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Meta label associated loss for fine-grained visual recognition

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Science China(Information Sciences) 2024年第6期67卷 230-247页

作者： Yanchao LI Fu XIAO Hao LI qun LI Shui yu School of Computer Science Nanjing University of Posts and Telecommunications School of Network Engineering Zhoukou Normal University School of Computer Science University of Technology Sydney

Recently, intensive attempts have been made to design robust models for fine-grained visual recognition, most notably are the impressive gains for training with noisy labels by incorporating a reweighting strategy into a meta-learning framework. However, it is limited to up or downweighting the contribution of an instance for label reweighting approaches in the learning process. To solve this issue, a novel noise-tolerant method with auxiliary web data is proposed. Specifically, first, the associations made from embeddings of well-labeled data with those of web data and back at the same class are measured. Next, its association probability is employed as a weighting fusion strategy into angular margin-based loss, which makes the trained model robust to noisy datasets. To reduce the influence of the gap between the well-labeled and noisy web data, a bridge schema is proposed via the corresponding loss that encourages the learned embeddings to be coherent. Lastly, the formulation is encapsulated into the meta-learning framework, which can reduce the overfitting of models and learn the network parameters to be noise-tolerant. Extensive experiments are performed on benchmark datasets, and the results clearly show the superiority of the proposed method over existing state-of-the-art approaches.

关键词： label associated loss weighting noisy samples fine-grained visual recognition noise-tolerant learning meta-learning

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Centroid Hom-associative Algebras and Centroid Hom-Lie Algebras

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Acta Mathematica Sinica,English Series 2024年第4期40卷 935-961页

作者： yu Xiu BAI Leonid A.BOKUT yu qun CHEN Ze Rui ZHANG Department of Mathematics Teaching Guangzhou Civil Aviation CollegeGuangzhou 510403P.R.China Sobolev Institute of Mathematics Novosibirsk 630090Russia Novosibirsk State University Novosibirsk 630090Russia School of Mathematical Sciences South China Normal UniversityGuangzhou 510631P.R.China

In this article,we construct free centroid hom-associative algebras and free centroid hom-Lie *** also construct some other relatively free centroid hom-associative algebras by applying the Gr?bner-Shirshov basis theory for(unital)centroid hom-associative ***,we prove that the"Poincaré-Birkhoff-Witt theorem"holds for certain type of centroid hom-Lie algebras over a field of characteristic 0,namely,every centroid hom-Lie algebra such that the eigenvectors of the mapβlinearly generates the whole algebra can be embedded into its universal enveloping centroid hom-associative algebra,and the linear basis of the universal enveloping algebra does not depend on the multiplication table of the centroid hom-Lie algebra under consideration.

关键词： Centroid hom-Lie algebra centroid hom-associative algebra Gr?bner-Shirshov basis

Propagation form of internal cracks induced by continuous casting soft reduction and control strategy for internal quality

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Journal of Iron and Steel Research(International) 2024年第3期31卷 622-633页

作者： Pu Wang Liang Chen qun-wei Tang wei-tao Li Shao-xiang Li Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China weifang Special Steel Group Co..Ltd. Weifang 262400ShandongChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

The propagation form of internal cracks induced by continuous casting soft reduction and the control strategy for enhancing the internal quality of 45 steel through industrial trials and a three-dimensional flow-heat transfer-solidification coupling model were *** results showed that the internal cracks induced by soft reduction exhibited a characteristic of being"coarse in the middle and fine at both ends",and displayed an elliptical arc distribution on the loose side of the strand cross *** cracks originated within the brittle temperature range and propagated inward to the liquid impenetrable temperature and outward to the zero ductility temperature or *** control strategy for enhancing the internal quality of the 45 steel strand through soft reduction is to adjust the casting speed or the reduction zone appropriately,ensuring that the central solid fraction of the reduction zone falls within the range of *** this point,a reasonable reduction amount is allocated to eliminate the center shrinkage cavities and center segregation,even if it results in minor reduction-induced cracks.

关键词： Continuous casting Soft reduction Crack propagation Internal quality Control strategy

Fragility crossover mediated by covalent-like electronic interactions in metallic liquids

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Materials Futures

Materials Futures 2024年第2期3卷 117-130页

作者： Hui-Ru Zhang Liang Gao yu-Hao Ye Jia-Xin Zhang Tao Zhang Qing-Zhou Bu qun Yang Zeng-wei Zhu Shuai wei Hai-Bin yu Wuhan National High Magnetic Field Center and School of Physics Huazhong University of Science and TechnologyWuhan 430074People’s Republic of China Department of Chemistry Aarhus University8000 AarhusDenmark iMAT Centre for Integrated Materials Research Aarhus University8000 AarhusDenmark

Fragility is one of the central concepts in glass and liquid sciences,as it characterizes the extent of deviation of viscosity from Arrhenius behavior and is linked to a range of glass ***,the intervention of crystallization often prevents the assessment of fragility in poor glass-formers,such as supercooled metallic *** experimental data on their compositional dependence are scarce,let alone fundamentally *** this work,we use fast scanning calorimetry to overcome this obstacle and systematically study the fragility in a ternary La–Ni–Al system,over previously inaccessible composition *** observe fragility dropped in a small range with the Al alloying,indicating an alloying-induced fragility *** use x-ray photoelectron spectroscopy,resistance measurements,electronic structure calculations,and DFT-based deep-learning atomic simulations to investigate the cause of this fragility *** results show that the fragility crossover can be fundamentally ascribed to the electronic covalency associated with the unique Al–Al *** findings provide insight into the origin of fragility in metallic liquids from an electronic structure perspective and pave a new way for the design of metallic glasses.

关键词： metallic glass fragility fast scanning calorimetry density functional theory deep learning potential

Torque Limit-based Inertial Control Method Based on Delayed Support for Primary Frequency Control of Wind Turbines

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 561-570页

作者： wei Gu Zaiyu Chen qun Li Minghui Yin Qiang Li yun Zou School of Automation Nanjing University of Science and TechnologyNanjing 210094China State Grid Jiangsu Electric Power Co. Ltd.Research InstituteNanjing 211103China

To avoid the secondary frequency dip caused by the steep drop of the electrical power of wind turbines(WTs)at the end of frequency support stage,the torque limit-based iner-tial control(TLIC)method sets the power reference as a linear function of rotor speed,rather than the step form for the step-wise inertial ***,the compensation effect on the frequency nadir(FN)caused by the load surge is weakened as the TLIC power is no longer in the step ***,the maximum point of the frequency response component(FRC)contributed by TLIC occurs earlier than the minimum point of FRC corresponding to the load surge,so that the FN cannot be adequately ***,this paper first investigates the relation between the peak and nadir times of FRCs stimulated by the TLIC and load *** this basis,with the compensation principle of matching the peak and nadir times of FRCs,the improved TLIC method based on delayed support is ***,the effectiveness of the proposed method is validated via the experiments on the test bench of wind-integrated power system.

关键词： Wind turbine frequency response component torque limit inertial control delayed support

Development of wet adhesion of honeybee arolium incorporated polygonal structure with three-phase composite interfaces

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Friction 2024年第2期12卷 215-230页

作者： Lulu LIANG Jieliang ZHAO qun NIU Li yu Xiangbing WU Wenzhong WANG Shaoze YAN Zhenglei yu School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Division of Intelligent and Biomechanical Systems State Key Laboratory of TribologyDepartment of Mechanical EngineeringTsinghua UniversityBeijing 100084China Key of Bionic Engineering Ministry of EducationJilin UniversityChangchun 130022China

Inspired by the dynamic wet adhesive systems in nature,various artificial adhesive surfaces have been developed but still face different ***,the theoretical mechanics of wet adhesives has never been sufficiently ***,we develop a novel adhesive mechanism for governing wet adhesion and investigate the biological models of honeybee arolium for reproducing the natural wet adhesive ***-nano structures of honeybee arolium and arolium-prints were observed by Cryogenic scanning electron microscopy(Cryo-SEM),and the air pockets were found in the contact interface ***,the adhesive models with a three-phase composite interface(including air pockets,liquid secretion,and hexagonal frames of arolium),were formed to analyze the wet adhesion of honeybee *** results of theoretical calculations and experiments indicated an enhanced adhesive mechanism of the honeybee by liquid self-sucking effects and air-embolism *** these effects,normal and shear adhesion can be adjusted by controlling the proportion of liquid secretion and air pockets in the contact ***,the air-embolism effects contribute to the optimal coupling of smaller normal adhesion with greater shear adhesion,which is beneficial for the high stride frequency of *** works can provide a fresh perspective on the development of bio-inspired wet adhesive surfaces.

关键词： honeybee arolium air pockets wet adhesion a three-phase interface self-sucking effects air-embolism effects

Salidroside Ameliorates Lung Injury Induced by PM_(2.5) by Regulating SIRT1-PGC-1αin Mice

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Biomedical and Environmental Sciences 2024年第4期37卷 367-376页

作者： LI Xiao Hong LIU yu Mei SHAN Hui TAN Jin Feng ZHOU Jian SONG yuan Jin LI Si Qi LIU Chen XU Dong qun yu Li LI Wan wei School of Public Health Shandong Second Medical UniversityWeifang 261053ShandongChina Key Laboratory of Health Inspection and Quarantine Weifang 261053ShandongChina weifang Environmental Monitoring Station Weifang 261042ShandongChina Department of Orthopedics The 80th Army Hospital of PLAWeifang 261000ShandongChina Environment and Health Related Product Safety Institute of Chinese Center for Disease Control and Prevention Beijing 100021China School of Basic Medicine Shandong Second Medical UniversityWeifang 261053ShandongChina

Objective This study aimed to clarify the intervention effect of salidroside(SAL)on lung injury caused by PM_(2.5) in mice and illuminate the function of SIRT1-PGC-1ɑ*** Specific pathogen-free(SPF)grade male C57BL/6 mice were randomly assigned to the following groups:control group,SAL group,PM_(2.5) group,SAL+PM_(2.5) *** the first day,SAL was given by gavage,and on the second day,PM_(2.5) suspension was given by intratracheal *** whole experiment consist of a total of 10 cycles,lasting 20 *** the end of treatment,blood samples and lung tissues were collected and *** of pathological changes in lung tissue using inverted microscopy and transmission electron *** expression of inflammatory,antioxidants,apoptosis,and SIRT1-PGC-1ɑproteins were detected by Western *** Exposure to PM_(2.5) leads to obvious morphological and pathologica changes in the lung of ***_(2.5) caused a decline in levels of antioxidant-related enzymes and protein expressions of HO-1,Nrf2,SOD2,SIRT1 and PGC-1ɑ,and an increase in the protein expressions of IL-6,IL-1β,Bax,caspase-9 and cleaved ***,SAL reversed the aforementioned changes caused by PM_(2.5) by activating the SIRT1-PGC-1α *** SAL can activate SIRT1-PGC-1ɑ to ameliorate PM2.5-induced lung injury.

关键词： PM_(2.5) Salidroside Oxidative stress Inflammation Apoptosis SIRT1-PGC-1α

Description of martensitic transformation kinetics in Fe-C-X(X = Ni,Cr,Mn,Si) system by a modified model

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1026-1036页

作者： Xiyuan Geng Hongcan Chen Jingjing Wang yu Zhang qun Luo Qian Li State Key Laboratory of Advanced Special Steels&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Ansteel Beijing Research Institute Co. LtdBeijing 102211China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044China

Controlling the content of athermal martensite and retained austenite is important to improving the mechanical properties of high-strength steels,but a mechanism for the accurate description of martensitic transformation during the cooling process must be *** present,frequently used semi-empirical kinetics models suffer from huge errors at the beginning of transformation,and most of them fail to exhibit the sigmoidal shape characteristic of transformation *** describe the martensitic transformation process accurately,based on the Magee model,we introduced the changes in the nucleation activation energy of martensite with temperature,which led to the varying nucleation rates of this model during martensitic *** to the calculation results,the relative error of the modified model for the martensitic transformation kinetics curves of Fe-C-X(X = Ni,Cr,Mn,Si) alloys reached 9.5% compared with those measured via the thermal expansion *** relative error was approximately reduced by two-thirds compared with that of the Magee *** incorporation of nucleation activation energy into the kinetics model contributes to the improvement of its precision.

关键词： Fe-C-X system martensitic transformation kinetics curve semi-empirical model nucleation activation energy

Hydroxylation of 3-nitrotyrosine by hydroxyl radical

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Chinese Chemical Letters 2007年第5期18卷 542-544页

作者： Jun Chen Dong wei qun Shi yu Fen Zhao Yan Mei Li Key Laboratory of Bioorganic Phosphorous Chemistry ＆ Chemical Biology （Ministry of Education） Department of Chemistry Tsinghua University Beijing 100084 China

Hydroxylation of 3-nitrotyrosine （3-NT） and 3-NT containing peptide Gly-nitroTyr-Gly in aqueous solution by hydroxyl radical were investigated with gamma irradiation. The structures of the hydroxylated products were confirmed by electrospray ionization mass spectrometry and ^1H NMR spectrometry. The reactivity of 3-nitrotyrosine has been investigated using density functional theory （DFT） calculation.

关键词： 3-Nitrotyrosine Hydroxyl radical DFT Selective hydroxylation