检索结果-南通市图书馆

Parallel Vision ■ Image Synthesis/Augmentation

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 782-784页

作者： Wenwen Zhang Wenbo Zheng qiang Li Fei-Yue wang the School of Computer Science Shaanxi Normal UniversityXi’an 710119China the School of Computer Science and Technology Wuhan 430070China the State Key Laboratory for Management and Control of Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China

Dear Editor,Scene understanding is an essential task in computer *** ultimate objective of scene understanding is to instruct computers to understand and reason about the scenes as humans *** vision is a research fram... 详细信息

关键词： instru explanation computer

Physics-data coupling-driven method to predict the penetration depth into concrete targets

在线全文

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2024年第3期14卷 184-192页

作者： Shuai Qin Hao Liu Jianhui wang qiang Zhao Lei Zhang Institute of Defense Engineering AMSLuoyang 471000China Harbin Engineering University Harbin 150001China

The projectile penetration process into concrete target is a nonlinear complex *** the increase ofexperiment data,the data-driven paradigm has exhibited a new feasible method to solve such complex ***,due to poor quality of experimental data,the traditional machine learning(ML)methods,whichare driven only by experimental data,have poor generalization capabilities and limited prediction ***,this study intends to exhibit a ML method fusing the prior knowledge with experiment *** newML method can constrain the fitting to experimental data,improve the generalization ability and the predic-tion *** results show that integrating domain prior knowledge can effectively improve theperformance of the prediction model for penetration depth into concrete targets.

关键词： Penetration into concrete Artificial neural networks Prior knowledge fusion Prediction model

Machine Learning-based Identification of Contaminated Images in Light Curve Data Preprocessing

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第4期24卷 287-295页

作者： Hui Li Rong-wang Li Peng Shu Yu-qiang Li Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Space Object and Debris Observation Chinese Academy of SciencesNanjing 210023China

Attitude is one of the crucial parameters for space objects and plays a vital role in collision prediction and debris *** light curves to determine attitude is the most commonly used *** photometric observations,outliers may exist in the obtained light curves due to various ***,preprocessing is required to remove these outliers to obtain high quality light *** statistical analysis,the reasons leading to outliers can be categorized into two main types:first,the brightness of the object significantly increases due to the passage of a star nearby,referred to as“stellar contamination,”and second,the brightness markedly decreases due to cloudy cover,referred to as“cloudy contamination.”The traditional approach of manually inspecting images for contamination is time-consuming and ***,we propose the utilization of machine learning methods as a *** Neural Networks and SVMs are employed to identify cases of stellar contamination and cloudy contamination,achieving F1 scores of 1.00 and 0.98 on a test set,*** also explore other machine learning methods such as ResNet-18 and Light Gradient Boosting Machine,then conduct comparative analyses of the results.

关键词： techniques:image processing methods:data analysis light pollution

Effects of thawing-induced softening on fracture behaviors of frozen rock

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 979-989页

作者： Ting wang Hailiang Jia qiang Sun Xianjun Tan Liyun Tang College of Geology and Environment Xi’an University of Science and TechnologyXi’an710054China College of Architecture and Civil Engineering Xi’an University of Science and TechnologyXi’an710054China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430064China

Due to the presence of ice and unfrozen water in pores of frozen rock,the rock fracture behaviors are susceptible to *** this study,the potential thawing-induced softening effects on the fracture behaviors of frozen rock is evaluated by testing the tension fracture toughness(KIC)of frozen rock at different temperatures(i.e.-20℃,-15℃,-12℃,-10℃,-8℃,-6℃,-4℃,-2℃,and 0℃).Acoustic emission(AE)and digital image correlation(DIC)methods are utilized to analyze the microcrack propagation during *** melting of pore ice is measured using nuclear magnetic resonance(NMR)*** results indicate that:(1)The KIC of frozen rock decreases moderately between-20℃ and-4℃,and rapidly between-4℃ and 0℃.(2)At-20℃ to-4℃,the fracturing process,deduced from the DIC results at the notch tip,exhibits three stages:elastic deformation,microcrack propagation and microcrack ***,at-4℃e0℃,only the latter two stages are observed.(3)At-4℃e0℃,the AE activities during fracturing are less than that at-20℃ to-4℃,while more small events are reported.(4)The NMR results demonstrate a reverse variation trend in pore ice content with increasing temperature,that is,a moderate decrease is followed by a sharp decrease and-4℃ is exactly the critical ***,we interpret the thawing-induced softening effect by linking the evolution in microscopic structure of frozen rock with its macroscopic fracture behaviors as follow:from-20℃ to-4℃,the thickening of the unfrozen water film diminishes the cementation strength between ice and rock skeleton,leading to the decrease in fracture ***-4℃ to 0℃,the cementation effect of ice almost vanishes,and the filling effect of pore ice is reduced significantly,which facilitates microcrack propagation and thus the easier fracture of frozen rocks.

关键词： Frozen sandstone Different thawing temperature Fracture toughness Microcrack propagation process Unfrozen water content

Crack mechanism of ground fissures in loess layer of Fenwei Basin, China

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

Journal of Mountain Science 2024年第5期21卷 1683-1696页

作者： LI Cong LU Quanzhong wang Feiyong LUO Wenchao XU qiang School of Geological Engineering and Geomatics Chang’an UniversityXi’an 710054China Key Laboratory of Western Mineral Resources and Geological Engineering Ministry of EducationXi’an 710054China Observation and Research Station of Ground Fissure and Land Subsidence Ministry of Natural ResourcesXi’an 710054China School of Engineering and Technology China University of GeosciencesBeijing 100083China

The Fenwei Basin, covered by loess, experiences severe ground fissure disasters. These disasters disrupt the continuity of the loess and pose significant threats to engineering construction safety along transportation routes. Nevertheless, the crack characteristics and the influence zone of ground fissures in the loess layer remain inadequately investigated. To effectively prevent and control ground fissure disasters, physical model tests and the PFC(particle flow code) numerical simulation method are used to investigate the crack mechanism of buried ground fissures in the loess layer. The results show that there are two main cracks in the layer profile, which have a Y-shape morphology. As the dip angle of the preset cracks increased from 60° to 90°, the main deformation zone at the surface gradually shifted towards the footwall. The process of crack propagation from depth to surface is divided into five stages. Additionally, the results confirm the accuracy of the width of the rupture zone d2in the footwall calculated by the cantilever beam theory. These findings can offer theoretical guidance for determining the avoidance distance of ground fissures in loess regions, as well as for implementing disaster prevention and corresponding control measures for various stages of buried ground fissure propagation.

关键词： Ground fissure Fenwei Basin Physical model test Particle flow code Crack propagation

Origin of the Yueguang gold deposit in Xinhua, Hunan Province, South China: insights from fl uid inclusion and hydrogen–oxygen stable isotope analysis

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第2期43卷 235-254页

作者： Hongxin Fan qiang wang Yulong Yang Yao Tang Hao Zou College of Earth Sciences Chengdu University of TechnologyChengdu 610059China College of Earth Sciences Jilin UniversityJilin 130061China

The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South *** represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,west of the Baimashan granitic *** order to discern the characteristics of the ore-formingﬂuids,the underlying mineralization processes,and establish a foundation for the origin of the Yueguang gold depositﬂuid inclusion micro-thermometry,as well as quartz hydrogen and oxygen isotope analysis,have been carried out on samples obtained from various stages of *** hydrothermal miner-alization stages within the Yueguang gold deposit can be categorized into three stages:(i)the barren,pre-ore quartz-pyrite stage(Stage Ⅰ),the quartz-pyrite-gold stage(Stage Ⅱ),and the post-ore quartz-carbonate stage(Stage Ⅲ),with the second stage being the main mineralization ***ﬂuid inclusions identiﬁed in samples from the main min-eralization stage can predominantly be described with the NaCl–H_(2)O and CO_(2)–NaCl–H_(2)O *** inclusions display homogenization temperatures ranging from 158.8 to 334.9℃,and theﬂuid salinity ranges from 0.3%to 4.0%(wt.%NaCl equiv.).Laser Raman spectroscopy analysis of individual inclusions further reveals the presence of gas-phases such as CO_(2),CH_(4),and N_(2).Isotopic analysis indicatesδ^(18)Oﬂuid values ranging from 3.95 to 6.7‰ and δDH_(2)O values ranging from-71.9 to-55.7‰.These results indi-cate that the ore-formingﬂuid of the Yueguang gold deposit belongs to metamorphic hydrothermalﬂuids of middle-low temperature and low *** the process of ore formation,gold is transported in the form of Au(HS)2-complexes,with gold deposition being driven byﬂuid ***,the Yueguang gold deposit is categorized as an orogenic gold deposit dominated by metamorphic hydrother-malﬂ*** may become a new target for gold exploration in the Baimashan region,central Hunan Province.

关键词： Hunan province Yueguang gold deposit Fluid inclusions Hydrogen–oxygen isotopes Laser Raman Fluid immiscibility Orogenic gold deposit

Modified electronic structure and enhanced hydroxyl adsorption make quaternary Pt-based nanosheets efficient anode electrocatalysts for formic acid-/alcohol-air fuel cells

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第5期92卷 142-150页

作者： Fengling Zhao qiang Yuan Siyang Nie Liang Wu Xun wang State-Local Joint Laboratory for Comprehensive Utilization of Biomass Center for R&D of Fine ChemicalsCollege of Chemistry and Chemical EngineeringGuizhou UniversityGuiyang 550025GuizhouChina Key Lab of Organic Optoelectronics&Molecular Engineering Tsinghua UniversityBeijing 100084China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Surface/interface engineering of a multimetallic nanostructure with diverse electrocatalytic properties for direct liquid fuel cells is desirable yet ***,using visible light,a class of quaternary Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)ultrathin nanosheets is fabricated and used as high-performance anode electrocatalysts for formic acid-/alcohol-air fuel *** modified electronic structure of Pt,enhanced hydroxyl adsorption,and abundant exterior defects afford Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C high intrinsic anodic electrocatalytic activity to boost the power densities of direct formic acid-/methanol-/ethanol-/ethylene glycol-/glycerol-air fuel cells,and the corresponding peak power density of Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C is respectively 129.7,142.3,105.4,124.3,and 128.0 mW cm^(-2),considerably outperforming Pt/*** in situ Fourier transform infrared reflection spectroscopy reveals that formic acid oxidation on Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C occurs via a CO_(2)-free direct *** functional theory calculations show that the presence of Ag,Bi,and Te in Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)suppresses CO^(*)formation while optimizing dehydrogenation steps and synergistic effect and modified Pt effectively enhance H_(2)O dissociation to improve electrocatalytic *** synthesis strategy can be extended to 43 other types of ultrathin multimetallic nanosheets(from ternary to octonary nanosheets),and efficiently capture precious metals(i.e.,Pd,Pt,Rh,Ru,Au,and Ag)from different water sources.

关键词： Pt-based nanosheets Modifiedelectronic structure Enhanced hydroxyl adsorption Formicacidand alcohol oxidation Direct liquid fuel cells

Heteroatom anchors Fe-Mn dual-atom catalysts with bi-functional oxygen catalytic activity for low-temperature rechargeable flexible Zn-air batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第3期90卷 610-620,I0014页

作者： Yuting He Hongtao Li Yi wang Yufei Jia Yongning Liu qiang Tan State Key Laboratory for Mechanical Behaviour of Materials School of Materials Science&EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina

M-N-C(M=Fe,Co,Ni,etc.) catalyst owns high catalytic activity in the oxygen catalytic reaction which is the most likely to replace the Pt-based *** it is still a challenge to further increase the active site *** article constructs the high-efficiency FeMn-N/S-C-1000 catalyst to realize ORR/OER bifunctional catalysis by hetero-atom,bimetal(Fe,Mn) doped simultaneously *** evaluated it as bi-functional electro-catalysts,FeMn-N/S-C-1000 exhibits excellent catalytic activity(E_(1/2)=0.924 V,E_(j=10)=1.617 V) in alkaline media,outperforms conventional Pt/C,RuO_(2) and most non-precious-metal catalysts reported recently,Such outstanding performance is owing to N,S co-coordinated with metal to form multi-types of single atom,dual atom active sites to carry out ***,nitrite poison test provides the proof that the active sites of FeMn-N/S-C are more than that of single-atom catalysts to promote catalytic reactions *** better understand the local structure of Fe and Mn active sites,XAS and DFT were employed to reveal that FeMn-N_5/S-C site plays the key role during ***,the FeMn-N/S-C-1000 based low-temperature rechargeable flexible Zn-air also exhibits superior discharge performance and extraordinary durability at-40℃.This work will provide a new idea to design diatomic catalysts applied in low-temperature rechargeable batteries.

关键词： Fe Mn-N/S-C-1000 ORR OER Rechargeable flexible Zn-air batteries

Research progress on temperature field evolution of hot reservoirs under low-temperature tailwater reinjection

在线全文

学校读者我要写书评

暂无评论

Journal of Groundwater Science and Engineering 2024年第2期12卷 205-222页

作者： Xin wang Guo-qiang Zhou Yan-guang Liu Ying-nan Zhang Mei-hua Wei Kai Bian School of Earth science and Engineering Hebei University of EngineeringHandan 056038HebeiChina Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological SciencesShijiazhuang 050061China Technology Innovation Center of Geothermal&Hot Dry Rock Exploration and Development Ministry of Natural ResourcesShijiazhuang 050061China Shanxi Key Laboratory for Exploration and Exploitation of Geothermal Resources Taiyuan 030024China Shanxi Geological Engineering Exploration Institute Taiyuan 030024China

This paper focuses on the study of the evolutionary mechanism governing the temperature field of geothermal reservoir under low-temperature tailwater reinjection conditions,which is crucial for the sustainable geothermal energy *** advancing exploitation of geothermal resources deepens,precise understanding of this mechanism becomes paramount for devising effective reinjection strategies,optimizing reservoir utilization,and bolstering the economic viability of geothermal energy *** article presents a comprehensive review of temperature field evolution across diverse heterogeneous thermal reservoirs under low-temperature tailwater reinjection conditions,and analyzes key factors influ-encing this *** evaluates existing research methods,highlighting their strengths and *** study identifies gaps in the application of rock seepage and heat transfer theories on a large scale,alongside the need for enhanced accuracy in field test results,particularly regarding computational effi-ciency of fractured thermal reservoir models under multi-well reinjection *** address these shortcomings,the study proposes conducting large-scale rock seepage and heat transfer experiments,coupled with multi-tracer techniques for field testing,aimed at optimizing fractured thermal reservoir models'computational efficiency under multi-well reinjection ***,it suggests integrat-ing deep learning methods into research *** initiatives are of significance in deepening the understanding of the evolution process of the temperature field in deep thermal reservoirs and enhancing the sustainability of deep geothermal resource development.

关键词： Geothermal reinjection Seepage heat transfer Tracer test Numerical simulation Thermal breakthrough