检索结果-南通市图书馆

Semi-super.ised remote sensing image scene classification with prototype-based consistency

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 459-470页

作者： Yang Li Zhang Li zi wang Kun wang Qifeng YU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Deep lear.ing significantly improves the accuracy of remote sensing image scene classification,benefiting from the large-scale ***,annotating the remote sensing images is time-consuming and even tough for *** neural networks tr.ined using a few labeled samples usually generalize less to new unseen *** this paper,we propose a semi-super.ised approach for remote sensing image scene classification based on the prototype-based consistency,by exploring massive unlabeled *** this end,we,first,propose a feature enhancement module to extract discriminative *** is achieved by focusing the model on the foreground ***,the prototype-based classifier.is introduced to the framework,which is used to acquire consistent feature *** conduct a series of experiments on NWPU-rESiSC45 and Aerial image Dataset(AiD).Our method improves the State-Of-The-Art(SOTA)method on NWPU-rESiSC45 from 92.03%to 93.08%and on AiD from 94.25%to 95.24%in terms of accuracy.

关键词： Semi-super.ised lear.ing remote sensing Scene classification Prototype network Deep lear.ing

rapid prediction of damaged ship roll motion responses in beam waves based on stacking algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第2期36卷 394-405页

作者： Xin-ran Liu Ting-qiu Li zi-ping wang School of Naval Architecture Ocean and Energy Power EngineeringWuhan University of TechnologyWuhan430063China

Accurate modeling for highly non-linear coupling of a damaged ship with liquid sloshing in waves is still of considerable interest within the computational fluid dynamics(CFD)and Ai *** paper describes a data-driven Stacking algorithm for fast prediction of roll motion response amplitudes in beam waves by constructing a hydrodynamics model of a damaged ship based on the dynamic overlapping grid CFD *** general idea is to optimize various parameters var.ing with four types of classical base models like multi-layer perception,support vector regression,random forest,and hist gradient boosting *** offers several attractive proper.ies in terms of accuracy and efficiency by choosing the standard DTMB 5415 model with double damaged compartments for *** is clearly demonstrated that the predicted response amplitude operator(rAO)in the regular beam waves agrees well with the experimental data available,which verifies the accuracy of the established damaged ship hydrodynamics *** high-quality CFD samples,therefore,implementation of the designed Stacking algorithm with its optimal combination can predict the damaged ship roll motion amplitudes effectively and accurately(e.g.,the coefficient of deter.ination 0.9926,the average absolute error 0.0955 and CPU 3s),by comparison of four types of typical base models and their various ***,the established Stacking algorithm provides one potential that can break through problems involving the time-consuming and low efficiency for large-scale lengthy CFD simulations.

关键词： Ship motion damaged ship computational fluid dynamics(CFD) machine lear.ing stacking algorithm

Thermodynamic and experimental study of high-temperature roasting of blast furnace gas ash for recovery of metallic zinc and iron

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 iron and Steel research international 2024年第1期31卷 108-120页

作者： zi-han wang Jing Guo Han-jie Guo Bin Li School of Metallur.ical Engineering University of Science and Technology BeijingBeijing100083China School of Metallur.ical Engineering Xi’an University of Architecture and TechnologyXi’an710055ShaanxiChina

A high-temperature reduction roasting method was used to achieve metallic iron and zinc recovery from blast furnace gas ash(BFA).The reduction processes for Zn-containing and Fe-containing oxides were analyzed in detail by using ther-modynamic equilibrium calculation and the principle of minimum free *** results showed that the main reaction in the system is the reduction of ZnFe_(2)_(4)and iron *** the full temperature range,iron oxides were more easily reduced than zinc *** of the amount of CO contained in the system,the reduction of ZnO to Zn was difficult to proceed below the boiling point(906℃)of *** the reduction temperature is below 906℃,the reduction process of zinc ferrate was ZnFe_(2)_(4)→ZnO;when the reduction temperature is above 906℃,its reduction process becomed ZnFe_(2)_(4)→ZnO→Zn(g).The metallization and dezincification rates of the BFA gradually increased with increasing reaction *** the C/O ratio increased,the metallization and dezincification rates first increased and then *** effect of reduction time on BFA reduction was similar to that of reaction temperature.

关键词： Blast furnace gas ash Thermodynamics zinc removal iron reduction High-temperature reduction roasting integrated utilization

reliable calculations of nuclear binding ener.ies by the Gaussian process of machine lear.ing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第6期35卷 130-144页

作者： zi-Yi Yuan Dong Bai Zhen wang Zhong-Zhou ren School of Physics Science and Engineering Tongji UniversityShanghai 200092China College of Science Hohai UniversityNanjing 211100China Key Laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China

reliable calculations of nuclear binding ener.ies are crucial for advancing the research of nuclear physics. Machine lear.ing provides an innovative approach to exploring complex physical problems. in this study, the nuclear binding ener.ies are modeled directly using a machine-lear.ing method called the Gaussian process. First, the binding ener.ies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good lear.ing ability of the Gaussian process in the studies of binding ener.ies. Then, the predictive power of the Gaussian process is studied by calculating the binding ener.ies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay ener.ies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding ener.ies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay ener.ies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding ener.ies. Finally, the α-decay proper.ies of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding ener.ies and α-decay proper.ies.

关键词： Nuclear binding ener.ies decay Machine lear.ing Gaussian process

Microstructure and mechanical proper.ies of a cast TriP-assisted multiphase stainless steel

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第3期21卷 221-228页

作者： Meng-xin wang zi-xiang Wu Jing-yu He Xiang Chen School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

Stainless steels are used in a wide range of complex environments due to their excellent corrosion *** stainless steels can offer an excellent combination of strength,toughness and corrosion resistance due to the coexistence of different *** microstructure and mechanical proper.ies of a novel cast multiphase stainless steel,composed of martensite,fer.ite,and austenite,were investigated following appropriate heat treatment processes:solution treatment at 1,050℃ for 0.5 h followed by water quenching to room temperature,and aging treatment at 500℃ for 4 h followed by water quenching to room *** show reversed austenite is formed by diffusion of Ni element during aging process,and the enrichment of Ni atoms directly deter.ines the mechanical stability of *** austenite with a lower Ni content undergoes a martensitic transformation during plastic *** tensile strength of the specimen exceeds 1,100 MPa and the elongation exceeds 24%after solid solution,and further.increases to 1,247 MPa and 25%after aging *** enhancement is due to the TriP effect of austenite and the precipitation of the nanoscale G-phase pinning dislocations in fer.ite and martensite.

关键词： multiphase stainless steel mechanical proper.ies TriP effect reversed austenite G-phase

A Method of Generating Semi-Experimental Biomedical Datasets

在线全文

学校读者我要写书评

暂无评论

Journal of Beijing institute of Technology 2024年第3期33卷 219-226页

作者： Jing wang Naike Du zi He Xiuzhu Ye School of information and Electronics Beijing Institute of TechnologyBeijing 100081China

This paper proposed a method to generate semi-experimental biomedical datasets based on full-wave simulation *** system noise such as antenna port couplings is fully considered in the proposed datasets,which is more realistic than synthetical *** this paper,datasets containing different shapes are constructed based on the relative per.ittivities of human ***,a back-propagation scheme is used to obtain the rough reconstructions,which will be fed into a U-net convolutional neural network(CNN)to recover the high-resolution *** results show that the network tr.ined on the datasets generated by the proposed method can obtain satisfying reconstruction results and is promising to be applied in real-time biomedical imaging.

关键词： electromagnetic imaging dataset biomedical imaging

Exploring the Pathogenesis of Autoimmune Liver Diseases from the Heterogeneity of Target Cells

在线全文

学校读者我要写书评

暂无评论

Journal of Clinical and Translational Hepatology 2024年第7期12卷 659-666页

作者： zi-Xuan Qiu Lin-Xiang Huang Xiao-Xiao wang zi-Long wang Xiao-He Li Bo Feng Peking Univer.ity People’s Hospital Peking University Hepatology InstituteBeijing Key Laboratory of Hepatitis C and Immunotherapy for Liver DiseasesBeijing International Cooperation Base for Science and Technology on NAFLD DiagnosisBeijingChina

The incidence of autoimmune liver diseases(ALDs)and research on their pathogenesis are increasing ***,except for autoimmune hepatitis,which responds well to immunosuppression,primary biliary cholangitis and primary sclerosing cholangitis are insensitive to immunosuppressive *** the known effects of the environment,genetics,and immunity on ALDs,the heterogeneity of target cells provides new insights into their *** review started by exploring the heterogeneity in the development,structures,and functions of hepatocytes and epithelial cells of the small and large bile *** example,cytokeratin(CK)8 and CK18 are primarily expressed in hepatocytes,while CK7 and CK19 are primarily expressed in intrahepatic ***,emer.ing technologies of single-cell rNA sequencing and spatial transcriptomic are being applied to study *** review offered a new perspective on understanding the pathogenic mechanisms and potential treatment strategies for ALDs.

关键词： Autoimmune hepatitis Primary biliary cholangitis Primary sclerosing cholangitis Disease heterogeneity Single-cell rNA sequencing Pathogenesis

Cavitation research with computational fluid dynamics:From Euler-Euler to Euler-Lagrange approach

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 Hydrodynamics 2024年第1期36卷 1-23页

作者： Bin Ji zi-yang wang Huai-yu Cheng rickard E.Bensow State Key Laboratory of Water resources Engineering and Management Wuhan UniversityWuhan430072China Department of Mechanics and Maritime Sciences Chalmers University of TechnologyGothenburgSweden

Unsteady cavitating flow often contains vapor structures with a wide range of different length scales,from micro-bubbles to large cavities,which issues a big challenge to precisely investigate its evolution mechanism by computational fluid dynamics(CFD)*** present work reviews the development of simulation methods for cavitation,especially the emer.ing Euler-Lagrange ***,the progress of the numerical investigation of hot and vital issues is discussed,including cavitation inception,cloud cavitation inner structure and its formation mechanism,cavitation erosion,and cavitation *** is indicated that the Euler-Lagrange method can deter.ine cavitation inception point *** cloud cavitation,the Euler-Lagrange method can reveal the source of microbubbles and their distribution law inside the shedding *** method also has advantages and great potential in assessing cloud cavitation-induced erosion and *** the ever-growing demands of cavitation simulation accuracy in basic research and engineering applications,how to improve the Euler-Lagrange method’s stability and applicability is still an open *** further promote the application of this advanced CFD simulation technology in cavitation research,some key issues are to be solved and feasible suggestions are put forward for further work.

关键词： numerical simulation Euler-Euler method Euler-Lagrange method bubble dynamicsgy,Gothenburg,Sweden

Enantioselective Alkylation of Aldehydes with Organoborons Enabled by Nickel/N-Heterocyclic Carbene Catalysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第18期42卷 2161-2165页

作者： Song-Yang Liu zi-Chao wang Shi-Liang Shi College of Chemistry and Material Science Shanghai Normal University100 Guilin RoadShanghai 200234China State Key Laboratory of Organometallic Chemistry Shanghai Institute of rganic ChemitryUniversity of Chinee Academy of Scienc Chinese Academy of Sciences345 Lingling RoadShanghai 200032China

Transition-metal-catalyzed asymmetric alkylation of aldehydes represents a str.ightforward strategy for the synthesis of chiral secondary ***,efficient methods using organoborons as coupling reagents are ***,we report a highly enantioselective nickel-catalyzed alkylation reaction of aldehydes,using readily available alkylborons as nucleophiles.A wide variety of chiral secondary alcohols were prepared from commer.ially available aldehydes with high *** key to the excellent enantioselectivity and chemoselectivity was the employment of a bulky C2-symmetric chiral NHC *** protocol features excellent enantiocontrol,mild conditions,and good functional group compatibility.

关键词： Enantioselective alkylation Nickel catalysis N-Heterocyclic carbene Organoborons Chiral alcohols Asymmetric catalysis C-C coupling Synthetic methods