检索结果-南通市图书馆

Microstructure Characteristics and Elevated Temperature Mechanical Properties of a B Containedβ-solidifiedγ-TiAl Alloy

引用

Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 738-746页

作者：王秀琦 guo ruiqi 刘国怀 LI Tianrui YANG Yuxuan CHEN Yang XIN Meiling WANG Zhaodong State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China School of Materials Science and Engineering Harbin Institute of Technology at ShenzhenShenzhen 518055China School of Metallurgical Engineering Anhui University of TechnologyMaanshan 243000China

The improved microstructure and enhanced elevated temperature mechanical properties of Ti-44Al-5Nb-(Mo,V,B)alloys were obtained by vacuum arc re-melting(VAR)and primary annealing heat treatment(HT)of 1260℃/6 h/Furnace cooling(FC).The phase transformation,microstructure evolution and tensile properties for as-cast and HTed alloys were *** indicate that three main phase transformation points are determined,T_(eut)=1164.3℃,T_(γsolv)=1268.3℃and T_(βtrans)=1382.8℃.There are coarse lamellar colonies(300μm in length)and neighbor reticular B2 andγgrain(3-5μm)in as-cast alloy,while lamellar colonies are markedly refined and multi-oriented(20-50μm)as well as the volume fraction and grain sizes of equiaxedγand B2 phases(about 15μm)significantly increase in as-HTed *** transformations involvingα+γ→α+γ+β/B2 and discontinuousγcoarsening contribute to the above ***(1-3μm)act as nucleation sites forβ_(eutectic) and produce massiveβgrains with different orientations,thus effectively refining the lamellar colonies and forming homogeneous multi-phase *** curves show both the alloys exhibit suitable performance at 800℃.As-cast alloy shows a higher ultimate tensile stress of 647 MPa,while a better total elongation of more than 41%is obtained for as-HTed *** mechanical properties improvement is mainly attributed to fine,multi-oriented lamellar colonies,coordinated deformation of homogeneous multi-phase microstructure and borides within lamellar interface preventing crack propagation.

关键词： TiAl alloy phase transformation heat treatment boride microstructure mechanical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

交叉包套轧制Ti-44Al-5Nb-1Mo-2V-0.2B合金的微观组织演化及力学性能

引用

金属学报 2024年第1期60卷 95-106页

作者：王秀琦李天瑞刘国怀郭瑞琪王昭东东北大学轧制技术与连轧自动化国家重点实验室沈阳110819 安徽工业大学冶金工程学院马鞍山243000

TiAl合金因其低密度、优异的高温强度、抗蠕变和抗氧化性能而在航空航天和汽车工业中具有广阔的应用前景,但其本质脆性和变形能力差的缺点严重限制其进一步发展。本工作通过交叉包套轧制(CHPR)和一步退火处理实现了800℃下超高塑性Ti-44... 详细信息

TiAl合金因其低密度、优异的高温强度、抗蠕变和抗氧化性能而在航空航天和汽车工业中具有广阔的应用前景,但其本质脆性和变形能力差的缺点严重限制其进一步发展。本工作通过交叉包套轧制(CHPR)和一步退火处理实现了800℃下超高塑性Ti-44Al-5Nb-1Mo-2V-0.2B合金板材的制备。利用SEM、EBSD、TEM和拉伸等实验方法考察了TiAl合金的热变形行为、不同轧制和热处理工艺对微观组织和力学性能的影响。结果表明,与单向包套轧制(UHPR)相比,CHPR板材沿厚度方向和板面方向均表现出更高的组织均匀性,微观组织由残余α_(2)/γ片层及其晶界的等轴γ、α_(2)和B2相组成,但残余片层的尺寸较小且含量明显降低,其原因是在CHPR的双向剪切力和压应力的作用下大量残余片层破碎并发生了完全再结晶。CHPR TiAl合金的高温流变软化机制主要包括片层弯曲扭折变形、β/B2相协调变形、α_(2)/γ片层的相变分解、初生和二次孪晶诱导的γ相动态再结晶。随后对CHPR合金进行1200~1340℃的退火热处理,1200℃条件下获得了等轴片层和等轴晶粒(α_(2)+γ+B2)的多相组织,部分晶粒达到了纳米级。1340℃条件下得到了近全片层组织。对UHPR和CHPR板材的横/纵向和1200℃退火热处理试样的拉伸性能进行比较,CHPR板材横纵向的拉伸性能更加均匀,再经1200℃退火热处理后获得的多相等轴组织具有最佳的强度-塑性匹配,室温下抗拉强度为624 MPa,延伸率为1.32%;800℃下抗拉强度为515 MPa,延伸率可达107.0%。分析试样的断裂行为可知,室温下3种试样的断裂方式为穿片层和解理断裂。800℃下断裂方式转变为韧性断裂,断裂失效机制以微孔联结机制为主,其中经过1200℃退火热处理的板材断口具有更小而深的韧窝,塑性最佳。精细的片层结构和均匀细小的等轴晶组织能够阻碍裂纹的扩展,有利于综合力学性能的提高。

关键词： TiAl合金交叉包套轧制热处理微观组织力学性能

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

实时输出视频的水下主动偏振成像

引用

光学精密工程 2024年第10期32卷 1443-1455页

作者：吴厚德翟予峥王洪昌李持尧郭睿琦大连海事大学信息科学技术学院辽宁大连116026

针对在水下主动偏振成像方法中,需要机械旋转相机前的检偏器获取正交偏振态图像,导致无法实时输出去后向散射视频的问题,提出了实时输出视频的水下主动偏振成像方法。首先,本方法将正交偏振切换位置从相机端更换到光源端,而相机端的检... 详细信息

针对在水下主动偏振成像方法中,需要机械旋转相机前的检偏器获取正交偏振态图像,导致无法实时输出去后向散射视频的问题,提出了实时输出视频的水下主动偏振成像方法。首先,本方法将正交偏振切换位置从相机端更换到光源端,而相机端的检偏器偏振状态保持不变,并论证了此改变并不影响去后向散射的效果;然后,设计了阵列正交偏振光源,即光源由偏振态正交的两组LED灯珠交错排列组成,通过独立的驱动电路分别控制两组灯珠,输出偏振态正交的偏振光,从硬件上取消了偏振态切换的机械结构;第三,设计了同步控制装置,分别控制光源输出的偏振态和相机拍照,实现了正交偏振态图像数据的采集;最后,通过流水线式主动偏振图像处理方法,实现实时的视频输出。实验结果表明,本方法可以实时输出去后向散射视频,且在去后向散射性能上,与机械式主动偏振成像方法性能接近,两者去后向散射性能的背离度均低于4%,图像EME值增长倍数最大可达17.96。本方法具有结构简单、成本低、输出帧频不受影响以及相机选择性多等优点,能够广泛应用在水下成像领域。

关键词：主动偏振成像去后向散射阵列正交偏振光源实时视频

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An adaptive p-FEM for three-dimensional concrete aggregate models

引用

International Journal of Modeling, Simulation, and Scientific Computing 2020年第1期11卷 1-27页

作者： ruiqi guo Yingxiong Xiao Civil Engineering and Mechanics College Xiangtan University Xiangtan 411105P.R.China

Numerical simulation for concrete aggregate models(CAMs)with different shape aggregates usually requires high accuracy and convergence near the material *** high memory usage will be needed for those traditional finite element methods such as the method by using mesh refinement throughout the ***,an adaptive p-version finite element method(p-FEM)is proposed in this paper for the solution of 3D CAM problems,and meanwhile the resulting adaptive computational algorithm and post-processing program are *** firstly focused two typical 3D weak discontinuity problems on the influence of different convergence criterions for the computational results of each point on the interface in order to verify the efficiency and convergence of the resulting p-FEM,and then this method is successfully applied to the numerical simulation of CAMs with different shape *** addition,an efficient hybrid realization method which combines ANSYS and Hypermesh software is also presented in order to quickly establish the geometric models of 3D *** numerical results have been shown that the proposed p-FEM can efficiently solve the concrete-like particle-reinforced composite problems and more accurate numerical results can be obtained under the case of fewer elements used in simulation of CAMs,even there being some elements with poor quality.

关键词： 3D aggregate model adaptive p-FEM material interface accuracy and convergence numerical simulation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

土壤改良措施对参田土壤微生物群落结构的影响

引用

江苏农业科学 2024年第12期52卷 261-268页

作者：郭瑞齐管仁伟王萌张华建窦家聪刘桂霞林慧彬山东省中医药研究院山东济南250014 山东中医药大学第二附属医院山东济南250001 山东省农业技术推广中心山东济南250000

为探究土壤改良措施对参田土壤微生物群落结构的影响,筛选老参田土壤改良最优方案,进行大田种植土壤改良试验,设置3个处理组,即棉隆土壤熏蒸组(A)、高锰酸钾化学消毒组(B)、微生物菌肥组(C),并以未改良土壤为空白对照组(CK)。通过高通... 详细信息

为探究土壤改良措施对参田土壤微生物群落结构的影响,筛选老参田土壤改良最优方案,进行大田种植土壤改良试验,设置3个处理组,即棉隆土壤熏蒸组(A)、高锰酸钾化学消毒组(B)、微生物菌肥组(C),并以未改良土壤为空白对照组(CK)。通过高通量测序技术分析不同处理方式下土壤微生物群落结构变化,综合评价不同参田土壤改良措施。结果表明,在12个改良参田土壤中共检测537766个细菌有效序列,701028个真菌有效序列;土壤细菌在门分类水平上,改良组放线菌门、绿弯菌门、厚壁菌门等的相对丰度均大于空白对照组,土壤真菌在门分类水平上,被孢霉门的相对丰度明显高于空白对照组。在微生物属分类水平上,处理组有益菌芽孢杆菌属、鞘氨醇单胞菌属、热酸菌属、青霉菌、毛壳菌属的相对丰度明显高于空白对照组,而引起植物病害的镰刀菌属、芽枝霉属在处理组中的相对丰度呈下降趋势。空白对照组土壤中鞘氨醇单胞菌属、热酸菌属的相对丰度高于处理组,在西洋参短期连作体系中,预测土壤中微生物可产生抵御病害的生防菌,维持植物正常生长。总之,在土壤改良措施中,3种处理方法都有利于有益菌和生防菌丰度的增加,土壤修复以C组最好,A组次之,B组效果较差。

关键词：西洋参高通量测序土壤改良连作障碍微生物

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Research progress of nanocellulose for electrochemical energy storage:A review

引用

Journal of Energy Chemistry 2020年第12期29卷 342-361页

作者： ruiqi guo Lixue Zhang Yun Lu Xiaoli Zhang Dongjiang Yang State Key Laboratory of Bio-fbers and Eco-textiles Shandong Collaborative Innovation Center of Marine BiobasedFibers and Ecological Textiles Institute of Marine Biobased MaterialsSchool of Environmental Science and EngineeringQingdao UniversityQingdao 266071ShandongChina College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071ShandongChina Department of Wood Anatomy and Utilization Research Institute of Wood IndustryChinese Academy of ForestryBeijing 100091China State Centre for International Cooperation on Designer Low-Carbon&Environmental Materials School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001HenanChina

Recently, in response to the major challenges in energy development and environmental issues, tremendous efforts are being devoted to developing electrochemical energy storage devices based on green sustainable resources. As a class of green materials, nanocellulose(NC) has received extensive attention. In this review, we summarize the research progress of NC derived materials in electrochemical energy storage. Specifically, we first introduce various synthesis methods based on NC and the pretreatment process to increase the conductivity. Then we focus on the specific application of NC in electrochemical energy storage devices. Finally, we summarize the previously reported work and put forward views on the further development of NC in the field of electrochemical energy storage.

关键词： Nano-structures Electrical properties Nanocellulose Energy storage field

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

New instant confirmation mechanism based on interactive incontestable signature in consortium blockchain

引用

Frontiers of Computer Science 2019年第6期13卷 1182-1197页

作者： Yan ZHU Khaled RIAD ruiqi guo guohua GAN Rongquan FENG School of Computer&Communication Engineering University of Science and Technology BeijingBeijing 100083China Mathematics Department Faculty of ScienceZagazig UniversityZagazig 44519Egypt School of Mathematical Sciences Peking UniversityBeijing 100871China

The blockchain is a radical innovation that has a considerable effect on payments,stock exchanges,cybersecurity,and computational ***,its limitations in terms of the uncertainty involved in transaction confirmation are *** this paper,we describe the design of a decentralized voting protocol for the election of a block generator in a consortium blockchain and propose a new system framework that allows fast and exact confirmation of all *** addition,to replace a transaction’s owner signature,a new interactive incontestable signature between the dealer and owner is used to confirm a *** means of this signature,the dealer can assure the owner that a transaction will be permanently included in the blockchain in a non-repudiation ***,the signatures of all transactions in a block share only one witness that provides membership proof between the block and these ***,a security and performance analysis shows that the proposed schemes are provably secure and highly efficient.

关键词： security blockchain signature consortium interactive proof

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research of an SHPB Device in Two-by-Two Form for Impact Experiments of Concrete-Like Heterogeneous Materials

引用

Acta Mechanica Solida Sinica 2021年第4期34卷 561-581页

作者： ruiqi guo Huiqi Ren Lei Zhang Zhilin Long Xiangyun Wu Hailu Wang Civil Engineering and Mechanics College Xiangtan UniversityXiangtan411105China Institute of Defense Engineering AMSPLALuoyang471023China

A split Hopkinson pressure bar(SHPB)device in two-by-two form,including the bar bundle form and the single cylindrical bar form,was designed in response to the demand for the dynamic mechanical experiments for brittle materials such as concrete,rock,*** stress waveforms generated through a projectile impacting two different types of incident bars have been studied based on the one-dimensional stress wave theory and numerical simulation *** last,based on the established two types of mesoscale concrete models with random convex polyhedral aggregates,we performed comparison analysis of SHPB numerical simulations for concrete materials with bar bundle and single cylindrical bar separately,so as to provide technical support for the manufacture and development of this experimental *** results showed that the introduced two-by-two form SHPB device expanded the scope of practical application,and the wave dispersion effect existing in a large-diameter bar can be evidently reduced when we employed the bar bundle form,indicating its applicability to the dynamic mechanical experiments of concrete-like heterogeneous materials.

关键词： SHPB Two-by-two form Numerical simulation Projectile Incident stress waveform

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

ZrO2-supported α-MnO2:Improving low-temperature activity and stability for catalytic oxidation of methane

引用

Progress in Natural Science:Materials International 2018年第3期28卷 296-300页

作者： Jingbo Jia Rui Ran ruiqi guo Xiaodong Wu Duan Weng Key Laboratory of Advanced Materials (MOE) School of Materials Science and EngineeringTsinghua University School of Transportation Science and Engineering Beihang University State Key Laboratory of New Ceramic and Fine Processing School of Materials Science and EngineeringTsinghua University

The single phaseα-Mn O2and in-situ supportedα-Mn O2/Zr O2with different ratios of Mn/Zr were synthesized by one-pot hydrothermal *** showed superior activity for catalytic oxidation of methane and even better than that of 1%Pt/*** T50of Mn O2/Zr O2catalysts with different ratios of Mn/Zr were located in the range of 315–335°C at a WHSV of 90 L g-1h-1,whereas that of Pt/Al2O3was 380°*** sulfur ageing,the Mn O2/Zr O2catalysts with Mn/Zr ratio of 2:1(2Mn O2/1Zr O2)and 1:1(1Mn O2/1Zr O2)exhibited satisfying sulfur resistance in comparison to the pure Mn *** 2Mn O2/1Zr O2catalyst also showed acceptable catalytic stability,and the addition of 10 vol%CO2had no obvious negative effect on its stability,whereas the addition of2.6 vol%H2O caused slight but reversible decreasing methane oxidative activity.

关键词： MnO2 ZrO2 support Methane oxidation Sulfur tolerance Stability

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

刚性弹体侵彻混凝土和花岗岩数值模拟研究

引用

湘潭大学学报（自然科学版） 2024年第4期46卷 28-39页

作者：刘兵郭瑞奇康雨嫣董杰湘潭大学机械工程与力学学院湖南湘潭411105 湘潭大学土木工程学院湖南湘潭411105

为了研究混凝土靶板和花岗岩靶板的抗侵彻能力,通过ANSYS/LS-DYNA有限元分析软件,对刚性弹体侵彻Holmquist-Johnson-Cook(HJC)模型混凝土靶板和花岗岩靶板的过程进行数值模拟,通过数值模拟结果与试验结果及理论公式计算结果的对比,验证... 详细信息

为了研究混凝土靶板和花岗岩靶板的抗侵彻能力,通过ANSYS/LS-DYNA有限元分析软件,对刚性弹体侵彻Holmquist-Johnson-Cook(HJC)模型混凝土靶板和花岗岩靶板的过程进行数值模拟,通过数值模拟结果与试验结果及理论公式计算结果的对比,验证数值模拟结果的有效性.结果表明,在相同条件下,刚性弹体在花岗岩靶板中受到的阻力大于相应的混凝土靶板,而且在刚性弹体同样的初始侵彻速度下,弹体侵彻混凝土靶板后的残余速度明显高于弹体侵彻花岗岩靶板后的残余速度,混凝土靶板的侵彻深度也明显高于花岗岩靶板的侵彻深度.针对刚性弹体正侵彻两种靶板结果的分析表明,花岗岩靶板相比混凝土靶板在抗击弹体侵彻能力方面更显著,可为防护工程结构设计提供支撑和依据.

关键词：刚性弹体混凝土靶花岗岩靶 HJC模型残余速度侵彻深度防护工程

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：