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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1115-1125页

作者： Binghui Hu yu Lei Hang Li Ziyi Wang Chao yu guozheng Kang Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace EngineeringSouthwest Jiaotong UniversityChengdu 610031China

The nonproportional multiaxial ratchetting of cast AZ91 magnesium (Mg) alloy was examined by performing a sequence of axial-torsional cyclic tests controlled by stress with various loading paths at room temperature (RT).The evolutionary characteristics and path dependence of multiaxial ratchetting were *** illustrate that the cast AZ91 Mg alloy exhibits considerable nonproportional additional softening during cyclic loading with multiple nonproportional multiaxial loading paths;multiaxial ratchetting presents strong path dependence,and axial ratchetting strains are larger under nonproportional loading paths than under uniaxial and proportional45°linear loading paths;multiaxial ratchetting becomes increasingly pronounced as the applied stress amplitude and axial mean stress ***,stress-strain curves show a convex and symmetrical shape in axial/torsional *** ratchetting exhibits quasi-shakedown after certain loading *** abundant experimental data obtained in this work can be used to develop a cyclic plasticity model of cast Mg alloys.

关键词： cast magnesium alloy ratchetting multiaxial loading loading path stress level

Micropillar compression using discrete dislocation dynamics and machine learning

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Theoretical & Applied Mechanics Letters 2024年第1期14卷 39-47页

作者： Jin Tao Dean Wei Junshi yu Qianhua Kan guozheng Kang Xu Zhang School of Mechanics and Aerospace Engineering Southwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China

Discrete dislocation dynamics(DDD)simulations reveal the evolution of dislocation structures and the interaction of *** study investigated the compression behavior of single-crystal copper micropillars using fewshot machine learning with data provided by DDD *** types of features are considered:external features comprising specimen size and loading orientation and internal features involving dislocation source length,Schmid factor,the orientation of the most easily activated dislocations and their distance from the free *** yielding stress and stress-strain curves of single-crystal copper micropillar are predicted well by incorporating both external and internal features of the sample as separate or combined *** is found that the machine learning accuracy predictions for single-crystal micropillar compression can be improved by incorporating easily activated dislocation features with external ***,the effect of easily activated dislocation on yielding is less important compared to the effects of specimen size and Schmid factor which includes information of orientation but becomes more evident in small-sized ***,incorporating internal features,especially the information of most easily activated dislocations,improves predictive capabilities across diverse sample sizes and orientations.

关键词： Discrete dislocation dynamics simulations Machine learning Size effects Orientation effects Microstructural features

Effects of plasma spraying process on microstructure and mechanical properties of Cr2AlC/410 composite coatings

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High-Speed Railway 2024年第2期2卷 110-115页

作者： Yihu Ma Chaosheng Ma guozheng Ma Wenbo yu Center of Materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China National Key Lab for Remanufacturing Army Academy of Armored ForcesBeijing 100072China

To investigate the influences of Cr2AlC mass fraction and supersonic plasma spraying process on the microstructure and mechanical properties of Cr2AlC reinforced 410 stainless steel composite coatings,the coatings containing different mass fractions of Cr2AlC were prepared and *** composite coating exhibited low porosity and high adhesion *** addition of Cr2AlC significantly enhanced the hardness of the composite coatings through particle ***,when the mass fraction of Cr2AlC was 20%,the aggregation of Cr2AlC resulted in a strong decrease in the coating preparation efficiency,as well as a decline in adhesion *** the supersonic plasma spraying process,the Ar flow rate mainly influenced the flight velocity of the particles,while the H2 flow rate and the current mainly affected the temperature of the plasma ***,all of them influenced the melting degree of particles and the quality of the *** lowest porosity and the highest hardness and adhesion strength could be obtained when the Ar flow rate is 125 L/min,the H2 flow rate is 25 L/min,and the current is 385 A.

关键词： MAX phase Plasma spray Parameter Coating

维普期刊数据库博看期刊评论

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基于物性结构的事件演化语义模型

语言科学 2017年第4期16卷 361-371页

作者：陈禹萧国政武汉大学文学院湖北武汉430072 湖北省语言与智能信息处理研究基地湖北武汉430072

事件演化即事件在篇章中依次变化,是篇章推进的主要手段。结合物性结构理论,同一话题下与不同话题间事件演化可构建出一套语义模型,该语义模型着重刻画事件间基于词汇语义的内部语义联系,并说明物性结构与题元结构的协同作用对事件演化... 详细信息

事件演化即事件在篇章中依次变化,是篇章推进的主要手段。结合物性结构理论,同一话题下与不同话题间事件演化可构建出一套语义模型,该语义模型着重刻画事件间基于词汇语义的内部语义联系,并说明物性结构与题元结构的协同作用对事件演化提供的语义触发动力与制约机制。

关键词：事件演化物性结构题元角色语义模型

富氢环境下镍钛形状记忆合金弹簧变形行为的实验和理论研究

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力学学报 2024年第2期56卷 422-432页

作者：姜晗于超康国政西南交通大学力学与航空航天学院成都610031

镍钛形状记忆合金器件在某些特定服役环境下不可避免地与氢接触,导致其力学性能发生改变.实验研究方面,通过对两种构型(弹簧指数为8.5和11.7)的镍钛合金弹簧进行异位电解充氢,随后对充氢和未充氢镍钛合金弹簧进行不同幅值的拉伸-卸载实... 详细信息

镍钛形状记忆合金器件在某些特定服役环境下不可避免地与氢接触,导致其力学性能发生改变.实验研究方面,通过对两种构型(弹簧指数为8.5和11.7)的镍钛合金弹簧进行异位电解充氢,随后对充氢和未充氢镍钛合金弹簧进行不同幅值的拉伸-卸载实验,揭示了氢对超弹性镍钛合金弹簧变形行为的影响.结果表明,氢会显著影响弹簧的相变硬化行为,并且使马氏体相变临界力下降地更为迅速.理论研究方面,基于实验结果,在不可逆热力学框架下构建了镍钛形状记忆合金力-扩散耦合本构模型.在该本构模型中,考虑了与弹性,马氏体相变和氢致膨胀相关的应变和氢浓度场对马氏体相变的影响.通过建立的Helmholtz自由能推导出相变行为的热力学驱动力.基于质量守恒定律和Fick定律,得到氢浓度场的演化方程.为了准确地描述充氢和未充氢镍钛合金弹簧的变形行为,在建立的本构模型基础上,进一步发展了描述弹簧力-扩散耦合变形行为并考虑其扭转、弯曲变形模式的半解析模型.通过与实验结果的对比,可以发现,提出的半解析理论模型能够很好地预测富氢环境下超弹性镍钛合金弹簧的变形行为.

关键词：镍钛形状记忆合金弹簧富氢环境力-扩散耦合半解析模型

环乳晕切口与放射状切口对乳腺纤维瘤疗效的系统评价

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武汉大学学报（医学版） 2018年第4期39卷 541-545,555页

作者：刘喜松余国政黄石市第一人民医院普外科湖北黄石435001 黄石市中心医院普外科湖北黄石435001

目的：利用系统评价和Meta分析的方法比较环乳晕切口与放射状切口对乳腺纤维瘤的疗效。方法：从万方、中国知网、Pubmed、EMBASE、Cochrane Library等电子数据库检索文献,并人工检索相关电子期刊,筛选出相关的临床随机对照试验,运用Met... 详细信息

目的：利用系统评价和Meta分析的方法比较环乳晕切口与放射状切口对乳腺纤维瘤的疗效。方法：从万方、中国知网、Pubmed、EMBASE、Cochrane Library等电子数据库检索文献,并人工检索相关电子期刊,筛选出相关的临床随机对照试验,运用Meta分析的方法对相关参数进行综合比较并做出评价。结果：最终纳入5篇中文文献,共计672名患者。环乳晕切口与传统放射状切口相比,在手术时间（P=0.17）、术中出血量（P=0.09）及复发率上并无差别（P=0.28）;但其并发症更少[RR（95%CI）=0.29（0.15,0.57）,P=0.000 4],患者满意度也更高[OR（95%CI）=7.74（2.88,20.84）,P〈0.000 1]。结论：环乳晕切口治疗女性乳腺纤维瘤具有明显优势,应成为临床首选。

关键词：环乳晕切口放射状切口乳腺纤维瘤 Meta分析

Fine Velocity Structure and Relocation of the 2010 M_L 5.1 Earthquake Sequence in the Rongchang Gas Field

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Earthquake Research in China 2012年第4期26卷 467-478页

作者： Wang Xiaolong Ma Shengli Lei Xinglin Guo Xin Wang Qiang yu guozheng Gou Xianbin Kuwahara Yasuto Imanishi Kazutoshi Jiang Xiadong Earthquake Administration of Chongqing Municipality State Key Laboratory of Earthquake Dynamics Institute of Geology CEA Geological Survey of Japan Hohai University Changzhou

Based on data collected from a temporal seismic network, and in addition to the data from some nearby permanent stations, we investigate the velocity structure and seismicity in the Rongchang gas field, where significant injection-induced seismicity has been identified. First, we use receiver functions from distant earthquakes to invert detailed 1-D velocity structures beneath typical stations. Then, we use the double-difference hypocenter location method to re-locate earthquakes of the 2010 MLS. 1 earthquake sequence that occurred in the region. The re-located hypocenters show that the 2010 MLS. 1 earthquake sequence was distributed in a small area surrounding major injection wells and clustered mostly along pre-existing faults. Major earthquakes show a focal depth less than 5km with a dominant depth of -2km, a depth of major reservoirs and injection wells. We thus conclude that the 2010 ML 5. 1 earthquake sequence might have been induced by the deep well injection of unwanted water at a depth - 3km in the Rongchang gas field.

关键词： Induced earthquake Receiver function Double difference location Rongchang

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关于感化及感化教育相关概念的辨析

湖北理工学院学报（人文社会科学版） 2015年第3期32卷 72-77页

作者：余国政湖北理工学院马克思主义学院湖北黄石435003

目前,学界对感化教育的概念还没有统一的界定。文章对感化与感知、感动、感染、感召等带"感"字词语,及感化与教化、转化等带"化"字词语进行了比较与辨析;指出感化不等同于教育,而是要以教育为导向,发挥自己特有的功能。感化教育是一种... 详细信息

目前,学界对感化教育的概念还没有统一的界定。文章对感化与感知、感动、感染、感召等带"感"字词语,及感化与教化、转化等带"化"字词语进行了比较与辨析;指出感化不等同于教育,而是要以教育为导向,发挥自己特有的功能。感化教育是一种潜移默化的过程,是教育者根据人们思想观念、品德形成的规律,以反映社会要求的情感信息影响受教育者,使受教育者在激发起一定的思想感情的基础上改变心理状态。

关键词：感化感化教育辨析界定

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大学生感化教育的功能探析

湖北理工学院学报（人文社会科学版） 2017年第6期34卷 62-65,74页

作者：余国政湖北理工学院马克思主义学院湖北黄石435003

在高校践行立德树人根本任务的过程中,大学生感化教育发挥着强大的功能。大学生感化教育功能具有多样性、层次性、直接性、发展性等特殊性。大学生感化教育除了具有育人、导向、强化、保证等共性功能外,还具有独特的感染功能、激励功能... 详细信息

在高校践行立德树人根本任务的过程中,大学生感化教育发挥着强大的功能。大学生感化教育功能具有多样性、层次性、直接性、发展性等特殊性。大学生感化教育除了具有育人、导向、强化、保证等共性功能外,还具有独特的感染功能、激励功能、协调功能和转化功能。影响和制约大学生感化教育功能有效发挥的因素有感化教育队伍、感化教育目标、感化教育艺术、感化教育对象等。

关键词：大学生感化教育功能

镁单晶塑性变形行为的晶体塑性耦合孪晶相场模拟

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Acta Mechanica Sinica 2024年第3期40卷 123-144页

作者：胡佳晨徐波于超康国政 Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace EngineeringSouthwest Jiaotong UniversityChengdu611756China Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan ProvinceSichuan UniversityChengdu610065China Institute of Applied Mechanics State Key Laboratory of Traction PowerSouthwest Jiaotong UniversityChengdu610031China

本文建立了一个晶体塑性-孪晶相场耦合模型来研究镁单晶的塑性变形行为.在晶体塑性模型中考虑了三种典型的滑移模式,即基面滑移、柱面滑移、锥面滑移,而在孪晶相场模型中考虑了化学能、梯度能和弹性能的作用.模拟结果表明:在沿孪生方向... 详细信息

本文建立了一个晶体塑性-孪晶相场耦合模型来研究镁单晶的塑性变形行为.在晶体塑性模型中考虑了三种典型的滑移模式,即基面滑移、柱面滑移、锥面滑移,而在孪晶相场模型中考虑了化学能、梯度能和弹性能的作用.模拟结果表明:在沿孪生方向剪切加载诱导孪晶的过程中,不同阶段的应力水平和不同方向孪晶界面的迁移率存在较大差异.孪晶在早期呈透镜状,而在侧向长大阶段呈平板状,并且孪晶出现后有基面滑移被激活;非基面滑移在基体完全转变为孪晶后被激活.在一个拉-压载荷周期内,不同取向的镁单晶中出现不同的塑性变形模式,当加载方向平行于c轴时,对应的变形模式为孪生-解孪-锥面滑移-复孪生;当加载方向垂直于c轴时,对应的变形模式为柱面滑移-柱面滑移孪生-孪生-解孪,这两种单晶均表现出强拉压不对称性;当加载方向与c轴夹角为45°时,仅发生基面滑移,不存在拉压不对称现象.

关键词： Magnesium single crystal Phase field model Twinning Dislocation slipping Crystalline orientation