430072HubeiChina Key Laboratory of Luminescence Analysis and Molecular Sensing Ministry of EducationSchool of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China Department of Electronic and Computer Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloon 999077Hong KongChina State Key Laboratory of Advanced Displays and Optoelectronics Technologies The Hong Kong University of Science and TechnologyClear Water BayKowloon 999077Hong KongChina

Although the performance of perovskite solar cells(PSCs)has been dramatically increased in recent years,stability is still the main obstacle preventing the PSCs from being *** device instability can be caused by a variety of reasons,including ions diffusion,surface and grain boundary defects,*** this work,the cross-linkable tannic acid(TA)is introduced to modify perovskite film through post-treatment *** numerous organic functional groups(–OH and C=O)in TA can interact with the uncoordinated Pb^(2+)and I^(-)ions in perovskite,thus passivating defects and inhibiting ions *** addition,the formed TA network can absorb a small amount of the residual moisture inside the device to protect the perovskite ***,TA modification regulates the energy level of perovskite,and reduces interfacial charge ***,following TA treatment,the device efficiency is increased significantly from 21.31%to 23.11%,with a decreased hysteresis ***,the treated device shows excellent air,thermal,and operational *** light of this,the readily available,inexpensive TA has the potential to operate as a multipurpose interfacial modifier to increase device efficiency while also enhancing device stability.

关键词： Tannic acid Defect passivation lons diffusion Hydrophilic Stability Perovskite solar cells

MR颅脑磁敏感加权成像评估高血压分级与脑内微出血的相关性

在线全文

学校读者我要写书评

暂无评论

医学影像学杂志 2024年第3期34卷 5-8页

作者：吴荣兴廖仁引周卫国周之明韦素冬冯景强广西柳钢医疗有限公司医院放射科广西柳州545001

目的探讨MR颅脑磁敏感加权成像(SWI)评估高血压分级与脑内微出血的相关性。方法选取在我院接受临床诊断和治疗的高血压患者300例,根据血压水平分为1级高血压组、2级高血压组、3级高血压组。所有患者均行MR颅脑SWI检查,比较三组患者脑微... 详细信息

目的探讨MR颅脑磁敏感加权成像(SWI)评估高血压分级与脑内微出血的相关性。方法选取在我院接受临床诊断和治疗的高血压患者300例,根据血压水平分为1级高血压组、2级高血压组、3级高血压组。所有患者均行MR颅脑SWI检查,比较三组患者脑微出血(CMBs)的检出数量,并分析CMBs检出数量与高血压分级的相关性。采用MedCalc软件计算SWI诊断不同高血压分级患者CMBs的敏感度、特异度、阳性预测值、阴性预测值。根据CMBs检查结果对CMBs进行分型,分析高血压分级和CMBs分型的相关性。结果3级高血压组患者CMBs阳性率和CMBs检出数量均高于1级高血压组和2级高血压组,差异有统计学意义(P0,P0.05)。3级高血压组患者Ⅰ型CMBs、Ⅱ型CMBs、Ⅴ型CMBs的阳性率均高于1级高血压组和2级高血压组,差异有统计学意义(P0.05)。结论脑内微出血和高血压病情密切相关,MR颅脑SWI对评估不同高血压分级患者CMBs的分布情况具有重要的应用价值。

关键词：磁敏感加权成像高血压分级脑微出血相关性分析

显式模拟类橡胶材料Mullins效应滞回圈

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

力学学报 2019年第2期51卷 484-493页

作者：王晓明吴荣兴肖衡宁波职业技术学院建筑工程学院浙江宁波315000 暨南大学力学和建筑工程学院广州51063

通过显式、直接的方法提出一个多轴可压缩应变能函数,用来模拟类橡胶材料在加载-卸载作用下,由于Mullins效应而产生的应力-应变滞回圈.本文的创新点在于将表征能量耗散的变量引入到应变能函数.新的弹性势具有以下两个特点:第一,在加载... 详细信息

通过显式、直接的方法提出一个多轴可压缩应变能函数,用来模拟类橡胶材料在加载-卸载作用下,由于Mullins效应而产生的应力-应变滞回圈.本文的创新点在于将表征能量耗散的变量引入到应变能函数.新的弹性势具有以下两个特点:第一,在加载情况下,新引入的变量不会对弹性势产生任何影响,因此,只要给出合适的形函数显式表达,3个基准实验,包括单轴拉伸和压缩,等双轴拉伸和压缩,以及平面应变,都可精确模拟;第二,新引入的变量在卸载情况下将被激活.在不同的卸载应力下,变量将发生改变,从而影响弹性势,使其最终产生不同的应力-应变关系卸载曲线,与对应的加载曲线共同构成应力-应变滞回圈.通过对Mullins效应实验数据进行分析和研究,得出了卸载形函数在不同卸载应力下变化的规律,并预测不同卸载应力下的应力-应变关系.最后,我们将得到精确匹配实验数据的数值模拟结果,从而证明本文方法不仅可以精确匹配至少3个基准实验,还可以模拟和预测类橡胶材料在加载-卸载作用下由于Mullins效应而产生的滞回圈.

关键词：显式类橡胶材料应变能弹性势 Mullins效应基准实验滞回圈

在线全文

学校读者我要写书评

暂无评论

表面波飞机结冰传感器的研究

压电与声光 2011年第5期33卷 679-682,686页

作者：吴荣兴胡海柯宁波大学机械与力学学院浙江宁波315211 慈溪市输变电工程有限公司浙江慈溪315300

首先分析了覆盖冰层的各向同性半无限大弹性体中的声表面波(SAW),求得了声表面波波速与冰层厚度间的关系。结果表明,当冰层厚度为0时,求得的波速与没有冰层覆盖相对应的半无限大弹性体的声表面波波速相同;当冰层厚度不断增加时,求得的... 详细信息

首先分析了覆盖冰层的各向同性半无限大弹性体中的声表面波(SAW),求得了声表面波波速与冰层厚度间的关系。结果表明,当冰层厚度为0时,求得的波速与没有冰层覆盖相对应的半无限大弹性体的声表面波波速相同;当冰层厚度不断增加时,求得的声表面波波速趋向于冰层中的波速。随后分析了基体是各向同性无限大弹性板的情况。计算结果表明,由于弹性板与冰层的相互作用,实际振动会出现多个声表面波模态和相应的波速。

关键词：声表面波传感器冰层飞机波速

基于有理插值方法模拟可压缩类橡胶材料多轴变形行为

在线全文

学校读者我要写书评

暂无评论

应用力学学报 2021年第4期38卷 1541-1550页

作者：王晓明吴荣兴肖衡宁波职业技术学院应用力学研究所宁波315800 暨南大学力学与建筑工程学院广州510632

提出一个多轴应变能函数来模拟可压缩类橡胶材料在载荷作用下的大变形行为。首先,基于对数应变构造三个不变量,使得应变能函数分别具备可压缩功能、多轴有效功能以及适用于多个变形模式的功能;其次,利用有理插值方法构造单轴形函数,并... 详细信息

提出一个多轴应变能函数来模拟可压缩类橡胶材料在载荷作用下的大变形行为。首先,基于对数应变构造三个不变量,使得应变能函数分别具备可压缩功能、多轴有效功能以及适用于多个变形模式的功能;其次,利用有理插值方法构造单轴形函数,并结合前面引入的三个不变量,通过哈密顿插值方法构建统一的应变能函数;最后,在单轴情况下,应变能函数通过对Hencky应变求导,可以得到对应变形模式下的应力-应变关系。本文通过调节泊松比的大小来控制体积变化从而实现模型的可压缩性;此应变能函数可以模拟单轴拉伸压缩、平面应变以及等双轴拉伸等至少三个基准试验。新方法得到的伸长比-应力关系、伸长比-体积比关系与经典试验数据结果作比较,进而证明方法的准确性和有效性。

关键词：大变形类橡胶材料可压缩基准试验