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Effect of hydrogen on deformation behavior of Alloy 725 revealed by in-situ bi-crystalline micropillar compression test

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Journal of Materials Science & Technology 2021年第8期67卷 243-253页

作者： xu lu Dong Wang Department of Mechanical and Industrial Engineering Norwegian University of Science and TechnologyNo-7491TrondheimNorway

Nickel-based Alloy 725 bi-crystalline micropillars with different types of grain boundaries(GBs)were compressed in hydrogen-free and in-situ hydrogen-charged conditions to investigate the hydrogen effect on the deformation behavior of the selected *** the presence of hydrogen,the compressive stresses on the micropillars increase regardless of the GB *** was proposed that this hydrogen-induced hardening behavior is the synergistic effect of hydrogen-enhanced dislocation multiplication and interactions,the pinning effect of hydrogen on dislocation motion,and hydrogen-enhanced lattice *** electron backscatter diffraction(t-EBSD)results demonstrate that both low-angle GBs and high-angle GBs can effectively suppress dislocation transmission through the GBs,resulting in dislocations pile up along the GBs in the hydrogen-charged *** contrast,this behavior was not observed in the micropillars with twin boundaries.

关键词： Hydrogen Nickel-based alloy Micropillar compression Plastic deformation Grain boundary

A dual-pass data assimilation scheme for estimating surface fluxes with FY3A-VIRR land surface temperature

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Science China Earth Sciences 2015年第2期58卷 211-230页

作者： xu TongRen LIU ShaoMin xu ZiWei LIANG ShunLin xu lu State Key Laboratory of Remote Sensing Science and School of Geography Beijing Normal University State Key Laboratory of Remote Sensing Science and College of Global Change and Earth System ScienceBeijing Normal University Department of Geographical Sciences University of Maryland College Park Information Technology Department National Library of China

In this work, a dual-pass data assimilation scheme is developed to improve predictions of surface flux. Pass 1 of the dual-pass data assimilation scheme optimizes the model vegetation parameters at the weekly temporal scale, and Pass 2 optimizes the soil moisture at the daily temporal scale. Based on ensemble Kalman filter(EnKF), the land surface temperature(LST) data derived from the new generation of Chinese meteorology satellite(FY3A-VIRR) are assimilated into common land model(CoLM) for the first time. Six sites, Daman, Guantao, Arou, BJ, Miyun and Jiyuan, are selected for the data assimilation experiments and include different climatological conditions. The results are compared with those from a dataset generated by a multi-scale surface flux observation system that includes an automatic weather station(AWS), eddy covariance(EC) and large aperture scintillometer(LAS). The results indicate that the dual-pass data assimilation scheme is able to reduce model uncertainties and improve predictions of surface flux with the assimilation of FY3A-VIRR LST data.

关键词： assimilation moisture latent weekly vegetation weather pixel covariance aperture Figure

The study on the dynamic response performance of PEMFC with electrodeposited RuO_2·xH_2O-Pt/C electrode

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Journal of Natural Gas Chemistry 2011年第3期20卷 256-260页

作者： Yanbo Wu Xiaoxin Wu Hongfeng xu lu lu Department of Environment ＆ Chemical Engineering Dalian Jiaotong University Dalian 116028 Liaoning China

Dynamic response performance of proton exchange membrane （PEM） fuel cells affects its durability and reliability significantly. In this study, electrodeposited RuO2 xH2O-Pt/C was prepared to promote the PEM fuel cell dynamic response performance. The prepared RuO2 xH2O-Pt/C was characterized by scanning electron microscopy （SEM） equipped with energy disperse spectroscopy （EDS）, which shows that RuO2 xH2O was electrodeposited on the surface of Pt/C. Performance of single cells with and without RuO2 xH2O-Pt/C at the cathode under a certain operating condition was studied using cyclic voltammetry, electrochemical impedance spectra （EIS） and polarization curve techniques. When the fuel cell modified with RuO2 xH2O-Pt/C was operated at lower pressure, a faster and more stable dynamic response could be found. Modifying with RuO2 xH2O-Pt/C composite material not only slightly increases the single cell performance but also dramatically improves the dynamic response performance, revealing that RuO2 xH2O-Pt/C can buffer the voltage undershoot whenever the current increases instantly.

关键词： PEMFC dynamic response RuO2· xH2O electrodeposite

HWM： a hybrid workload migration mechanism of metadata server cluster in data center

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Frontiers of Computer Science 2017年第1期11卷 75-87页

作者： Jian lu Huanqing DONG Junwei ZHANG Zhenjun LIU lu xu Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

In data center, applications of big data analytics pose a big challenge to massive storage systems. It is signif- icant to achieve high availability, high performance and high scalability for PB-scale or EB-scale storage systems. Meta- data server （MDS） cluster architecture is one of the most effective solutions to meet the requirements of applications in data center. Workload migration can achieve load balance and energy saving of duster systems. In this paper, a hybrid workload migration mechanism of MDS cluster is proposed and named as HWM. In HWM, workload of MDS is classi- fied into two categories： metadata service and state service, and they can be migrated rapidly from a source MDS to a target MDS in different ways. Firstly, in metadata service migration, all the dirty metadata of one sub file system is flushed to a shared storage pool by the source MDS, and then is loaded by the target MDS. Secondly, in state service mi- gration, all the states of that sub file system are migrated from source MDS to target MDS through network at file granular- ity, and then all of the related structures of these states are reconstructed in target MDS. Thirdly, in the process of work- load migration, instead of blocking client requests, the source MDS can decide which MDS will respond to each request according to the operation type and the migration stage. The proposed mechanism is implemented in the Blue Whale MDS cluster. The performance measurements show that the HWM mechanism is efficient to migrate the workload of a MDS cluster system and provides low-latency access to metadata and states.

关键词： data center metadata server cluster hybrid workload migration metadata service state service low-latency access

Soil Salinity and Soil Water Content Estimation Using Digital Images in Coastal Field:A Case Study in Yancheng City of Jiangsu Province,China

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Chinese Geographical Science 2022年第4期32卷 676-685页

作者： xu lu MA Hongyuan WANG Zhichun School of Geography Geomatics and PlanningJiangsu Normal UniversityXuzhou 221116China Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130012China

Soil is the essential part for agricultural and environmental sciences,and soil salinity and soil water content are both the important influence factors for sustainable development of agriculture and ecological *** camera,as one of the most popular and convenient proximal sensing instruments,has its irreplaceable position for soil properties *** this study,we collected 52 soil samples and photographs at the same time along the coast in Yancheng City of Jiangsu *** carefully analyzed the relationship between soil properties and image brightness,and found that soil salt content had higher correlation with average image brightness value than soil water *** the brightness levels,the high correlation coefficients between soil salt content and brightness levels concentrated on the high brightness values,and the high correlation coefficients between soil water content and brightness levels focused on the low brightness *** significance levels(P)determined different brightness levels related to soil properties,hence P value setting can be an optional way to select brightness levels as the input variables for modeling soil *** these information,random forest algorithm was applied to develop soil salt content and soil water content inversion models using randomly 70%of the dataset,and the rest data for testing *** results showed that soil salt content model had high accuracy(R_(v)^(2)=0.79,RMSE_(v)=12 g/kg,and RPD_(v)=2.18),and soil water content inversion model was barely satisfied(R_(v)^(2)=0.47,RMSE_(v)=3.04%,and RPD_(v)=1.38).This study proposes a method of modeling soil properties with a digital *** unmanned aerial vehicle(UAV),it has potential popularization and application value for precise agriculture and land management.

关键词： soil salinity soil water content coastal soil digital image

Effect of Oxygen and Bacteria on the Property of Polymer Gel

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Journal of Natural Gas Chemistry 2007年第4期16卷 437-441页

作者： Weidong Jiang Xiangguo lu Xinxia xu Laboratory of Enhanced Recovery of Education Ministry Daqing Petroleum Institute Daqing 163318 Heilongjiang China

The viscosity property of Cr^3＋, Al^3＋, and compound ion cross-linked polymer gel solution in the anaerobic and aerobic environment was investigated aiming at meeting the practical demand of the oil field. The viscosity reserving effect after adding the biocide and the gelation in the anaerobic and aerobic environments was also studied in the paper. The results indicate that the viscosity of the cross-linked polymer gel solution caused by the water produced in aerobic environment is higher than that in anaerobic environment, and that the viscosity value of the cross-linked polymer gel solutions after adding biocides has improved to some extent and polymer gel has gelated well in anaerobic environment.

关键词： anaerobic and aerobic environment cross-linked polymer viscosity biocide experimental research

Inner Modulation in Quasicrystals and Approximants

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Chinese Physics Letters 1998年第9期15卷 665-667页

作者： xu lu MAI Zhen-hong Institute of Physics&Center for Condensed Matter Physics Chinese Academy of SciencesBeijing 100080

Through a detailed analysis,it is found out that a quasilattice can be considered as one consisting of several mutually incommensurate interpenetrating sublattices,each sublattice being a modulated crystalline *** modulation periods in one sublattice are given by the basic periodicities of the other *** analyzed is the approximant quasilattice whose sublattices being mutually *** the density wave picture,the combination of crystal structures into one quasicrystal(or approximant)phase can be done in a natural procedure.

关键词： mutually quasi lattice

Three-dimensional structural features and the toxicity of aminobenzenes and phenols

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Science China Chemistry 2003年第5期46卷 431-438页

作者： xu lu(许禄) YANG Jiaan(杨嘉安) Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China

For a QSAR of the toxicity of aminobenzenes in environment and their structures, the projection areas of the molecules in 3D space were calculated. The combinations of the projection areas and quantum chemical as well as topological parameters were performed for the methods of regression analysis and neural network, and much better results than that by using CoMFA were achieved.

关键词： aminobenzene, regression analysis, neural network, 3D projection area, QSAR.

Heterologous viral suppressor of RNA silencing breaks protein-based viral immunity in mixed viral infection

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Science China(Life Sciences) 2021年第10期64卷 1788-1791页

作者： xu lu Feng Li Key laboratory of Horticultural Plant Biology(MOE) College of Horticulture and Forestry SciencesHuazhong Agricultural UniversityWuhan 430070China Interdisciplinary Sciences Research Institute Huazhong Agricultural UniversityWuhan 430070China

Dear Editor:RNA silencing confers immunity against most viruses and is initiated by host Dicer processing of viral doublestranded RNA into virus-derived small interfering RNA(siRNA)(Guo et al.,2019).Viruses that cause plant disease usually evolve viral suppressor of RNA silencing(VSR)to inhibit antiviral silencing(Li and Ding,2006).Some plant nucleotide-binding leucine-rich repeat proteins(NLRs)emerge as immune receptors to recognize specific virus and trigger rapid hypersensitive response(HR)at infection site to protect plants from devastating viruses(Cui et al.,2015;Deng et al.,2018).Recent studies showed that NLR immune receptors are subjected to negative regulation by plant miRNAs(Deng et al.,2018).It is well known that in some cases,mixed virus infections lead to synergism in susceptible plants due to cooperative inhibition of antiviral silencing by multiple VSRs(Pruss et al.,1997).In case of mixed virus infection in a plant with NLR targeting a single virus,heterologous VSR might play dual roles for the NLR-targeted *** one hand,the VSR may promote virulence by cooperative inhibition of antiviral silencing.

关键词： immunity infection