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Partitioning behavior and lattice misfit of γ/γ’phases in Ni-based superalloys with different Mo additions

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Rare Metals 2021年第4期40卷 920-927页

作者： Zhe Ma yan-ling pei Liang Luo Lu Qin Shu-Suo Li Sheng-Kai Gong School of Materials Science and Engineering Beihang UniversityBeijing 100191China

A low-density single crystal(LDS) alloy with the composition of high Mo content was *** extra 1.5 wt% Mo was added in the Alloy A with the composition of Ni-6.5 Al-8.0 Mo-2.4 Cr-6.2 Ta-4.9 Co-1.5 Re-(0.01-0.05) Y(wt%) to study the influence of Mo on the lattice parameter and partitioning *** electron microscope(SEM) with energy-dispersive spectrometer(EDS),transmission electron microscopy(TEM)and high-temperature X-ray diffraction(HT-XRD) were used to observe the microstructure,analyze the elemental content and measure the lattice parameter of the *** natural lattice misfit was calculated by lattice constants which were measured by HT-XRD at the temperature from 25 to 1150℃,and the results showed that the lattice misfit would be more and more negative with temperature *** was found that 1.5 wt% addition of Mo will increase the absolute value of the lattice misfit of γ/γ’phases and the volume fraction of γ’,and at the same time,influence the elemental distribution in γ and γ’ phases,especially Re and *** has a higher partitioning ratio(k) after the addition of Mo.

关键词： Ni-based superalloys Mo Lattice misfit High-temperature X-ray diffraction(HT-XRD) Partitioning behavior

Effect of trace Ce on high-temperature oxidation behavior of an Al-Sicoated Ni-based single crystal superalloy

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Journal of Iron and Steel Research International 2019年第1期26卷 78-83页

作者： Xiao-juan Pang Shu-suo Li Lu Qin yan-ling pei Sheng-kai Gong School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Ni-based single crystal superalloy IC21 with different Ce con tents was prepared by screw selection method,and Al-Si coatings were prepared by pack *** oxidation and transient oxidation were carried out at 1150℃ to investigate the effect of Ce on the high-temperature oxidation behavior of Al-Si *** cyclic oxidation at 1150℃,the addition of trace Ce decreased the mass gain of the Al-Si-coated samples and effectively improved oxidation perform a nee and spallation *** specimens without Ce doping,microstructure examinatio n revealed that bulkyγ-Ni3Al precipitated in oxidized coating because of high Al con sumption,and this finding suggests that Ce inhibits the consumption of Al in the coating during *** slows down the Ininsformation of O-Al2O3 to oc-Al2O3 and improves the adhesion of the oxide scale.

关键词： Single crystal superalloy Trace Ce Al-Si coating Oxidation behavior AlO3

Improved mechanical properties of Ni-rich Ni3Al coatings produced by EB-PVD for repairing single crystal blades

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Rare Metals 2017年第7期36卷 556-561页

作者： Jing-Yong Sun yan-ling pei Shu-Suo Li Hu Zhang Sheng-Kai Gong School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Active control of turbine blade tip clearance for aircraft engine continues to be a concern in engine opera- tion, because turbine blades are subjected to wear and therefore cause an increasing tip clearance between the rotating blades and the shroud and also reduce the engine efficiency. In this work, a Ni-rich Ni3A1 coating with γ＇/γ two-phase microstructure was deposited by electron beam physical vapor deposition （EB-PVD）, which worked as repairing the worn blade tips of single crystal blades. Nb molten pool was used to increase the molten pool tem- perature and thus to enhance the deposition rate. The microstructures and mechanical properties can be modified by the deposition temperatures and the following heat treatments. All coatings consist of γ＇ and γ phases. At deposition temperature of 600 ℃, a dense microstructure can be achieved to produce a coating with grain size of 1 μm and microhardness of -HV 477. After being heated for 4 h at a temperature of 1,100 ℃, the coatings have a more uniform microstructure, and microhardness maintains at a high level of -HV 292. Effect of Hf and Zr on EB-PVD Ni3Al repair coating will be further investigated.

关键词： Repair coating Ni3A1 Electron beamphysical vapor deposition Blades tips Single crystal Heat treatment

Effect of applied stress on r'-rafting behavior in a Ni-based singlecrystal superalloy:experiments and finite element analysis

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Journal of Iron and Steel Research International 2019年第3期26卷 259-267页

作者： Yuan-chao Yu Yi Ru Yong Shang yan-ling pei Shu-suo Li Sheng-kai Gong School of Materials Science and Engineering Beihang University Beijing 100191 China

The effect of applied tensile stress on the r'-rafting behavior for a Ni-based single-crystal superalloy with more negative misfit was *** conducting interrupted creep tests at high temperature,it indicated that the increase in the applied stress accelerates the r'-rafting(directional coarsening of yr phase).In the early stage of rafting,the r'-cubes start interconnecting at the ends of the parallel-to-applied-stress r'-*** distributions of misfit stress,coherent strain and strain energy density of the r/r'phases are then calculated by finite element *** calculation results show that the rafting acceleration is mainly ascribed to the reduced strain energy density in the parallel-to-applied-stress r'-channel that is driven from the couple interaction of external load and misfit *** dislocation network formation,resulting from the misfit-induced increase in resolved shear stress,also contributes to the r'-rafting.

关键词： Ni-based superalloy High lattice misfit Rafting Finite element analysis Misfit stress Strain energy density

Directional solidification behavior of turbine blades in DZ125 alloy:design of blade numbers on assembly

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Rare Metals 2021年第5期40卷 1134-1144页

作者： Yong Shang yan-ling pei Sheng-Kai Gong Yi Ru Yuan-Chao Yu Ru-Hao Zhou Shu-Suo Li Hui-Bin Xu School of Materials Science and Engineering Beihang UniversityBeijing 100191China

The influence of blades assembly,i.e.,the blade number on the solidification process,heat exchange and grain structure on a directionally solidified Ni-based superalloy DZ125 was investigated by combining the experimental and simulation *** casting process was simulated thermodynamically by ProCAST software,where the interface heat transfer coefficient was precisely determined by a measurement with *** is a good agreement between experimental and simulation *** was interestingly found that with the number of blades increasing from 6 to 10,due to the decrease in radiation absorption efficiency,the maximum temperature and the heating rate decrease in the mold,during the preheat *** the withdrawal procedure,increased assembly numbers reduce the radiation exchange from mold to the enclosure,resulting in the decrease in cooling rate and temperature gradient of the *** the end of withdrawal,the slower cooling rate of the outside balances the temperature distribution of internal and external surfaces on the rabbet of blade.

关键词： Directional solidification Superalloy ProCAST Interfacial heat transfer coefficient

Remaining Life Prediction Method for Photovoltaic Modules Based on Two-Stage Wiener Process

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Energy Engineering 2025年第1期122卷 331-347页

作者： Jie Lin Hongchi Shen Tingting pei yan Wu School of Electrical Engineering and Information Engineering Lanzhou University of TechnologyLanzhou730050China

Photovoltaic (PV) modules, as essential components of solar power generation systems, significantly influence unitpower generation *** service life of these modules directly affects these costs. Over time, the performanceof PV modules gradually declines due to internal degradation and external environmental *** cumulativedegradation impacts the overall reliability of photovoltaic power generation. This study addresses the complexdegradation process of PV modules by developing a two-stage Wiener process model. This approach accountsfor the distinct phases of degradation resulting from module aging and environmental influences. A powerdegradation model based on the two-stage Wiener process is constructed to describe individual differences inmodule degradation processes. To estimate the model parameters, a combination of the Expectation-Maximization(EM) algorithm and the Bayesian method is employed. Furthermore, the Schwarz Information Criterion (SIC) isutilized to identify critical change points in PV module degradation trajectories. To validate the universality andeffectiveness of the proposed method, a comparative analysis is conducted against other established life predictiontechniques for PV modules.

关键词： Photovoltaic modules degradation stochastic processes lifetime prediction

The linear self-attracting diffusion driven by the weighted-fractional Brownian motion II: The parameter estimation

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Science China Mathematics 2025年

作者： Litan yan Rui Guo Wenyi pei Department of Statistics College of Science Donghua University School of Statistics and Mathematics Zhejiang Gongshang University

Let Ba,bbe a weighted-fractional Brownian motion with Hurst indexes a and b such that a>-1and 0≤b<1∧（1+a）.In this paper,we consider the linear self-attracting diffusion ■ interacting diffusion (see Cranston and Le Jan （1995）).Under the continuous observation,we study asymptotic ■ converges in distribution to the sum of the chi-square random variable with 1 degree of freedom and the random variable Z1a,b.

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A behavioral study of affective arousal by pictures on female tonic pain

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A behavioral study of affective arousal by pictures on femal...

中国生理学会第23届全国会员代表大会暨生理学学术大会

作者： yan-ling YIN,pei-pei WANG,Jun-Fa LI,Zhao-Ran CHEN Department of Neurobiology and Beijing Institute for Neuroscience,Capital Medical University,Beijing 100069,China

＜正＞Objective To investigate the modulation of affective pictures on experimental tonic cold and heat pain in a behavioral *** Fifteen healthy female subjects went through the tonic cold and tonic heat stimulation when watching the affective pictures in a counter-balanced order,in which the pictures were grouped into the pleasant,the unpleasant and the neutral picture *** pain tolerance time（PTT） was *** The PTT of heat pain test was prolonged when watching the pleasant and unpleasant pictures contrast to that of watching the neutral[Pleasant:（145.27±15.99） s and Unpleasant:（146.20±13.68） s vs Neutral:（86.73±12.93） s, P＜0.01,n=15).However,no significant difference was observed in the cold pain test under the different experimental conditions[Pleasant:（78.80±14.81） s and Unpleasant:（74.73±15.78） s vs Neutral:（68.80±15.85） s,P＞0.05,n=15).There was a positive correlation between the residual difference of arousal and the residual difference of heat PTT in pleasant and neutral picture sets（r=0.546,P=0.035）.Conclusion Besides the emotional valence,the arousal may be one of the key elements that modulate the tonic pain.

关键词： tonic heat pain tonic cold pain affective pictures arousal

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浅析无线传感器网络的密钥管理

电脑知识与技术 2009年第8期5卷 6166-6168页

作者：闫培玲河南大学计算机与信息工程学院河南开封475000

集传感器技术、嵌入式计算技术、分布式信息处理技术及无线通信技术于一体的无线传感器网络，因其广阔的应用前景而受到学术界和工业界的高度重视。在大多数应用环境中用户对无限传感器网络的安全能力有很高的要求，因此安全成为制约无... 详细信息

集传感器技术、嵌入式计算技术、分布式信息处理技术及无线通信技术于一体的无线传感器网络，因其广阔的应用前景而受到学术界和工业界的高度重视。在大多数应用环境中用户对无限传感器网络的安全能力有很高的要求，因此安全成为制约无限传感器网络广泛应用的关键。为此文章深入分析和讨论了无线传感器网络密钥管理方面的一些基础内容，并主要对目前一些经典的密钥管理方案进行原理阐述和性能分析。

关键词：无线传感器网络密钥管理无线通信节点安全