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Weak and Strong Convergence of Self Adaptive Inertial Subgradient Extragradient Algorithms for Solving Variational Inequality Problems

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Journal of Harbin Institute of Technology(New Series) 2024年第2期31卷 38-49页

作者： Yao Li hongwei liu Jiamin Lv School of Mathematics and Statistics Xidian UniversityXi'an710126China

Many solutions of variational inequalities have been proposed,among which the subgradient extragradient method has obvious advantages.Two different algorithms are given for solving variational inequality problem in this paper.The problem we study is defined in a real Hilbert space and has L-Lipschitz and pseudomonotone condition.Two new algorithms adopt inertial technology and non-monotonic step size rule,and their convergence can still be proved when the value of L is not given in advance.Finally,some numerical results are designed to demonstrate the computational efficiency of our two new algorithms.

关键词： variational inequality inertial method non-monotonic step size rule Lipschitz continuity pseudomonotone mapping

The human-derived novel gut commensal Luoshenia tenuis regulates body weight and food intake in mice

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Food Science and Human Wellness 2024年第2期13卷 830-841页

作者： Yu Jiang Mengxuan Du Lisheng Xie Minzhi Jiang Yaokun Zhang Mingxia Bi Chang liu hongwei liu Shuangjiang liu State Key Laboratory of Microbial Technology Shandong UniversityQingdao 266237China State Key Laboratory of Microbial Resources Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China College of Life Science Hebei UniversityBaoding 071000China State Key Laboratory of Mycology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China

Many studies have revealed that gut microbes modulate host metabolism.In this study,we characterized the therapeutic effects of a novel gut commensal Luoshenia tenuis against host metabolic disorders.First,by in silico analysis,we demonstrated that the L.tenuis was prevalent in the gut microbiomes of healthy humans but were depleted specifically in obesity cohorts.Further in vitro cultivation revealed that L.tenuis produced short chain fatty acids that were verified to modulate host metabolism and some other volatile metabolites to benefit hosts by anti-inflammation and anti-tumor.Second,gavage of the L.tenuis significantly decreased the body weight gain and food intake of high-fat diet-feeding C57BL/6J mice,which was in parallel with the changed expression level of genes related to satiety and feeding behavior.We then performed the gavage trial using diet induced obese mice,and it revealed that the administration of L.tenuis alleviated significantly the abnormal glucose and lipid metabolisms and reduced the inflammatory response.In summary,this study revealed a previously-unknown human gut commensal microbe that benefited host metabolism,and set the stage for the development of novel next-generation probiotic applicable for treatment of obesity and related metabolic disorders.

关键词： Luoshenia tenuis Gut microbe Feeding behavior Obesity Next-generation probiotic

Stable α-CsPbI3 with extremely red emission for expanding the color gamut

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Science China(Information Sciences) 2024年第5期67卷 311-317页

作者： Yong ZHANG Xin WEI Lei GAO Weijie ZHAO Changjiu SUN Junli WEI Mingjian YUAN Zhenhua NI Junpeng LU hongwei liu School of Physics and Key Laboratory of MEMS of the Ministry of Education Southeast University Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Renewable Energy Conversion and Storage Center (RECAST) College of Chemistry Nankai University Jiangsu Key Lab on Opto-Electronic Technology School of Physics and TechnologyNanjing Normal University

The wider color gamut represents the better reproducibility of the real natural colors. Perovskite materials exhibit promising potential in full-color wide-gamut displays because of the wide tunability and high saturability of their photon emission. However, the full-color wide gamut(>100% Rec.2020) has not been constructed due to the lack of the extreme red primary color(～700 nm). Herein, the widest color gamut is realized, whereinα-CsPbI3 is used to generate the extreme red primary color. An in-situ encapsulation approach is advised to stabilizeα-CsPbI3 at room temperature by means of polyvinylpyrrolidone(PVP).Theα-CsPbI3 encapsulated by PVP(denoted as P-CPI) shows highly saturated(FWHM(full width at half maximum) ～28 nm) and extremely(～697 nm) red emission. The green emission is provided by P-CPBr(CsPbBr3 with PVP) which is also synthesized using the universal in-situ encapsulation approach. With the assistance of a commercial Ga N chip, the RGB gamut is extended to the widest(151% NTSC, 113%Rec.2020).

关键词： all-inorganic perovskite wide color gamut LED display carrier recombination

Sugarcane leaves-derived polyphenols alleviate metabolic syndrome and modulate gut microbiota of ob/ob mice

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Food Science and Human Wellness 2024年第2期13卷 633-648页

作者： Li Sun Tao Wang Baosong Chen Cui Guo Shanshan Qiao Jinghan Lin Huan Liao Huanqin Dai Bin Wang Jingzu Sun hongwei liu State Key Laboratory of Mycology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China Savaid Medicine School University of Chinese Academy of SciencesBeijing 100101China Guangxi Academy of Sciences Nanning 530007China

Sugarcane leaves-derived polyphenols(SLP)have been demonstrated to have diverse health-promoting benefits,but the mechanism of action has not been fully elucidated.This study aimed to investigate the anti-metabolic disease effects of SLP and the underlying mechanisms in mice.In the current study,we prepared the SLP mainly consisting of three flavonoid glycosides,three phenol derivatives,and two lignans including one new compound,and further demonstrated that SLP reduced body weight gain and fat accumulation,improved glucose and lipid metabolism disorders,ameliorated hepatic steatosis,and regulated short-chain fatty acids(SCFAs)production and secondary bile acids metabolism in ob/ob mice.Notably,SLP largely altered the gut microbiota composition,especially enriching the commensal bacteria Akkermansia muciniphila and Bacteroides acidifaciens.Oral gavage with the above two strains ameliorated metabolic syndrome(MetS),regulated secondary bile acid metabolism,and increased the production of SCFAs in high-fat diet(HFD)-induced obese mice.These results demonstrated that SLP could be used as a prebiotic to attenuate MetS via regulating gut microbiota composition and further activating the secondary bile acids-mediated gut-adipose axis.

关键词： Sugarcane leaves-derived polyphenols Metabolic syndrome Bacteroides acidifaciens Akkermansia muciniphila Secondary bile acids metabolism

Modulated-ISRJ rejection using online dictionary learning for synthetic aperture radar imagery

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Journal of Systems Engineering and Electronics 2024年第2期35卷 316-329页

作者： WEI Shaopeng ZHANG Lei LU Jingyue liu hongwei College of Oceanography and Space Informatics China University of Petroleum(East China)Qingdao 266580China School of Electronics Engineering Xidian UniversityXi’an 710071China School of Electronics and Communication Engineering Shenzhen Campus of Sun Yat-sen UniversityGuangzhou 518107China School of Computer Science and Technology Xidian UniversityXi’an 710071China

In electromagnetic countermeasures circumstances,synthetic aperture radar(SAR)imagery usually suffers from severe quality degradation from modulated interrupt sampling repeater jamming(MISRJ),which usually owes considerable coherence with the SAR transmission waveform together with periodical modulation patterns.This paper develops an MISRJ suppression algorithm for SAR imagery with online dictionary learning.In the algorithm,the jamming modulation temporal properties are exploited with extracting and sorting MISRJ slices using fast-time autocorrelation.Online dictionary learning is followed to separate real signals from jamming slices.Under the learned representation,time-varying MISRJs are suppressed effectively.Both simulated and real-measured SAR data are also used to confirm advantages in suppressing time-varying MISRJs over traditional methods.

关键词： synthetic aperture radar(SAR) modulated interrupt sampling jamming(MISRJ) online dictionary learning

Decomposition of mean skin friction in incident shock wave/turbulent boundary layer interaction flows at Mach 2.25

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中国航空学报:英文版 2023年第9期36卷 178-194页

作者： Junyi DUAN Fulin TONG Xinliang LI hongwei liu LHD Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Aerodynamics China Aerodynamics Research and Development CenterMianyang 621000China

The evolution characteristics of the mean skin friction beneath the supersonic turbulent boundary layer that interacts with incident shock waves at Mach 2.25 are analyzed using Direct Numerical Simulation(DNS). The separated and attached boundary layers in the interaction region that respectively correspond to 33.2° and 28° incident shock angles are considered. The mean skin friction recovery rate for the separated boundary layer is much gentler and distinctly less than that for the attached case where the skin friction completes its recovery within one boundary layer thickness. The novel mean skin friction decomposition method for compressible flows proposed by the recent research is applied in the interaction region to investigate the internal evolution characteristics quantitatively. The results reveal that the three decomposition components are distinctly unequal between the two cases. The contributions of the turbulent motions at different scales to the associated term are focused on using empirical mode decomposition technology. It indicates that the outer large-scale structures dominate separation and reattachment regions, while contributions from inner small-scale structures are limited. In contrast, contributions from the outer largescale structures are dramatically reduced in the attached case, which results in the outer large-scale and inner small-scale motions being of equal importance.

关键词： Compressible flow Boundary layers Direct numerical simulation Shock waves Skin friction Turbulent flow

Limitations of the homogenization process of bulk martensitic mold steel-depending on the comprehensive manifestation of various strengthening

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Journal of Materials Science & Technology 2022年第22期117卷 120-132页

作者： Hanghang liu Paixian Fu hongwei liu Chen Sun Ningyu Du Dianzhong Li Shenyang National Laboratory for Materials Science Shenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

A homogenization treatment(1250 °C + 12 h) was carried out to minimize the micro-segregation of bulk 718H martensitic mold steel, as verified by advanced experimental characterization and kinetic model of diffusion. However, new research found that there are still limitations in the use of the homogenization process. The result indicates that the chemical heterogeneity can be significantly reduced after homogenization. The segregation ratio of Cr and Mo elements of sample decreased by 40.9% and 35.6% of the original level, respectively. Simultaneously, the test steel with higher strength and toughness is produced by controlling micro-segregation tempered from 540 °C to 650 °C. Importantly, it reveals that the impact energy is increased by up to 27.3%. The isotropy of impact energy in different directions can reach 0.89,resulting in an overall improvement in the isotropy. Toughness mainly depends on the orientation relationship between the crack propagation direction and the band segregation region. The chain carbides formed due to the decomposition of the micro-segregated region during tempering are considered the main source of cracks. The more evenly distributed the subsequent tempered carbides after homogenization, resulting in an increase in toughness. However, an abnormal phenomenon is found in which the yield strength after homogenization is lower than that of the untreated sample tempered at 700 °C. This result can be attributed to the combined influences of precipitation strengthening and fine grain strengthening by analyzing various strengthening mechanisms. The mutually restrictive strengthening effect leads to the limitations of the homogenization process of bulk martensitic mold steel.

关键词： Martensitic mold steel Strength-toughness Micro-segregation Synergistic strengthening

Characterizations of the biomineralization film caused by marine Pseudomonas stutzeri and its mechanistic effects on X80 pipeline steel corrosion

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Journal of Materials Science & Technology 2022年第30期125卷 15-28页

作者： Haixian liu Wen Chen Yu Tan Guozhe Meng Hongfang liu YFrank Cheng hongwei liu School of Chemical Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China Research Institute of Natural Gas Technology Southwest Oil&Gasfield CompanyChina National Petroleum CorporationChengdu 610000China Department of Mechanical and Manufacturing Engineering University of CalgaryCalgaryAlberta T2N 1N4Canada Key Laboratory for Large-Format Battery Materials and System Ministry of EducationHubei Key Laboratory of Materials Chemistry and Service FailureSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Microbiologically influenced corrosion(MIC)of steel generates a corrosion product film,which can also be called biomineralization film.It is critical to understand the structure of biomineralization film since it dominates the corrosion behavior of metal.In this work,Pseudomonas stutzeri(P.stutzeri)was isolated from seawater,and the biomineralization film caused by marine P.stutzeri was characterized by Transmission electron microscopy(TEM),scanning electron microscopy(SEM),X-ray diffraction(XRD),etc.The mechanistic effects of the biomineralization film on X80 pipeline steel corrosion were also investigated.The results indicate that the minerals are mainly composed of nano FeOand FeOOH,according to TEM and XRD results.The particle sizes of biominerals are below 10 nm.This work also provides an insight strategy to prepare nanomaterials by MIC caused by P.stutzeri.In addition,P.stutzeri can grow well with COas a carbon source and iron as an electron donor.The corrosion rates(CRs)of specimens are closely related to the structure of biomineralization film.The CRs increase with the decrease of initial cell concentration.P.stutzeri with an initial concentration of 10~7 cells/mL can promote the formation of a compact biomineralization film with a thickness of 145.8±4.8μm,leading to corrosion inhibition with a CR of 0.058±0.008 mm/y.But some corrosion pits can be observed due to the formation of small anodes.Electrochemical impedance spectroscopy(EIS)data show higher impedance values and two time-constants,which imply the formation of a compact biomineralization film.

关键词： Biomineralization Nanomaterials MIC Pseudomonas stutzeri Steel

Subgradient Extragradient Methods for Equilibrium Problems and Fixed Point Problems in Hilbert Space

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Journal of Harbin Institute of Technology(New Series) 2022年第1期29卷 15-23页

作者： Lulu Yin hongwei liu School of Mathematics and Statistics Xidian UniversityXi′an 710126China

Inspired by inertial methods and extragradient algorithms,two algorithms were proposed to investigate fixed point problem of quasinonexpansive mapping and pseudomonotone equilibrium problem in this study.In order to enhance the speed of the convergence and reduce computational cost,the algorithms used a new step size and a cutting hyperplane.The first algorithm was proved to be weak convergence,while the second algorithm used a modified version of Halpern iteration to obtain strong convergence.Finally,numerical experiments on several specific problems and comparisons with other algorithms verified the superiority of the proposed algorithms.

关键词： subgradient extragradient methods inertial methods pseudomonotone equilibrium problems fixed point problems Lipschitz⁃type condition