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Equivalence between the internal observability and equation

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 89-97页

作者： liu Wen-jun TU Zhi-yu School of Mathematics and Statistics Nanjing University of Information Science and TechnologyNanjing 210044China

This paper is concerned with a third order in time linear Moore-Gibson-Thompson equation which describes the acoustic velocity potential in ultrasound wave *** by the work of Kaltenbacher,Lasiecka and Marchand(Control Cybernet.2011,40:971-988),we establish an observability inequality of the conservative problem,and then discuss the equivalence between the exponential stabilization of a dissipative system and the internal observational inequality of the corresponding conservative system.

关键词： Moore-Gibson-Thompson equation internal observability exponential stability

Effect of MgO-Cr_(2)O_(3) and Mg0-MgAl_(2)0_(4)-based refractories on refractory-steel interface reaction and cleanliness of pipeline steel

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Journal of Iron and Steel Research(International) 2024年第4期31卷 849-860页

作者： guang-mei Yang Cheng Yuan Chang liu Qiang Wang guang-qiang Li Yong-shun Zou Ao Huang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

The interaction of MgO-MgAl_(2)O_(4)-based and MgO-Cr_(2)O_(3)-based refractories with X70 molten steel was studied by immersion experiments at 1560℃.The effects of immersion time(30 and 60 min)on the contents of total oxygen(TO),Al,Nb,Si,Mn,and Cr as well as the composition,number density,and size distribution of inclusions in the molten steel were *** influence of the penetration and erosion degree of the molten steel to the refractory on the steel-refractory interface layer was *** results show that,at 1560℃,the MgO-MgAl_(2)O_(4)-based refractory can better control the contents of TO and the composition of molten steel compared with the MgO-Cr_(2)O_(3)-based *** TO content is only 16×10^(-4) wt.%in the molten steel after reacted with the Mg0-MgAl_(2)O_(4)-based refractory at the end point of refining,4 accounting for 11.5%of that reacted with the MgO-Cr_(2)O_(3)-based refractory(139×10^(-4) wt.%).The number density of inclusions is only 14 mm^(-2),and the average size ofinclusions is only 1.31μm,with thelargest proportion of inclusions in 1-2μm(70%).The Al_(2)O_(3)-MnS-CaO complex inclusions in the original steel changed to complex inclusions dominated by Cr-Nb-Mn-S-O and ***_(2)O_(3),corresponding to the MgO-Cr_(2)O_(3)-based and MgO-MgAl_(2)O_(4)-based refractories,*** ***_(2)O_(3) layer was formed at the reaction interface between MgO-MgAl_(2)O_(4)-based refractory and molten steel,which is helpful to restrict the erosion of refractories and the pollution of molten *** damage mechanism of the MgO-Cr_(2)O_(3)-based refractory is mainly permeation and chemical reaction,while the damage of the MgO-MgAl_(2)O_(4)-based refractory is mainlyscouring erosion.

关键词： MgO-Cr_(2)O_(3)-based refractory MgO-MgAl O_(4)-based refractory Nonmetallic inclusion Erosion interface layer Steel penetration

Quasi-2D weak lensing cosmological constraints using the PDF-SYM method

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 44-58页

作者： Zhenjie liu jun Zhang Hekun Li Zhi Shen Cong liu Department of Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai 200240China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China

Cosmic shear statistics,such as the two-point correlation function(2PCF),can be evaluated with the PDF-SYM method instead of the traditional weighted-sum *** makes use of the full PDF information of the shear estimators,and does not require weightings on the shear estimators,which can in principle introduce additional systematic *** work presents our constraints on S8and?mfrom the shear-shear correlations using the PDF-SYM *** data we use is from the z-band images of the Dark Energy Camera Legacy Survey(DECa LS),which covers about 10000 deg2with more than 100 million *** shear catalog is produced by the Fourier Quad method,and well tested on the real data itself with the field-distortion *** main approach is called quasi-2D as we do use the photo-z information of each individual galaxy,but without dividing the galaxies into redshift *** mainly use galaxy pairs within the redshift interval between 0.2 and 1.3,and the angular range from 4.7 to 180 *** analysis yields S8=0.762±0.026 and?m=0.234±0.075,with the baryon effects and the intrinsic alignments *** results are robust against redshift *** check the consistency of our results by deriving the cosmological constraints from auto-correlations ofγ1andγ2separately,and find that they are consistent with each other,but the constraints from theγ1component are much weaker than that fromγ*** implies a much worse data quality ofγ1,which is likely due to additional shear uncertainties caused by CCD electronics(according to the survey strategy of DECa LS).We also perform a pure 2D analysis,which gives S8=0.81_(-0.04)^(+0.03)and?m=0.25_(-0.05)^(+0.06).Our findings demonstrate the potential of the PDF-SYM method for precision cosmology.

关键词： weak lensing shear-shear correlations cosmological parameters observations analysis

Energy-efficient buffer and service rate allocation in manufacturing systems using hybrid machine learning and evolutionary algorithms

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Advances in Manufacturing 2024年第2期12卷 227-251页

作者： Si-Xiao Gao Hui liu jun Ota Key Laboratory of Traffic Safety on Track of Ministry of Education Institute of Artificial Intelligence and Robotics(IAIR)School of Traffic and Transportation EngineeringCentral South UniversityChangsha410075People’s Republic of China Research into Artifacts Center for Engineering School of EngineeringThe University of TokyoTokyoJapan

Currently,simultaneous buffer and service rate allocation is a topic of interest in the optimization of manufacturing *** allocation problems have been solved previously to satisfy economic requirements;however,owing to the progress of green manufacturing,energy conservation and environmental protection have become increasingly ***,an energy-efficient approach is developed to maximize the throughput and minimize the energy consumption of manufacturing systems,subject to the total buffer capacity,total service rate,and predefined energy *** energy-efficient approach integrates the simulated annealing-non-dominated sorting genetic algorithm-II with the honey badger algorithm-histogram-based gradient boosting regression *** former algorithm searches for Pareto-optimal solutions of sufficient *** latter algorithm builds prediction models to rapidly calculate the throughput,energy consumption,and energy *** examples show that the proposed hybrid approach can achieve a better solution quality compared with previously reported ***,the prediction models can rapidly evaluate manufacturing systems with sufficient *** study benefits the multi-objective optimization of green manufacturing systems.

关键词： Energy-efficient allocation Multi-objective optimization Energy efficiency Energy consumption Machine learning

Aspirin suppresses hepatocellular carcinoma progression by inhibiting platelet activity

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World Journal of Gastrointestinal Oncology 2024年第6期16卷 2742-2756页

作者： Li-jun Zhao Zhi-Yin Wang Wei-Ting liu Li-Li Yu Hao-Nan Qi Jie Ren Chen-guang Zhang Hematology Laboratory The First Affiliated Hospital of Xinxiang Medical UniversityXinxiang 453100Henan ProvinceChina Xinxiang Key Laboratory of Tumor Microenvironment and Immunotherapy School of Medical TechnologyXinxiang Medical UniversityXinxiang 453003Henan ProvinceChina School of Public Health Xinxiang Medical UniversityXinxiang 453003Henan ProvinceChina

BACKGROUND Hepatocellular carcinoma(HCC)is the most common malignant liver disease in the ***(PLTs)are known to play a key role in the maintenance of liver homeostasis and the pathophysiological processes of a variety of liver *** is the most classic antiplatelet ***,the molecular mechanism of platelet action and whether aspirin can affect HCC progression by inhibiting platelet activity need further *** To explore the impact of the antiplatelet effect of aspirin on the development of *** Platelet-rich plasma,platelet plasma,pure platelet,and platelet lysate were prepared,and a coculture model of PLTs and HCC cells was ***-8 analysis,apoptosis analysis,Transwell analysis,and real-time polymerase chain reaction(RT-PCR)were used to analyze the effects of PLTs on the growth,metastasis,and inflammatory microenvironment of ***-PCR and Western blot were used to detect the effects of platelet activation on tumor-related signaling *** was used to block the activation and aggregation of PLTs both in vitro and in vivo,and the effect of PLTs on the progression of HCC RESULTS PLTs significantly promoted the growth,invasion,epithelial-mesenchymal transition,and formation of an inflammatory microenvironment in HCC *** PLTs promoted HCC progression by activating the mitogenactivated protein kinase/protein kinase B/signal transducer and activator of transcription three(MAPK/AKT/STAT3)signaling ***,aspirin inhibited HCC progression in vitro and in vivo by inhibiting platelet *** PLTs play an important role in the pathogenesis of HCC,and aspirin can affect HCC progression by inhibiting platelet *** results suggest that antiplatelet therapy has promising application prospects in the treatment and combined treatment of HCC.

关键词： Platelets Antiplatelet therapy Hepatocellular carcinoma Aspirin Antitumor

Friction moment calculation method for tapered roller bearings under combined loads

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Science China Technological Sciences 2024年第8期67卷 2565-2578页

作者： LI XinBin liu Jing HUANG SuHe PAN guang School of Marine Science and Technology Northwestern Polytechnical University Key Laboratory for Unmanned Underwater Vehicle Northwestern Polytechnical University System Engineering Research Institute

Tapered roller bearings(TRBs) can withstand axial loads, radial loads, and overturning moments. The performance, safety, and efficiency of rotating machinery are directly influenced by the friction moments within the TRBs. However, most current research has relied on empirical formulas that focus on axial loads. Additionally, the friction coefficient between the rollers and the inner ring rib has been defined using simple empirical methods. In actual applications, the loads on TRBs are not purely axial or radial, and simple empirical friction coefficients do not adequately account for the varying lubrication conditions. To address this challenge, this study proposes an improved method for calculating the friction moments of TRB under combined axial and radial loads. This study employs a calculation method for sliding friction coefficients that can model dry, boundary, elastohydrodynamic, and mixed lubrication conditions. To demonstrate the advantages of the proposed method, the friction moments obtained using the existing and proposed methods are compared. Additionally, the influence of TRB structural parameters on the friction moment is discussed. An experimental study is conducted to validate the effectiveness of the proposed method. The findings provide valuable insights for designing TRB structural parameters to minimize friction moments.

关键词： tapered roller bearing friction moment structural parameters combined loads

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Memory Trace for Fear Extinction:Fragile yet Reinforceable

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Neuroscience Bulletin 2024年第6期40卷 777-794页

作者： Ying liu Shuai Ye Xin-Ni Li Wei-guang Li Department of Rehabilitation Medicine State Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain ScienceHuashan HospitalInstitute for Translational Brain ResearchFudan UniversityShanghai200032China

Fear extinction is a biological process in which learned fear behavior diminishes without anticipated reinforcement,allowing the organism to re-adapt to ever-changing *** on the behavioral hypothesis that extinction is new learning and forms an extinction memory,this new memory is more readily forgettable than the original fear *** brain’s cellular and synaptic traces underpinning this inherently fragile yet reinforceable extinction memory remain *** questions are about the whereabouts of the engram neurons that emerged during extinction learning and how they constitute a dynamically evolving functional construct that works in concert to store and express the extinction *** this review,we discuss recent advances in the engram circuits and their neural connectivity plasticity for fear extinction,aiming to establish a conceptual framework for understanding the dynamic competition between fear and extinction memories in adaptive control of conditioned fear responses.

关键词： Fear extinction memory Memory trace Fear relapse Medial prefrontal cortex Basolateral amygdala Ventral hippocampus Insular cortex Synaptic adaptations

Numerical simulations for radon migration and exhalation behavior during measuring radon exhalation rate with closed-loop method

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Nuclear Science and Techniques 2024年第1期35卷 81-95页

作者： Ming Xia Yong-jun Ye Shu-Yuan liu School of Resources Environment and Safety Engineering University of South ChinaHengyang 421001China Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang 421001China

Accurate measurements of the radon exhalation rate help identify and evaluate radon risk regions in the *** these measurement methods,the closed-loop method is frequently ***,traditional experiments are insufficient or cannot analyze the radon migration and exhalation patterns at the gas–solid interface in the accumulation *** CFD-based technique was applied to predict the radon concentration distribution in a limited space,allowing radon accumulation and exhalation inside the chamber intuitively and *** this study,three radon exhalation rates were defined,and two structural ventilation tubes were designed for the *** consistency of the simulated results with the variation in the radon exhalation rate in a previous experiment or analytical solution was *** effects of the vent tube structure and flow rate on the radon uniformity in the chamber;permeability,insertion depth,and flow rate on the radon exhalation rate and the effective diffusion coefficient on back-diffusion were *** on the results,increasing the inser-tion depth from 1 to 5 cm decreased the effective decay constant by 19.55%,whereas the curve-fitted radon exhalation rate decreased(lower than the initial value)as the deviation from the initial value increased by approximately 7%.Increasing the effective diffusion coefficient from 2.77×10^(-7) to 7.77×10^(-6) m^(2) s^(-1) made the deviation expand from 2.14 to 15.96%.The conclusion is that an increased insertion depth helps reduce leakage in the chamber,subject to notable back-diffusion,and that the closed-loop method is reasonably used for porous media with a low effective diffusion coefficient in view of the back-diffusion *** CFD-based simulation is expected to provide guidance for the optimization of the radon exhalation rate measurement method and,thus,the accurate measurement of the radon exhalation rate.

关键词： Radon exhalation Numerical simulation Accumulation chamber

Effect of heat treatment on microstructure and mechanical properties of selective laser-melted PH13-8Mo stainless steel

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Journal of Iron and Steel Research(International) 2024年第4期31卷 945-955页

作者： Yuan Zhang Xiang liu Chang-jun Wang Chang liu School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Central Iron&Steel Research Institute Co. Ltd.Beijing 100081China

PH13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the NiAl and M23C precipitates form,which are the major strengthening phases of PH13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(WC)+0℃×2 h air cooling(AC)+540℃×4 h *** this heat treatment process,PH13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of NiAl and M23Co precipitates and the change of volume fraction of the retained austenite.

关键词： High-strength stainless steel-Selective laser melting-Heat treatment Microstructure Mechanical property