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One-Dimensional Fractal Curves and Fractal Dimension Determination

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International Journal of Minerals,Metallurgy and materials 1998年第3期12卷 165-168页

作者： Qikai Li yue Zhang wuyang chu(Applied science School, university of science and technology beijing, beijing 100083, china) Applied science School University of Science and Technology Beijing Beijing 100083 China

Various methods for evaluating the fractal curves were reviewed and simulated on computer. It is shown box-counting and power spectrum methods generally give poor measuring results, while yard and variation methods could obtain good results. However,owing to multiple influencing factors, further study needs to be done before widespread application of variation method. In order to improve the measuring accuracy of yard method, a new method has been propoed to measure the fractal dimension by changing the instrumental resolutions.

关键词： fractal fractal dimension computer simulation

INTERPHASE　STRESS　CORROSION　CRACKING　OF　ALLOY　Ti－24Al－11Nb　IN　METHANOL　SOLUTION

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Acta Metallurgica Sinica(English Letters) 1996年第2期9卷 121-128页

作者： ZHANG yue chu wuyang XIAO Jimei(Department of materials physics,university of science and technology beijing,beijing 100083,china) OUYANG Shixi YUAN Runzhang(State Key Laboratory for Synthesis and Processing of Advanced materials.Wuhan university of Techn Univ of science and technology Beijing Beijing China

For alloy Ti-24Al-11Nb,stress corrosion cracking(SCC) in methanol solution and hydrogen induced cracking(HIC) during dynamic charging at room temperature have been *** has shown that the normalised threshold stress intensities of SCC failure for various microstructures are KISCC/KC =0.53 0.69 and the threshold value for SCC arresting KISCC/ KIC=*** threshold values of HIC during dynamic charging are close to that of SCC,but da/dt or fracture time of HIC is one to three orders of magnitude smaller or longer than that of SCC,*** surface for HIC is also different from that for *** the Ti-24Al-Nb alloy-methanol systein,a kind of inierphase SCC has been found For the microstructures resulting from furnace cooling,SCC initiated and propagated preferentially along theα2/βinterphase boundaries,displaying the microstructure on the fracture surface of ***,there is no interphase SCC for the microstructure resulting from air cooling.

关键词： Ti-24Al-11Nb,hydrogen induced cracking,interphase stress corrosion cracking methanol

A New Method for Fractal Dimension Determination by STM at Nanometer Scale

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International Journal of Minerals,Metallurgy and materials 1999年第1期13卷 64-68页

作者： Qikai Li yue Zhang wuyang chu Chen Wang chunli Bai (Applied science School. university of science and technology beijing, beijing 100083. china)(Chemical Institute, Chinese Academy of science, beijing 100080. china) Applied science School University of Science and Technology Beijing Beijing 100083 China Chemical Institute Chinese Academy of Science Beijing 100080 China

A new method for determining the fractal dimension by STM at nanomeler scale has been ***- Mandelbrot fractal curves were used to verify the accuracy and reliability. The Computer simulation showed that fractal dimen- sion obtained with this method generally outran the traditional yard method. The new method has been applied to the fractal dimension determination of the fractures of Ti3Al and Ti-24Al-11Nb alloys. The results show that the fractal dimension of Ti-24Al-11Nb alloy is higher than that of Ti3Al, and it varies with the crark extending orientation.

关键词： fractal dimension STM nanometer scale Ti-Al alloy

Fractal Dimensions of Hydrogen Induced Brittle Fracture of Titanium Aluminide

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Journal of materials science & technology 1993年第5期9卷 338-342页

作者： yue ZHANG Yanbin WANG lijie qiao wuyang chu Chimei HSIAO Dept.of materials physics,university of science and technology,beijing,beijing,100083,china

The relationship between the stress intensity factor K_1~* required for brittle crack initiation and propa- gation and the fractal dimension D_F of the fracture surface was derived,i.e, InK_1~*=(1/2)In2γE'+(1/2)In(d_f/L_0)(1-D_F) The real surface energy can be calculated based on the measured linear relation of the InK_1~* vs D_F, The equation is not only suitable for the overload fracture but also for the delayed fracture,e.g. hydrogen induced cracking (HIC) and stress corrosion cracking (SCC).The experiment results showed that the hydrogen induced delayed cracking occurred in the Ti-24AI-11 Nb alloy during dy- namic charging,and the threshold stress intensity factor was very low,i.e..K_(IH)/K_(IC)= *** ex- perimental relationship between the stress intensity factor K_1~* and D_F was consistent with the theo- retical equation.

关键词： titanium aluminide hydrogen induced cracking tractal dimension

Molecular Dynamics Simulation of Dealloyed Layer-induced Tensile Stress in Cu_3Au

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Journal of university of science and technology beijing 2001年第4期8卷 295-298页

作者： Qikai L, yue Zhang, Mark Hoffman, wuyang chu 1)materials science and Engineering School. university of science and technology beijing. beijing 100083, china 2)School of materials science & Engineering, university of New South Wales, Sydney 2052, Austral materials science and Engineering School University of Science and Technology Beijing Beijing 100083 China School of materials science and Engineering University of New South Wales Sydney NSW 2052 Australia

During stress corrosion cracking of Cu3Au alloy, there is a dealloyed layer on its surface because of preferential dissolution of Cu, and there is a linear distribution of Cu vacancy concentration in the dealloyed layer. Molecular dynamics simulation has been done on the three-dimensional crystal (about 148 000 atoms) by employing the embedded-atom method (EAM) potential. Simulation shows that Cu3Au crystal in which there is a dealloyed layer on one surface and one end is fixed will be deflected after relaxing for a long time because of a tensile stress generated at or near the dealloyed layer interface. The deflection and then the tensile stress increase with increasing the depth of dealloyed layer and the vacancy concentration in the dealloyed layer.

关键词： dealloyed layer-induced stress molecular dynamics simulation Cu3Au

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数字孪生校园的设计与实现

电子技术（上海） 2024年第1期53卷 74-75页

作者：李午阳匡迎春胡超沈岳湖南农业大学信息与智能科学技术学院湖南410128

阐述校园中的教学、管理、安全问题原因,提出基于人工智能、数字孪生技术的数字孪生校园建设方案,分析新型智慧课堂、智慧安防的应用方案,从而实现教学及管理的升级。

关键词：智慧校园数字孪生智慧课堂智慧安防

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双层石墨烯/PET基底多界面作用力分析

材料科学与工程学报 2022年第6期40卷 929-939页

作者：龚露阳乐午阳刘文台周何乐子周华民华中科技大学材料成形与模具技术国家重点实验室湖北武汉430074

研究大尺寸双层石墨烯/基底结构的多界面作用力对其在工程领域的实际应用具有十分重要的现实意义。本研究设计了一种从宏观尺寸分析石墨烯/PET结构界面作用力的方法,通过内聚力模型定义石墨烯/PET和石墨烯/石墨烯界面的本构关系,基于剪... 详细信息

研究大尺寸双层石墨烯/基底结构的多界面作用力对其在工程领域的实际应用具有十分重要的现实意义。本研究设计了一种从宏观尺寸分析石墨烯/PET结构界面作用力的方法,通过内聚力模型定义石墨烯/PET和石墨烯/石墨烯界面的本构关系,基于剪滞模型的基本原理,将石墨烯轴向应力作为分析对象,得到在不同的界面刚度、界面剪切强度和界面粘着能时,PET受拉过程中界面作用力的变化以及双层石墨烯边界距离变化。同时进行了宏观拉伸实验,通过光学显微镜和拉曼光谱分析得到双层石墨烯边界距离变化和石墨烯受损情况数据,验证有限元分析结果,最终确认实际的界面参数。该研究结果为探索非单层石墨烯/基底结构多界面作用力参数提供了一种新思路。

关键词：石墨烯/基底结构界面作用力内聚力模型有限元模拟

Effect of Post-weld Tempering on the Microstructure and Mechanical Properties in the Simulated HAZs of a High-Strength-High-Toughness Combination Marine Engineering Steel

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Acta Metallurgica Sinica(English Letters) 2020年第3期33卷 391-402页

作者： Wen-Chao Dong Ming-yue Wen Hui-Yong Pang Shan-Ping Lu Shenyang National Laboratory for materials science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of materials science and Engineering University of Science and Technology of ChinaShenyang 110016China wuyang Iron and Steel Co.Ltd. Pingdingshan 462500China

The effects of tempering temperatures on the microstructure and mechanical properties of the simulated coarse-grain heataffected zone(CGHAZ) and inter-critical heat-affected zone(ICHAZ) were investigated for a high-strength-high-toughness combination marine engineering *** results demonstrate that the microstructure of the simulated CGHAZ and ICHAZ after tempering is characterized by tempering sorbites and coarse grain in the simulated *** tempering temperature increases,the tensile strength of the simulated CGHAZ and ICHAZ decreases and the Charpy absorbed energy of the simulated ICHAZ at-50℃increases remarkably,but the impact toughness of the simulated CGHAZ is not *** tempering at 550℃,the coarse flake carbides,which distribute at the prior austenite grain and martensite lath boundaries,deteriorate the impact toughness of the simulated *** the increase in tempering temperature,the morphology and the size of the carbides gradually change from coarse flake to fine granular,which is beneficial to the improvement of impact ***,the coarse-grain size of the simulated CGHAZ and the M23 C6-type carbide precipitated along the grain boundaries weakens the enhancing effect of carbides on impact toughness.

关键词： High-strength-high-toughness combination steel Post-weld heat treatment Heat-affected zones(HAZs) Carbides Impact toughness

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基于深度学习的跑道前视红外图像轮廓线提取

电讯技术 2019年第2期59卷 179-184页

作者：袁雷程岳牛文生罗午阳航空工业西安航空计算技术研究所西安710068 机载弹载计算机航空科技重点实验室西安710068

针对前视红外图像中的机场跑道检测问题,提出了基于深度学习的端到端的实时检测算法。算法首先利用深度学习在物体特征表达上的优点,采用当前主流端到端的YOLO(You Only LookOnce) V2检测算法提取候选目标,寻找跑道所在位置;然后在已经... 详细信息

针对前视红外图像中的机场跑道检测问题,提出了基于深度学习的端到端的实时检测算法。算法首先利用深度学习在物体特征表达上的优点,采用当前主流端到端的YOLO(You Only LookOnce) V2检测算法提取候选目标,寻找跑道所在位置;然后在已经获取跑道所在边框的基础上,在神经网络最后一层采用多尺度线段检测器(Line Segment Detector,LSD)进行精确的线段检测;最后对所检测的线段进行融合,提取轮廓线。真实实验数据表明,该算法基本上能满足机场轮廓提取实时性好、提取精度高、抗干扰性强等要求。

关键词：机场跑道检测前视红外(FLIR)图像轮廓提取深度学习