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Effects of Long-term Creep at Elevated Temperatures on Rupture Ductility in 9Cr-1Mo-V-Nb-N Steel

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Journal of Materials Science & Technology 1998年第3期14卷 226-230页

作者： Zhu, Lihui Zhao, Qinxin gu, haicheng Lu, Yansun Xian Jiao Tong Univ Sch Mat Sci & Engn Xian 710049 Peoples R China

Besides the creep strength, creep ductility has also been recognized as an important material parameter, since low ductility is often associated with notch sensitivity and concomitant premature failure, especially brittle fracture. Creep rupture data of 9Cr-1Mo-V-Nb-N show that the creep ductility decreases with decreasing stress at constant temperature or with decreasing temperature at constant stresses. SEM and TEM were used to investigate the mechanism of rupture ductility after long term creep was related to the decrease of mobile dislocation density, the coarsening and coalescence of carbides and the decrease of shear lip size. (Edited author abstract) 8 Refs.

关键词： Steel

CYCLIC DEFORMATION BEHAVIOR OF ZIRCALOY-4 AT DIFFERENT TEMPERATURES

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Acta Metallurgica Sinica(English Letters) 1995年第3期8卷 219-225页

作者： XIAO Lin gu haicheng KUANG Zhenbang(Xi’an Jiaotong University, China Xi'an Jiaotong Univ Xi'an China

Fatigue lifetime curves of Zircaloy-4 at different temperatures were measured, and the fatigued dislocation configurations were investigated using transmission electron microscopy. Ii was found that prismatic slip is the primary deformation mode. for Zircaloy-4fatigued at RT prismatic plus Pyramidal slip at 400℃,and prismatic plus (0001) basic slip at 600℃. The corresponding dislocation configurations are parallel dislocation lines al RT, elongated cells at 400℃ and two sets of mutually Perpendicular dislocation bands at 600℃.respectively. The relationship among. fatigue deformation mode, dislocation configuration and lifetime is discussed.

关键词： Zircaloy-4,.fatigue dislocation configuration slip system

Ceramics Surface Modification by Excimer Laser Metal Coating

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Journal of Materials Science & Technology 1994年第6期10卷 463-465页

作者： Weidou ZHU and haicheng gu(Dept. of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an, 710049, China) Xi'an Jiaotong Univ Xi'an China

Thin metallic layers (~ 2 μm) of Ni were deposited on polycrystalline Al2O3. ZrO2 and (Ce-TZP)+Al2O3 ceramic substrates. and further irradiated with pulsed excimer (Xeno chloride) laser pulses. The laser energy density was varied from 0.21 to 0.81 J / cm2 to optimize bending strength. For ZrO2 ceramic, it was found that the strength increases from 530 to 753 MPa at 0.51 J / cm2 irradiation. For Al2O3 and (Ce-TZP)+ Al2O3 the fracture strength also increases in varying degree. The causes of strength increment were discussed.

关键词： Ceramics Surface Modification by Excimer Laser Metal Coating Res

A lightweight false alarm suppression method in heterogeneous change detection

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Journal of Systems Engineering and Electronics 2024年第4期35卷 899-905页

作者： XU Cong HE Zishu LIU haicheng School of Electronic and Information Engineering Heilongjiang Institute of EngineeringHarbin 150026China School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

Overlooking the issue of false alarm suppression in heterogeneous change detection leads to inferior detection *** paper proposes a method to handle false alarms in heterogeneous change detection.A lightweight network of two channels is bulit based on the combination of convolutional neural network(CNN)and graph convolutional network(GCN).CNNs learn feature difference maps of multitemporal images,and attention modules adaptively fuse CNN-based and graph-based features for different *** with a new kernel filter adaptively distinguish between nodes with the same and those with different labels,generating change *** evaluation on two datasets validates the efficacy of the pro-posed method in addressing false alarms.

关键词： convolutional neural network(CNN) graph convolu-tional network(GCN) heterogeneous change detection lightweight false alarm suppression

FATIguE DISLOCATION CONFIguRATIONS IN HEXAGONAL ZIRCALOY-4

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Chinese Journal of Aeronautics 1996年第2期9卷 122-125页

作者： Xiao Lin(Institute of Engineering Mech., Xi’an Jiaotong University, Xi’an, China, 710049)gu haicheng(Institute for Strength of Metals, Xi’an Jiaotong University, Xi’an, China, 710049) Institute of Engineering Mech. Xi'an Jiaotong University Xi'an 710049 China Institute for Strength of Metals Xi'an Jiaotong University Xi'an 710049 China

Fatigue dislocation configurations of Zircaloy-4 at 470℃×1h stress-relieved condition and 620℃×1h recrystallized condition were analyzed using TEM. Theresults show that: {1 0 1 0} prismatic slip is the primary deformation mode at RT. Prismatic and pyramidal slips are activated simultaneously at 400℃. The typicalsubstructure is the elongated dislocation lines at RT; whereas at 400℃, it is rectangularcells in stress-relieved specimens, and elongated cells plus dipole perpendicular cellboundary in recrystallized specimens. The relationship map among dislocation configuration, test temperature and cyclic strain range is established, finally.

关键词： Zircaloy (trademark) fatigue (materials) dislocations (materials) configuration interaction slip

Cross-diffusion induced Turing instability of Hopf bifurcating periodic solutions in the reaction-diffusion enzyme reaction model

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International Journal of Biomathematics 2024年第4期17卷 133-150页

作者： haicheng Liu Wenshuo Yuan Bin Ge Jihong Shen College of Mathematical Sciences Harbin Engineering University Harbin 150001 HeilongjiangP.R.China

Aiming at the spatial pattern phenomenon in biochemical reactions,an enzyme-reaction Sporns-Seelig model with cross-diffusion is chosen as study *** the central manifold theory,normal form method,local Hopf bifurcation theorem and perturbation theory,we study Turing instability of the spatially homogeneous Hopf bifurcation periodic *** last,the theoretical results are verified by numerical simulations.

关键词： Sporns-Seelig model diffusion Hopf bifurcation periodic solutions Turing instability

离心喷射沉积Ti-48Al-2Mn-2Nb的断裂韧度

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稀有金属材料与工程 2000年第1期29卷 17-20页

作者：陈文哲张飒钱匡武顾海澄福州大学福州350002 西安交通大学西安710049

着重研究了采用真空离心喷射沉积成形的Ti48Al2Mn2Nb金属间化合物及经热等静压处理的合金样品的室温断裂韧度。采用三点弯曲试验方法进行测试,结果表明,喷射沉积合金样品的平均断裂韧度值为236MPam12,最大值约28MPam12,而经热等静压后... 详细信息

着重研究了采用真空离心喷射沉积成形的Ti48Al2Mn2Nb金属间化合物及经热等静压处理的合金样品的室温断裂韧度。采用三点弯曲试验方法进行测试,结果表明,喷射沉积合金样品的平均断裂韧度值为236MPam12,最大值约28MPam12,而经热等静压后样品的平均断裂韧度仅为153MPam12。结果分析认为,层片状组织对裂纹扩展的抗力比γ等轴晶的抗力高得多,因而,具有层片状组织的离心喷射沉积合金样品显示了比具有γ等轴晶加层片组织的热等静压样品更高的室温断裂韧度。

关键词： TiAl 有序合金离心喷射沉积热等静压断裂韧度

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工业纯钛低温拉伸和循环变形中的孪生行为

材料研究学报 2000年第B1期14卷 194-199页

作者：宋西平顾海澄西安交通大学金属材料强度国家重点实验室西安市710049

在－１９６℃下对钛进行了拉伸和低周循环变形，观察分析了变形后试样的微观组织结果表明，工业纯钛在－１９６℃拉伸变形后，强度比在室温下拉伸变形有了明显的提高，塑性也有明显的增加；在－１９６℃下循环变形时，循环应力－应变... 详细信息

在－１９６℃下对钛进行了拉伸和低周循环变形，观察分析了变形后试样的微观组织结果表明，工业纯钛在－１９６℃拉伸变形后，强度比在室温下拉伸变形有了明显的提高，塑性也有明显的增加；在－１９６℃下循环变形时，循环应力－应变曲线位于－１９６℃静拉伸应力一应变曲线的上方，显示出明显的循环硬化特征微观组织观察表明，一１９６℃拉伸及循环变形试样中存在着大量的李晶，且孪晶数量随着循环应变幅及循环周次的增加而增加．在工业纯钛－１９６℃下的拉伸及循环变形中孪生起重要作用．

关键词：工业纯钛低温拉伸低温循环变形孪生行为应力-应变曲线

The Inherent Law of the Unpredictability of Financial Asset Price Fluctuations: Multistability and Chaos

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Journal of Systems Science & Complexity 2024年第2期37卷 776-804页

作者： gu Enguo Huanghe University of Science and Technology Zhengzhou 450006China

This paper aims at understanding the price dynamics generated by the interaction of traders relying on heterogeneous expectations in an asset pricing *** the present work the authors analyze a financial market populated by five types of boundedly rational speculators-two types of fundamentalists,two types of chartists and trend followers which submit buying/selling orders according to different trading *** authors formulate a stock market model represented as a 2 dimensional piecewise linear discontinuous *** proposed contribution to the existing financial literature is two ***,the authors perform study of the model involving a 2 dimensional piecewise linear discontinuous map through a combination of qualitative and quantitative *** authors focus on the existence conditions of chaos and the multi-stability regions in parameter *** border collision bifurcation curves and basins of multi-attractors are also *** authors find that chaos or quasi-period exists only in the case of fixed point being a saddle(regular or flip)and that the coexistence of multiple attractors may exist when the fixed point is an attractor,but it is common for spiral and flip fixed points.

关键词： BCB curve chaos financial market heterogeneous agents multiple attractors piecewise linear discontinuous map