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MULTI-GRANULARITY EVOLUTION ANALYSIS OF SOFTWARE USING COMPLEX NETWORK THEORY

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Journal of Systems Science & Complexity 2011年第6期24卷 1068-1082页

作者： Weifeng PAN Bing li Yutao ma Jing liU State Key Laboratory of Software Engineering Wuhan University Wuhan 430072 China School of Computer Science and Information Engineering Zhejiang Gongshang University Hangzhou 310018 China School of Computer Wuhan University Wuhan 430072 China Complex Networks Research Center Wuhan University Wuhan 430072 China

Software systems are a typical kind of man-made complex systems. Understanding their evolutions can lead to better software engineering practices. In this paper, the authors use complex network theory as a tool to analyze the evolution of object-oriented （OO） software from a multi-granularity perspective. First, a multi-granularity software networks model is proposed to represent the topological structures of a multi-version software system from three levels of granularity. Then, some parameters widely used in complex network theory are applied to characterize the software networks. By tracing the parameters＇ values in consecutive software systems, we have a better understanding about software evolution. A case study is conducted on an open source OO project, Azureus, as an example to illustrate our approach, and some underlying evolution characteristics are uncovered. These results provide a different dimension to our understanding of software evolutions and also are very useful for the design and development of OO software systems.

关键词： Complex networks multi-granularity software evolution software system.

Mechanical Behavior and Failure Mechanisms of Carbon Fiber Composite Pyramidal Core Sandwich Panel after Thermal Exposure

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Journal of materials Science & Technology 2013年第9期29卷 846-854页

作者： Jiayi liu Zhengong Zhou linzhi Wu li ma Center for Composite materials and Structures Harbin Institute of Technology

An attempt has been made here to evaluate the effect of thermal exposure on the mechanical behavior and failure mechanisms of carbon fiber composite sandwich panel with pyramidal truss core under axial compression. Analytical formulae for the collapse strength of composite sandwich panel after thermal exposure were derived. Axial compression tests of composite laminates and sandwich panels after thermal exposure were conducted at room temperature to assess the degradation caused by the thermal exposure. Experimental results showed that the failure of sandwich panel are not only temperature dependent, but are time dependent as well. The decrease in residual compressive strength is mainly attributed to the degradation of the matrix and the degradation of fiber-matrix interface, as well as the formation of cracks and pores when specimens are exposed to high temperature. The measured failure loads obtained in the experiments showed reasonable agreement with the analytical predictions.

关键词： Composite Thermal exposure Mechanical properties Sandwich panel

Single-Crystalline Organoiridium Complex for Gas-Triggered Chromogenic Switches and Its Applications on CO Detection and Reversible Scavenging

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Chinese Journal of Chemistry 2019年第8期37卷 763-768页

作者： li-Ying Sun Yuan-Yuan An li-li ma Ying-Feng Han Key Laboratory of Synthetic and Natural Functional Molecule Chemistry College of Chemistry and Materials ScienceNorthwest UniversityXi'anShaaxi 710127China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002China

Summary of main observation and conclusion Nonporous molecular single crystals of coordinatively unsaturated 16-electron metallacycle are found to undergo highly selective-yet reversible-binding of CO over CH4,H2,N2,CO2,various volatile organic compounds and water,through binding of the molecule to its metal *** monoxide is taken up by black crystals and subsequently liberated from the corresponding orange CO adduct by reversible metal coordination,the structural evidence obtained from in situ X-ray *** single-crystallinity of the metallacycle is retained even after several *** material,when adsorbed on silica,shows remarkable sensitivity and selectivity for CO,allowing visual CO sensing in the solid *** metallacycle offer the possibility of serving as readily regenerable scavenger for removing trace CO from gas mixtures with N2.

关键词： Gas-Triggered Chromogenic Switches Applications CO Detection Reversible Scavenging

Microstructure and Mechanical Properties of TWIP Steel Joints

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Journal of Iron and Steel Research International 2014年第8期21卷 749-756页

作者： li-li ma Ying-hui WEI li-feng HOU Bin YAN College of materials and Engineering Taiyuan University of Technology

As a new type of high manganese steel, the twinning induced plasticity （TWIP） steels have attracted a growing interest in the automotive industry due to their good performance. Thin plates of TWIP steel were welded by laser beam welding （LBW） and gas tungsten arc welding （GTAW）. The microstructure result shows that GTAW joint has obvious heat-affected zone （HAZ）, while the HAZ of LBW joint is almost invisible. The X-ray diffraction result shows that the phase compositions of both joints are austenitic and no phase transition occurs. Energy disper- sive spectrometry result shows that there is violent evaporation of Mn element in LBW joint, while the proportion of Mn element in GTAW joint is almost unchanged. Tensile tests and micro-hardness measurements were performed to take into account the mechanical properties of joints manufactured by the two different processes. The micro-hard- ness profiles of both joints present a typical saddle distribution, and the hardness of GTAW seam is lower than that of LBW seam. The failure positions of LBW joints are all located in base metal while the GTAW joints are all at the weld toe due to the softening of HAZ. By means of scanning electron microscopy, a typical ductile fracture is observed in LBW joint, while a brittle fracture with quasi-cleavage fracture characteristic is observed in GTAW joint.

关键词： TWIP steels high manganese steels LBW GTAW

Discrete Morse Flow for Yamabe Type Heat Flows

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Journal of Partial Differential Equations 2023年第1期36卷 48-57页

作者： ma li ZHENG Wei School of mathematics and Physics University of Science and Technology BeijingBeijing 100083China

In this paper,we study the discrete Morse flow for either Yamabe type heat flow or nonlinear heat flow on a bounded regular domain in the whole *** show that under suitable assumptions on the initial data g one has a weak approxi-mate discrete Morse flow for the Yamabe type heat flow on any time *** phenomenon is very different from the smooth Yamabe flow,where the finite time blow up may exist.

关键词： Discrete Morse flow Yamabe type flow critical exponent nonlinear heat flow

Enhanced Fracture Toughness of Pressureless-sintered SiC Ceramics by Addition of Graphene

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Journal of materials Science & Technology 2016年第7期32卷 633-638页

作者： Qisong li Yujun Zhang Hongyu Gong Haibin Sun Wenjie li li ma Yanshuang Zhang Key Laboratory for liquid-Solid Structural Evolution & Processing of materials of Ministry of Education Shandong University School of materials and Chemical Engineering Zhongyuan University of Technology Key Laboratory of Special Functional Aggregated materials Ministry of Education Shandong University Shandong Baona New materials Co. Ltd.

To enhance the fracture toughness of pressureless-sintered SiC ceramic, graphene was introduced as an additive. The effects of graphene contents on the fracture toughness, bending strength, micro-hardness, phase compositions, and microstructure evolutions of the SiC ceramics were investigated in detail by scanning electron microscopy, energy dispersive X-ray spectroscopy, and metallographic microscopy. The fracture toughness, bending strength and micro-hardness increased initially, and then decreased with the graphene content increasing from 0 to 5.0 wt%. The highest fracture toughness of 5.65 MPa m1/2 was obtained for sample with 1.0 wt% graphene sintered at 2130 ℃ for 1 h in At, which was about 22.6% higher than that of SiC sample without graphene. In addition, the highest bending strength and microhardness of 434.14 MPa and 29.21 GPa corresponded to the SiC samples with graphene content of 0.5 wt% and 2.0 wt%, respectively.

关键词： SiCGrapheneFracture toughnessBending strengthMicro-hardness

Two new species of Trypoxylon Latreille, 1796 from China (Hymenoptera: Crabronidae)

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Zoological Systematics 2024年第4期49卷 309-319页

作者： Yan Fu Qiang li li ma Department of Entomology College of Plant ProtectionYunnan Agricultural UniversityKunmingYunnan 650201PR.China

Two new species of the genus Trypoxylon,namely *** Fu&li,*** *** Fu&li,***.,are described and illustrated from Guizhou,Guangdong,Guangxi and Zhejiang Provinces,*** two species,*** Tsuneki,1956 and *** Tsuneki,1968,are... 详细信息

关键词： Crabroninae Trypoxylini taxonomy Trypoxylon China

Review:A survey for image resizing

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第9期15卷 697-716页

作者： Xiao liN Ying-lan ma li-zhuang ma Rui-ling ZHANG Department of Computer Science and Engineering Shanghai Jiao Tong University Academy of Information Technology Luoyang Normal University Department of Computer Science College of Engineering University of Illinois at Urbana-Champaign

Image resizing is a key technique for displaying images on different devices, and has attracted much attention in the past few years. This paper reviews the image resizing methods proposed in recent years, gives a detailed comparison on their performance, and reveals the main challenges raised in several important issues such as preserving an important region, minimizing distortions, and improving efficiency. Furthermore, this paper discusses the research trends and points out the possible hotspots in this field. We believe this survey can give some guidance for researchers from relevant research areas, offering them an overall and novel view.

关键词： Image resizing Saliency measures Cropping Seam carving Warping

A New and Efficient Synthesis of 2H-3, 1-Benzoxazine Compounds

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Chinese Chemical Letters 2005年第11期16卷 1424-1426页

作者： Jia Rong li Shu ling ma School of Chemical Engineering and Environment Beijing Institute of Technology Beijing 100081

2H-3, 1-Benzoxazine derivatives were synthesized by cyclocondensation of 5-nitro-2- cyanoaniline with relative ketone or aldehyde with ZnCl2 as a catalyst. This is a new efficient synthetic route of 2H-3, 1-benzoxazin... 详细信息

关键词： 2H-3 1-Benzoxazine cyclocondensation synthesis