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Applied Mathematics and Mechanics(English Edition) 2025年第01期 25-36页

作者： Jue ZHU Longyuan LI Ningtao ZHU Zhejiang Provincial Engineering Research Center for the Safety of Pressure Vessel and Pipeline Key Laboratory of Impact and Safety Engineering (ningbo University) Ministry of Education School of Engineering Computing and Mathematics University of Plymouth Xi'an Zhanshi Testing & Engineering Co.Ltd.

Carbon nanotubes(CNTs) have garnered great attention in recent years due to their outstanding electrical, thermal, and mechanical properties. The incorporation of small amounts of CNTs in polymers can substantially improve the sensitivity of the polymer's electrical conductivity. This paper presents a modified Maxwell model to evaluate the electrical conductivity of CNTs-filled polymer composites by introducing a transition zone to account for the tunneling effect. In this modified Maxwell model, the CNTs-filled polymer composite is modeled as a three-phase composite, consisting of a matrix(polymer), inclusions(CNTs), and a transition zone(tunneling zone). The effective electrical conductivity(EEC) of the composite is calculated based on the volume fractions and electrical conductivities of the matrix, inclusions, and transition zone. The model's validity is confirmed through the use of available test data, which demonstrates its capability to accurately capture the nonlinear conductivity behavior observed in CNTs-polymer composites. This study offers valuable insights into the design of high-performance conductive polymer nanocomposites, and enhances the understanding of electrical conduction mechanisms in CNT-dispersed polymer composites.

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Cyclic performance and simplified pushover analyses of precast segmental concrete bridge columns with circular section

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Earthquake Engineering and Engineering Vibration 2016年第2期15卷 297-312页

作者： Bu Zhanyu Guo Jian Zheng Rongyue Song Jianwei George C.Lee Faculty of Architectural Civil Engineering and Environment Ningbo University College of Civil Engineering and Architecture Zhejiang University of Technology Department of Civil Structural and Environmental Engineering University at Buffalo

In recent years, precast segmental concrete bridge columns became prevalent because of the benefits of accelerated construction, low environmental impact, high quality and low life cycle costs. The lack of a detailed configuration and appropriate design procedure to ensure a comparable performance with monolithic construction has impeded this structural system from being widely used in areas of high seismicity. In this study, precast segmental bridge column cyclic loading tests were conducted to investigate the performance of unbonded post-tensioned segmental bridge columns. One monolithic and two precast segmental columns were tested. The preeast segmental column exhibited minor damage and small residual displacement after the maximum 7% cyclic drift; energy dissipation （ED） can be enhanced byadding ED bars. The experimental results were modeled by a simplified pushover method （SPOM）, as well as a fiber model （FIBM） finite element method. Forty-five cases of columns with different aspect ratios, axial load ratios and ED bar ratios were analyzed with the SPOM and FIBM, respectively. Using these parametric results, a simplified design method was suggested by regressive analysis. Satisfactory correlation was found between the experimental results and the simplified design method for preeast segmental columns with different design parameters.

关键词： precast concrete segmental column simplified pushover fiber model

Fabrication of Cr coating on AZ31 magnesium alloy by magnetron sputtering

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中国有色金属学会会刊：英文版 2008年第A01期18卷 329-333页

作者：吴国松汪爱英丁克俭徐采云代伟徐爱娇 ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Institute of Biological science and Technology Beijing Jiao Tong University

Chromium-plating is considered an effective method to improve surface properties of metal *** sputtering was applied to prepare Cr coating on AZ31 magnesium alloy and the influence of bias voltage on properties of Cr coating was *** obtained coatings present an(110) preferred texture and have a developed columnar *** increasing bias voltage,the surface structure of Cr coating becomes *** of the Cr-coated AZ31 have much higher surface microhardness than bare *** Cr coating deposited on AZ31 at bias voltage of -150 V has a higher corrosion potential than *** result of the immersion test shows that it decreases the damaged area compared with bare *** failure of the coated AZ31 is mainly attributed to the existence of through-thickness defects in the coating.

关键词： AZ31镁合金铬耐蚀性能单壳焊结构

Bifurcations of traveling wave solutions and exact solutions to generalized Zakharov equation and Ginzburg-Landau equation

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Applied Mathematics and Mechanics(English Edition) 2011年第12期32卷 1615-1622页

作者：戴振祥徐园芬 School of Information and Art Ningbo Institute of Education Junior College Zhejiang Wanli University

This paper studies the dynamic behaviors of some exact traveling wave solutions to the generalized Zakharov equation and the Ginzburg-Landau equation. The effects of the behaviors on the parameters of the systems are also studied by using a dynamical system method. Six exact explicit parametric representations of the traveling wave solutions to the two equations are given.

关键词： planar dynamical system periodic wave solution nonlinear wave equation

A meshless method based on moving Kriging interpolation for a two-dimensional time-fractional diffusion equation

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Chinese Physics B 2014年第4期23卷 91-97页

作者：葛红霞程荣军 Faculty of Maritime and Transportation Ningbo University ningbo Institute of Technology Zhejiang University

Fractional diffusion equations have been the focus of modeling problems in hydrology, biology, viscoelasticity, physics, engineering, and other areas of applications. In this paper, a meshfree method based on the moving Kriging inter- polation is developed for a two-dimensional time-fractional diffusion equation. The shape function and its derivatives are obtained by the moving Kriging interpolation technique. For possessing the Kronecker delta property, this technique is very efficient in imposing the essential boundary conditions. The governing time-fractional diffusion equations are transformed into a standard weak formulation by the Galerkin method. It is then discretized into a meshfree system of time-dependent equations, which are solved by the standard central difference method. Numerical examples illustrating the applicability and effectiveness of the proposed method are presented and discussed in detail.

关键词： meshless method moving Kriging interpolation time-fractional diffusion equation

Comparative studies of open qubit via Bloch equation and master equation of Redfield form

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Chinese Physics B 2010年第10期19卷 85-91页

作者：沈燕卢俞平梁先庭 Department of Physics and Institute of Modern Physics Ningbo University

In this paper, we investigate the dynamics of an open qubit model by solving two sets of its reduced dynamical equations. One set of the equations is the well-known Bloch equations and the other is the widely investigated master equations of Redfield form. Both of them are obtained from the perturbation approximation which demands the system of interest weakly coupled to its environment. It is shown that the qubit has a longer decoherence and relaxiation time as the dynamics is described by the Redfield equantions.

关键词： reduced dynamics relaxation decoherence

Element-free Galerkin method for a kind of KdV equation

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Chinese Physics B 2010年第6期19卷 7-12页

作者：王聚丰孙凤欣程荣军 ningbo Institute of Technology Zhejiang University ningbo University of Technology

The present paper deals with the numerical solution of the third-order nonlinear KdV equation using the element-free Calerkin （EFG） method which is based on the moving least-squares approximation. A variational method is used to obtain discrete equations, and the essential boundary conditions are enforced by the penalty method. Compared with numerical methods based on mesh, the EFG method for KdV equations needs only scattered nodes instead of meshing the domain of the problem. It does not require any element connectivity and does not suffer much degradation in accuracy when nodal arrangements are very irregular. The effectiveness of the EFG method for the KdV equation is investigated by two numerical examples in this paper.

关键词： element-free Galerkin method meshless method KdV equation

Stress-corrosion coupled damage localization induced by secondary phases in bio-degradable Mg alloys:phase-field modeling

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Journal of Magnesium and Alloys 2024年第1期12卷 361-383页

作者： Chao Xie Shijie Bai Xiao Liu Minghua Zhang Jianke Du The Faculty of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211P.R.China Key Laboratory of High Temperature Wear Resistant Materials Preparation Technology of Hunan Province Hunan University of Science and TechnologyXiangtan 411201P.R.China

In this study,a phase-field scheme that rigorously obeys conservation laws and irreversible thermodynamics is developed for modeling stress-corrosion coupled damage(SCCD).The coupling constitutive relationships of the deformation,phase-field damage,mass transfer,and electrostatic field are derived from the entropy *** SCCD localization induced by secondary phases in Mg is numerically simulated using the implicit iterative algorithm of the self-defined finite *** quantitative evaluation of the SCCD of a C-ring is in good agreement with the experimental *** capture the damage localization,a micro-galvanic corrosion domain is defined,and the buffering effect on charge migration is *** cases are investigated to reveal the effect of localization on corrosion acceleration and provide guidance for the design for resistance to SCCD at the crystal scale.

关键词： Phase field Mg alloys Stress-corrosion coupled damage Damage localization Finite element method

Localized CdS homojunctions with optimal ratio of high and low index facets to dynamically boost H_(2)O splitting into H_(2)energy

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Journal of Materials science & Technology 2024年第4期171卷 94-100页

作者： Xiaojun Wang Yiqi Zhang Shujuan Jiang Jiakun Su Shaoqing Song School of Materials science&Chemical Engineering Ningbo UniversityNingbo 330013China School of New Energy Ningbo University of TechnologyNingbo 315336China Tchnology Center China Tobacco Jiangxi Industrial LLCNanchang 330096China

Localized CdS homojunctions with optimal ratio of high and low index facets are constructed to dy-namically boost H_(2)O splitting into H_(2)energy by hydrothermal method in combination with *** density functional theory,hall effect,and in situ diffuse reflectance infrared Fourier transform spec-troscopy,it is revealed that photo-irradiated e^(−)and h^(+)can be spatially separated and directionally trans-ferred to the reductive high-index facet{002}and oxidative low-index facet{110}of localized CdS homo-junction induced by Fermi level difference of both high and low index facets to dehydrogenate ^(∗)-OH and coupled ^(∗)-O intermediates for H_(2)and O_(2)yield,respectively,along with a solar conversion into hydrogen of 1.93%by AM 1.5 G irradiation at 65℃.The study work suggests a scientific perspective on the optimal ratio of high and low index facets to understand photo-generated charge carrier transfer dynamically and their photocatalytic principle for H_(2)O splitting reaction in kinetics.

关键词： Photocatalytic H_(2)evolution Homojunction Localized field Ratio of high low index facets In-situ DRIFTS

CONVERGENCE ANALYSIS OF THE LOPING OS-EM ITERATIVE VERSION OF THE CIRCULAR RADON TRANSFORM

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Acta Mathematica Scientia 2014年第6期34卷 1875-1884页

作者：郭娟王金平 Faculty of science Ningbo University

The loping OS-EM iteration is a numerically efficient regularization method for solving ill-posed problems. In this article we investigate the loping OS-EM iterative method in connection with the circular Radon transform. We show that the proposed method converges weakly for the noisy data. Numerical tests are presented for a linear problem related to photoacoustic tomography.

关键词： ill-posed equations regularization loping OS-EM iteration circular Radon transform