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A biarc-based shape optimization approach to reduce stress concentration effects

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Acta Mechanica Sinica 2014年第3期30卷 370-382页

作者： Liang Meng Wei-hong Zhang Ji-hong zhu Liang Xia Engineering Simulation and Aerospace Computing (ESAC) Northwestern Polytechnical University

In order to avoid stress concentration, the shape boundary must be properly designed via shape optimiza- tion. Traditional shape optimization approach eliminates the stress concentration effect by using free-form curve to present the design boundaries without taking the machin- ability into consideration. In most numerical control （NC） machines, linear as well as circular interpolations are used to generate the tool path. Non-circular curves, such as non- uniform rotational B-spline （NURBS）, need other more ad- vanced interpolation functions to formulate the tool path. Forming the circular tool path by approximating the opti- mal free curve boundary with arcs or biarcs is another op- tion. However, these two approaches are both at a cost of sharp expansion of program code and long machining time consequently. Motivated by the success of recent researches on biarcs, a reliable shape optimization approach is pro- posed in this work to directly optimize the shape boundaries with biarcs while the efficiency and precision of traditional method are preserved. Finally, the approach is validated by several illustrative examples.

关键词： Structural shape optimization Biarc Curvefitting NURBS Stress concentration

Combining optical and X-ray observations of galaxy clusters to constrain cosmological parameters

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Research in Astronomy and Astrophysics 2011年第7期11卷 776-786页

作者： Heng Yu Zong-hong zhu Department of Astronomy Beijing Normal University Beijing 100875 China

Galaxy clusters present unique advantages for cosmological *** we collect a new sample of 10 lensing galaxy clusters with X-ray observations to constrain cosmological *** redshifts of the lensing clusters lie between 0.1 and 0.6,and the redshift range of their arcs is from 0.4 to *** clusters are selected carefully from strong gravitational lensing systems which have both X-ray satellite observations and optical giant luminous arcs with known *** arcs usually appear in the central region of clusters,where mass can be traced with luminosity quite *** on gravitational lensing theory and a cluster mass distribution model,we can derive a ratio using two angular diameter *** is the distance between lensing sources and the other is that between the deflector and the source. Since angular diameter distance relies heavily on cosmological geometry,we can use these ratios to constrain cosmological ***,X-ray gas fractions of galaxy clusters can also be a cosmological *** there are a dozen parameters to be fitted,we introduce a new analytic algorithm,Powell＇s UOBYQA（Unconstrained Optimization By Quadratic Approximation） ,to accelerate our *** result demonstrates that this algorithm is an effective fitting method for such a continuous multi-parameter *** find an interesting fact that these two approaches are separately sensitive toΩΛandΩ*** combining them,we can get reasonable fitting values of basic cosmological parameters：ΩM=0.26 ＋0.04 -0.04,andΩΛ=0.82 ＋0.14 -0.16.

关键词： X-rays:galaxies:clusters—gravitational lensing—cosmological parameters

Yetter–Drinfeld Modules over the Hopf–Ore Extension of the Group Algebra of Dihedral Group

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Acta Mathematica Sinica,English Series 2012年第3期28卷 487-502页

作者： hong zhu Hui Xiang CHEN Department of Information Science School of Mathematical and PhysicalChangzhou University School of Mathematical Science Yangzhou University

Let k be an algebraically closed field of characteristic zero, and Dn be the dihedral group of order 2n, where n is a positive even integer. In this paper, we investigate Yetter-Drinfeld modules over the Hopf-Ore extension A（n,0） of kDn. We describe the structures and properties of simple Yetter Drinfeld modules over A（n, 0）, and classify all simple Yetter-Drinfeld modules over A（n, 0）.

关键词： Dihedral group Hopf-Ore extension Yetter-Drinfeld module

UAV-assisted cooperative offloading energy efficiency system for mobile edge computing

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Digital Communications and Networks 2024年第1期10卷 16-24页

作者： Xue-Yong Yu Wen-Jin Niu Ye zhu hong-Bo zhu Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing210003China Engineering Research Centerof Health Service System Based on Ubiquitous Wireless Networks Ministry of EducationNanjng Universityof Posts and Telecommunications Nanjing210003China

Reliable communication and intensive computing power cannot be provided effectively by temporary hot spots in disaster areas and complex terrain ground *** this has greatly developed the application and integration of UAV and Mobile Edge Computing(MEC)to the Internet of Things(loT).However,problems such as multi-user and huge data flow in large areas,which contradict the reality that a single UAV is constrained by limited computing power,still *** to allowing UAV collaboration to accomplish complex tasks,cooperative task offloading between multiple UAVs must meet the interdependence of tasks and realize parallel processing,which reduces the computing power consumption and endurance pressure of *** the computing requirements of the user terminal,delay constraint of a computing task,energy constraint,and safe distance of UAV,we constructed a UAV-Assisted cooperative offloading energy efficiency system for mobile edge computing to minimize user terminal energy ***,the resulting optimization problem is originally nonconvex and thus,difficult to solve *** tackle this problem,we developed an energy efficiency optimization algorithm using Block Coordinate Descent(BCD)that decomposes the problem into three convex ***,we jointly optimized the number of local computing tasks,number of computing offloaded tasks,trajectories of UAV,and offloading matching relationship between multi-UAVs and multiuser *** results show that the proposed approach is suitable for different channel conditions and significantly saves the user terminal energy consumption compared with other benchmark schemes.

关键词： Computation offloading Internet of things(IoT) Mobile edge computing(MEC) Block coordinate descent(BCD)

Surface quality of extruding metal special-shape products and frictional behavior in optimized die cavity

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 468-471页

作者： QI hong-yuan zhu Heng-jun School of Mechanical and Electric Control Engineering Beijing Jiaotong University Beijing 100044 China School of Mechanical and Electric Control Engineering Beijing Jiaotong University Beijing 100044 China

With the help of Complex Function Mapping theory, the complicated three-dimensional deformation problems are transferred into two-dimensional problems, and the function of strain ratio field is analyzed in the metal plastic extruding deformation. Taking the strain-hardening effect of metal deformation into account, the relationship between friction behavior and optimized mathematical model is analyzed by the numerical analysis friction energy dissipation function. As a result, the method of lowering the material hardening and decreasing the reduction ratio over multi-procedures can be used to improve the surface quality of metal special-shape extrusion products.

关键词： special-shape products extrusion surface quality Conformal Mapping

An advanced higher-order theory for laminated composite plates with general lamination angles

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Acta Mechanica Sinica 2011年第5期27卷 720-729页

作者： Zhen Wu hong zhu Wan-Ji Chen Key Laboratory of Liaoning Province forComposite Structural Analysis of Aerocraft and Simulation Shenyang Aerospace University 110136 Shenyang China

This paper proposes a higher-order shear deformation theory to predict the bending response of the laminated composite and sandwich plates with general lamination *** proposed theory a priori satisfies the continuity conditions of transverse shear stresses at ***,the number of unknown variables is independent of the number of *** first derivatives of transverse displacements have been taken out from the inplane displacement fields,so that the C 0 shape functions are only required during its finite element *** to C 0 continuity requirements,the proposed model can be conveniently extended for implementation in commercial finite element *** verify the proposed theory,the fournode C 0 quadrilateral element is employed for the interpolation of all the displacement parameters defined at each nodal point on the composite *** results show that following the proposed theory,simple C 0 finite elements could accurately predict the interlaminar stresses of laminated composite and sandwich plates directly from a constitutive equation,which has caused difficulty for the other global higher order theories.

关键词： Laminated and sandwich composites Higherorder theory C 0 continuity requirement Transverse shear stress

Enhancement strategies of targetability, response and photostability for in vivo bioimaging

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Science China Chemistry 2019年第2期62卷 189-198页

作者： Kaizhi Gu Wei-hong zhu Xiaojun Peng Shanghai Key Laboratory of Functional Materials Chemistry Key Laboratory for Advanced Materials and Institute of Fine Chemicals Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterSchool of Chemistry and Molecular Engineering East China University of Science & Technology State Key Laboratory of Fine Chemicals Dalian University of Technology

Analyses of the physiology and pathology of active biochemical species in their native contexts are critical for early diagnosis and therapy. Optical imaging has emerged as one of the promising modalities for noninvasive and real-time visualization of important biomolecules or biological events, and it has witnessed major advances in the field of imaging in vitro and in vivo. In this review, we present a survey of common approaches and tactics for enhanced targetability, response rate, and photostability in bioimaging applications. Recently developed and representative examples are illustrated on the cellular and tissue levels.

关键词： fluorescent probe bioimaging targetability response rate photostability

Experimental investigation of the effect of the wall proximity on the mode transition of a vortex-induced vibrating flexible pipe and the evolution of wall-impact

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Journal of Hydrodynamics 2022年第2期34卷 329-353页

作者： hong-jun zhu hong-lei Zhao Yi-pu Xie Xu Zhang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China

The present work experimentally investigates the vortex-induced vibration(VIV)and the pipe-wall impact of a flexible pipe in an oblique *** flexible pipe with an aspect ratio of 86.67 and an oblique angle of 30°is immersed in the water flow with the initial gap ratio in the range of 0.2–0.8 and *** space-time varying oscillation responses in both the in-line and cross-flow directions are recorded using the non-intrusive optical measurement with high-speed cameras in the normal reduced velocity range of 3.40–*** oblique flow induces the spatial variations of the inclination angle to the flexible pipe as a result of the bending deformation during the ***,the flexible pipe experiences an asymmetrical response along the span and an out-of-sync mode transition in the in-line and cross-flow *** the gap ratio decreases,the VIV response is suppressed,and the vibration regions of lower modes are prolonged with the result of the delay of higher excited ***,the wall proximity results in an upward deflection of the equilibrium position,and this offset is enlarged with the decrease of the gap *** occurrence of the pipe-wall impact depends on the amplitude of the spatial-temporal varying oscillation and the dominant response *** pipe-wall impact patterns are proposed in terms of the number and the length of the contact pipe *** evolution of the pipe-wall impact pattern with the increase of the normal reduced velocity is closely related to the variations of the dominant response mode and the amplitude and the alteration of its spatial distribution.

关键词： Wall proximity oblique flow wall impact mode transition vortex-induced vibration(VIV)

Life-cycle assessment and techno-economic analysis of the production of wood vinegar from Eucommia stem: a case study

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Frontiers of Chemical Science and Engineering 2023年第8期17卷 1109-1121页

作者： Ji-Lu Zheng Ya-hong zhu Yan-Yan Dong Ming-Qiang zhu College of Forestry Northwest A&F UniversityYangling 712100China College of Mechanical and Electronic Engineering Northwest A&F UniversityYangling 712100China Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China

This research undertook a case study of the life-cycle assessment and techno-economic analysis of the slow pyrolysis of Eucommia stem for the production of wood vinegar and activated *** results showed that the production of one ton of wood vinegar via the slow pyrolysis of Eucommia stem show comparatively low global warming potential(2.37×10^(2) kg CO_(2) eq),primary energy demand(3.16×10^(3) MJ),acidification potential(2.19 kg SO2 eq),antimony depletion potential(3.86×10^(–4) kg antimony eq),and ozone depletion potential(7.46×10^(–6) kg CFC-11 eq)and was more environmentally friendly than the production of dilute acetic acid(12 wt%)via petrochemical ***,the total capital investment,total product cost,and cash flowsheet were provided in the techno-economic ***,the net present value,internal rate of return,and dynamic payback period of the production process were *** findings indicated that while this production process is cost-effective,it might not be economically attractive or could generate investment *** increase in the added value of the wood vinegar and the activated carbon could remarkably improve the economic feasibility of this production process.

关键词： life-cycle assessment techno-economic analysis wood vinegar activated carbon Eucommia