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Generalized area operators on L^p（R^n）

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Frontiers of mathematics in China 2014年第5期9卷 1051-1072页

作者： Ruifang HU bolin ma Xianmin XU Institute of mathematics Jiaxing University Jiaxing 314001 China

We introduce the generalized area operators by using nonnegative measures defined on upper half-spaces R＋^n＋1. The characterization of the boundedness and compactness of the generalized area operator from LP（]Rn） to Lq（IRn） is investigated in terms of s-Carleson measures with 1 〈 p, q 〈＋∞. In the case of p = q = 1, the weak type estimate is also obtained.

关键词： L^p(R^n) Space area operator s-Carleson measure

Influence of uniaxial tensile pre-strain on forming limit curve by using biaxial tensile test

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Chinese Journal of Aeronautics 2020年第8期33卷 2268-2280页

作者： Wennan YUAN Min WAN Xiangdong WU bolin ma Xu LU Bing YANG Department of Mechanical Engineering and Automation Beijing University of Aeronautics and AstronauticsBeijing 100083China Research Institute of Baosteel Shanghai 201900China

This paper focused on the effect of pre-strain on forming limit curves(FLC)of 5754-O aluminum alloy sheet through utilizing biaxial tensile *** on Swift model and Yld2000-2 d yield criterion,the dimensions of cruciform specimen was optimized through applying finite element method for increasing the strain at specimen *** that,with the recommended specimen size,the cruciform specimen was tested under various stroke ratios to experimentally characterize the limit strains under different pre-strain ***,the biaxial tensile tests were simulated by Abaqus to obtain the limit strains and validate the material *** can be observed in both experiments and simulations that the pre-strained uniaxial tension followed by plane tension or equi-biaxial tension can improve the formability of sheet ***,the strain path change affects the trend of first derivative of strain rate difference between neighboring points with respect to *** early increase occurred and then fell back to the stable value,the steady evolution continued until to a new increase reaching the critical *** M–K prediction approach was simulated to verify the influence of pre-strain on *** can be found that the early increase peaks of the major strain incremental ratio rose with the amplitude of ***,the phenomenon of pseudolocalization caused by the strain path change was explained through evolution of stress state inside the groove.

关键词： Aluminum alloy sheet Biaxial tensile tests Formability M–K model Yld2000-2d

Feasibility evaluation of failure models for predicting forming limit of metal foils

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Chinese Journal of Aeronautics 2020年第9期33卷 2461-2471页

作者： Bao MENG Jiejie SHI Yiyun ZHANG Cheng CHENG bolin ma Min WAN School of Mechanical Engineering and Automation Beihang UniversityBeijing 100083China

Forming limit of metal foil is an important index to evaluate its formability,and is of considerable significance to improve the quality of *** ductile fracture(DF)behavior in microscale plastic deformation is remarkably affected by the geometry and grain *** explore the size-dependent forming limit curve(FLC),the Holmberg and marciniak tests of SUS304 foils with the thicknesses of less than 0.1 mm and diverse grain sizes were *** addition,the validity and feasibility of three types of existing failure models including Swift/Hill,marciniakKuczynski(M-K)and DF criteria for predicting the micro-scaled FLCs were *** is found that the Swift/Hill model possesses the worst accuracy with predicting deviation above 50%.Four classical DF criteria including Freudenthal,Ayada,Brozzo and Oh show great difference,and Oh model considering plastic anisotropy presents the best *** predicted deviation of M-K model is aggravated with increasing grain size and decreasing foil thickness,which is attributed to the intensified free surface roughening and transformation of fracture mechanism with *** research thus provides a deeper understanding and valuable reference for the widespread application of FLC in microforming.

关键词： Failure criteria Forming limit Metal foil Microforming Size effect

Anti-Attacking Modeling and Analysis of Cyberspace Mimic DNS

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China Communications 2022年第5期19卷 218-230页

作者： Lei He Quan Ren bolin ma Weili Zhang Jiangxing Wu Institute of information technology Information Engineering Universityzhengzhou 450001China

With the rapid development of information technology,the cyberspace security problem is increasingly *** of dynamic defense technology have emerged such as moving target defense and mimic *** paper aims to describe the architecture and analyze the performance of Cyberspace Mimic DNS based on generalized stochastic Petri *** propose a general method of anti-attacking *** general attack and special attack model,the available probability,escaped probability and nonspecial awareness probability are adopted to quantitatively analyze the system *** we expand the GSPN model to adjust to engineering practice by specifying randomness of different output *** result shows that the proposed method is effective,and Mimic system has high anti-attacking *** deal with the special attack,we can integrate the traditional defense mechanism in engineering ***,we analyze the performance of mimic DNSframework based on multi-ruling proxy and input-output desperation,the results represent we can use multi ruling or high-speed cache servers to achieve the consistent cost of delay,throughput compared with single authorized DNS,it can effectively solve 10%to 20%performance loss caused by general ruling proxy.

关键词： cyberspace mimic DNS generalized stochastic Petri net anti-attacking modeling performance

THE BOUNDEDNESS OF MULTILINEAR COMMUTATORS FROM L^p(R^n) TO TRIEBEL-LIZORKIN SPACES

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Analysis in Theory and Applications 2007年第2期23卷 112-128页

作者： Yanping Chen bolin ma University of Science and Technology Beijing China Hunan University China

Let b^→=（b1,…,bm）,bi∈∧°βi（R^n）,1≤i≤m,0〈βi〈β,0〈β〈1,[B^→,T]f（x）=∫R^n（b1（x）-b1（y））…（bm（x）-bm（y））K（x-y）f（y）dy,where K is a Calder6n-Zygmund kernel. In this paper, we show that [b^→,T] is bounded from L^p（R^n） to Fp^β,∞（R^n）,as well as [b^→,1α]form L^p （R^n） to Fp^β,∞（R^n）,where 1/q=1/p-α/n.

关键词： multilinear commutator Calderon-Zygmund kernel Lipschitz space,Triebel-Lizorkin space

Dislocation reconfiguration during creep deformation of an Al-Cu-Li alloy via electropulsing

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Journal of materials Science & Technology 2022年第35期130卷 27-34页

作者： Chang Zhou Lihua Zhan He Li Chunhui Liu Yongqian Xu bolin ma Youliang Yang Minghui Huang College of Mechanical and Electrical Engineering Central South UniversityChangsha410083China State Key Laboratory of High Performance Complex manufacturing Central South UniversityChangsha410083China Light Alloys Research Institute Central South UniversityChangsha410083China

Creep mechanism was well-known to be mainly dominated by the dislocation sliding and climbing during creep deformation. Here we study the creep deformation of an Al-Cu-Li alloy with the assistance of electropulsing and subsequent microstructural observations. We find that creep strain increased drastically under electropulsing and was almost twelve times as much as that of the non-pulsed sample. Microstructural observations confirmed that dislocation reconfiguration happens via electropulsing, namely helical dislocations being opened rapidly. This opened dislocation structure can possess a much higher mobility than the initial helical dislocation, which mostly responsible for the greatly increased creep strain. Our results revealed a new mechanism accountable for the distinctly electroplastic creep deformation.

关键词： Dislocation reconfiguration Electroplasticity Al-Cu-Li alloy Creep deformation

ZERO TRANSMISSION AND ITS APPLICATION IN HIGH SPEED CNC maCHINE TOOLS

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Chinese Journal of Mechanical Engineering 2000年第3期13卷 184-189页

作者： Zhang bolin, ma Ping, Xiao Shuhong ,Li Yiping, Xiao Zhanglin (Department of Mechanical and Electronical Engineering,Guangdong University of Technology) 广东工业大学广东广州

In order to realize high speed machining,the special requirements for the transmission and sturctrue of CNC machine tool have to be satisfied.A high speed spindle unit driven by a built-in motor is *** oil-water heat exchange system is used for cooling the spindle *** spindle is supported by Si_4N_3 ceramic ball angular contact bearings. An oil-air lubricator is used to lubricate and cool the spindle *** special structures are taken for balancing the spindle.

关键词： High speed machining machine tool Spindle Ceramic ball bearing\

L^2(R^n) BOUNDEDNESS FOR COMMUTATORS OF OSCILLATORY SINGULAR INTEGRAL OPERATORS

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Analysis in Theory and Applications 2000年第2期16卷 37-44页

作者： ma bolin Hu Guoen Department of Applied mathematics Hunan University410082ChangshaPeople’s Republic of China Lab.mathematics and its Application Peking University100871BeijingPeople’s Republic of China Department of Applied mathematics Institute of Information Engineering of ZhengzhouP.O.Box 1001-47450002ZhengzhouPeople’s Republic of China

The commutators of oscillatory singular integral operators with homogeneous kernel $\frac{{\Omega (x)}}{{\left| x \right|^n }}$ are studied, where Ω is homogeneous of degree zero, has mean value zero on the unit sphere. It is proved that Ω∈L (logL)K+1(Sn-1) is a sufficient condition under which the k-th order commutator is bounded on L2(Rn).

关键词： oscillatory integral operator multiplier singularity

ALMOST-EVERY WHERE CONVERGENCE OF BOCHNER-RIESZ MEANS IN BESSEL POTENTIAL SPACES

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Analysis in Theory and Applications 1997年第4期13卷 13-18页

作者： ma bolin (Zhejiang University ,China) 1. Center for mathematical sciences Zhejiang University 310027 Hangzhou P. R. China

In this paper, we consider the almost everywhere convergenc of Bochner-Riesz means below the critical index in Bessel potential spaces and a>0) and find out the relation between the index of Bochner -Riesz means and t... 详细信息

关键词： oscillatory integral operator multiplier singularity