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Microstructure evolution and mechanical properties of brazing joint for ultra-thin-walled Inconel 718 considering grain size effect and brazing temperature

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Chinese Journal of Aeronautics 2024年第2期37卷 541-556页

作者： Rui ZHAO Yueshuai song hui KANG Min WAN School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Jiangxi Research Institute of Beihang University Jiangxi 330000China

The systematic investigation of the mechanical properties and microstructure evolution process of ultra-thin-walled Inconel 718 capillary brazing joints is of great significance because of the exceptionally high demands on its *** achieve this objective,this study investigates the impact of three distinct brazing temperatures and five typical grain sizes on the brazed joints’mechanical properties and microstructure evolution *** evolution analysis was conducted based on Electron Back Scatter Diffraction(EBSD),Scanning Electron Microscopy(SEM),X-Ray Diffraction(XRD),High-Resolution Transmission Electron Microscopy(HRTEM),and Focused Ion Beam(FIB).Besides,the mechanical properties and fracture behavior were studied based on the uniaxial tension tests and in-situ tension *** findings reveal that the brazing joint’s strength is higher for the fine-grain capillary than the coarse-grain one,primarily due to the formation of a dense branch structure composed of G-phase in the brazing *** effects of grain size,such as pinning and splitting,are amplified at higher brazing ***,micro-cracks initiate around brittle intermetallic compounds and propagate through the eutectic zone,leading to a cleavage fracture *** fracture stress of fine-grain specimens is higher than that of coarse-grain due to the complex micro-crack ***,this study contributes significantly to the literature by highlighting the crucial impact of grain size on the brazing properties of ultra-thin-walled Inconel 718 structures.

关键词： EYWORDS Ultra-thin-walled structure Brazing Inconel 718 Grain size effect Brazing temperature

A theoretical model for impact protection of flexible polymer material

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 217-226页

作者： huifeng Xi hui Pan song Chen Heng Xiao MOE Key Lab of Disaster Forecast and Control in Engineering School of Machanics and Construction EngineeringJinan UniversityGuangzhou 510632China Doctor Workstation of Xuwen County Guangdong Hydropower Energy Co. Ltd.Xuwen 524100China

The relationship between the protective performance of flexible polymer material and material parameters(elasticmodulus,viscosity coefficient)is explored,an impact collision motion equation between two bodies is establishedfrom the viscoelastic material constitutive,and the relationship between the kinematic response and the materialparameters is *** on the Kelvin constitutive model,a theoretical model for impact between the pro-tective body and the protected body is established,then the dynamic response is *** feasibility of themodel was verified by drop hammer experiment,and the material parameters(elastic modulus,viscosity coeffi-cient)were obtained by *** model is discretized and the relationship between local impact response andmaterial parameters is *** discussion results on the relationship between the impact response and theprotective material performance indicate that adjusting the elastic modulus,viscosity coefficient,and thicknessof the protective material can effectively improve protective effect.

关键词： Flexible polymer material Viscoelastic material Kelvin modelDynamic response Elastic modulus and viscosity coefficient

A method for extracting the preseismic gravity anomalies over the Tibetan Plateau based on the maximum shear strain using GRACE data

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Earth and Planetary Physics 2024年第4期8卷 589-608页

作者： hui Wang DongMei song XinJian Shan Bin Wang College of Oceanography and Space Informatics China University of Petroleum(East China)Qingdao 266580China PCI Technology Group Co. Ltd.Guangzhou 510660China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266200China State Key Laboratory of Earthquake Dynamics Beijing 100029China

The occurrence of earthquakes is closely related to the crustal geotectonic movement and the migration of mass,which consequently cause changes in *** Gravity Recovery And Climate Experiment(GRACE)satellite data can be used to detect gravity changes associated with large ***,previous GRACE satellite-based seismic gravity-change studies have focused more on coseismic gravity changes than on preseismic gravity ***,the noise of the north–south stripe in GRACE data is difficult to eliminate,thereby resulting in the loss of some gravity information related to tectonic *** explore the preseismic gravity anomalies in a more refined way,we first propose a method of characterizing gravity variation based on the maximum shear strain of gravity,inspired by the concept of crustal *** offset index method is then adopted to describe the gravity anomalies,and the spatial and temporal characteristics of gravity anomalies before earthquakes are analyzed at the scales of the fault zone and plate,*** this work,experiments are carried out on the Tibetan Plateau and its surrounding areas,and the following findings are obtained:First,from the observation scale of the fault zone,we detect the occurrence of large-area gravity anomalies near the epicenter,oftentimes about half a year before an earthquake,and these anomalies were distributed along the fault ***,from the observation scale of the plate,we find that when an earthquake occurred on the Tibetan Plateau,a large number of gravity anomalies also occurred at the boundary of the Tibetan Plateau and the Indian ***,the aforementioned experiments confirm that the proposed method can successfully capture the preseismic gravity anomalies of large earthquakes with a magnitude of less than 8,which suggests a new idea for the application of gravity satellite data to earthquake research.

关键词： Gravity Recovery And Climate Experiment(GRACE)data maximum shear strain offset index K preseismic gravity anomalies Tibetan Plateau fault zone

Balanced Fracturing and Cold-welding of Magnesium during Ball Milling Assisted by Carbon Coating:Experimental and Molecular Dynamic Simulation

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 895-903页

作者：韩宗盈 DONG hui DING Guoyang ZHANG Jiale song Xiufang College of Energy Storage Technology Shandong University of Science and TechnologyQingdao 266590China College of Chemical and Biological Engineering Shandong University of Science and TechnologyQingdao 266590China

The lignite-derived carbon from self-protection pyrolysis was employed to balance the fracturing and cold-welding of magnesium during ball *** size analysis indicates that the introduction of lignite-derived carbon can effectively reduce the particle size of Mg while the introduction of graphite does no ***,the effect of lignite-derived carbon on crystallite size reduction of Mg is also better than graphite.A moderate cold-welding phenomenon was observed after ball-milling Mg with the lignite-derived carbon,suggesting less Mg is wasted on the milling vials and *** dynamic simulations reveal that the balanced fracturing and cold-welding of magnesium during ball milling is mainly attributed to the special structure of the lignite-derived carbon:graphitized short-range ordered stacking function as dry lubricant and irregular shape/sharp edge function as milling *** preliminary findings in current study are expected to offer implications for designing efficient Mg-based hydrogen storage materials.

关键词： magnesium lignite-derived carbon cold-welding ball milling molecular dynamic

Study on a probabilistic algorithm for the forming and 3D characterization of special-shaped surfaces under profile grinding

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Advances in Manufacturing 2024年第2期12卷 288-299页

作者： Zhao-Qing Zhang Kai-Ning Shi Yao-Yao Shi Yi-hui song Zhe He Ya-song Pu School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an710072People’s Republic of China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an710072People’s Republic of China Engineering Research Center of Advanced Manufacturing Technology for Aero Engine(Northwestern Polytechnical University) Ministry of EducationXi’an710072People’s Republic of China

Profile grinding is the most crucial method for the ultra-precision machining of special-shaped ***,profile grinding produces a unique machining profile,and many random factors in the machining process lead to complex surface *** this study,the structural and probabilistic characteristics of the profile grinding of a special-shaped surface were analyzed,and a probabilistic algorithm for the forming and 3D characterization of special-shaped surfaces under profile grinding was *** forming process of a GH738 blade tenon tooth surface was considered as an example to demonstrate the *** comparison results showed that the simulation results had similar surface characteristics to the measurement results,and the relative error range of the 3D roughness parameter was 0.21%–19.76%,indicating an accurate prediction and characterization of the complex special-shaped surface under the action of multiple factors.

关键词： Special-shaped surface Profile grinding Surface morphology 3D characterization

Cross-species transmission and host range genes in poxviruses

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Virologica Sinica 2024年第2期39卷 177-193页

作者： Chen-hui Yang A-Ling song Ye Qiu Xing-Yi Ge College of Biology Hunan Provincial Key Laboratory of Medical VirologyHunan UniversityChangsha410012China

The persistent epidemic of human mpox, caused by mpox virus (MPXV), raises concerns about the future spread ofMPXV and other poxviruses. MPXV is a typical zoonotic virus which can infect human and cause smallpox-likesymptoms. MPXV belongs to the Poxviridae family, which has a relatively broad host range from arthropods tovertebrates. Cross-species transmission of poxviruses among different hosts has been frequently reported andresulted in numerous epidemics. Poxviruses have a complex linear double-strand DNA genome that encodeshundreds of proteins. Genes related to the host range of poxvirus are called host range genes (HRGs). This reviewbriefly introduces the taxonomy, phylogeny and hosts of poxviruses, and then comprehensively summarizes thecurrent knowledge about the cross-species transmission of poxviruses. In particular, the HRGs of poxvirus aredescribed and their impacts on viral host range are discussed in depth. We hope that this review will provide acomprehensive perspective about the current progress of researches on cross-species transmission and HRGvariation of poxviruses, serving as a valuable reference for academic studies and disease control in the future.

关键词： Poxvirus Host range gene(HRG) Host spectrum Cross-species transmission

Interfacial friction effects on sealing performances of elastomer packer

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Petroleum Science 2024年第3期21卷 2037-2047页

作者： Peng-Cheng Wang Ming-hui Chen Jim Jenkinson Yong-Xin song Li Sun Department of Mechanical Engineering University of HoustonHoustonTX77024USA Guren Nanomaterials Suzhou215127JiangsuChina Department of Marine Engineering Dalian Maritime UniversityDalian116026LiaoningChina

Elastomer sealing performance is of critical importance for downhole tools application including the use of fracturing(Frac)plugs during multi-stage hydraulic *** practice sealing performances of such plugs are normally evaluated through pressure tests,and in numerical simulation studies,maximum contact stress,average contact stress and contact length data are used to determine sealing quality between a packer and *** previous studies,the impact of friction forces on sealing performance is often *** work aims to fill this knowledge gap in determining the influence of friction forces on elastomer packer sealing *** first determined the most appropriate constitutive hyperelastic model for the elastomers used in frac *** we compared analytical calculation results with Finite Element Analysis simulation using a simplified tubular geometry and showed the significant influences on interfacial friction on elastomer packer stress distribution,deformation,and contact stress after *** the demonstration of validity of FEA method,we conducted systematic numerical simulation studies to show how the interfacial friction coefficients can affect the maximum contact stress,average contact stress,contact stress distribution,and maximum mises stress for an actual packer used in plug *** addition,we also demonstrated how the groove in a packer can affect packer deformation and evolvement during setting with the consideration of interfacial *** study underscores the critical role that friction forces play in Frac plug performance and provides a new dimension for optimizing packer design by controlling interfacial interactions at the packer contact surfaces.

关键词： Elastomer seal Friction Sealing performance Contact stress

Integrating theory with the nanoreactor concept to synthesize hollow carbon sphere-encapsulated PtNi alloys for enhanced H_(2) generation

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Carbon Energy 2024年第7期6卷 150-162页

作者： Yufeng Wu Minwei song Ziyi Zhao Guang-hui Wang Changlong Wang Didier Astruc Institute of Circular Economy Faculty of Materials and ManufacturingBeijing University of TechnologyBeijingChina Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdaoChina ISM UMR CNRS N°5255Universitéde BordeauxTalence CedexFrance

The rational design of efficient bimetallic nanoparticle(NP)catalysts is challenging due to the lack of theoretical understanding of active components and insights into the mechanisms of a specific ***,we report the rational design of nanoreactors comprising hollow carbon sphere-confined PtNi bimetallic NPs(PtNi@HCS)as highly efficient catalysts for hydrogen generation via ammonia borane hydrolysis in *** both density functional theory calculations and molecular dynamics simulations,the effects of an active PtNi combination and the critical synergistic role of a hollow carbon shell on the molecule diffusion adsorption behaviors are *** isotope effects and theoretical calculations allow the clarification of the mechanism,with oxidative addition of an O-H bond of water to the catalyst surface being the rate-determining *** remarkable catalytic activity of the PtNi@HCS nanoreactor was also utilized for successful tandem catalytic hydrogenation reactions,using in situ-generated H_(2) from ammonia borane with high *** concerted design,theoretical calculations,and experimental work presented here shed light on the rational elaboration of efficient nanocatalysts and contribute to the establishment of a circular carbon economy using green hydrogen.

关键词： ammonia borane hydrogen nanoalloy nanoreactor solid catalyst

Left lower lobe sleeve resection for the clear cell variant of pulmonary mucoepidermoid carcinoma:A case report

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World Journal of Clinical Cases 2024年第8期12卷 1422-1429页

作者： Xiao-hui Yu Wen-Xiang Wang De-song Yang Liang-hui Gong Department of Pathology Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of MedicineCentral South UniversityChangsha 410031Hunan ProvinceChina The Second Department of Thoracic Surgery Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of MedicineCentral South UniversityChangsha 410031Hunan ProvinceChina

BACKGROUND Pulmonary mucoepidermoid carcinoma(PMEC)is a rare malignancy that arises from minor salivary glands within the tracheobronchial *** clear cell variant of PMEC is exceptionally uncommon and presents notable diagnostic challenges,primarily attributable to its morphological similarity to other tumors containing clear *** SUMMARY A 22-year-old male,formerly in good health,came in with a two-month duration of persistent cough and production of *** imaging and bronchoscopy examinations revealed a 2 cm tumor in the distal left main bronchus,which resulted in complete atelectasis of the left *** assessment via positron emission tomography/computed tomography scans and endoscopic biopsy confirmed the primary malignant nature of the tumor,charac-terized by clear cell morphology in most of the tumor *** patient underwent a left lower lobe sleeve resection accompanied by systematic mediastinal lymph node *** pathology analysis subsequently revealed a CRTC3-MAML2 gene fusion,leading to a definitive pathological diagnosis of the clear cell variant of PMEC,staged as *** surgery,the patient experienced a smooth recovery and exhibited no signs of recurrence during the one-and-a-half-year follow-up *** This article describes an unusual case of a clear cell variant of PMEC characterized by the presence of a CRTC3-MAML2 gene fusion in a 22-year-old *** patient underwent successful left lower lobe sleeve *** case underscores the distinctive challenges associated with diagnosing and treating this uncommon malignancy,underscoring the importance of precise diagnosis and personalized treatment strategies.

关键词： Pulmonary mucoepidermoid carcinoma Clear cell variant CRTC3-MAML2 gene fusion Sleeve lobectomy Case report