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Ideals in Morita Rings and Morita Semigroups

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Acta Mathematica Sinica,English Series 2005年第4期21卷 893-898页

作者： yu qun chen yun FAN Zhi Feng HAO Department of Mathematics South China Normal University Guangzhou 510631 P. R. China Department of Mathematics Wuhan University Wuhan 430072 P. R. China Department of Applied Mathematics South China University of Technolog Guangzhou 510641 P. R. China

We characterize the lattice of all ideals of a Morita ring （semigroup） when the corresponding pair of rings （semigroups） in the Morita context are Morita equivalent s-unital （like-unitv） rings （semigroups）.

关键词： Ideal Morita ring Morita semigroup

Data-driven active vibration control for helicopter with trailing-edge flaps using adaptive dynamic programming

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Chinese Journal of Aeronautics 2024年第6期37卷 151-166页

作者： yu chen qun ZONG Xiuyun ZHANG Jinna LI School of Electrical and Information Engineering Tianjin UniversityTianjin 300072China School of Information and Control Engineering Liaoning Petrochemical UniversityFushun 113001China

The helicopter Trailing-Edge Flaps(TEFs)technology is one of the recent hot topics in morphing wing *** employing controlled deflection,TEFs can effectively reduce the vibration level of ***,designing specific vibration reduction control methods for the helicopters equipped with trailing-edge flaps is of significant practical *** paper studies the optimal control problem for helicopter-vibration systems with TEFs under the framework of adaptive dynamic programming combined with Reinforcement Learning(RL).Time-delay and disturbances,caused by complexity of helicopter dynamics,inevitably deteriorate the control performance of vibration *** solve this problem,a zero-sum game formulation with a linear quadratic form for reducing vibration of helicopter systems is presented with a virtual *** this context,an off-policy reinforcement learning algorithm is developed to determine the optimal control *** algorithm utilizes only vertical vibration load data to achieve a policy that reduces vibration,attains Nash equilibrium,and addresses disturbances while compensating for time-delay without knowledge of the dynamics of the helicopter *** effectiveness of the proposed method is demonstrated in a virtual platform.

关键词： Active control Adaptive dynamic program-ming Helicopter rotor Vibration control Zero-sum game

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

Very long wave infrared quantum dot photodetector up to 18μm

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Light(Science & Applications) 2024年第4期13卷 772-782页

作者： Xiaomeng Xue qun Hao Menglu chen School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China. Westlake Institute for Optoelectronics FuyangHangzhou 311421China. Physics Department Changchun University of Science and TechnologyChangchun 130022China

Colloidal quantum dots(CQDs)are of interest for optoelectronic devices because of the possibility of high-throughput solution processing and the wide energy gap tunability from ultraviolet to infrared *** may question about the upper limit on the CQD wavelength *** date,although the CQD absorption already reaches terahertz,the practical photodetection wavelength is limited within mid-wave *** figure out challenges on CQD photoresponse in longer wavelength,would reveal the ultimate property on these ***’s more,it motivates interest in bottom-up infrared photodetection with less than 10%cost compared with epitaxial growth semiconductor *** this work,developing a re-growth method and ionic doping modification,we demonstrate photodetection up to 18μm wavelength on HgTe *** liquid nitrogen temperature,the responsivity reaches 0.3 A/W and 0.13 A/W,with specific detectivity 6.6×108 Jones and 2.3×109 Jones for 18μm and 10μm CQD photoconductors,*** work is a step toward answering the general question on the CQD photodetection wavelength limitation.

关键词： quantum wave ultraviolet

The Mixed-Mode Fatigue Crack Propagation Model of Piezoelectric Materials Under Electric Fatigue Loading by the Jk-Integral

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Acta Mechanica Solida Sinica 2024年第4期37卷 634-641页

作者： Xianghua chen Chunguang Wang qun Li The Institute of Xi’an Aerospace Solid Propulsion Technology Xi’an710025China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an710049China

The electric fatigue load has a significant effect on the crack propagation behavior and failure life of piezoelectric materials and devices. In this paper, an electrical mixed-mode fatigue crack propagation model for piezoelectric materials is proposed based on the piezoelectric Jk-integral theory. The crack initiation, propagation, and life prediction criteria of piezoelectric materials under electric fatigue loading are given by this model, and the finite element simulation model is established to study the electrical mixed-mode crack propagation behavior of piezoelectric structures. Meanwhile, the electrical mixed-mode fatigue crack propagation model is applied to the fatigue crack propagation behavior of a piezoelectric typical defective structure, the crack–hole interference model. The mixed-mode crack propagation, fatigue life, and the interference behavior between the crack and hole at various hole locations of the crack–hole interference model are well recognized by this model. The crack propagation behavior under different electrical load intensities is also considered. The results show that the hole in front of the crack tip inhibits crack propagation to a certain extent, and the strength of electrical load affects the fatigue life of piezoelectric materials and structures. Therefore, the proposed electrical mixed-mode fatigue crack propagation model provides a reference for predicting the mixed-mode fatigue crack propagation behavior and fatigue life of piezoelectric structures under electric fatigue loading.

关键词： Configurational force J k-integral Piezoelectric Mixed-mode crack propagation Life prediction

A refined representation method of the particle size distribution curve based on grading entropy

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Particuology 2024年第5期88卷 302-311页

作者： Xing Li qun chen Zhaozhao Liu cheng Zhou chen Wang chen chen State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China

The particle size distribution(PSD)curve is an important expression of the basic properties of the *** characteristic parameters such as median particle size D_(50),effective particle size D_(10),and some combinations of characteristic parameters can only represent some points of the PSD curve,failing to represent all information of the PSD *** this paper,a fraction characteristic parameter F that could reflect the fraction size variation of the PSD curve was introduced based on grading *** a new presentation method of the A-B-F three parameters was proposed for a refined representation of the PSD *** was found that the newly constructed model not only better represents the differences in the width of PSD curves but also has a higher sensitivity than the A-B two-parameter model proposed by Lő*** PSD curves with similar distributions,the new presentation method has a higher degree of discrimination than that of the D_(50)-C_(u)-C_(c) three-parameter or the four-parameter combination G_(c) proposed by ***,the application of this new method in describing the spatial nonuniformity distribution of depositions and predicting the soil hydraulic conductivity was *** research results can provide a reference for the refined representation of PSD curves.

关键词： Grading entropy Particle size distribution curve Refined representation

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

Mitochondrial dysfunction affects hepatic immune and metabolic remodeling in patients with hepatitis B virus-related acute-onchronic liver failure

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World Journal of Gastroenterology 2024年第8期30卷 881-900页

作者： yu Zhang Xiao-Ling Tian Jie-qun Li Dong-Sheng Wu Qiang Li Bin chen Department of Hepatology Institute of HepatologyThe First Affiliated Hospital of Hunan University of Chinese MedicineChangsha 410021Hunan ProvinceChina Department of Liver Transplant Transplant Medical Research CenterThe Second Xiangya Hospital of Central South UniversityChangsha 410011Hunan ProvinceChina Department of Surgery The First Affiliated Hospital of Hunan University of Chinese MedicineChangsha 410021Hunan ProvinceChina

BACKGROUND Immune dysregulation and metabolic derangement have been recognized as key factors that contribute to the progression of hepatitis B virus(HBV)-related acute-on-chronic liver failure(ACLF).However,the mechanisms underlying immune and metabolic derangement in patients with advanced HBV-ACLF are *** To identify the bioenergetic alterations in the liver of patients with HBV-ACLF causing hepatic immune dysregulation and metabolic *** Liver samples were collected from 16 healthy donors(HDs)and 17 advanced HBV-ACLF patients who were eligible for liver *** mitochondrial ultrastructure,metabolic characteristics,and immune microenvironment of the liver were *** focus was given to organic acid metabolism as well as the function and subpopulations of macrophages in patients with *** Compared with HDs,there was extensive hepatocyte necrosis,immune cell infiltration,and ductular reaction in patients with *** patients,the liver suffered severe hypoxia,as evidenced by increased expression of hypoxia-inducible factor-1α.Swollen mitochondria and cristae were observed in the liver of *** number,length,width,and area of mitochondria were adaptively increased in *** metabolomics analysis revealed that mitochondrial oxidative phosphorylation decreased,while anaerobic glycolysis was enhanced in patients with *** findings suggested that,to a greater extent,hepa-tocytes used the extra-mitochondrial glycolytic pathway as an energy *** with HBV-ACLF had elevated levels of chemokine C-C motif ligand 2 in the liver homogenate,which stimulates peripheral monocyte infiltration into the *** and functional analysis of macrophage subsets revealed that patients with ACLF had a high abundance of CD68^(+)HLA-DR^(+)macrophages and elevated levels of both interleukin-1βand transforming growth factor-β1 in their *** abundance of CD206^(+)CD163^(+)macrophag

关键词： Acute-on-chronic liver failure Hypoxia-inducible factor-1α Mitochondria Metabolic phenotype Immune cells

Cause analysis of expressway traffic accidents based on accident statistics of Hunan provincial expressway in 2012-2018

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Transportation Safety and Environment 2024年第1期6卷 83-92页

作者： Xinyu Liu Shengjun Huang qun chen Business school Foshan UniversityFoshan 528225GuangdongChina School of Traffic and Transportation Engineering Central South UniversityChangsha 410075HunanChina Hunan Provincial Expressway Traffic Police Station Law Enforcement DepartmentChangsha 410007HunanChina

Based on the 2012–2018 accident statistics on the Hunan Provincial Expressway in China,this paper analyses the proportion to which various factors contribute to accidents,as well as the trends over *** 2012 to 2018,the total number of general procedure handling accidents(*** accidents)increased first and then decreased,while the number of accidents and deaths per 1000 kilometres decreased year by *** total number of simple procedure handling accidents(*** accidents)increased year by year,but the number of accidents per 1000 kilometres remained relatively ***,fatigued driving,improper driving operation,failure to maintain a safe distance from the preceding vehicle and pedestrians entering the expressway are the main causes of general procedure handling *** to maintain a safe distance from the preceding vehicle as required and improper driving operation accounted for approximately 2/3 of the simple procedure handling *** view of the accidents caused by these factors,how to use law enforcement,education,science and technology and facilities construction to further reduce the occurrence of expressway traffic accidents is discussed.

关键词： expressway traffic accident cause analysis