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Fractional Sobolev-Poincar Inequalities in Irregular Domains

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Chinese Annals of Mathematics,Series B 2017年第3期38卷 839-856页

作者： chang-Yu guo Department of Mathematics and Statistics University of Jyvaskyla P.O. Box 35 FI-40014 JyvaskylaFinland Department of Mathematics University of Fribourg Chemin du Musee 23 CH-1700 FribourgSwitzerland.

This paper is devoted to the study of fractional(q, p)-Sobolev-Poincar′e inequalities in irregular domains. In particular, the author establishes(essentially) sharp fractional(q, p)-Sobolev-Poincar′e inequalities in s-John domains and in domains satisfying the quasihyperbolic boundary conditions. When the order of the fractional derivative tends to 1, our results tend to the results for the usual derivatives. Furthermore, the author verifies that those domains which support the fractional(q, p)-Sobolev-Poincar′e inequalities together with a separation property are s-diam John domains for certain s, depending only on the associated data. An inaccurate statement in [Buckley, S. and Koskela, P.,Sobolev-Poincar′e implies John, Math. Res. Lett., 2(5), 1995, 577–593] is also pointed out.

关键词： Fractional Sobolev-Poincar inequality s-John domain Quasihyperbolic boundary condition

Confluence of asymmetric catalysis and electrosynthesis in sustainable chemical transformations

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Science China Chemistry 2024年第3期67卷 755-758页

作者： Qinglin Zhang Kang Liang chang guo Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of ChinaHefei 230026China

Electrosynthesis has gained widespread recognition for its extraordinary ability to precisely control the redox *** outstanding capability enables the direct conversion of non-functionalized substrates into reactive intermediates by utilizing easily accessible starting materials, eliminating the need for preliminary functionalization procedures and allowing for unconventional bond activations.

关键词： Confluence of asymmetric catalysis and electrosynthesis in sustainable chemical transformations

An Application-Oriented Cache Allocation and Prefetching Method for Long-Running Applications in Distributed Storage Systems

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Chinese Journal of Electronics 2019年第4期28卷 773-780页

作者： guo chang LI Ying LIU Hongzhi WU Zhonghai School of Electronics Engineering and Computer Science Peking University National Engineering Research Center For Software Engineering Peking University School of Software and Microelectronics Peking University

Characteristics of long-running applications in cloud and big data environment are various and significantly influence the performance of cache *** gap between existing cache systems and the increasing performance requirements motivates us to propose the Application-oriented cache allocation and prefetching method(ACAP) to improve data access performance. An application-oriented cache allocation approach is designed based on hit count growth rates for a higher overall hit rate. Two application-oriented sequential prefetching approaches are proposed to improve the hit rate and prefetching accuracy by learning average read sizes of long-running applications. Based on correlation of data accesses, a parallelized correlated-directed prefetching approach is proposed to further increase the hit *** approaches are intergrated to obtain the maximized hit rate and prefetching accuracy. Experimental results on12 public real system traces show that ACAP achieves14.03%(up to 33.82%) higher prefetching accuracy and2.01%(up to 7.54%) higher hit rate compared with the best combination of baselines.

关键词： Cache prefetching Cache allocation Distributed storage system Resource management

Dynamic kinetic stereodivergent transformations of propargylic ammonium salts via dual nickel and copper catalysis

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Chinese Chemical Letters 2024年第8期35卷 265-269页

作者： Ruilong Geng Lingzi Peng chang guo Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of ChinaHefei 230026China

The dynamic kinetic asymmetric transformation of racemic propargylic ammonium salts with prochiral aldimine esters through a stereodivergent propargylation is catalyzed by dual nickel and copper ***,a diverse range of optically activeα-quaternary amino esters were produced via C-N bond cleavage with high reaction efficiency and stereoselectivity(up to>99%ee).By selection of the appropriate pair-wise combination of catalyst configurational isomers,all four possible stereoisomers of the corresponding propargylation products are obtained in high yields with excellent regio-,diastereo-,and enantioselectiv-ities.

关键词： Stereodivergent propargylation Dual catalysis C-N bond cleavage Azaomethine ylides Internal propargylic ammonium salts Excellent stereoselectivity

Experiment and evaluation of wrinkling strain in a corner tensioned square membrane

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Acta Mechanica Sinica 2014年第3期30卷 430-436页

作者： Lan Lan chang-guo Wang Hui-Feng Tan Center for Composite Materials National Key Laboratory of Science and Technology on Advanced Composites in Special EnvironmentsHarbin Institute of Technology

Prediction of wrinkling characteristics is strongly correlated with the strain perpendicular to wrinkling direc- tion. In this paper, the strain field of wrinkled membrane is tested by VIC-3D system based on the digital image correlation technique. Experimental results are validated by the tension wrinkling simulation. The experimental strain perpendicular to wrinkling direction is analyzed in depth. The wrinkling strain of a square wrinkled membrane under corner tension is extracted from experimental strain perpendicular to wrinkling direction. A quantitative characterization format of the experimental wrinkling strain is proposed. A modified prediction method of wrinkling amplitude is presented based on the experimental wrinkling strain. The re- sults show that the precision of modified prediction model has improved 13.2% compared with the classical prediction model. The results reveal that the modified model can give an accurate prediction of the wrinkling amplitude.

关键词： Membrane structure. Wrinkle Wrinkling strain.Digital image correlation Wrinkling amplitude

Transformation Characteristics and Microstructure of Rail under Low Stress during Continuous Cooling

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Journal of Wuhan University of Technology(Materials Science) 2021年第2期36卷 269-279页

作者： CEN Yaodong CHEN Lin chang guo ZHAO Leicheng School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014010China

To obtain a better understanding the thermal stress of a rail,the thermal simulator was used to measure the expansion curves of different stresses loaded during the continuous cooling process of U75V *** transformation plasticity model was *** experimental results show that stress can accelerate the transformation process of *** the same cooling rate is accelerated with the increase of stress,the transformation process of pearlite is accelerated,and the proportion of plastic strain transformation in total strain *** the same stress,the process of transformation of pearlite decreases with the increase in cooling rate,and the proportion of transformation plastic strain in total strain *** considering the transformation plasticity,the axial residual stress is more consistent with the actual working condition,the accuracy of the transformation plasticity model is higher;during the continuous cooling process,and the loading stress has a significant influence on the *** the stress increases,the orientation of the pearlite lamellae becomes disordered,the pearlite lamellae are bent,the lamellae spacing is no longer uniform,and the hardness is improved.

关键词： rail transformation plasticity microstructure

Research on cutting vibration characteristics of face-milling involute gear

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Defence Technology（防务技术） 2017年第5期13卷 380-384页

作者： Cheng-zhe JIN chang guo Yun GAO School of Mechanical Engineering Shenyang Ligong UniversityShenyangPeople's Republic of China

Traditional machining methods, such as gear hobbing, gear shaping and gear milling, etc, are commonly used for cutting machining of gear tooth profile, which cannot meet huge machining demand of gears to a certain extent. This article proposes to utilize a face-milling machining method in involute gear machining, which can be used to reduce production cost effectively. Cutting vibration generated during cutting machining has a direct effect on the machining accuracy and machined surface quality of workpiece. Therefore, it is desiderated to perform in-depth research regarding this issue. ADAMS software was used to establish a rigid-flexible coupling virtual prototyping model of face-milling gear milling system and a cutting vibration system model. Cutting vibration analysis was performed for face-milling gear by adopting quick sine frequency sweep method, so that the frequency response characteristics of workpiece in three directions X, Y and Z and space were acquired. The research results will provide reference and theoretical foundation for actual application of face-milling gear machining technology.

关键词： Gear Face-milling Vibration ADAMS

Some Properties for the Largest Component of Random Geometric Graphs with Applications in Sensor Networks

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Acta Mathematicae Applicatae Sinica 2009年第4期25卷 579-592页

作者： Ge Chen Tian-de guo chang-long Yao School of Mathematical Science Graduate University of Chinese Academy of Sciences Beijing 100049 China

In this paper we consider the standard Poisson Boolean model of random geometric graphs G（Hλ,s; 1） in Rd and study the properties of the order of the largest component L1 （G（Hλ,s; 1）） . We prove that ElL1 （G（Hλ,s; 1））] is smooth with respect to A, and is derivable with respect to s. Also, we give the expression of these derivatives. These studies provide some new methods for the theory of the largest component of finite random geometric graphs （not asymptotic graphs as s - co） in the high dimensional space （d 〉 2）. Moreover, we investigate the convergence rate of E[L1（G（Hλ,s; 1））]. These results have significance for theory development of random geometric graphs and its practical application. Using our theories, we construct and solve a new optimal energy-efficient topology control model of wireless sensor networks, which has the significance of theoretical foundation and guidance for the design of network layout.

关键词： Random geometric graph the largest component wireless sensor networks topology control

A Nonlinear Explicit Model of A Non-Circular Subsea Tunnel-Liner System with An FGM Inverted Arch Under Mechanical Loading and Fire Fields

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China Ocean Engineering 2024年第5期38卷 855-865页

作者： HE Jie chang guo-yong LIU Yang LI Zhao-chao School of Civil Engineering Hunan University of TechnologyZhuzhou 412007China School of Civil Engineering Changsha University of Science and TechnologyChangsha 410114China

This paper proposes an explicit scheme to analyze the failure of a subsea polyhedral tunnel-liner system with an inverted arch under mechanical loading and fire *** thin-walled liner is made of Functionally Graded Materials(FGMs),which may improve the stability behavior of the tunnel-liner *** pressure is inevitable in the liner since underground water may penetrate the cracks of the tunnel,and reach the outer surface of the *** addition,an elevated temperature loading is taken into account,considering that fire may occur in the tunnel-liner *** the combination of mechanical loading and thermal loading,the liner deforms into a single-lobe shape,which is depicted by a trigonometric *** total potential energy is expressed quantitatively after the energy approach and thin-walled shell theory are *** minimum potential energy is obtained when the critical buckling *** critical buckling pressure is calculated,which considers the effect of the thermal *** present analytical prediction is subsequently compared precisely with other closed-form ***,the effects of several parameters,such as the geometric shapes,temperature variations,and volume fraction indices,are discussed to further survey the buckling performance of the nonlinear buckling of an FGM polyhedral liner with an inverted *** may address a polyhedral liner with fewer polyhedral sides,and a lower volume fraction index is recommended to rehabilitate cracked tunnels in engineering applications.

关键词： tunnel-liner system with an inverted arch volume fraction index mechanical and thermal loadings rehabilitation buckling