检索结果-南通市图书馆

Mechanical and Damping Behavior of Age-Hardened and Non-age-hardened Al Alloys After Friction Stir Processing

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2019年第9期32卷 1135-1141页

作者： Hiang-Jie Jiang Bing Zhang chong-yu liu Zhen-Xing Yang Zong-Yi Ma College of Material Science and Engineering Guilin University of TechnologyGuilin 541004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Alnan Aluminium Co. Ltd.Nanning 530031China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

This study investigated the microstructure,mechanical,and damping properties of a non-age-hardened Al alloy(5086)and an age-hardened Al alloy(7075)after friction stir processing(FSP).Microstructural analyses indicate that FSP led the grain refinement of samples,and the grains size decreased with the decrease in the tool rotation ***,FSP with low rotation rate promotes theηphase precipitation in the 7075 alloy,causing the micron-sized particles in the 5086 alloy to break *** being subjected to FSP with low rotation rate,the 5086 and 7075 alloys exhibited excellent mechanical and damping *** improved properties were ascribed to their equilibrium grain boundaries,fine grain,low density of dislocations,high fraction of high misorientation angle,and uniform particle distribution.

关键词： Aluminum alloy Mechanical properties Damping

Effects of Sc and Zr microalloying on the microstructure and mechanical properties of high Cu content 7xxx Al alloy

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2019年第12期26卷 1559-1569页

作者： chong-yu liu Guang-biao Teng Zong-yi Ma Li-li Wei Bing Zhang Yong Chen College of Material Science and Engineering Guilin University of TechnologyGuilin 541004China Guangdong JMA Aluminum Profile Factory(Group)Co. Ltd.Foshan 528200China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

The effects of Sc and Zr microalloying on the microstructure and mechanical properties of a 7xxx Al alloy with high Cu content(7055)during casting,deformation,and heat treatment were *** addition of Sc and Zr not only refined the grains but also transformed theθ-phase into the W-phase in the 7055 *** Sc and Zr additions enhanced the hardness and yield strength of the 7055-T6 alloy by strengthening the grain boundaries and Al3(Sc,Zr)***,a further increase in the Sc and Zr fractions did not refine the grains but instead resulted in the formation of the large-sized W-phase and primary coarse Al3(Sc,Zr)phase and subsequently deteriorated the mechanical properties of the *** 7055 alloy with 0.25Sc addition exhibited the best mechanical property among the prepared alloys.

关键词： aluminum alloys microstructural evolution mechanical property grain refinement

The first 10 m resolution thermokarst lake and pond dataset for the Lena Basin in the 2020 thawing season

在线全文

学校读者我要写书评

暂无评论

Big Earth Data 2024年第2期8卷 302-332页

作者： Yining yu Fengming Hui yu Zhou chong liu Xiao Cheng School of Geospatial Engineering and Science Sun Yat-sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)ZhuhaiChina Key Laboratory of Comprehensive Observation of Polar Environment (Sun Yat-sen University)Ministry of EducationZhuhaiChina Guangdong Provincial Key Laboratory of Geodynamics and Geohazards School of Earth Sciences and EngineeringSun Yat-sen UniversityZhuhaiChina

Climate warming rates in the Arctic are far greater than the global average,exerting stronger impacts on permafrost degradation and thermokarst landform *** lakes and ponds(TLPs),which are widely distributed in the Lena Basin in the Russian Arctic,play a vital role in altering local ***,the detailed distribution of TLPs in the Lena Basin still remains poorly *** this study,we built the first 10 m resolution TLP dataset for the Lena Basin in the 2020 thawing season by utilizing 4902 Sentinel-2 images.A robust mapping workflow was developed and implemented in the Google Earth Engine(GEE)*** accu-racy assessment demonstrates a satisfactory accuracy(93.63%),and our results exhibit a better consistency with real TLPs than global water body products.A total of 380,477 TLPs(~0.53%of the total surface area of the Lena Basin)were identified,showing an uneven distribution in the five *** TLPs were found to be mainly located within plain areas,with an active layer thickness in the range of 80-100 *** higher ground ice content and mean annual ground temperature were favorable for TLP *** dataset will be valuable for investigating the complex interac-tion between TLPs and *** will also serve as a baseline product for better incorporating thermokarst processes into perma-frostclimate models.

关键词： Thermokarst lakes and ponds Lena Basin permafrost GEE Sentinel-2

Mechanical properties and thermal stability of 7055 Al alloy by minor Sc addition

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2020年第6期39卷 725-732页

作者： chong-yu liu Guang-Biao Teng Zong-Yi Ma Li-Li Wei Wen-Biao Zhou Hong-Feng Huang Hai-Quan Qi Key Laboratory of New Processing Technology for Nonferrous Metal and Materials Ministry of EducationGuilin University of TechnologyGuilin 541004China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Alnan Aluminium Co. LtdNanning 530000China

This study investigated the effect of 0.25 wt%Sc addition on the microstructure and mechanical properties of AA 7055 *** addition of Sc obviously refined the grains of AA 7055 alloy during casting,homogenizing,rolling,solution,and aging treatments due to the formation of primary and precipitate Al3(Sc,Zr)*** recrystallization and precipitation of AA 7055 alloy were inhibited during heat treatments by Sc *** Sccontaining AA 7055 alloy exhibited higher thermal stability than AA 7055 alloy during homogenizing treatment,because of the grain boundary pinning effect of nano-sized Al3(Sc,Zr)*** its structure characteristics such as fine grains,fineη′phase,and lessηphase,AA 7055 alloy with added Sc showed good mechanical properties after aging at 120℃for 24 h,with an ultimate tensile strength(UTS)of 679 MPa and elongation(EL)of 14%.This work provides an effective strategy to fabricate AlZn-Mg(-Cu)series(7 xxx)alloys with excellent mechanical properties.

关键词： Al alloy Sc addition Microstructure Mechanical properties

Deep Global Multiple-Scale and Local Patches Attention Dual-Branch Network for Pose-Invariant Facial Expression Recognition

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第4期139卷 405-440页

作者： Chaoji liu Xingqiao liu chong Chen Kang Zhou School of Electrical and Information Engineering Jiangsu UniversityZhenjiang212013China School of Electrical Engineering Yancheng Institute of TechnologyYancheng224051China

Pose-invariant facial expression recognition(FER)is an active but challenging research topic in computer *** with the involvement of diverse observation angles,FER makes the training parameter models inconsistent from one view to *** study develops a deep global multiple-scale and local patches attention(GMS-LPA)dual-branch network for pose-invariant FER to weaken the influence of pose variation and selfocclusion on recognition *** this research,the designed GMS-LPA network contains four main parts,i.e.,the feature extraction module,the global multiple-scale(GMS)module,the local patches attention(LPA)module,and the model-level fusion *** feature extraction module is designed to extract and normalize texture information to the same *** GMS model can extract deep global features with different receptive fields,releasing the sensitivity of deeper convolution layers to pose-variant and *** LPA module is built to force the network to focus on local salient features,which can lower the effect of pose variation and self-occlusion on recognition ***,the extracted features are fused with a model-level strategy to improve recognition *** experimentswere conducted on four public databases,and the recognition results demonstrated the feasibility and validity of the proposed methods.

关键词： Pose-invariant FER global multiple-scale(GMS) local patches attention(LPA) model-level fusion

Nanopore design of sulfur doped hollow carbon nanospheres for superior potassium-ion battery anodes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 2103-2114页

作者： Zhen-Dong liu Hui-Yan Feng yu-Chen Wang Fei Wang yue liu Jian-Xiao Yang yue Gu Jun Tan chong Ye Cheng-Zhi Zhang Ji Hua Laboratory Foshan 528000China School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology College of Materials Science and EngineeringHunan UniversityChangsha 410082China

Sulfur doped carbonaceous materials are promising anodes for potassium-ion batteries because of their ability to bridge active sites and induce C/S electron coupling,resulting in increased ion storage capacitance However,the large potassium ions could cause significant volume expansion and structure collapse during operation in sulfur doped carbonaceous anodes,which lead to rapidly capacity sacrifice during long-term *** design for anchoring sulfur atom in carbon skeleton is a novel way to alleviate the structure collapse and maintain the cycling ***,this study developed a controlled nanopore and sulfur doped carbon sphere structure(S-NPHCSs).In potassium-ion batteries S-NPHCSs anode demonstrated exceptional performance with a high reversible capacity of 247 mAh·g^(–1)after 50 cycles at 0.2 A·g^(–1)and delivered a long cycle stability of 600 cycles at a high current density of 1.0 A·g^(–1).Interconnected nanopores and doped sulfur structure not only expand the accumulation space and offer ample active sites for diffusion and adsorption of potassium ions,but also build stable channels through nanopore structure to ensure the cyclic *** finding provides a fundamental theory for designing nanopore structures and introducing sulfur doped carbonaceous materials to enhance capacitive potassium storage and long cycle stability.

关键词： Nanopore Carbon materials Sulfur doping Anode Potassium-ionbatteries

Spatial distribution of shallow landslides caused by Typhoon Lekima in 2019 in Zhejiang Province, China

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第5期21卷 1564-1580页

作者： CUI yulong YANG liu XU chong ZHENG Jun School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan 232001China National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Department of Civil Engineering Zhejiang UniversityHangzhou 310058China

In recent years, the coastal region of Southeast China has witnessed a significant increase in the frequency and intensity of extreme rainfall events associated with landfalling typhoons. The hilly and mountainous terrain of this area, combined with rapid rainfall accumulation, has led to a surge in flash floods and severe geological hazards. On August 10, 2019, Typhoon Lekima made landfall in Zhejiang Province, China, and its torrential rainfall triggered extensive landslides, resulting in substantial damage and economic losses. Utilizing high-resolution satellite images, we compiled a landslide inventory of the affected area, which comprises a total of 2,774 rainfallinduced landslides over an area of 2965 km2. The majority of these landslides were small to mediumsized and exhibited elongated, clustered patterns. Some landslides displayed characteristics of high-level initiation, obstructing or partially blocking rivers, leading to the formation of debris dams. We used the inventory to analyze the distribution pattern of the landslides and their relationship with topographical, geological, and hydrological factors. The results showed that landslide abundance was closely related to elevation, slope angle, faults, and road density. The landslides were predominantly located in hilly and low mountainous areas, with elevations ranging from 150 to 300 m, slopes of 20 to 30 degrees, and a NE-SE aspect. Notably, we observed the highest Landslide Number Density(LND) and Landslide Area Percentage(LAP) in the rhyolite region. Landslides were concentrated within approximately 4 km on either side of fault zones, with their size and frequency negatively correlated with distances to faults, roads, and river systems. Furthermore, under the influence of typhoons, regions with denser vegetation cover exhibited higher landslide density, reaching maximum values in shrubland areas. In areas experiencing significantly increased concentrated rainfall, landslide density also showed a corr

关键词： Typhoon rainfall Landslide characteristics Spatial distribution Southeast coastal region

Insights into the provenance implication of leaf wax n-alkanes along the lower Yellow River

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第6期67卷 2001-2018页

作者： Liang ZHANG Jinzhao liu chong JIANG Fei ZHANG Zhisheng AN School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710054China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China National Observation and Research Station of Earth Critical Zone on the Loess Plateau of Shaanxi Xi’an 710061China

Serving as one of the largest rivers in terms of both sediment and organic carbon transport fluxes in the world,the Yellow River plays a crucial role in regional biogeochemical process as well as in the global carbon ***,although a large number of studies have been carried out on the flux,composition,source and seasonal variation of total particulate organic carbon in the Yellow River so far,studies on molecular biomarkers at different spatial and temporal scales are still *** this study,we focus on the molecular and hydrogen isotopic properties of leaf wax n-alkanes among different types of samples which obtained from different seasons(flood ***-flood)along the lower Yellow *** molecular distribution of n-alkanes show that the riparian topsoils are subject to inputs from the overlying vegetation,while the suspended sediments from the flood season are characterized by the mixing of soil materials which originate from various stratigraphy with different ages on the Chinese Loess *** to the contrasting hydrodynamic conditions,the n-alkanes in suspended sediments also show distinct molecular composition between flood and non-flood ***,considering the effect of climatic factors,the proportion of monocots in flood-season suspended sediments is calculated from a semi-quantitative perspective using δ^(2)H_(wax).Our findings may bring to light new considerations for the interpretation of leaf wax proxies in studies of organic matter sources of Yellow River.

关键词： Molecular distribution Hydrogen isotopic composition Leaf wax n-alkanes Suspended sediments Lower Yellow River

Advances in theoretical calculations of organic thermoelectric materials

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第8期35卷 112-127页

作者： Shaohua Zhang Liyao liu Yingqiao Ma chong-an Di Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China

Organic thermoelectric(OTE)materials and devices have garnered significant attention in the past decade for flexible and wearable *** to the numerous combinations of different backbones,side chains,and functional groups for polymer molecules,further efficient developments of high perfor-mance OTEs rely on reverse and rational molecular design as well as fundamental understanding to the structure-property relationship,which both require precise theoretical ***,many theo-retical efforts and progresses have been made to predict TE properties and develop high performance OTE ***,we present first the general methods and principles for OTE theoretical ***,the latest theoretical advances regarding the effects of molecular design,chemical dop-ing,ambipolar charge transport etc.,to TE conversion are carefully *** theoretical advances not only significantly deepen the fundamental understanding of OTEs,but also provide precise guidance to the molecular design of OTE ***,we propose several perspectives for future theoretical investigations of OTEs.

关键词： Organic thermoelectricity Theoretical study Organic semiconductor Structure-property relation Single-molecular device