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Mechanical model of round window membrane under reverse excitation

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Applied Mathematics and Mechanics(English Edition) 2016年第10期37卷 1341-1348页

作者： Yiqiang CHEN wenjuan yao Department of Civil Engineering Shanghai University

According to the vibration characteristics of the round window, a mechani- cal model of a round window membrane is established. The Euler equation of the round window and the complementary boundary conditions are derived by the variational prin- ciple. Combined with the Bessel function, an analytical solution of the round window displacement is obtained by MATHEMATICA. Combined with clinical characteristics of round window membrane lesion, the effect of sound transmission due to thickening of the round window membrane caused by the otitis media, shrinkage of the round window membrane area caused by otosclerosis, and hardening of the round window membrane itself is analyzed. The results show that with thickening of the round window membrane, the displacement of the round window membrane is decreased. In the meantime, with hardening of the round window membrane and shrinkage of the membrane area, the max- imum displacement Of the round window membrane is gradually reduced, leading to a decrease in sound transmission. Thus, the analyticM analysis can avoid interference of environment and the technical level of personnel, and it can evaluate transmission per- formance of the round window membrane efficiently, providing a theoretical basis for the reverse excitation of artificial prosthesis.

关键词： round window variational principle Euler equation complementary boundary condition Bessel function

Revealing the contribution of basilar membrane's biological activity to the mechanism of the cochlear phonosensitive amplification

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Applied Mathematics and Mechanics(English Edition) 2023年第5期44卷 823-840页

作者： J.Y.LIANG wenjuan yao Genomic Medicine Institute Lerner Research InstituteCleveland Clinic FoundationClevelandOH 44106U.S.A. Shanghai Institute of Applied Mathematics and Mechanics Shanghai UniversityShanghai 200072China School of Mechanics and Engineering Science Shanghai UniversityShanghai 200072China

Explaining the mechanism of the cochlear active phonosensitive amplification has been a major problem in *** basilar membrane(BM)is the key *** 1960,Nobel Laureate von B′ek′esy first discovered BM's traveling wave *** that time,BM's models only have considered the traveling wave but not the biological ***,a new model considering changes of BM's stiffness in space and time is established based on the immersed boundary method to describe its biological *** not only reproduces the results of traveling wave motion but also explains the mechanization on the generation of traveling *** important discovery is that changes of BM's stiffness in space and time will cause the unstable global resonance,which will induce amplification of sounds in *** important inference is that biological activity shall be included in the application of mechanical principles to the analysis of life,which is the essential difference between biomechanics and general mechanics.

关键词： basilar membrane(BM) biological activity mechanical analysis cochlear phonosensitive amplification

Mechanical model of organ of Corti

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Applied Mathematics and Mechanics(English Edition) 2017年第6期38卷 867-876页

作者： Yiqiang CHEN wenjuan yao Shaofeng LIU Department of Civil Engineering Shanghai University

According to the vibration characteristics of the organ of Corti （OC）, seven hypotheses are made to simplify the structure of the model, and a mechanical OC model is established. Using the variational principle, a displacement analytical expression is solved under a certain pressure. The results are in good agreement with experimental data, showing the validity of the formula. Combined with the damage caused by noise in clinic, it is found that the hardening of outer hair cells and outer stereocilia can lead to loss of hearing and generation of threshold shift. In addition, the results show that high frequency resonance occurs at the bottom of the basilar membrane （BM）, and low frequency resonance occurs at the top of the BM. This confirms the frequency selective characteristics of the BM. Further, using this formula can avoid interference of the envi- ronment and the technical level of the test personnel, and can evaluate performance of the OC objectively.

关键词： organ of Corti (OC) variational principle hardening of outer hair cells(OHCs) hardening of outer stereocilia threshold shift

Temperature stress analysis for bi-modulus beam placed on Winkler foundation

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Applied Mathematics and Mechanics(English Edition) 2017年第7期38卷 921-934页

作者： Jinling GAO wenjuan yao Jiankang LIU Department of Civil Engineering Shanghai University Shanghai Open Steel Structure Co. Ltd.

The materials with different moduli in tension and compression are called bi-modulus materials. Graphene is such a kind of materials with the highest strength and the thinnest thickness. In this paper, the mechanical response of the bi-modulus beam subjected to the temperature effect and placed on the Winkler foundation is studied. The differential equations about the neutral axis position and undetermined parameters of the normal strain of the bi-modulus foundation beam are established. Then, the analytical expressions of the normal stress, bending moment, and displacement of the foundation beam are derived. Simultaneously, a calculation procedure based on the finite element method （FEM） is developed to obtain the temperature stress of the bi-modulus struc- tures. It is shown that the obtained bi-modulus solutions can recover the classical modulus solution, and the results obtained by the analytical expressions, the present FEM proce- dure, and the traditional FEM software are consistent, which verifies the accuracy and reliability of the present analytical model and procedure. Finally, the difference between the bi-modulus results and the classical same modulus results is discussed, and several reasonable suggestions for calculating and optimizing the certain bi-modulus member in practical engineering are presented.

关键词： bi-modulus beam Winkler foundation temperature stress analytical so-lution secondary development of program

Numerical simulation of Corti stimulated by fluid in tunnel of Corti

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Applied Mathematics and Mechanics(English Edition) 2017年第5期38卷 737-748页

作者： Yiqiang CHEN wenjuan yao Shaofeng LIU Department of Civil Engineering Shanghai UniversityShanghai 200444China

In this paper, the effect of fluid in a tunnel of Corti （TC） on organ of Corti （OC） is studied. A three-dimensional OC model including basilar membrane （BM）, tectorial membrane （TM）, inner and outer hair cells （OHCs）, and reticular lamina （RL） is established by COMSOL. An initial pressure is applied to the fluid in the TC. The frequency response of the structure is analyzed, and the displacement of the BM is achieved. The results are in good agreement with the experimental data, confirming validity of the finite element model. Based on the model, the effect of fluid in the TC on the OC is studied. The results show that, when the pressure gradient is absent in the fluid, with the increase of the initial fluid pressure, the displacement of the BM increases. However, when the initial fluid pressure increases to a certain value, the increase rate of the displacement of the BM becomes very slow. The movement of the fluid amplifies the BM movement. Furthermore, the movement of the fluid can strengthen the movement of the OHCs and the shear movement of the stereocilia, especially in the vicinity of the characteristic frequency at which the amplification effect reaches a peak. Nevertheless, a pressure gradient in the fluid affects the BM movement.

关键词： tunnel of Corti (TC) organ of Corti (OC) frequency response fluidpressure

The unmediated choline sensor based on layered double hydroxides in hydrogen peroxide detection mode

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Science China Chemistry 2009年第12期52卷 2281-2286页

作者： DING ShouNian SHAN Dan yao wenjuan XUE HuaiGuo SUN YueMing COSNIER Serge School of Chemistry&Chemical Engineering Southeast UniversityNanjing 211189China Key Laboratory of Environmental Materials&Environmental Engineering of Jiangsu Province Yangzhou 225002China School of Chemistry&Chemical Engineering Yangzhou UniversityYangzhou 225002China Départment de Chimie Moléculaire UMR-5250 ICMG FR-2607CNRS UniversitéJoseph FouierBP-53Grenoble 38041France

In this work,we have developed a novel choline biosensor on the basis of immobilization of choline oxidase (ChOx) by the attractive materials layered double hydroxides (LDHs). Amperometric detection of choline was evaluated by holding the modified electrode at 0.5 V (vs. SCE). Due to the special properties of LDHs ([Zn3-Al-Cl]),such as chemical inertness,high porosity,and swelling property,the [Zn3-Al-Cl]/ChOx modified electrode exhibited an enhanced analytical performance. The biosensor provided a linear response to choline over a concentration range from 3.7 × 10-6 to 6.3 × 10-4 M with a low detection limit of 3 × 10-7 M based on S/N=3. The apparent Michaelis-Menten constant was calculated to be 1.38 mM. In addition,the interaction between ChOx and LDHs has also been investigated using FT-IR spectroscopy.

关键词： layered double hydroxides clay choline oxidase choline biosensor

A NON-LOCAL DIFFUSION EQUATION FOR NOISE REMOVAL

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Acta Mathematica Scientia 2022年第5期42卷 1779-1808页

作者： Jingfeng SHAO Zhichang GUO wenjuan yao Dong YAN Boying WU School of Mathematics Harbin Institute of TechnologyHarbin 15000China School of Mathematics University of California at IrvineIrvine 92697U.S.A.

In this paper,we propose a new non-local diffusion equation for noise removal,which is derived from the classical Perona-Malik equation(PM equation)and the regularized PM *** the convolution of the image gradient and the gradient,we propose a new diffusion *** to the use of the convolution,the diffusion coefficient is ***,the solution of the new diffusion equation may be discontinuous and belong to the bounded variation space(BV space).By virtue of Young measure method,the existence of a BV solution to the new non-local diffusion equation is *** results illustrate that the new method has some non-local performance and performs better than the original PM and other methods.

关键词： image denoising non-local diffusion BV solutions Perona-Malik method

炭、石墨材料孔结构特征描述及其对综合性能的影响（英文）

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稀有金属材料与工程 2019年第8期48卷 2488-2494页

作者：樊磊姚文娟上海大学土木工程系上海200072 上海大学上海市应用数学和力学研究所上海200072

随着传统行业、新兴产业的不断升级,炭、石墨材料(CGM)已成为支撑高新技术发展的重要战略资源和基础矿物原料。目前针对CGM的研究主要围绕宏观性能,对其孔结构的系统报道较少。众所周知,CGM的宏观性能取决于其微观结构,而孔结构的研究... 详细信息

随着传统行业、新兴产业的不断升级,炭、石墨材料(CGM)已成为支撑高新技术发展的重要战略资源和基础矿物原料。目前针对CGM的研究主要围绕宏观性能,对其孔结构的系统报道较少。众所周知,CGM的宏观性能取决于其微观结构,而孔结构的研究又占据了微观结构的重要一环。因此,本文回顾了CGM的应用与发展,总结传统CGM的孔结构特征,在此基础上,对比讨论了传统CGM与多孔石墨烯及3D多孔石墨烯复合材料孔结构的内在差异,并进一步分析孔结构特征对其综合性能的影响和内在联系。为阐述CGM物理和化学性能、材料改性、性能优化及新工艺的设计提供理论依据。

关键词：炭、石墨材料多孔石墨烯孔结构孔分类综合性能

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基于敏感模态单元应变能法结构损伤识别

中南大学学报（自然科学版） 2013年第7期44卷 3014-3023页

作者：张效忠姚文娟上海大学土木工程系上海200072 衢州学院建筑工程学院浙江衢州324000

根据结构损伤前后特征值变化率选择对损伤单元应变能变化灵敏度较高的模态,建立一种高效的并具有较好鲁棒性的结构损伤识别的方法。从结构振动方程出发,推导结构损伤前后特征值变化率和应变能变化的关系式,建立一个由特征值变化率、单... 详细信息

根据结构损伤前后特征值变化率选择对损伤单元应变能变化灵敏度较高的模态,建立一种高效的并具有较好鲁棒性的结构损伤识别的方法。从结构振动方程出发,推导结构损伤前后特征值变化率和应变能变化的关系式,建立一个由特征值变化率、单元损伤因子、单元损伤灵敏度因子以及单元损伤修正因子组成的结构损伤识别方程。应用单元损伤修正因子建立结构的损伤定位指标,并应用结构损伤识别方程式推导出单元损伤程度因子的解析表达式。应用本方法对一新型防浪提结构进行单一处损伤和多处损伤的损伤位置识别和损伤程度识别,最后,对本文提出的损伤识别方法的抗噪声性能进行测试。研究结果表明:本方法具有较好的鲁棒性,并且识别结果具有较高的精度,表明本文提出方法具有高效性。

关键词：特征值变化率单元应变能结构损伤识别方程鲁棒性