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Uncovering of the formation of rare earth texture and pseudo fiber bimodal microstructure in the high ductility Mg-2Gd-0.4Zr alloy during extrusion

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Journal of Materials Science & Technology 2024年第5期172卷 166-184页

作者： Tianxu Zheng Yaobo Hu Chao Zhang Tianshuo Zhao bin Jiang Fusheng Pan Aitao tang College of Materials Science and Engineering Chongqing UniversityChongqing400044China National Engineering Research Center for Magnesium Alloys Chongqing400044China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai200240China

The aim of this research was to elucidate the underlying mechanism involved in the formation of rare earth(RE)texture and pseudo fiber bimodal microstructure in the high ductility Mg-2Gd-0.4Zr *** microstructure and texture evolution during the extrusion process were analyzed using various tech-niques,including optical microscopy(OM),scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),and electron probe microanalysis(EPMA).The findings revealed that the RE texture in the extruded Mg-2Gd-0.4Zr alloy emerged during the dynamic recrystallization(DRX)process and was further strengthened during the subsequent static recrystallization and grain growth *** nu-cleation and growth of grains in the streamline region of Zr particles were delayed in comparison to other regions due to the pinning effect of Zr particles,ultimately resulting in the formation of pseudofiber bi-modal microstructure in the extruded Mg-2Gd-0.4Zr alloy.

关键词： Magnesium alloys Ductility Rare earth texture Bimodal microstructure

Ultrasonic manifestations and age distribution of internal abdominal hernia in children

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中国医学影像技术 2024年第8期40卷 1204-1207页

作者： KUANG bin YANG Chunjiang tang Yi Department of Ultrasound Children's Hospital of Chongqing Medical UniversityNational Clinical Research Center for Child Health and DisordersMinistry of Education Key Laboratory of Child Development and DisordersChongqing Key Laboratory of Pediatric Metabolism and Inflammatory DiseasesChongqing 400014China

Objective To observe the ultrasonic manifestations and age distribution of internal abdominal hernia in *** Data of 53 children with internal abdominal hernia confirmed by operation were retrospectively *** ultrasonic findings were observed,and the age distribution of children was *** Among 53 cases,"cross sign"was observed in 22 cases(22/53,41.51%),and"hernia ring beak sign"was detected in 26 cases(26/53,49.06%)by preoperative ultrasound,according to which 21 cases were diagnosed as internal abdominal hernia,with the accuracy of 39.62%(21/53).Meanwhile,manifestations of intestinal obstruction were noticed in 48 cases(48/53,90.57%),and intestinal necrosis was considered in 22 cases(22/53,41.51%).Four cases were misdiagnosed as intestinal perforation,appendicitis,intestinal atresia and volvulus,each in 1 *** onset age of postoperative adhesive band internal hernia was larger than that of mesenteric hiatal hernia(P0.05).Intestinal ischemic necrosis was found in 25 cases,while the incidence of intestinal necrosis in children aged≤1 year,>1 and≤3 years,>3 and≤7 years and those>7 years was 66.67%(12/18),33.33%(4/12),36.36%(4/11)and 41.67%(5/12),*** The characteristic ultrasonic findings of internal abdominal hernia in children included"cross sign"and"hernia ring beak sign".Internal abdominal hernia in children under 1 year had high risk of intestinal necrosis.

关键词： hernia,abdominal children ultrasonography

Influence of pore structure on thermal stress distribution inside coal particles during primary fragmentation

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Particuology 2024年第2期85卷 49-61页

作者： Kai Qiao Shan Zhong Siyang tang Ke Yang Hairong Yue Kui Ma Lei Song bin Liang School of Chemical Engineering Sichuan UniversityChengdu610065China Institute of New Energy and Low-carbon Technology Chengdu610207China

Thermal stress is an important reason of coal particle primary fragmentation,during which the role of pore structure is *** stress induced fragmentation experiments were conducted with low volatile coal/char particles,and the results show that the fragmentation severity enhances with increasing *** porous thermal stress models were developed with finite element method,and the influences of the pore shape,size,position and porosity on the thermal stress were *** maximum thermal stress inside particle increases with pore curvature,the pore position affects the thermal stress more significantly at the particle center and *** expectation of the maximum tensile thermal stress linearly increases with porosity,making the particles with higher porosity easier to fragment,contrary to the conclusion deduced from the devolatilization *** obtained results are valuable for the analysis of different thermal processes concerning the thermal stresses of the solid feedstocks.

关键词： Coal particle Primary fragmentation Thermal stress Pore structure Porosity

Numerical study of a bi-directional in-band pumped dysprosium-doped fluoride fiber laser at 3.2μm

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Frontiers of Information Technology & Electronic Engineering 2024年第7期25卷 1017-1024页

作者： Lingjing LI Chunyang MA Nian ZHAO Jie PENG bin LIU Haining JI Yuchen WANG Pinghua tang School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China Research Center of Circuits and Systems Peng Cheng LaboratoryShenzhen 518055China Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201899China

Dy^(3+)-doped fluoride fiber lasers have important applications in environment monitoring,real-time sensing,and polymer *** present,achieving a high-efficiency and high-power Dy^(3+)-doped fluoride fiber laser in the mid-infrared(mid-IR)region over 3μm is a scientific and technological ***,Dy^(3+)-doped fluoride fiber lasers use a unidirectional pumping method,which suffers from the drawback of high thermal loading density on the fiber tips,thus limiting power *** this study,a bi-directional in-band pumping scheme,to address the limitations of output power scaling and to enhance the efficiency of the Dy^(3+)-doped fluoride fiber laser at 3.2μm,is investigated numerically based on rate equations and propagation *** simulation results reveal that the optical‒optical efficiency of the bi-directional in-band pumped Dy^(3+)-doped fluoride fiber laser can reach 75.1%,approaching the Stokes limit of 87.3%.The potential for further improvement of the efficiency of the Dy^(3+)-doped fluoride fiber laser is also *** bi-directional pumping scheme offers the intrinsic advantage of mitigating the thermal load on the fiber tips,unlike unidirectional pumping,in addition to its high *** a result,it is expected to significantly scale the power output of Dy^(3+)-doped fluoride fiber lasers in the mid-IR regime.

关键词： Mid-infrared laser Fiber laser Bi-directional pumping

The effect of Ti and Zr content on the structure,mechanics and energy-release characteristics of Ti—Zr—Ta alloys

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Defence Technology（防务技术） 2024年第1期31卷 343-350页

作者： Jia-yu Meng Jing-zhi He bin Zhang Jin Chen Shun Li Dun Niu Yu tang Xi’an Modern Chemistry Research Institute Xi'an710065China College of Aerospace Science and Engineering National University of Defense TechnologyChangsha410073China

Energetic structural materials(ESMs)are a new type of structural materials with bearing and damage *** this work the microstructure,mechanical properties and energy release characteristics of multi-element Ti-Zr-Ta alloys with good casting performance were *** microstructure of the Ti_(x)ZrTa alloys gradually change from BCC+HCP to single BCC structure with the increase of *** the Ti_(2)Zr_(y)Ta alloys was still uniform and single BCC structure with the increase of *** evolution of microstructure and composition then greatly affect the mechanical properties and energy-release characteristics of Ti-Zr-Ta *** synergistic effect of dual phase structure increases the fracture strain of Ti_(x)ZrTa(x=0.2,0.5)with the Ti content decreases,while the fracture strain of Ti_(x)ZrTa(x=2.0,3.0,4.0)gradually increase with the Ti content increases caused by the annihilation of the obstacles for dislocation *** as Zr content increases,the fracture strain of Ti_(2)Zr_(y)Ta alloys decrease,then the oxidation reaction rate and fragmentation degree gradually *** higher oxidation rate and the lager exposed oxidation area jointly leads the higher releasing energy efficiency of Ti_(x)ZrTa alloys with low Ti content and Ti_(2)Zr_(y)Ta alloys with high Zr content.

关键词： Energetic structural materials Ti-Zr-Ta Multi-element alloy Energy release characteristics

Impacts of Future Changes in Heavy Precipitation and Extreme Drought on the Economy over South China and Indochina

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Advances in Atmospheric Sciences 2024年第6期41卷 1184-1200,I0022-I0034页

作者： bin tang Wenting HU Anmin DUAN Yimin LIU Wen BAO Yue XIN Xianyi YANG State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 101408China State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen UniversityXiamen 361005China Chinese Academy of Sciences the CAS Institutes of Science and DevelopmentBeijing 101408China School of Public Policy and Management University of Chinese Academy of SciencesBeijing 101408China

Heavy precipitation and extreme drought have caused severe economic losses over South China and Indochina(INCSC)in recent *** the areas with large gross domestic product(GDP)in the INCSC region are distributed along the coastline and greatly affected by global warming,understanding the possible economic impacts induced by future changes in the maximum consecutive 5-day precipitation(RX5day)and the maximum consecutive dry days(CDD)is critical for adaptation planning in this *** on the latest data released by phase 6 of the Coupled Model Intercomparison Project(CMIP6),future projections of precipitation extremes with bias correction and their impacts on GDP over the INCSC region under the fossil-fueled development Shared Socioeconomic Pathway(SSP5-8.5)are *** indicate that RX5day will intensify robustly throughout the INCSC region,while CDD will lengthen in most regions under global *** changes in climate consistently dominate the effect on GDP over the INCSC region,rather than the change of *** only considering the effect of climate change on GDP,the changes in precipitation extremes bring a larger impact on the economy in the future to the provinces of Hunan,Jiangxi,Fujian,Guangdong,and Hainan in South China,as well as the Malay Peninsula and southern Cambodia in ***,timely regional adaptation strategies are urgent for these ***,from the sub-regional average viewpoint,over two thirds of CMIP6 models agree that maintaining a lower global warming level will reduce the economic impacts from heavy precipitation over the INCSC region.

关键词： CMIP6 heavy precipitation extreme drought South China Indochina economic impact

Red algal evidence for a marine regression during closure of the Paleo-Asian Ocean in the Junggar Basin and its linkage to hydrocarbon generation

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Science China Earth Sciences 2024年第9期67卷 2845-2863页

作者： Ruijie ZHANG Jian CAO Lizeng BIAN Wenxuan HU Liuwen XIA bin ZHANG Yong tang Wenjun HE School of Earth Sciences and Engineering Nanjing University PetroChina Xinjiang Oilfield Company

The closure of the Paleo-Asian Ocean was a significant geological event in northern Pangea during the Carboniferous-Permian. It had a significant effect on climate, biota, and environmental conditions of the Late Paleozoic Ice Age, and resulted in the development of vast energy resources. This paper reports on the first discovery of marine red algal fossils in the Junggar Basin and its linkage to hydrocarbon generation. Red algae occur mainly in the Fengcheng Formation（ca. 300 Ma） and provide direct fossil evidence for closure of the Paleo-Asian Ocean. The red algal fossils contain well-preserved reproductive organs, such as cystocarps and carpospores. High concentrations of C27steranes(C27regular steranes/sum of C27–C29regular steranes×100=14.30%–21.30%) and the marine biomarker 24-n-propylcholesterane(C30diasterane [βα20S]/sum of C27–C30diasteranes [βα20S]×100=1.15%–1.85%) were detected in the red-algae-bearing hydrocarbon source rocks. Thermal experiments that simulate hydrocarbon generation show that the oil generation potential of the red-algae-bearing source rocks is363.71 mg g–1total organic C. This result, combined with oil-source rock correlations, indicates these rocks contributed to the formation of oil and gas resources, particularly in the marginal areas of the depression. The lake basin inherited the water and biological conditions of the Paleo-Asian Ocean during a marine regression, which was an important factor in the development of these high-quality hydrocarbon source rocks in an alkaline saline lake. The results advance our understanding of the evolution of the Paleo-Asian Ocean, interactions between the ocean and a lake during the deposition of terrestrial hydrocarbon source rocks,and whether red algae can effectively generate hydrocarbons.

关键词： Biotic precursor 24-n-propylcholesterane Regressive lake basin Fengcheng Formation Junggar Basin

Probabilistic modeling of multifunction radars with autoregressive kernel mixture network

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Defence Technology（防务技术） 2024年第5期35卷 275-288页

作者： Hancong Feng Kaili.Jiang Zhixing Zhou Yuxin Zhao Kailun Tian Haixin Yan bin tang School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

The task of modeling and analyzing intercepted multifunction radars(MFRs)pulse trains is vital for cognitive electronic *** methodologies predominantly rely on prior information or heavily constrained models,posing challenges for non-cooperative *** paper introduces a novel approach to model MFRs using a Bayesian network,where the conditional probability density function is approximated by an autoregressive kernel mixture network(ARKMN).Utilizing the estimated probability density function,a dynamic programming algorithm is proposed for denoising and detecting change points in the intercepted MFRs pulse *** results affirm the proposed method's efficacy in modeling MFRs,outperforming the state-of-the-art in pulse train denoising and change point detection.

关键词： Probabilistic forecasting Multifunction radar Unsupervised learning Change point detection Outlier detection

Geochronology and Geochemistry of Ore-related Granitoids in the Giant Gariatong Rb Deposit,Tibet and Implications for Rb Metallogeny in China

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 83-103页

作者： LIN bin tang Juxing tang Pan SUN Yan QI Jing MSANTOSH XIE Jinling DENG Shilin LI Faqiao XIE Fuwei ZHOU Aorigele MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China SinoProbe Laboratory Chinese Academy of Geological SciencesBeijing 100094China The Key Laboratory of the Ministry of Education on Solid Waste Treatment and Recycling School of Environment and ResourceSouthwest University of Science and TechnologyMianyangSichuan 621010China School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China Department of Earth Sciences University of AdelaideAdelaide SA-5005Australia Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 610031China Regional Geological Survey Team of the Tibetan Bureau of Geology and Mineral Exploration and Development Lhasa 851400China College of Earth Science and Key Laboratory of Tectonic Controlled Mineralization and Oil Reservoirs Chengdu University of TechnologyChengdu 610059China

Rubidium(Rb)deposits mostly occur in the South China and Central Asia orogenic belts and are often closely associated with highly differentiated *** study investigates a newly-discovered giant Rb deposit at Gariatong in the Central Lhasa terrane in *** field studies and logging data revealed that the Rb mineralization mainly occurs in monzogranite and is related to ***-ICP-MS U-Pb dating of zircon yielded ages of 19.1±0.2 Ma and 19.0±0.2 Ma for greisenized monzogranite and fresh monzogranite,*** monzogranites are characterized as strongly peraluminous,with high contents of SiO2,Al2O3,K2O and Na2O as well as a high differentiation *** are enriched in light rare earth and large ion lithophile elements with significant negative Eu anomalies and depleted high fieldstrength *** and geochemical features of these ore-related monzogranites suggest that they are highly fractionated S-type granites,derived from remelting of crustal materials in a post-collisional *** geochemistry of zircon and apatite points to a low oxygen fugacity of the ore-related monzogranite during the magma’s *** discovery of the Gariatong Rb deposit suggests that the Central Lhasa terrane may be an important region for rare metal mineralization.

关键词： LA-ICP-MS U-Pb dating geochemistry Rb metallogeny Gariatong Tibet