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Elastic-plastic contact force history and response characteristics of circular plate subjected to impact by a projectile

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Acta Mechanica Sinica 2007年第4期23卷 415-425页

作者： l.B.Chen F.Xi j.l.yang Solid Mechanics Research Center,Beihang University,Beijing 100083.China Shandong Institute of Architecture and Engineering,jinan 250014,China Solid Mechanics Research Center Beihang University Beijing China Shandong Institute of Architecture and Engineering Jinan China

A new elastic-plastic impact-contact model is proposed in this paper. By adopting the principle of minimum acceleration for elastic-plastic continue at finite deformation, and with the aid of finite difference method, the proposed model is applied in the problem of dynamic response of a clamped thin circular plate subjected to a projectile impact centrally. The impact force history and response characteristics of the target plate is studied in detail. The theoretical predictions of the impact force and plate deflection are in good agreements with those of lDA experimental data. linear expressions of the maximum impact force/transverse deflection versus impact velocity are given on the basis of the theoretical results.

关键词： Elastic-plastic contact model ImpactCircular plate Contact force Minimum principleof acceleration

Rare-earth-niobate high-entropy ceramic foams with enhanced thermal insulation performance

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journal of Materials Science & Technology 2022年第21期116卷 94-102页

作者： R.W.yang Y.P.liang j.Xu X.Y.Meng j.T.Zhu S.Y.Cao M.Y.Wei R.X.Zhang j.l.yang F.Gao State Key laboratory of Solidification Processing MIIT Key Laboratory of Radiation Detection Materials and DevicesSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an710072China NPU-QMUl joint Research Institute of Advanced Materials and Structure Northwestern Polytechnical UniversityXi’an710072China State Key laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing100084China State Key laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China

The introduction of porous structures into high-entropy ceramics is expected to further improve its thermal insulation *** this work,a series of novel rare-earth-niobate high-entropy ceramic foams((Dy_(0.2)Ho_(0.2)Y_(0.2)Er_(0.2)Yb_(0.2))_(3)NbO_(7))with hierarchical pore structures were prepared by a particle-stabilized foaming ***-scale analysis reveals that high entropy causes atom displacement and lattice *** high-entropy ceramic foams exhibit high porosity(90.13%-96.13%)and ultralow thermal conductivity(0.0343-0.0592 W/(m·K))at room ***-entropy ceramic foam prepared by a 20 wt%slurry sintered at 1500℃has the porosity of 96.12%and extremely low thermal conductivity of 0.0343 W/(m·K).The existence of walls and secondary pores contributes to reduced thermal *** is a temperature difference of over 800℃between frontside and backside of the sample under fire resistance *** research indicates that these as-prepared high-entropy ceramic foams are expected to be promising thermal insulation materials.

关键词： Rare-earth niobate High-entropy ceramic foams Particle-stabilized foaming Atomic-scale analysis Thermal conductivity

A Structural Model for C60 on Metal Surfaces

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电子显微学报 1997年第4期 129-130页

作者： D.liu 1,2 \ \ j.l.yang 1\ \ Z.Q.Wu 1\ \ j.G.Hou 1 (1 Structure Research laboratory and Fundamental Physics Center University of Science and Technology of China,Hefei,Anhui 230026,P.R.China) (2 College of Science and Engineering,Hainan University,Ha

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关键词： Surfaces Model Structural Metal

A novel classification method for mild adolescent idiopathic scoliosis using 3D ultrasound imaging

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Medicine in Novel Technology and Devices 2021年第3期11卷 151-161页

作者： D.yang T.T.Y.lee K.K.l.lai Y.S.Wong l.N.Wong j.l.yang T.P.lam R.M.Castelein j.C.Y.Cheng Y.P.Zheng Department of Biomedical Engineering The Hong Kong Polytechnic UniversityHong KongChina SH Ho Scoliosis Research lab Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing UniversityDepartment of Orthopaedics&TraumatologyThe Chinese University of Hong KongHong KongChina Department of Orthopaedic Surgery University Medical Center Utrechtthe Netherlands Spine Center Xinhua Hospital Affiliated to Shanghai Jiaotong University School of MedicineShanghaiChina

Mild adolescent idiopathic scoliosis(AIS),with Cobb<20°,was hypothesized as the right stage to intervene to prevent *** curve can be categorized into either structural or non-structural depending on the spine morphol... 详细信息

Mild adolescent idiopathic scoliosis(AIS),with Cobbl or non-structural depending on the spine morphology(flexibility).Using X-ray to characterize AIS curves remains the clinical gold standard whilecompromising the risks of radiation *** previous works,3D ultrasound imaging had proved the reli-ability of the coronal spinal curvature measurement This research aimed at developing a mild AIs clasificationscheme through examining spine flexibility using 3D ultrasound *** the preliminary study,90 mild AIS subjects(21 M and 69 F;Age:14.5±1.7 years old;Cobb:18.2±6.4°)underwent both 3D ultrasound and X-ray scanning on the same *** each case,a clinician measured Cobbs and denoted major curve as ground *** Asymmetry Index(BAl)was developed to indicate the presence of a possible structural *** curve classification was coded to a modfied lenke classification for mild cases(m-lenke).The results of 3D ultrasound classification were evaluated with the *** was shown that 70.1%of the subjects had identical curve clssification results and 72.0%had the correct major curve ***-dominated curves had distinctive performance(p=0.91,r=0.91)against *** study demonstrated the possibility of a 3D ultrasound-based method for mild AIS curve *** could be partially explained by the limitations of the ultrasound scanning in proximal thoracicreg *** studies will validate the proposed method with a larger cohort.

关键词： AIS classification 3D ultrasound Mild AIS Spine flexibility

Spalling characteristics of high-temperature treated granitic rock at different strain rates

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journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1280-1288页

作者： l.F.Fan Q.H.yang X.l.Du The Key laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing100124China

The dynamic spalling characteristics of rock are important for stability analysis in rock *** paper presented an experimental investigation on the dynamic spalling characteristics of granite with different temperatures and strain rates.A series of dynamic spalling tests with different impact velocities were conducted on thermally treated granite at different *** dynamic spalling strengths of granite with different temperatures and strain rates were determined.A model was proposed to correlate the dynamic spalling strength of granite,high temperature and strain *** results show that the spalling strength of granite decreases with increasing ***,the spalling strength of granite with a higher strain rate is larger than that with a lower strain *** proposed model can describe the relationship among dynamic spalling strength of granite,high temperature and strain rate.

关键词： Dynamic spalling characteristics High temperature Strain rate Dynamic loading Granite

Application of Gaussian Beam Summation Migration in Reflected In-seam Wave Imaging

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 276-284页

作者： HAN jianguang lÜQingtian ZHANG Zhiheng yang Shun WANG Shuo Chinese Academy of Geological Sciences Beijing 100037China Shandong Taishan Resources Exploration Co. Ltd.Jinan 250104China

The geological conditions for coal mining in China are complex,with various structural issues such as faults and collapsed columns seriously compromising the safety of coal mine ***-seam wave exploration is an effective technique for acquiring detailed information on geological structures in coal seam working ***,the existing reflected in-seam wave imaging technique can no longer meet the exploration precision requirements,making it imperative to develop a new reflected in-seam wave imaging *** study applies the Gaussian beam summation(GBS)migration method to imaging coal seams'reflected in-seam wave ***,with regard to the characteristics of the reflected in-seam wave data,methods such as wavefield removal and enveloped superposition are employed for the corresponding wavefield separation,wave train compression and other processing of reflected in-seam ***,imaging is performed using the GBS migration *** feasibility and effectiveness of the proposed method for reflected in-seam wave imaging are validated by conducting GBS migration tests on 3D coal-seam fault models with different dip angles and *** applying the method to reflected in-seam wave data for an actual coal seam working face,accurate imaging of a fault structure is obtained,thereby validating its practicality.

关键词： reflected in-seam wave Gaussian beam summation migration numerical tests fault

A Tutorial Review of the Solar Power Curve: Regressions, Model Chains, and Their Hybridization and Probabilistic Extensions

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Advances in Atmospheric Sciences 2024年第6期41卷 1023-1067页

作者： Dazhi yang Xiang’ao XIA Martin jános MAYER School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Key laboratory for Middle Atmosphere and Global Environment Observation(lAGEO) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Department of Energy Engineering Faculty of Mechanical EngineeringBudapest University of Technology and EconomicsMűegyetem rkp.3Budapest H-1111Hungary

Owing to the persisting hype in pushing toward global carbon neutrality,the study scope of atmospheric science is rapidly *** numerous trending topics,energy meteorology has been attracting the most attention *** essential skill of solar energy meteorologists is solar power curve modeling,which seeks to map irradiance and auxiliary weather variables to solar power,by statistical and/or physical *** this regard,this tutorial review aims to deliver a complete overview of those fundamental scientific and engineering principles pertaining to the solar power *** power curves can be modeled in two primary ways,one of regression and the other of model *** classes of modeling approaches,alongside their hybridization and probabilistic extensions,which allow accuracy improvement and uncertainty quantification,are scrutinized and contrasted thoroughly in this review.

关键词： review energy meteorology solar power curve model chain solar power prediction

High-efficiency Carbonation Modification Methods of Recycled Coarse Aggregates

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journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 386-398页

作者：张美香 yang Xiaolin 丁亚红 SUN Bo ZHANG Xianggang lÜXiuwen Department of Civil Engineering Henan Polytechnic UniversityJiaozuo 454150China College of Architectural Engineering Xinyu UniversityXinyu 336500China

To solve the problem of only surface carbonation and realize high-efficiency carbonation of recycled coarse aggregate,the method of carbonated recycled coarse aggregate with nano materials pre-soaking was first put *** carbonation effect of modified recycled coarse aggregate with three different carbonation methods was evaluated,and water absorption,apparent density and crush index of modified recycled coarse aggregate were *** with XRD,SEM,and MIP microscopic analysis,the high-efficiency carbonation strengthening mechanism of modified recycled coarse aggregate was *** experimental results show that,compared with the non-carbonated recycled coarse aggregate,the physical and microscopic properties of carbonated recycled coarse aggregate are *** method of carbonation with nano-SiO_(2) pre-soaking can realize the high-efficiency carbonation of recycled coarse aggregate,for modified recycled coarse aggregate with the method,water absorption is reduced by 23.03%,porosity is reduced by 44.06%,and the average pore diameter is 21.82 *** high-efficiency carbonation strengthening mechanism show that the pre-socked nano-SiO_(2) is bound to the hydration product Ca(OH)_(2) of the old mortar with nano-scale C-S-H,which can improve the CO_(2) absorption rate,accelerate the carbonation reaction,generate more stable CaCO_(3) and nano-scale silica gel,and bond to the dense three-dimensional network structure to realize the bidirectional enhancement of nano-materials and pressurized *** is concluded that the method of carbonation with nano-SiO_(2) pre-soaking is a novel high-efficiency carbonation modification of recycled coarse aggregate.

关键词： recycled coarse aggregate pressurized carbonation high-efficiency carbonation nano-SiO2 strengthening mechanism

Coordinate-wise monotonic transformations enable privacy-preserving age estimation with 3D face point cloud

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Science China(life Sciences) 2024年第7期67卷 1489-1501页

作者： Xinyu yang Runhan li Xindi yang Yong Zhou Yi liu jing-Dong j.Han School of life Sciences Peking UniversityBeijing 100871China Peking-Tsinghua Center for life Sciences Academy for Advanced Interdisciplinary StudiesCenter for Quantitative Biology(CQB)Peking UniversityBeijing 100871China Beijing Key lab of Traffic Data Analysis and Mining School of Computer and Information TechnologyBeijing Jiaotong UniversityBeijing 100044China Clinical Research Institute Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai 200025China

The human face is a valuable biomarker of aging,but the collection and use of its image raise significant privacy *** we present an approach for facial data masking that preserves age-related features using coordinate-wise monotonic *** first develop a deep learning model that estimates age directly from non-registered face point clouds with high accuracy and *** show that the model learns a highly indistinguishable mapping using faces treated with coordinate-wise monotonic transformations,indicating that the relative positioning of facial information is a low-level biomarker of facial *** visual perception tests and computational3D face verification experiments,we demonstrate that transformed faces are significantly more difficult to perceive for human but not for machines,except when only the face shape information is *** study leads to a facial data protection guideline that has the potential to broaden public access to face datasets with minimized privacy risks.

关键词： face point cloud age estimation face verification privacy coordinate-wise monotonic transformation

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