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Data-driven surrogate model for aerodynamic design using separable shape tensor method

Chinese Journal of Aeronautics 2024年第9期37卷 41-58页

作者： Bo PANG Yang ZHANG Junlin li Xudong WANG Min CHANG Junqiang bai State Key Laboratory for Srrenglh and Vibration of Mechanical Structures Xi'an Jiaotong UniversityXi'an 710049China Unmanned System Research Institute Northwestern Polytechmical UniversityXi'an 710072China

In the context of increasing dimensionality of design variables and the complexity of con-straints,the effcacy of Surrogate-Based Optimization(SBO)is *** traditional linear and nonlinear dimensionality reduction algorithms are mainly to decompose the mathematical matrix composed of design variables or objective functions in various forms,the smoothness of the design space cannot be guaranteed in the process,and additional constraint functions need to be added in the optimization,which increases the calculation *** study presents a new parameterization method to improve both problems of *** new parameterization is addressed by decoupling affine transformations(dilation,rotation,shearing,and translation)within the Grassmannian sub-manifold,which enables a separate representation of the physical information of the airfoil in a high-dimensional *** upon this,Principal Geodesic Analysis(PGA)is employed to achieve geometric control,compress the design space,reduce the number of design variables,reduce the dimensions of design variables and enhance predictive performance during the surrogate optimiza-tion *** comparison,a dimensionality reduction space is defined using 95%of the energy,and RAE 2822 for transonic conditions are used as *** method significantly enhances the optimization efficiency of the surrogate model while effectively enabling geometric *** three-dimensional problems,it enables simultaneous design of planar shapes for various components of the aircraft and high-order perturbation *** was applied to the ONERA M6 wing,achieving a lift-drag ratio of 18.09,representing a 27.25%improvement com-pared to the baseline *** comparison to conventional surrogate model optimization methods,which only achieved a 17.97%improvement,this approach demonstrates its superiority.

关键词： Aerodynamicdesign Grassmannian manifold Shape parameterization Surrogate-based optimiza-tion Data dimensionality reduction

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Simultaneous detection of flare-associated kink oscillations and extreme-ultraviolet waves

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Science China(Technological Sciences) 2024年第5期67卷 1592-1601页

作者： li Dong HOU ZhenYong bai XianYong li Chuan FANG Matthew ZHAO HaiSheng WANG JinCheng NING ZongJun Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing210023China Yunnan Key Laboratory of the Solar Physics and Space Science Kunming650216China School of Earth and Space Sciences Peking UniversityBeijing100871China National Astronomical Observatories Chinese Academy of SciencesBeijing100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing100049China School of Astronomy and Space Science Nanjing UniversityNanjing210023China Key Laboratory of Modern Astronomy and Astrophysics Ministry of EducationNanjing UniversityNanjing210023China Columbus Academy GahannaOhio43230USA Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing100049China Yunnan Observatories Chinese Academy of SciencesKunming650216China

Kink oscillations,which are frequently observed in coronal loops and prominences,are often accompanied by extreme-ultraviolet(EUV)***,much more needs to be explored regarding the causal relationships between kink oscillations and EUV *** this article,we report the simultaneous detection of kink oscillations and EUV waves that are both associated with an X2.1 flare on 2023 March 03(SOL2023-03-03T17:39).The kink oscillations,which are almost perpendicular to the axes of loop-like structures,are observed in three coronal loops and one *** short loop shows in-phase oscillation within the same period of 5.2 min at three *** oscillation could be triggered by the pushing of an expanding loop and interpreted as the standing kink *** lags are found between the kink oscillations of the short loop and two long loops,suggesting that the kink wave travels in different *** kink oscillations of one long loop and the prominence are possibly driven by the disturbance of the coronal mass ejection(CME),and that of another long loop might be attributed to the interaction of the EUV *** onset time of the kink oscillation of the short loop is nearly same as the beginning of an EUV *** fact demonstrates that they are almost *** EUV wave is most likely excited by the expanding loop structure and shows two *** leading component is a fast coronal wave,and the trailing one could be due to the stretching magnetic field lines.

关键词： coronal loops solar flares solar prominence solar oscillations extreme-ultraviolet wave magnetohydrodynamic

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Effect of two-step solid solution on microstructure andδphase precipitation of Inconel 718 alloy

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2199-2207页

作者： Enyu liu Qingshuang Ma Xintong li Aoxue Gao Jing bai liming Yu Qiuzhi Gao Huijun li School of Materials Science and Engineering Northeastern UniversityShenyang 110819China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China School of Materials Science&Engineering Tianjin UniversityTianjin 300354China School of Mechanical Materials and Mechatronic EngineeringUniversity of WollongongWollongongNSW 2522Australia

Inconel 718 is the most popular nickel-based superalloy and is extensively used in aerospace,automotive,and energy indus-tries owing to its extraordinary thermomechanical *** effects of different two-step solid solution treatments on microstructure andδphase precipitation of Inconel 718 alloy were studied,and the transformation mechanism fromγ″metastable phase toδphase was *** precipitates were statistically analyzed by X-ray *** results show that theδphase content firstly increased,and then decreased with the temperature of the second-step solid *** changes in microstructure andδphase were studied by scanning electron microscopy and transmission electron *** intragranularδphase formed in Inconel 718 alloy at the second-[100]_(δ)[011]γ step solid solution temperature of 925℃,and its orientation relationship withγmatrix was determined as//and(010)_(δ)//(111)γ.Furthermore,the Vickers hardness of different heat treatment samples was measured,and the sample treated by second-step solid solution at 1010℃ reached the maximum hardness of HV 446.84.

关键词： Inconel 718 alloy two-step solid solution treatment δphase γ″-δtransformation

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Large deflection deformation behavior of a Zr-based bulk metallic glass for compliant spinal fixation application

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Journal of Materials Science & Technology 2024年第6期173卷 86-99页

作者： Diao-Feng li Chun-Guang bai Zhi-Qiang Zhang Hui-Bo Zhang Nan li Jian Zhao Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

A novel compliant spinal fixation designed based on the concept of compliant mechanisms can reduce the stress-shielding effect and adjacent segment degeneration(ASD)effectively,but propose higher requirements for the properties of the used *** metallic glasses(BMGs),as a kind of young biomaterials,exhibiting excellent comprehensive properties,which are attractive for compliant spinal ***,according to the practical service condition of the basic elements in compliant spinal fixation,large deflection deformation behaviors of Zr_(61)Ti_(2)Cu_(25)Al_(12)(at.%,ZT1)BMG beam,including elastic,yielding and plastic were investigated *** was shown that the theoretical nonlinear analytical solution curve as the benchmark not only with the capacity to predict the nonlinear load-deflection relation within the elastic deformation regime,but also assists to capture the yielding event roughly,which can be used as a powerful design tool for *** capture the beginning of the yielding event exactly,bending proof strength(σ_(p),0.05%)accompanied with tiny permanent strain of 0.05% was proposed and determined for BMGs in biomedical implant applications,which is of significance for setting the allowable operating limits of the basic flexible *** approach of interrupted loading-unloading cycles,plastic deformation driven by the bending moment can be classified into two typical stages:the initial stage which mainly characterized by the nucleation and intense interaction of abundant shear bands when the plastic strain below the critical value,and the second stage which dominated by the progressive propagation of shear bands and coupled with the emergence of shear offsets on tensile *** plasticity of BMG beam structures depends on the BMG's inherent plastic zone size(rp).When the half beam thickness less than that of the rp,the plastic deformation of BMGs will behave in a stable manner,which can be acted as the margin of safety effectiv

关键词： Metallic glasses Biomaterials Compliant spinal fixation Large deflection deformation Plastic deformation

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Promoted hydrogenation of CO2 to methanol over single-atom Cu sites with Na+-decorated microenvironment

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National Science Review 2024年第06期11卷 264-272页

作者： li-li ling Xinyu Guan Xiaoshuo liu Xiao-mei Lei Zhongyuan lin Hai-Long Jiang Hefei National Research Center for Physical Sciences at the Microscale Department of Chemistry University of Science and Technology of China School of Energy and Power Engineering North China Electric Power University School of Energy and Environment Southeast University

Although single-atom Cu sites exhibit high efficiency in CO2hydrogenation to methanol,they are prone to forming Cu nanoparticles due to reduction and aggregation under reaction conditions,especially at high ***,single-atom Cu sites stabilized by adjacent Na+ions have been successfully constructed within a metal-organic framework（MOF）-based catalyst,namely *** is found that the electrostatic interaction between the Na+and Hδ-species plays a pivotal role in upholding the atomic dispersion of Cu in MOF-808-NaCu during CO2hydrogenation,even at temperatures of up to 275℃.This exceptional stabilization effect endows the catalyst with excellent activity(306 g·kgcat-1·h-1),high selectivity to methanol（93%） and long-term stability at elevated reaction temperatures,far surpassing the counterpart in the absence of Na+（denoted as MOF-808-Cu）.This work develops an effective strategy for the fabrication of stable single-atom sites for advanced catalysis by creating an alkali-decorated microenvironment in close proximity.

关键词： single-atom sites metal–organic framework CO2 hydrogenation heterogeneous catalysis alkali-metal decoration

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An improved particle filter indoor fusion positioning approach based on Wi-Fi/PDR/geomagnetic field

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Defence Technology（防务技术） 2024年第2期32卷 443-458页

作者： Tianfa Wang litao Han Qiaoli Kong Zeyu li Changsong li Jingwei Han Qi bai Yanfei Chen College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao266590China Key Laboratory of Geomatics and Digital Technology of Shandong Province Shandong University of Science and TechnologyQingdao266590China

The existing indoor fusion positioning methods based on Pedestrian Dead Reckoning(PDR)and geomagnetic technology have the problems of large initial position error,low sensor accuracy,and geomagnetic *** this study,a novel indoor fusion positioning approach based on the improved particle filter algorithm by geomagnetic iterative matching is proposed,where Wi-Fi,PDR,and geomagnetic signals are integrated to improve indoor positioning *** important contribution is that geomagnetic iterative matching is firstly proposed based on the particle filter *** the positioning process,an iterative window and a constraint window are introduced to limit the particle generation range and the geomagnetic matching range *** position is corrected several times based on geomagnetic iterative matching in the location correction stage when the pedestrian movement is detected,which made up for the shortage of only one time of geomagnetic correction in the existing particle filter *** addition,this study also proposes a real-time step detection algorithm based on multi-threshold constraints to judge whether pedestrians are moving,which satisfies the real-time requirement of our fusion positioning *** experimental verification,the average positioning accuracy of the proposed approach reaches 1.59 m,which improves 33.2%compared with the existing particle filter fusion positioning algorithms.

关键词： Fusion positioning Particle filter Geomagnetic iterative matching Iterative window Constraint window

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TL1A Promotes Fibrogenesis in Colonic Fibroblasts via the TGF-β1/Smad3 Signaling Pathway

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Current Medical Science 2024年第3期44卷 519-528页

作者： Jia SONG Dong-lei SUN Chen-yang li Yu-xin LUO Qian liU Yue YAO Hong ZHANG Ting-ting YANG mei SONG Xin-li bai Xiao-lan ZHANG Department of Gastroenterology The Second Hospital of Hebei Medical UniversityHebei Key Laboratory of GastroenterologyHebei Institute of GastroenterologyHebei Clinical Research Center for Digestive DiseasesShijiazhuang050000China Department of Pediatrics The Second Hospital of Hebei Medical UniversityShijiazhuang050000China

Objective Intestinal fibrosis is a refractory complication of inflammatory bowel disease(IBD).Tumor necrosis factor ligand-related molecule-1A(TL1A)is important for IBD-related intestinal fibrosis in a dextran sodium sulfate(DSS)-induced experimental colitis *** study aimed to explore the effects of TL1A on human colonic *** A trinitrobenzene sulfonic acid(TNBS)-induced experimental colitis model of LCK-CD2-TL1A-GFP transgenic(Tg)or wild-type(WT)mice was established to determine the effect and mechanism of TL1A on intestinal *** human colonic fibroblast CCD-18Co cell line was treated concurrently with TL1A and human peripheral blood mononuclear cell(PBMC)*** proliferation and activation of CCD-18Co cells were detected by BrdU assays,flow cytometry,immunocytochemistry and Western *** metabolism was tested by Western blotting and real-time quantitative polymerase chain reaction(RT-qPCR).Results The level of collagen metabolism in the TNBS+ethyl alcohol(EtOH)/Tg group was greater than that in the TNBS+EtOH/WT *** growth factor-β1(TGF-β1)and p-Smad3 in the TNBS+EtOH/Tg group were upregulated as compared with those in the TNBS+EtOH/WT *** proliferation of CCD-18Co cells was promoted by the addition of human PBMC supernatant supplemented with 20 ng/mL TL1A,and the addition of human PBMC supernatant and TL1A increased CCD-18Co proliferation by 24.4%at 24 ***1A promoted cell activation and increased the levels of COL1A2,COL3A1,and TIMP-1 in CCD-18Co *** of CCD-18Co cells with TL1A increased the expression of TGF-β1 and *** TL1A promotes TGF-β1-mediated intestinal fibroblast activation,proliferation,and collagen deposition and is likely related to an increase in the TGF-β1/Smad3 signaling pathway.

关键词： tumor necrosis factor ligand-related molecule-1A fibrosis inflammatory bowel disease myofibroblasts transforming growth factor-β1

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Integrating Zeolite and Layered Double Hydroxide for Highly Selective Catalytic Production ofγ-Valerolactone

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CCS Chemistry 2024年第3期6卷 652-662页

作者： Mingkun Gao Guoju Yang Guangyuan He Risheng bai Jialiang li Yinghao liu Qiang Zhang Guangrui Chen Donghai mei Jihong Yu State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryInternational Center of Future ScienceJilin UniversityChangchun 130012 School of Materials Science and Engineering Tiangong UniversityTianjin 300387

The production ofγ-valerolactone(GVL)from biomass derivatives levulinic acid(LA)based on acidbase metallic catalysts offers a sustainable pathway to the synthesis of valuable chemicals and ***,the development of efficient metallic catalysts with tunable Lewis acid–base and Brønsted acid sites remains a ***,for the first time,we integrated zeolite and layered double hydroxide(LDH),in a core–shell structure,wherein zeolite and CoFe-LDH provided the Brønsted acidic sites and Lewis acid sites,***,oxygen vacancies(OV_(x))acting as Lewis bases were generated on the surface of LDH via Ga *** efficient cascade catalytic reaction from LA to GVL was successfully achieved over the designed Beta@LDH-OVx catalyst,affording a superior conversion of LA(>99.9%)and an impressive selectivity to GVL(89.18%).Importantly,the“memory effect”of LDH endowed the catalyst with excellent regeneration of metal active *** functional theory calculations revealed that the introduced OVx facilitated the adsorption of carbonyl oxygen in LA and boosted the production of GVL through the synergistic effect of acid/base sites in the composite *** work presents a rational design route for the construction of multifunctional catalysts by coupling zeolites and LDHs for highly selective catalytic conversion of biomass.

关键词： zeolite layered double hydroxide oxygen vacancies biomass γ-valerolactone

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Predictive modeling for postoperative delirium in elderly patients with abdominal malignancies using synthetic minority oversampling technique

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1227-1235页

作者： Wen-Jing Hu Gang bai Yan Wang Dong-mei Hong Jin-Hua Jiang Jia-Xun li Yin Hua Xin-Yu Wang Ying Chen Intensive Care Unit Shanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China Department of Anesthesia and Perioperative Medicine Shanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China Department of Nursing Shanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China Department of Thyroid Breast and Vascular SurgeryShanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China

BACKGROUND Postoperative delirium,particularly prevalent in elderly patients after abdominal cancer surgery,presents significant challenges in clinical *** To develop a synthetic minority oversampling technique(SMOTE)-based model for predicting postoperative delirium in elderly abdominal cancer *** In this retrospective cohort study,we analyzed data from 611 elderly patients who underwent abdominal malignant tumor surgery at our hospital between September 2020 and October *** incidence of postoperative delirium was recorded for 7 d *** were divided into delirium and non-delirium groups based on the occurrence of postoperative delirium or not.A multivariate logistic regression model was used to identify risk factors and develop a predictive model for postoperative *** SMOTE technique was applied to enhance the model by oversampling the delirium *** model’s predictive accuracy was then *** In our study involving 611 elderly patients with abdominal malignant tumors,multivariate logistic regression analysis identified significant risk factors for postoperative *** included the Charlson comorbidity index,American Society of Anesthesiologists classification,history of cerebrovascular disease,surgical duration,perioperative blood transfusion,and postoperative pain *** incidence rate of postoperative delirium in our study was 22.91%.The original predictive model(P1)exhibited an area under the receiver operating characteristic curve of *** comparison,the SMOTE-based logistic early warning model(P2),which utilized the SMOTE oversampling algorithm,showed a slightly lower but comparable area under the curve of 0.856,suggesting no significant difference in performance between the two predictive *** This study confirms that the SMOTE-enhanced predictive model for postoperative delirium in elderly abdominal tumor patients shows performance equivalent to that of tradi

关键词： Elderly patients Abdominal cancer Postoperative delirium Synthetic minority oversampling technique Predictive modeling Surgical outcomes

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Analysis of Weakly Nonlinear Evolution Characteristics of Flow in the Constant Curvature Bend

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Advances in Applied Mathematics and Mechanics 2024年第1期16卷 101-121页

作者： Bin li Haijue Xu Yuchuan bai Ziqing Ji Skate Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China Institute for Sedimentation on River and Coastal Engineering Tianjin 300072China

The meandering river is an unstable system with the characteristic of nonlinearity,which results from the instability of the flow and *** on the hydrodynamic nonlinearity of the bend,we use the weakly nonlinear theory and perturbation method to construct the nonlinear evolution equations of the disturbance amplitude and disturbance phase of two-dimensional flow in meandering *** influence of the curvature,Re and the disturbance wave number on the evolution of disturbance amplitude and disturbance phase are ***,the spatial and temporal evolution of the disturbance vorticity is *** research results show:that the curvature makes the flow more stable;that in the evolution of the disturbance amplitude effected by curvature,Re and the disturbance wave number,exist nonlinear attenuation with damping disturbances,and nonlinear explosive growth with positive disturbances;that the asymmetry distribution of the disturbance velocities increases with the curvature;that the location of the disturbance vorticity’s core area changes periodically with disturbance phase,and the disturbance vorticity gradually attenuates/increases with the decrease of the disturbance phase in the evolution process of damping/positive *** results shed light on the construction of the interaction model of hydrodynamic nonlinearity and geometric nonlinearity of bed.

关键词： Curvature bend hydrodynamics weakly nonlinearity disturbance vorticity

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