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A quasi-in-situ EBSD study of the thermal stability and grain growth mechanisms of CoCrNi medium entropy alloy with gradient-nanograined structure

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Journal of Materials Science & Technology 2022年第14期109卷 54-63页

作者： P.-C.Zhao B.Guan y.-G.Tong R.-Z.Wang X.Li X.-C.Zhang S.-T.Tu Key Laboratory of Pressure Systems and Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China College of Automobile and Mechanical Engineering Changsha University of Science and TechnologyChangshaChina

The thermal stability and mechanical properties of a gradient-nanograined structure(GNS)CoCrNi medium entropy alloy(MEA)processed by ultrasonic surface rolling were studied by using isothermal/isochronal annealing tests combined with quasi-in-situ electron backscatter diffraction(EBSD)characterization and Vickers micro-hardness(HV)measurements.A layer by layer high-throughput investigation method was used to quantitatively study the grain growth kinetics and grain boundary evolution with different initial grain sizes,which could effectively save specimen and time *** grain nucleation and growth,as well as shrink and disappearance process throughΣ3 coincidence site lattice boundary migration with slightly lattice rotation during annealing were directly *** layer by layer grain growth kinetics and calculated activation energy indicate that the thermal stability of nanograined top surface layer is relatively higher than that of nano-twined subsurface layer for the gradient CoCrNi MEA processed by ultrasonic surface *** analysis show that the grain boundary relaxation and dynamic recrystallization of the topmost nano-grains led to the decrease of grain boundary energy,thus improving their thermal *** present work provided theoretical basis for the application of CoCrNi MEA at high ***,the high-throughput method on the investigation of grain stability by using gradient structure can be easily extended to other materials and it is of great significance for understanding the microstructural evolution of gradient materials.

关键词： Medium entropy alloy Grain growth Gradient materials Nanostructured materials Annealing High throughput

THE LIQUIDUS OF THE TERNARy Ag-Cu-Si ALLOy SySTEM

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Acta Metallurgica Sinica(English Letters) 1998年第5期11卷 325-328页

作者： Z.G.Liu X.M.Luo G.S.Guo C.X.He G.B.Li Q.y.Zhang Inst of Precious Metals Kunming China

The liquidus of the ternary Ag-Cd-Si alloy system in the Ag-Cu rich region was determined by DTA. The ternary Ag-Cd-Si system was divided into two ternary systems Ag-Cu-Cuo.76Si0.24 and Ag-Cu0.76Si0.24-Si by the section of Ag-Cu0.76 *** is one ternary eutectic point for both the systems with the composition of 12. 5at. %Ag+71. 7at.%Cu+15.8at. %Si and 30at.% Ag+44.7at.%Cu+25.3at.%Sirespectivelg and the temperatures of the eutectic points are 740 and 705℃ respectively.

关键词： Ag-Cd-Si ternary sytem liquidus

EFFECT OF CERIUM ION IMPLANTATION ON THE AQUEOUS CORROSION BEHAVIOR OF ZIRCONIUM

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Acta Metallurgica Sinica(English Letters) 2004年第6期17卷 812-816页

作者： D.Q.Peng X.D.Bai Q.G.Zhou X.W.Chen R.H.yu X.y.Liu DepartmentofMaterialsScienceandEngineering TsinghuaUniversityBeijing100084ChinaManuscriptreceived9September2003

In order to study the influence of cerium ion implantation on the aqueous corrosion behavior of zirconium, specimens were implanted by cerium ions with a dosage range from 1×1016 to 1×1017 ions/cm2 at about 150℃, using MEVVA source at an acceler ative voltage of 40kV. The valence of the surface layer was analyzed by X-ray photo- electron spectroscopy (XPS); Three-sweep potentiodynamic polarization measurement was employed to value the aqueous corrosion resistance of zirconium in a 0.5mol/L H2SO4 solution. It was found that a remarkable decline in the aqueous corrosion behavior of zirconium implanted with cerium ions compared with that of the as-received zirconium. Finally, the mechanism of the corrosion resistance decline of the cerium-implanted zirconium is discussed.

关键词： zirconium corrosion resistance cerium ion implantation potentio- dynamic polarization X-ray photoelectron spectroscopy (XPS)

Fatigue lifetime evaluation of high pressure hydrogen storage vessel for fuel cell vehicles

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Fatigue lifetime evaluation of high pressure hydrogen storag...

双防线可恢复性能斜交网格结构耗能机制和抗震性能研究

第九届全国氢能学术会议

作者： H.y.Bie,J.y Zheng,P.Xu,y.L.Liu,H.G Chen Zhejiang University,China

＜正＞The fatigue failure properties of the lightweight high pressure hydrogen storage vessel for fuel cell vehicle（FCV） which consists of the Al liner-carbon/epoxy composite laminates largely affect its reliability and *** a finished hydrogen vessel,many factors such as the pressure cyclic range,the cyclic frequency,the temperature and humidity are related with

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世界地震工程 2019年第3期35卷 37-44页

作者：李天翔 yang T.y. 童根树浙江大学建筑工程学院土木工程系杭州310058 同济大学地震工程国际联合研究中心上海200092

为提高斜交网格结构的抗震性能,提出一种双防线可恢复性能斜交网格结构。双防线可恢复性能斜交网格结构采用剪切耗能段和特定梁端塑形铰进行集中耗能,使主体结构构件保持弹性。剪切耗能段不承受和传递重力荷载,易在震后修复或更换,使建... 详细信息

为提高斜交网格结构的抗震性能,提出一种双防线可恢复性能斜交网格结构。双防线可恢复性能斜交网格结构采用剪切耗能段和特定梁端塑形铰进行集中耗能,使主体结构构件保持弹性。剪切耗能段不承受和传递重力荷载,易在震后修复或更换,使建筑可迅速恢复功能。为实现目标耗能机制,对等效能量塑形设计法进行改进以适用于可恢复性能斜交网格结构,并进行结构设计举例。采用OpenSees软件对所设计结构建立详细的有限元计算模型,进行非线性动力时程分析,以验证双防线耗能机制并评估抗震性能。分析结果表明:(1)小震、中震和大震下的结构顶部位移角分别为0.28%、0.8%和1.7%,与性能设计目标基本相同;(2)中震时剪切耗能段屈服,特定梁端未出现塑性铰;(3)大震时,特定梁端出现塑性铰以增加结构耗能能力,剪切耗能段屈服且处于延性范围内。因此新型可恢复性能斜交网格结构具有有效的双防线耗能机制,在中震后可迅速修复,在大震中可保持延性,实现“中震可修,大震不倒”的性能目标。

关键词：斜交网格可恢复性能剪切耗能段塑形设计非线性动力分析

地面堆载作用下黏弹性地层盾构施工诱发土体响应时域解

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岩土工程学报 2021年第1期43卷 34-42页

作者：张治国张洋彬张成平王志伟 PAN y T 上海理工大学环境与建筑学院上海200093 中国铁道科学研究院高速铁路轨道技术国家重点实验室北京100081 北京交通大学城市地下工程教育部重点实验室北京100044 Department of Civil and Environmental Engineering National University of SingaporeSingapore119077

目前针对软土地层盾构施工诱发周围土体变形影响的研究一般是基于瞬时开挖工况,较少考虑黏弹性土体的流变特性,也较少考虑地表堆载给盾构隧道施工所带来的影响。从地基黏弹性角度出发,引入隧道洞周的椭圆化收敛变形模式,采用复变函数理... 详细信息

目前针对软土地层盾构施工诱发周围土体变形影响的研究一般是基于瞬时开挖工况,较少考虑黏弹性土体的流变特性,也较少考虑地表堆载给盾构隧道施工所带来的影响。从地基黏弹性角度出发,引入隧道洞周的椭圆化收敛变形模式,采用复变函数理论并运用Laplace变换技术,提出了地表堆载作用下盾构隧道开挖引起的周围土体位移和应力的时域解。依托相关工程监测数据与简化时域解对比,得到了较好的一致性。研究结果表明:所得出的时域解能较好地反映地表堆载作用下盾构隧道开挖对周围土体位移场的影响,以及地层变形随时间的发展趋势。在地表堆载影响下,随着时间推移,开挖引起的地层变形不断增加,沉降速率则呈现出逐渐衰弱直至为零规律,而堆载突变导致其地表沉降值尤其沉降速率变化显著。研究成果对黏性地层密集堆载群范围内的隧道施工控制具有一定理论指导意义。

关键词：盾构隧道地表堆载黏弹性椭圆化收敛变形时域解

Phosphatic microspherules and their geobiological implications from the Frasnian-Famennian transition at the yangdi section, Guilin, South China

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Science China Earth Sciences 2014年第6期57卷 943-956页

作者： HUANG Cheng GONG yiMing State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences

Abundant perfectly-preserved phosphatic microspherules have been discovered across the Frasnian-Famennian （F-F） transition from the yangdi section in Guilin, Guangxi, South China. They are mostly spherical or elliptical in shape and about 150 gin in diameter with smooth exterior surfaces. Each microspherule consistently possesses a small dimple on the surface. The internal texture of microspherules consists of concentric light-colored apatite and dark-colored organic matter bands alternating around a central core. Conodonts have also been found preserved together with phosphatic microspherules in the same horizon, and the abundance of the former is obviously higher than that of the latter. Laser Raman spectral studies show close similarities in spectral patterns between the outer shells of phosphatic microspherules and the blade of the conodont genus Palmatolepis sp., as well as between the microspherule nucleus and the platform of the same conodont genus. Furthermore, the statistical results and geochemical data demonstrate that the elevated abundance of phosphatic microspherules roughly coincides with the blooms of bacteria and algae, but is later than the sharp increase of oceanic nutrients. The phosphatic microspherules are inter- preted here to be the ＇otoliths＇ secreted by conodont animals based on the compositional similarities between phosphatic mi- crospherules and conodonts and their interrelated abundances. In addition, an analogous study reveals morphological and tex- tural similarities between fish otoliths and phosphatic microspherules. The formation of phosphatic microspherules is probably related to seawater eutrophication. We speculate that the explosive growth of bacteria and algae is probably caused by the en- richment of nutrients that is most likely associated with the increase of terrestrial inputs, submarine hydrothermal activities or the upwelling anoxic bottom waters in the late Devonian, which would stimulate the conodont animals to secrete

关键词： microspherules conodont animal otoliths eutrophication Devonian F-F South China

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基于分数Weierstrass散射模型的海面漏油区域表面浮油的原油权重因子估计

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中国科学：地球科学 2014年第8期44卷 2328-2338页

作者：李洋陶然盛新庆北京理工大学信息与电子学院北京100081

海洋原油泄漏过程中,原油在海洋表面会发生乳化反应,形成油水乳化物.原油所占的油水乳化物体积的权重因子是海面漏油监控中的一个非常重要的参数.基于二维分数Weierstrass散射模型和全极化SAR数据,提出了海面漏油区域表面浮油的原油权... 详细信息

海洋原油泄漏过程中,原油在海洋表面会发生乳化反应,形成油水乳化物.原油所占的油水乳化物体积的权重因子是海面漏油监控中的一个非常重要的参数.基于二维分数Weierstrass散射模型和全极化SAR数据,提出了海面漏油区域表面浮油的原油权重因子的估计方法.利用所提出的估计方法,分析了2010年4月20日美国墨西哥湾"深水地平线"钻井平台漏油事件中的无人载机合成孔径雷达L波段的全极化数据.分析和比较的结果表明所提出的原油权重因子估计方法是准确的和有效的.

关键词：漏油无人载机合成孔径雷达深水地平线钻井平台分数Weierstrass散射模型

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卵黄高磷蛋白磷酸肽的制备及钙结合性质研究

无锡轻工大学学报（食品与生物技术） 2000年第4期19卷 325-330页

作者：江波 y.Mine 无锡轻工大学食品学院江苏无锡214036 圭尔夫大学食品科学系

以卵黄高磷蛋白质为原料 ,经碱法脱磷、胰蛋白酶水解后分离制备得到一种新型的卵黄高磷蛋白磷酸肽 (PPP) .卵黄高磷蛋白质经 0 .1,0 .2 ,0 .3,0 .4mol/LNaOH处理 3h ,脱磷率分别为34.6 % ,81.6 % ,92 .5% ,96 .3% .SDS PAGE电泳结果显... 详细信息

以卵黄高磷蛋白质为原料 ,经碱法脱磷、胰蛋白酶水解后分离制备得到一种新型的卵黄高磷蛋白磷酸肽 (PPP) .卵黄高磷蛋白质经 0 .1,0 .2 ,0 .3,0 .4mol/LNaOH处理 3h ,脱磷率分别为34.6 % ,81.6 % ,92 .5% ,96 .3% .SDS PAGE电泳结果显示 ,脱磷卵黄高磷蛋白质经胰蛋白酶水解后 ,产物为小分子肽 .经BaCl2 法和超滤法分离得到的磷酸肽的平均氨基酸残基数分别为 10个与2 0个 .对PPP的钙结合能力进行了研究并同商品化酪蛋白磷酸肽 (CPP)进行了比较 .PPP能有效地与钙络合 ,因而它在功能食品中有着较好的应用前景 .

关键词：卵黄高磷蛋白质磷酸肽蛋黄钙吸收促进剂