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Transverse shear and normal deformation effects on vibration behaviors of functionally graded micro-beams

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Applied Mathematics and Mechanics(English Edition) 2020年第9期41卷 1303-1320页

作者： Zhu SU Lifeng WANG Kaipeng sun jie sun State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China Shanghai Institute of Satellite Engineering Shanghai 201109China

A quasi-three dimensional model is proposed for the vibration analysis of functionally graded(FG)micro-beams with general boundary conditions based on the modified strain gradient *** consider the effects of transverse shear and nor-mal deformations,a general displacement field is achieved by relaxing the assumption of the constant transverse displacement through the *** conventional beam theories including the classical beam theory,the first-order beam theory,and the higher-order beam theory are regarded as the special cases of this *** material proper-ties changing gradually along the thickness direction are calculated by the Mori-Tanaka *** energy-based formulation is derived by a variational method integrated with the penalty function method,where the Chebyshev orthogonal polynomials are used as the basis function of the displacement *** formulation is validated by some comparative examples,and then the parametric studies are conducted to investigate the effects of transverse shear and normal deformations on vibration behaviors.

关键词： quasi-three dimensional theory modified strain gradient theory function-ally graded(FG)micro-beam size effect vibration general boundary condition

ITERATIVE METHODS FOR THE FORWARD-BACKWARD HEAT EQUATION

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Journal of Computational Mathematics 2005年第4期23卷 419-424页

作者： Xiao-liang Cheng jie sun Department of Mathematics Zhejiang University Hangzhou 310028 China Department of Mathematics Zhejiang University of Finance and Economics Hangzhou 310012 China

In this paper we propose the finite difference method for the forward-backward heat equation. We use a coarse-mesh second-order central difference scheme at the middle line mesh points and derive the error estimate. Then we discuss the iterative method based on the domain decomposition for our scheme and derive the bounds for the rates of convergence. Finally we present some numerical experiments to support our analysis.

关键词： Forward-backward heat equation Finite difference method Iterative method Coarse mesh

Promise and challenge of vanadium-based cathodes for aqueous zinc-ion batteries

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Journal of Energy Chemistry 2021年第3期30卷 655-667页

作者： Yaru Zhang Aibing Chen jie sun Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China College of Chemical and Pharmaceutical Engineering Hebei University of Science and TechnologyShijiazhuang 050018HebeiChina State Key Laboratory of Organic–Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China

Aqueous zinc-ion batteries(ZIBs)have got wide attention with the increasing demands for energy resource *** has a number of merits compared with lithium-ion batteries,such as enhanced safety,low cost and environmental ***-based materials have been developed to serve as the cathodes of ZIBs for many *** there are also some challenges to construct high performance ZIBs in the ***,we reviewed the research progress of vanadium-based cathodes and discussed the energy storage mechanisms in *** addition,we summarized the major challenges faced by vanadium-based cathodes and the corresponding ways to improve electrochemical performance of ***,some excellent vanadium-based cathodes are summarized to pave the way for future research in ZIBs.

关键词： Zinc-ion batteries Vanadium-based cathodes Energy storage mechanisms

Numerical Study of New-Type Receiver with Axially-Hollow Spiral Deflector for Parabolic Trough Direct-Steam-Generation Loop of Concentrating Solar Power System

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Journal of Thermal Science 2023年第2期32卷 597-610页

作者： SHI Yaolu sun jie WEI Jinjia School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'an 710049China Adv Energy Sci&Technol Guangdong Lab Foshan Xianhu LabXianhu Hydrogen ValleyFoshan 528200China

The thermal stress-induced deformation issue of receiver is crucial to the performance and reliability of a parabolic-trough(PT) concentrating solar power(CSP) system with the promising direct steam generation(DSG) *** objective of the present study is to propose a new-type receiver with axially-hollow spiral deflector and optimize the geometric structure to solve the above *** this end,optical-flow-thermal multi-physics coupling models have been established for the preheating,boiling and superheating sections of a typical PT-DSG *** simulation results show that our proposed new-type receiver demonstrates outstanding comprehensive *** can minimize the circumferential temperature difference through the spiral deflector while lower the flow resistance cost through the axially hollow structure at the same *** quantitatively evaluated by the temperature uniformity improvement(ε_(ΔT)) and the performance evaluation criteria(PEC),different designs are achieved based on different optimal *** ε_(ΔT)is of primary importance,the optimal design with torsional ratio of 1 is achieved,with ε_(ΔT)=25.4%,25.7%,41.5% and PEC=0.486,0.878,0.596corresponding to preheating,boiling,superheating sections,*** PEC is of primary importance,the optimal design with torsional ratio of 6-6.5 is achieved,with PEC=0.950,2.070,0.993 and ε_(ΔT)=18.2%,13.3 %,19.4% corresponding to preheating,boiling,superheating sections,respectively.

关键词： concentrating solar power parabolic though collector direct steam generation performance evaluation criteria axially-hollow spiral deflector

Perovskite/organic tandem solar cells

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Journal of Semiconductors 2023年第2期44卷 1-3页

作者： jie sun Liming Ding Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

In recent years,the power conversion efficiency(PCE)for single-junction perovskite solar cells(PSCs)[1,2]has reached 25.7%,approaching the Shockley-Queisser limit(S-Q limit).Further enhancing efficiency is *** solar cells offer an effective way to further increase the efficiency beyond S-Q ***,perovskite/silicon tandem solar cells(TSCs)[3−5]have achieved a PCE of 31.3%[6].However,the complicated preparation processes and high cost hinder their commercialization *** contrast,thin-film perovskite/organic TSCs have the advantages of solution processability,low cost,and flexibility,making them to be promising candidates for the next-generation photovoltaic technology.

关键词： perovskite approaching hinder

On the usefulness of an assisted driving Hamiltonian for quantum adiabatic evolution

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Chinese Physics B 2018年第11期27卷 409-411页

作者： jie sun Songfeng Lu School of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 China College of Educational Information and Technology Hubei Normal University Huangshi 435002 China Shenzhen Huazhong University of Science and Technology Research Institute Shenzhen 518063 China

In our recent work we showed, by investigating the initialization of some unusual forms of assisted driving Hamiltonians, that the addition of an assisted driving Hamiltonian is not always useful in quantum adiabatic evolution. These unusual forms are those that are not the relatively fixed ones that are widely used in the literature. In this paper, we continue this study, providing further evidence for the validity of the conclusion above by researching some relatively more complex forms of assisted driving scheme, which generalize the ones studied in our previous work.

关键词： quantum adiabatic evolution assisted driving Hamiltonian quantum computing

On the time-independent Hamiltonian in real-time and imaginary-time quantum annealing

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Chinese Physics B 2020年第10期29卷 167-171页

作者： jie sun Songfeng Lu Hubei Engineering Research Center on Big Data Security School of Cyber Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China School of Internet Anhui UniversityHefei 230039China Shenzhen Huazhong University of Science and Technology Research Institute Shenzhen 518063China

We present the analog analogue of Grover's problem as an example of the time-independent Hamiltonian for applying the speed limit of the imaginary-time Schrödinger equation derived by Okuyama and Ohzeki and the new class of energy-time uncertainty relation proposed by Kieu. It is found that the computational time of the imaginary-time quantum annealing of this Grover search can be exponentially small, while the counterpart of the quantum evolution driven by the real-time Schrödinger equation could only provide square root speedup, compared with classic search. The present results are consistent with the cases of the time-dependent quantum evolution of the natural Grover problem in previous works. We once again emphasize that the logarithm and square root algorithmic performances are generic in imaginary-time quantum annealing and quantum evolution driven by real-time Schrödinger equation, respectively. Also, we provide evidences to search deep reasons why the imaginary-time quantum annealing can lead to exponential speedup and the real-time quantum annealing can make square root speedup.

关键词： time-independent Hamiltonian imaginary-time quantum annealing quantum speed limit the energy-time uncertainty relation continuous Grover's search

Correlation between Single Factor Material Constitutive Model Parameters and Temperature for Ti6Al4V Alloy

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Chinese Journal of Mechanical Engineering 2010年第5期23卷 574-581页

作者： YANG Yong LI Jianfeng sun jie Department of Mechanical Engineering Qingdao Technological University Qingdao 266033 China Department of Mechanical Engineering Shandong University Jinan 250061 China

Accurate material constitutive model is considered highly necessary to perform finite element simulation and ***,it is difficult to establish the material constitutive model because of uncertainty of mathematical relationship and constraint of existing experimental *** present,there exists considerable gap between finite element simulation result and actual cutting *** emphases were put on investigating the correlation between ＂single factor＂ material constitutive model parameters and temperature for Ti6Al4V alloy,and also establishment of material constitutive model for this kind of *** analyses based on dislocation theory and material functional relations showed that material model was deeply affected by variation *** the least squares best fit to the available quasi-static and high-speed impact compression experiment data,material parameters at various temperatures were *** curves analyses and material parameters comparison showed that the ＂single factor＂ material constitutive model parameters were temperature *** the mathematical mapping between material parameters and temperature,＂single factor＂ material constitutive model of Ti6Al4V alloy was established,which was proven to be right by comparing with experimental *** work makes clear that the ＂single factor＂ material constitutive model parameters of Ti6Al4V alloy are temperature *** the same time,an accurate material constitutive model is established,which helps to optimize cutting process and control machining distortion for Ti6Al4V alloy aerospace parts.

关键词： metal cutting Ti6Al4V alloy finite element method material constitutive model

Recent Advances in Drilling Tool Temperature:A State‑of‑the‑Art Review

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Chinese Journal of Mechanical Engineering 2022年第6期35卷 23-62页

作者： Zhaoju Zhu Xinhui sun Kai Guo jie sun Jianfeng Li School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350116China School of Mechanical Engineering Shandong UniversityJinan 250061China

Drilling is regarded as the most complex manufacturing process compared with other conventional machining *** the drilling process,most of the energy consumed in metal cutting is converted to heat and increases temperature *** resulting thermal phenomena are important since they influence the mode of deformation,the final metallurgical state of the machined surface,and the rate of tool ***,understanding the temperature characteristics in the drilling process is crucial for enhancing the drill performance and process *** efforts have been conducted to measure and control the drilling tool temperature ***,very few studies have been conducted from a comprehensive perspective to review all the *** address this gap in the literature,a rigorous review concerning the state-of-the-art results and advances in drilling tool temperature is presented in this paper by referring to the wide comparisons among literature *** multiple aspects of drilling tool temperature are precisely detailed and discussed in terms of theoretical analysis and thermal modeling,methods for temperature measuring,the effect of cutting parameters,tool geometries and hole-making methods on temperature and temperature controlling by different cooling *** conclusion,several possible future research directions are discussed to offer potential insights for the drilling community and future researchers.

关键词： Drilling Tool temperature Advance materials Cutting characteristics