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Effect of cerium on abrasive wear behaviour of hardfacing alloy

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Journal of Rare Earths 2012年第1期30卷 69-73页

作者： xing Shule yu Shengfu DENG yu DAI Minghui yu lu State Key laboratory of Material Forming and Mould&Die Designing Huazhong University of Science and TechnologyWuhan 430074China

Hardfacing alloys with different amounts of ceria were prepared by self-shielded flux cored arc *** abrasion tests were carried out using the dry sand-rubber wheel machine according to JB/T 7705-1995 *** hardness of hardfacing deposits was meas-ured by means of HR-150Al Rockwell hardness test and the fracture toughness was measured by the indentation *** characterization and surface analysis were made using optical microscopy,scanning electron microscopy（SEM） and energy spectrum *** results showed that the wear resistance was determined by the size and distribution of the carbides,as well as by the matrix *** main wear mechanisms observed at the surfaces included micro-cutting and micro-pl.ughing of the *** addition of ceria improved the hardness and fracture toughness of hardfacing deposits,which would increase the resistance to plastic deformation and scratch,thus the wear resistance of hardfacing alloys was improved.

关键词： abrasive wear carbides rare earth oxides

High-brightness near-infrared luminescent bioprobes based on lanthanide-doped Na3CrF6 nanoparticles

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Science China Materials 2024年第12期67卷 4113-4114页

作者： yun xing Shiqi yu Datao Tu Xueyuan Chen State Key laboratory of Structural Chemistry Fujian Key Laboratory of Nanomaterialsand CAS Key Laboratory of Design and Assembly of Functional NanostructuresFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian Science&Technology Innovation laboratory for Optoelectronic Information of China Fuzhou 350108China university of Chinese Academy of Sciences Beijing 100049China

Over the past decade,near-infrared(NIR)luminescent materials have emerged as a frontier in photonics and material science,finding diverse applications in bioimaging,encryption,and photodetection[1].Particularly,NIR nanoprobes are widely utilized in life science and clinical medicine because of their high spatial resolution,deep tissue penetration,low optical absorption and scattering,and minimal autofluorescence[2,3].

关键词： nanoparticles frontier utilized

Equi-invariability,bounded invariance complexity and l-stability for control systems

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Science China Mathematics 2021年第10期64卷 2275-2294页

作者： xing-fu Zhong Zhi-jing Chen yu Huang School of Mathematics and Statistics Guangdong University of Foreign StudiesGuangzhou 510006China School of Mathematics and Systems Science Guangdong Polytechnic Normal UniversityGuangzhou 510665China School of Mathematics Sun Yat-sen UniversityGuangzhou 510275China

In this paper,we introduce the notions of bounded invariance complexity,bounded invariance complexity in the mean and mean lyapunov-stability for control *** we characterize these notions by introducing six types of *... 详细信息

关键词： equi-invariability invariance complexity dichotomy theorem control set invariance entropy

Texture property and weakening mechanism of Mg-3Al-1Zn alloy by interactive alternating forward extrusion

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Journal of Magnesium and Alloys 2023年第2期11卷 684-693页

作者： Ye Wang Feng li yu Wang xing Mao Xiao School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040P R China Key laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080P R China Southwest Technique and Engineering Reasearch Institute Chongqing 400039P R China

The interactive alternating forward extrusion(AFE) method can realize the change of texture type and the weakening of texture *** AZ31 magnesium alloy as an example, the texture evolution of interactive AFE was studied. The results show that all kinds of dynamic recrystallization(DRX) behaviors can weaken the texture to vary degrees. The weakening effect of twinning-induced recrystallization(TDRX)behavior was particularly significant. During the interactive AFE process, the c-axis of most grains rotated under the external force, and tended to be 90° angle with the ED direction, forming a stable fiber texture. In addition, with the increase of loading passes, the starting of {0001} basal slip system became more and more difficult. The(10–10) texture formed by {10–10} prismatic slip system after sixth passes was the main texture type. With the increase of forming temperature, the starting ability of {10–10} prismatic slip systems increased, and the(10–10) texture formed by prismatic slip system above 623 K dominated.

关键词： Magnesium alloy Alternating extrusion Texture Recrystallization Grain orientation

Risk Assessment of Multi‑Hazards in Hangzhou:A Socioeconomic and Risk Mapping Approach using the CatBoost‑SHAP Model

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International Journal of Disaster Risk Science 2024年第4期15卷 640-656页

作者： Bofan yu Jiaxing Yan yunan li Huaixue xing The Institute of Geological Survey of China university of Geosciences(Wuhan) China University of Geosciences(Wuhan)Wuhan 430074China China Geological Survey Nanjing CenterNanjing 210016China

As the global push for sustainable urban development progresses, this study, set against the backdrop of Hangzhou City,one of China's megacities, addressed the conflict between urban expansion and the occurrence of urban geological *** on the predominant geological hazards troubling Hangzhou-urban road collapse, land subsidence, and karst collapse-we introduced a Categorical Boosting-SHapley Additive exPlanations(CatBoost-SHAP) model. This model not only demonstrates strong performance in predicting the selected typical.urban hazards, with area under the curve(AuC) values reaching 0.92, 0.92, and 0.94, respectively, but also, through the incorporation of the explainable model SHAP, visually presents the prediction process, the interrelations between evaluation factors, and the weight of each factor. Additionally, the study undertook a multi-hazard evaluation, producing a susceptibility zoning map for multiple hazards, while performing tailored analysis by integrating economic and population density factors of Hangzhou. This research enables urban decision makers to transcend the “black box” limitations of machine learning, facilitating informed decision making through strategic resource allocation and scheduling based on economic and demographic factors of the study area. This approach holds the potential to offer valuable insights for the sustainable development of cities worldwide.

关键词： Hangzhou city Multi-hazard risk assessment Machine learning Machine learning interpretability Socioeconomic analysis urban sustainability development

Tunable band structures of polycrystalline graphene by external and mismatch strains

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Acta Mechanica Sinica 2012年第6期28卷 1539-1544页

作者： Jiang-Tao Wu xing-Hua Shi yu-Jie Wei lNM Institute of Mechanics Chinese Academy of Sciences

lacking a band gap largely limits the application of graphene in electronic devices. Previous study shows that grain boundaries （GBs） in polycrystalline graphene can dra- matically alter the electrical properties of graphene. Here, we investigate the band structure of polycrystalline graphene tuned by externally imposed strains and intrinsic mismatch strains at the GB by density functional theory （DFT） cal.u- lations. We found that graphene with symmetrical GBs typ- ically has zero band gap even with large uniaxial and biax- ial strain. However, some particular asymmetrical GBs can open a band gap in graphene and their band structures can be substantially tuned by external strains. A maximum band gap about 0.19 eV was observed in matched-armchair GB （5, 5） I （3, 7） with a misorientation of θ = 13° when the applied uniaxial strain increases to 9%. Although mismatch strain is inevitable in asymmetrical GBs, it has a small influence on the band gap of polycrystalline graphene.

关键词： Graphene Grain boundary Defects Strain and gap

Thermoelastic stress analysis of multilayered films in a micro-thermoelectric cooling device

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Acta Mechanica Sinica 2012年第6期28卷 1644-1650页

作者： yu-Mei Yang xing-Zhe Wang Wen-Jie Zhang Key laboratory of Mechanics on Environment and Disaster in Western China The Ministry of Education of China College of Civil Engineering and Mechanics Lanzhou University

This paper presents an analytical solution for the thermoelastic stress in a typical in-plane＇s thin-film micro- thermoelectric cooling device under different operating con- ditions. The distributions of the permissible temperature fields in multilayered thin-films are analytically obtained, and the characteristics, including maximum temperature dif- ference and maximum refrigerating output of the thermo- electric device, are discussed for two operating conditions. Analytical expressions of the thermoelastic stresses in the layered thermoelectric thin-films induced by the tempera- ture difference are formulated based on the theory of mul- tilayer system. The results demonstrate that, the geometric dimension is a significant factor which remarkably affects the thermoelastic stresses. The stress distributions in layers of semiconductor thermoelements, insulating and support- ing membrane show distinctly different features. The present work may profitably guide the optimization design of high- efficiency micro-thermoelectric cooling devices.

关键词： Thermoelectric cooling device Multilayeredthin-film Thermoelastic stress - Analytical solution

Molecular cloning and expression patterns of two small heat shock proteins from Chilo suppressalis(Walker)

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Journal of Integrative Agricul.ure 2020年第6期19卷 1522-1529页

作者： SONG Jie lu Ming-xing Du yu-zhou College of Horticul.ure and Plant Protection/lnstitute of Applied Entomology Yangzhou UniversityYangzhou 225009P.R.China Joint International Research laboratory of Agricul.ure and Agri-Product Safety Ministry of EducationYangzhou UniversityYangzhou 225009P.R.China

Small heat shock protei ns(sHSPs)are a very complex protei n superfamily that increase in sect temperature tolera *** order to deeply understand the function and role of sHSPs in Chilo suppressalis(Walker),this study isolated and identified two CsHSP genes lacking introns from ***,Cshsp23.9 and *** cDNA full-length of Cshsp23.9 and Cshsp27.3 were 909 and 1036 bp encoding 220 and 242 amino acids,*** with homologs and phylogenetic analysis indicated Cshsp23.9 and Cshsp27.3 were two new types of Cshsps in ***-time quantitative PCR(qPCR)revealed that Cshsp23.9 had the highest relative expression in hindgut compared with other tissues(head,epidermis,foregut,midgut,fat body,Malpighian tubules,and hemocytes),while Cs/?sp27.3 expressed the highest in fat body con *** n exposed to thermal stress from-11 to 43°C for 2 h,two genes showed differe nt expression ***23.9 did not respond to low temperature,but could be up-regulated by high temperature and the highest expression temperature was at 36°***27.3 could only be induced by mild temperature,with the highest expression at 15 and 30°*** conclusion,Cshsp23.9 and Cshsp27.3 existed in different tissues/organs of ***,and played different important roles in *** to resist temperature stress and regulate physiological activities.

关键词： sHSPs Chilo suppressalis expression tissues temperature

Stability Analysis of Rainfall-Triggered Toe-Cut Slopes and Effectiveness Evaluation of Pile-Anchor Structures

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Journal of Earth Science 2021年第5期32卷 1104-1112页

作者： Xi Xu yuanchuang xing Zhen Guo yu Huang Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key laboratory of Geotechnical and underground Engineering of the Ministry of Education Tongji UniversityShanghai 200092China

Slope toe excavation strongly influences the stress balance of natural slopes and redistributes the stress of the slope body. Consequently, the sliding failure of toe-cut slopes is increasingly becoming more frequent, particularly in regions with persistent rainfall. The effects of external factors, namely, toe excavation and persistent rainfall, which lead to toe-cut slope failure were investigated through the numerical analysis of typical toe-cut slopes in the southeastern coastal region of China. Based on the grey relational theory, sensitivity analysis was carried out on the controlling factors to determine the degree of influence exerted by the external factors on the stability of toe-cut slopes. The stability analysis of toe-cut slopes reinforced by pileanchor structures under earthquake conditions was carried out using pseudo-static analysis. The safety factor of toe-cut slopes significantly decreases as the excavation height, rainfall duration, and rainfall intensity increase. The slope stability is more sensitive to the excavation height of a toe-cut slope than it is to rainfall. The stability of a toe-cut slope reinforced by a pile-anchor structure was also analyzed under rainfall and earthquake conditions using the limit equilibrium method and pseudo-static analysis, respectively. The slope stability significantly improved when the slope was reinforced by a pile-anchor structure, even when the slope was subjected to persistent rainfall and earthquakes. The findings of this study can provide important guidance for the prevention of geological disasters in mountainous areas.

关键词： toe-cut slope pile-anchor structure slope stability limit equilibrium method pseudo-static analysis

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