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MODIFIED STOCHASTIC EXTRAGRADIENT METHODS FOR STOCHASTIC VARIATIONAL INEQUALITY

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Journal of Computational Mathematics 2024年第2期42卷 390-414页

作者： ling zhang lingling Xu School of Management and Economic Beijing Institute of TechnologyBeijing 100081China School of Mathematical Sciences Nanjing Normal UniversityNanjing 210023China School of Mathematical Sciences and Jiangsu Key Laboratory for NSLSCS Nanjing Normal UniversityNanjing 210023China

In this paper,we consider two kinds of extragradient methods to solve the pseudo-monotone stochastic variational inequality ***,we present the modified stochastic extragradient method with constant step-size(MSEGMC)and prove the convergence of *** the strong pseudo-monotone operator and the exponentially growing sample sequences,we establish the R-linear convergence rate in terms of the mean natural residual and the oracle complexity O(1/ǫ).Second,we propose a modified stochastic extragradient method with adaptive step-size(MSEGMA).In addition,the step-size of MSEGMA does not depend on the Lipschitz constant and without any line-search ***,we use some numerical experiments to verify the effectiveness of the two algorithms.

关键词： Stochastic variational inequality Pseudo-monotone Modified stochastic ex-tragradient methods Adaptive step-size

Numerical study on the effective thermal conductivity and thermal tortuosity of porous media with different morphologies

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Science China(Technological Sciences) 2024年第6期67卷 1685-1694页

作者： DU Shen LI Dong LI Meng-jie HE Ya-ling Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an710049China

Effective thermal conductivity and thermal tortuosity are crucial parameters for evaluating the effectiveness of heat conduction within porous *** direct pore-scale numerical simulation method is applied to investigate the heat conduction processes inside porous structures with different *** thermal conduction performances of idealized porous structures are directly compared with real foams across a wide range of *** foam structures are reconstructed using X-ray computed tomography and image processing techniques,while Kelvin and Weaire-Phelan structures are generated through periodic unit cell *** detailed temperature fields inside the porous structures are determined by solving the heat conduction equation at the pore *** results present that the equivalent thermal conductivity of Kelvin and Weaire-Phelan structures is similar to and greater than that of the real foam structure with the same strut *** thermal tortuosity of real foam structure is relatively larger and the heat conduction path becomes straighter by adopting the anisotropic *** thermal tortuosity of the fluid channels for Kelvin,Weaire-Phelan,and real foam structures is close to *** thermal conductivity of porous structures with heat transfer fluid increases as the thermal conductivity ratio of fluid to solid becomes larger.A small porosity of porous media leads to a larger equivalent thermal conductivity due to the dominant contribution of porous skeleton in the heat conduction *** derived from parallel and series models,as well as the Maxwell-Eucken models,provide decent predictions of effective thermal conductivity,with an average error of less than 8%in the entire range of thermal conductivity ratio.

关键词： volumetric solar receiver porous morphology direct pore-scale simulation equivalent thermal conductivity thermal tortuosity empirical correlation

Multi-instance partial-label learning: towards exploiting dual inexact supervision

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Science China(Information Sciences) 2024年第3期67卷 48-61页

作者： Wei TANG Weijia zhang Min-ling zhang School of Computer Science and Engineering Southeast University Key Laboratory of Computer Network and Information Integration (Southeast University) Ministry of Education School of Information and Physical Sciences The University of Newcastle

Weakly supervised machine learning algorithms are able to learn from ambiguous samples or labels, e.g., multi-instance learning or partial-label learning. However, in some real-world tasks, each training sample is associated with not only multiple instances but also a candidate label set that contains one groundtruth label and some false positive labels. Specifically, at least one instance pertains to the ground-truth label while no instance belongs to the false positive labels. In this paper, we formalize such problems as multi-instance partial-label learning(MIPL). Existing multi-instance learning algorithms and partial-label learning algorithms are suboptimal for solving MIPL problems since the former fails to disambiguate a candidate label set, and the latter cannot handle a multi-instance bag. To address these issues, a tailored algorithm named MIPLGP, i.e., multi-instance partial-label learning with Gaussian processes, is *** first assigns each instance with a candidate label set in an augmented label space, then transforms the candidate label set into a logarithmic space to yield the disambiguated and continuous labels via an exclusive disambiguation strategy, and last induces a model based on the Gaussian processes. Experimental results on various datasets validate that MIPLGP is superior to well-established multi-instance learning and partial-label learning algorithms for solving MIPL problems.

关键词： machine learning multi-instance partial-label learning multi-instance learning partial-label learning Gaussian processes

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Editorial

The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 1-2页

作者： zhang jie Beijing University of Posts and Telecommunications Beijing 100876China

Integrated circuits(ICs)have become the cornerstone of the information age,driving scientific and technological revolutions and symbolizing strategic national *** the continuous adjustment of economic structure and the changing of international relationships,the pivotal role of ICs and related sectors has become increasingly *** address Chinese critical“bottleneck”challenges in this domain,it is necessary to strengthen the research on semiconductor devices,IC design,and manufacturing technologies.

关键词： corners driving symbol

Revealing effect of Al content on oxidation of novel Co-Cr-Nb-W carbide-strengthened superalloy

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Rare Metals 2024年第9期43卷 4521-4534页

作者： Chen ling Shang-Ping Li jie Hou He-Li Luo Central Iron & Steel Research Institute Beijing GAONA Materials&Technology Co. Ltd.

The high-temperature oxidation behavior of novel Co-Cr-Nb-W carbide-strengthened wear-resistance alloys with different Al contents（1wt%, 2wt% and 3wt%）at 950, 1000 and 1050 °C was thoroughly investigated by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and field emission electron probe analyzer. The porous property of Nb C in-situ oxidation products（Nb2O5, Co Nb2O6and Co4Nb2O9） induces a multi-layered oxide scale with micropores and ***-Cr-Nb-W alloy with 1 wt% Al undergoes catastrophic oxidation and spalling above 1000 °C. The outward transportation of Cr and Co is effectively restrained by a continuous Al2O3scale formed around Nb C in-situ oxidation region when Al content reaches 3 wt%. The β-Co Al in Co-Cr-Nb-W alloy with 3 wt% Al has an oxidation priority over eutectic carbides and the alloy matrix which are both enriched with Cr, thereby preventing the formation of Cr-depletion area and improving the self-healing ability of the oxide film. A slight change in Al content has a remarkable influence on the cooperative effect of Al and Cr and multiplies the antioxidant capacity of Co-Cr-Nb-W alloy above 1000 °C.

关键词： High-temperature oxidation behavior Microstructure Oxidation kinetics Superalloy Wear-resistant alloy

Ocular surface changes in moderate-to-severe acne vulgaris

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International Journal of Ophthalmology(English edition) 2024年第6期17卷 1049-1057页

作者： Ci-Yi Pan Dong-jie Sun Han-ling Li Li Ma Min zhang Song-Yuan Tang Hui zhang Department of Ophthalmology First Affiliated Hospital of Kunming Medical UniversityKunming 650032Yunnan ProvinceChina Department of Dermatology First Affiliated Hospital of Kunming Medical UniversityKunming 650032Yunnan ProvinceChina Department of Stomatology the First People’s Hospital of Yunnan ProvinceKunming 650100Yunnan ProvinceChina Institute of Health Studies School of Public HealthKunming Medical UniversityKunming 650500Yunnan ProvinceChina

AIM:To investigate ocular surface disorders and tear function changes in patients with acne vulgaris and explore the potential relationship between acne vulgaris and dry ***:This cross-sectional study included right eyes of 53 patients with acne vulgaris and 54 healthy *** participants completed the Ocular Surface Disease Index(OSDI)*** following ocular surface-related parameters were measured:tear meniscus height(TMH),noninvasive tear breakup time(NIBUT),Schirmer I test(SIT),lipid layer thickness(LLT)score of the tear film,meibum score,meibomian gland orifice obstruction score,the ratio of meibomian gland loss,conjunctival hyperemia score,and corneal fluorescein staining(CFS)***:The stability of the tear film decreased in acne vulgaris *** the acne group,the TMH and NIBUT were lower,whereas the OSDI,meibum score,meibomian gland orifice obstruction score,ratio of meibomian gland loss,and conjunctival hyperemia score were higher compared with controls(P0.05).In two dry eye groups,the TMH,NIBUT,and LLT score were lower in the acne with dry eye(acne-DE)group,and the meibum score,meibomian gland orifice obstruction score,ratio of meibomian gland loss and conjunctival hyperemia score in the acne-DE group were higher(P0.05).CONCLUSION:Patients with moderate-to-severe acne vulgaris are more likely to experience dry eye than those without acne *** tear film stability and meibomian gland structure dysfunction are more pronounced in patients with moderate-to-severe acne and dry eye.

关键词： acne vulgaris meibomian gland dysfunction dry eye tear film

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

Investigation on crystallization behavior between(Sc_(x)Yb_(1−x))O_(1.5)and CMAS:A new insight in the effect of Sc substitution

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Journal of Advanced Ceramics 2024年第6期13卷 789-799页

作者： Guangheng zhang Jinyu Shi jie zhang Jingyang Wang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Environmental barrier coatings(EBCs)with thermomechanical robustness against calcium–magnesium–aluminum–silicate(CMAS)deposits are in high *** aim of this work was to clarify the influence of Sc^(3+)on the crystallization behavior of Yb-based coatings against CMAS *** reaction products of solid solutions with compositions traversing the Sc_(2)O_(3)–Yb_(2)O_(3)system indicate that Sc^(3+)tends to form[BO_(6)]coordination polyhedra in the crystal structure to promote the formation of garnet and diopside,while Yb^(3+)occupies 7-,8-,and 9-coordinate sites to crystallize apatite and *** transformation of crystalline products from apatite/silicocarnotite to garnet/diopside greatly improves the efficiency of CMAS melt consumption and facilitates the prevention of its further penetration and *** on the commonality of cation occupancy in crystallography,an A(CaO+YbO_(1.5))–B(ScO_(1.5)+MgO+AlO_(1.5))–T(SiO_(2))pseudoternary phase diagram is established,which has great potential for describing phase equilibrium in coating-deposit systems and can provide guidance for the compositional design of corrosion-resistant coatings.

关键词： crystallization behavior cation partitioning scandium-ytterbium oxide(Sc_(x)Yb_(1−x))O_(1.5)solid solution calcium-magnesium-aluminum-silicate(CMAS)deposit pseudoternary phase diagram

Strong Edge Coloring of Outerplane Graphs with Independent Crossings

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 467-477页

作者： Ke-jie LI Xin zhang School of Mathematics and Statistics Xidian UniversityXi’an 710071China

The strong chromatic index of a graph is the minimum number of colors needed in a proper edge coloring so that no edge is adjacent to two edges of the same *** outerplane graph with independent crossings is a graph embedded in the plane in such a way that all vertices are on the outer face and two pairs of crossing edges share no common end *** is proved that every outerplane graph with independent crossings and maximum degreeΔhas strong chromatic index at most 4Δ-6 if Δ≥4,and at most 8 ifΔ≤*** bounds are sharp.

关键词： outer-1-planar graph IC-planar graph strong edge coloring crossing