检索结果-南通市图书馆

Phase Selection and Microhardness of Directionally Solidified AlCoCrFeNi_(2.1) Eutectic High-Entropy Alloy

Acta Metallurgica Sinica(English Letters) 2022年第8期35卷 1281-1290页

作者： Peng Peng Shengyuan Li Weiqi Chen yuanli xu xudong Zhang Zhikun Ma Jiatai Wang School of Materials Science and Energy Lanzhou UniversityLanzhou 730000China Gansu Institute of Metrology Lanzhou 730071China School of Physics and Electronic Information Engineering Qinghai Normal UniversityXining 810000China

In the present work,the solidification behaviors and microhardness of directionally solidified AlCoCrFeNi_(2.1) eutectic highentropy alloy(EHEA)obtained at different growth velocities are *** microstructure of the as-cast AlCoCrFeNi_(2.1) EHEA is composed of bulky dendrites(NiAl phase)and lamellar eutectic structures,indicating that the actual composition of the alloy slightly deviates from the eutectic ***,it is interesting to observe that the full lamellar structure of this alloy is obtained through directional *** order to explain this phenomenon,the maximum interface temperature criterion and the interface response function(IRF)theory are applied to calculate the velocity range of the transition from the primary phase to the eutectic,which is 1.2–2×10^(4)μm/***,microhardness is one of the important parameters to measure the mechanical properties of ***,the microhardness test is performed,and the test result indicates that the microhardness(HV)increased with increasing growth velocity(V)or decreased with increasing lamellar spacing(λ).The dependences ofλand HV on V are determined by using a linear regression *** relationships between theλ,V and HV are given as:λ=11.62V^(-0.48),HV=305.5V 0.02 and HV=328.1λ^(0.04),*** microhardness of the AlCoCrFeNi_(2.1) EHEA increases from 312.38 HV to 329.54 HV with the increase in growth velocity(5–200μm/s).Thus,directional solidification is an effective method to improve the mechanical properties of alloys.

关键词： Directional solidification Eutectic high-entropy alloy Phase selection Microstructure Microhardness

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

定向凝固Cu-50%Sn包晶合金显微组织演变

引用

铸造技术 2024年第6期45卷 532-542页

作者：彭鹏刘林喻杨新甘露杨文超徐远丽兰州大学材料与能源学院甘肃兰州730000 西北工业大学凝固技术国家重点实验室陕西西安710072

随着科学技术的进步,越来越多的包晶合金因其优良性能广泛应用于工业生产领域,比如Fe-Cr-Ni、Ti-Al、Nd-Fe-B合金以及应用于电子封装领域的Cu-Sn合金等。随着电子信息产业向微型化和多功能化方向发展,对集成电路的机械、电子和热性能提... 详细信息

随着科学技术的进步,越来越多的包晶合金因其优良性能广泛应用于工业生产领域,比如Fe-Cr-Ni、Ti-Al、Nd-Fe-B合金以及应用于电子封装领域的Cu-Sn合金等。随着电子信息产业向微型化和多功能化方向发展,对集成电路的机械、电子和热性能提出了更高的要求。本文以Cu-50%Sn(原子分数)包晶合金(L+Cu^(3)Sn→Cu6Sn5)作为研究对象,通过布里奇曼定向凝固法,在显微镜下对组织进行观察和测量,研究淬火固液界面的凝固组织随凝固条件改变而产生的变化。生长距离、温度梯度一定时,随着生长速度的增大,初生相Cu^(3)Sn经历了胞状→胞/枝状→枝晶状组织转变,Cu^(3)Sn相的尺寸与间距均随生长速度的增大而减小;生长速度、生长距离一定时,随着温度梯度的增大,初生相Cu^(3)Sn相由块状与枝晶状转变为胞状组织;生长速度、温度梯度一定时,随着生长距离的增大,初生相Cu^(3)Sn由块状与胞/枝状转变为胞状组织,且Cu^(3)Sn相尺寸发生小幅细化。基于上述实验结果,绘制了关于生长速度、温度梯度及生长距离条件下的显微组织选择图,进一步阐明了凝固条件的改变对Cu-50%Sn(原子分数)包晶合金显微组织的影响。

关键词：定向凝固包晶合金凝固组织金属间化合物

来源：

维普期刊数据库

同方期刊数据库

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

Effect of Aspect Ratio on the Evolution of Shear Bands in Zr_(61.7)Al_8Ni_(13)Cu_(17)Sn_(0.3)Bulk Metallic Glass

引用

Journal of Materials Science & Technology 2017年第1期33卷 99-104页

作者： Wenli Ma yuanli xu Bo Shi Jiangong Li Institute of Materials Science and Engineering and MOE Key Laboratory for Magnetism and Magnetic Materials Lanzhou UniversityLanzhou 730000China

Zr61.7A18Ni13Cu17Sn0.3 bulk metallic glass samples with different aspect ratios in the range of 0.25-2.25 were deformed by compression, and the effect of aspect ratio on the evolution of shear bands was investigated. It is found that for the deformed Zr61.7AlaNi13CulTSno3 bulk metallic glass, the average shear band spacing decreases and the shear band density increases monotonically as the aspect ratio increases from 0.25 to 2.25. A minimal average shear band spacing of 0.478μm is achieved for the sample with an aspect ratio of 2.25. In addition, the fractions of shear bands with spacings below 100 and 50 nm are about 12.84% and 6.76%, respectively, for the sample with an aspect ratio of 2.25. The reason for the formation of a higher density of shear bands can probably be attributed to the increase of the driving force for the samole with a larger aspect ratio.

关键词： Metallic glass Aspect ratio Shear band Compressive deformation

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

Analysis on fluid permeability of dendritic mushy zone during peritectic solidification in a temperature gradient

引用

Journal of Materials Science & Technology 2021年第12期71卷 169-176页

作者： Peng Peng Jinmian Yue Anqiao Zhang xudong Zhang yuanli xu Institute of Materials Science and Engineering Lanzhou UniversityLanzhou730000China School of Physical Science and Technology Lanzhou UniversityLanzhou730000China

Compared with the growing applications of peritectic alloys,none research on the fluid permeability K of dendritic network during peritectic solidification has been reported *** fluid permeability K of dendritic network in the mushy zone during directional solidification of Sn-Ni peritectic alloy was investigated in this *** on the experimental results demonstrates that both the temperature gradient zone melting(TGZM)and Gibbs-Thomson(G–T)effects have obvious influences on the morphology of dendritic network during directional *** is realized through different stages of liquid diffusion within dendritic mushy zone by these effects during directional *** TGZM effect is demonstrated to play a more important role as compared with the G–T effect during directional ***,it is shown that the evolution of dendrite network is more complex during peritectic solidification due to the involvement of the peritectic *** the specific surface SV,analytical expression based on the Carman–Kozeny model was proposed to analyze the fluid permeability of dendritic mushy zone in directionally solidified peritectic *** addition,it is interesting to find a rise in permeability K after peritectic reaction in both theoretical predication and experimental results,which is different from that in other *** theoretical predictions show that this rise in fluid permeability K after peritectic reaction is caused by the remelting/resolidification process on dendritic structure by the TGZM and G–T effects during peritectic solidification.

关键词： Alloys Diffusion behaviour Directional solidification Peritecticm icrostructures Solid/liquid interface

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

Macrosegregation and thermosolutal convection-induced freckle formation in dendritic mushy zone of directionally solidified Sn-Ni peritectic alloy

引用

Journal of Materials Science & Technology 2021年第16期75卷 21-26页

作者： Peng Peng Anqiao Zhang Jinmian Yue xudong Zhang yuanli xu Institute of Materials Science and Engineering Lanzhou UniversityLanzhou730000China School of Physical Science and Technology Lanzhou UniversityLanzhou730000China

Compared with the growing applications of peritectic alloy,none research on the freckle formation during peritectic solidification has been reported *** on the dendritic mushy zone of Sn-36 at.%Ni peritectic alloy during directional solidification at different growth velocities shows that the freckles are formed in two different regions:region I before peritectic reaction and region II after peritectic *** addition,more freckles can be observed at lower growth *** on the experimental results demonstrates that both the temperature gradient zone melting(TGZM)and Gibbs-Thomson(G–T)effects have obvious influences on the morphology of dendritic network during directional *** current theories onKI Rayleigh number Racharacterizing the thermosolutal convection of dendritic mushy zone to predict freckle formation through the maximum of Ra can only explain the existence of region I while the appearance of region II after peritectic reaction cannot be ***,a new Rayleigh number RaP is proposed in consideration of evolution of dendritic mushy zone by both effects and peritectic *** prediction of RaPalso shows a maximum after peritectic reaction in addition to that before peritectic reaction,thus,agreeing well with the freckle formation in region *** addition,more severe thermosolutal convection can be predicted by the new Rayleigh number RaP at lower growth velocities,which further demonstrates the reliability of RaP in describing the dependence of freckle formation on growth velocity.

关键词： Directional solidification Thermosolutal convection Dendritic solidification Peritectic microstructures

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

Experimental investigation of effects of bio-additives on fuel economy of the gasoline engine

引用

Science China(Technological Sciences) 2008年第8期51卷 1177-1185页

作者： YAO ChunDe ZHANG ZhiHui xu yuanli HUANG Yu Stake Key Laboratory of Engines Tianjin UniversityTianjin 300072China

The matter extracted from palm oil was considered as gasoline additive. The effect of various percentages (0.2%, 0.4% and 0.6%) of the bio-additives on fuel economy of SI engine respectively running on prime gasoline, gasoline with known compo- nents, ethanol gasoline, and methanol gasoline under typical urban operation condition 2000 r/min was investigated. The results showed that the bio-additives can remarkably improve the fuel economy of SI engine while operating on all kinds of fuel. The optimal ratio of bio-additive to gasoline depends on the fuel used and on the different engine operating conditions. Besides, the experiments of constant volume combustion bomb, analysis of in cylinder processes, the synchrotron ra- diation and high-temperature friction were conducted to probe into the mechanism of the bio-additive impact on fuel economy. It indicated that the bio-additives can increase the maximum cylinder combustion pressure, improve exhaust emissions and largely reduce the frication coefficient.

关键词： gasoline engine bio-additives fuel economy

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

Diffusion-induced abnormal tertiary dendrite during peritectic solidification in a temperature gradient

引用

Journal of Materials Science & Technology 2021年第13期72卷 197-201页

作者： Peng Peng Anqiao Zhang Jinmian Yue xudong Zhang yuanli xu Institute of Materials Science and Engineering Lanzhou UniversityLanzhou 730000China School of Physical Science and Technology Lanzhou UniversityLanzhou 730000China

*** Dendritic structure are commonly encountered during solidification[1-4],especially in systems freezing with relatively low entropies of transformation[1,5].Generally speaking,the dendritic structure is composed of primary dendrite stem,secondary branch and even tertiary and higher order dendrite arms[1].Different kinds of models have been proposed for describing the growth of primary dendrite[1-5]and secondary dendrite arms[1,6,7].

关键词： solidification transformation Diffusion

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

连续流条件下蒽-铈协同催化的苄位碳氢键选择性氧化反应

引用

化学学报 2023年第5期81卷 435-440页

作者：徐袁利潘辉杨义左智伟四川轻化工大学化学与环境工程学院晨光高性能氟材料创新中心四川自贡643000 中国科学院上海有机化学研究所金属有机化学国家重点实验室上海200032

苄位氧化反应是有机合成中重要的官能团转化方法之一,但传统的苄位氧化反应通常需要高温和强氧化剂等严苛条件.报道了一种在连续流微反应器中实现的蒽-铈协同催化的苄位选择性氧化反应,使用9,10-二溴蒽(DBA)和铈-醇配合物作为光催化剂,... 详细信息

苄位氧化反应是有机合成中重要的官能团转化方法之一,但传统的苄位氧化反应通常需要高温和强氧化剂等严苛条件.报道了一种在连续流微反应器中实现的蒽-铈协同催化的苄位选择性氧化反应,使用9,10-二溴蒽(DBA)和铈-醇配合物作为光催化剂,氧气为绿色氧化剂,以很高的效率在室温条件下制备了各种芳香酮类化合物.该体系可以在数分钟内实现完全转化,具有操作简便、反应条件温和、选择性高、废物少和适用性广等优点,并且容易实现规模放大和连续生产.

关键词：苄位氧化蒽-铈协同催化可见光催化连续流光反应

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

Salinity fronts shape spatial patterns in zooplankton distribution in Hangzhou Bay

引用

Acta Oceanologica Sinica 2024年第6期43卷 96-106页

作者： Yepeng xu Yiqi Wang Lin Zhan Yijun Ou Kangning Jia Ming Mao xuyu Zhu Zhibing Jiang yuanli Zhu Wei Huang Ping Du Jiangning Zeng Lu Shou Feng Zhou Key Laboratory of Marine Ecosystem Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Key Laboratory of Nearshore Engineering Environment and Ecological Security of Zhejiang Province Hangzhou 310012China State Key Laboratory of Satellite Ocean Environment Dynamics Ministry of Natural ResourcesHangzhou 310012China Nantong Marine Environmental Monitoring Center Ministry of Natural ResourcesNantong 226002China Key Laboratory of Ocean Space Resource Management Technology Ministry of Natural ResourcesHangzhou 310012China Observation and Research Station of Marine Ecosystem in the Yangtze River Delta Ministry of Natural ResourcesZhoushan 316021China

Ocean fronts play important roles in nutrient transport and in the shaping ecological *** zones in small bays are typically small in scale,have a complex structure,and they are spatially and temporally variable,but there are limited data on how biological communities respond to this *** Bay,a mediumsized estuary in China,is an ideal place in which to study the response of plankton to small-scale ocean fronts,because three water masses(Qiantang River Diluted Water,Changjiang River Diluted Water,and the East China Sea current) converge here and form dynamic salinity fronts throughout the *** investigate zooplankton communities,and temperature,salinity and chlorophyll a(Chl a) in Hangzhou Bay in June(wet perio d) and December(dry period) of 2022 and examine the dominant environmental factors that affect zooplankton community spatial *** then match the spatial distributions of zooplankton communities with those of salinity fronts.S alinity is the most important explanatory variable to affect zooplankton community spatial variability during both wet and dry periods,in that it contributes>60% of the variability in community ***,the spatial distributions of zooplankton match well with salinity *** December,with weaker Qiantang River Diluted Water and a stronger secondary Changjiang River Plume,zooplankton communities occur in moderate salinity(MS,salinity range 15.6±2.2) and high salinity(HS,22.4±1.7) regions,and their ecological boundaries closely match the Qiantang River Diluted Water *** June,different zooplankton communities occur in low salinity(LS,3.9±1.0),MS(11.7±3.6) and HS(21.3±1.9) *** the LS region occurs abnormally in the central bay rather than its apex because of the anomalous influence of rising and falling tides during the sampling perio d,the ecological boundaries still match salinity ***-salinity or brackish-water zooplankter taxa are relatively more abunda

关键词： zooplankton spatial distribution salinity fronts Hangzhou Bay

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

柔性基础对ICF装置稳定性的影响

引用

强激光与粒子束 2011年第6期23卷 1569-1573页

作者：陈学前徐元利中国工程物理研究院总体工程研究所四川绵阳621900

为探讨土-结构相互作用(SSI)对惯性约束聚变(ICF)装置在地脉动作用下响应的影响,建立了某ICF装置刚性地基和柔性地基两种有限元模型。通过设置人工虚拟边界的弹簧单元和阻尼装置来考虑SSI效应,并且通过设置具有概率意义的弹簧刚度和阻... 详细信息

为探讨土-结构相互作用(SSI)对惯性约束聚变(ICF)装置在地脉动作用下响应的影响,建立了某ICF装置刚性地基和柔性地基两种有限元模型。通过设置人工虚拟边界的弹簧单元和阻尼装置来考虑SSI效应,并且通过设置具有概率意义的弹簧刚度和阻尼系数,来模拟岩土特性参数的不确定性。两个模型地脉动随机响应结果的对比分析,揭示了柔性地基条件下SSI效应及岩土地基参数不确定性对装置的影响。研究表明,考虑岩性地基的柔性时,ICF装置主要部位的位移响应和转角响应分别放大了1.24和1.49倍。

关键词：惯性约束聚变装置土-结构相互作用地脉动动力学分析

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：