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Improvement of impact properties of Al-Si-Mg alloy via solution treatment and joint modification with Sr and La

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Rare Metals 2024年第7期43卷 3301-3313页

作者： Xiong-Ling Zheng Shao-Xiang Li jia-Le Ma Qing-Yan Xu Hai-Dong zhao Zhi-Qiang Han Key Laboratory for Advanced Materials Processing Technology Ministry of EducationSchool of Materials Science and EngineeringTsinghua UniversityBeijing 100084China National Engineering Research Center of Near-Net Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China

An effort to obtain superior impact properties for Al-7Si-0.35 Mg alloy is presented,where modification with 0.02 wt% Sr and 0.1 wt% La as well as solution treatment was jointly *** samples were solution treated at 535℃ for 15 min to 12 *** microstructure,fracture mechanism,and their correlation with the impact properties of the alloy were studied in detail mainly through optical microscopy(OM),scanning electron microscopy(SEM) and oscillography impact *** results show that the addition of Sr and La refined the eutectic Si particles significantly from~ 2.05 μm(modified with Sr alone) to~ 0.75 μm in as-cast microstructure,leading to a very homogeneous distribution of spheroidized Si particles in the alloy solution treated at 535℃ for 8 *** alloy exhibits excellent impact toughness up to 75 J·cm^(-2),which is much higher than the maximum impact toughness of the alloys modified by Sr alone(~ 46 J·cm^(-2)).The major reason for this remarkable increase in the impact property is the dramatic increase in crack initiation *** dispersoid-free zones(DFZs)near the eutectic regions mainly consist of the ductile Al-matrix,which exhibits excellent *** ductile Al-matrix of the DFZs hinders the crack propagation,resulting in a significant increase in crack propagation energy.

关键词： Aluminum alloys Modification Solution treatment Microstructure Impact properties Fracture mechanism

Improving actionable warning identification via the refined warning-inducing context representation

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Science China(Information Sciences) 2024年第5期67卷 321-322页

作者： Xiuting GE Chunrong FANG Xuanye LI Quanjun ZHANG jia LIU Zhihong zhao Zhenyu CHEN State Key Laboratory for Novel Software Technology Nanjing University

Static analysis tools(SATs) have shown potential ability in software quality assurance [1]. However, SATs report an overwhelming number of warnings, where most warnings are unactionable ones(i.e., warnings that are not acted on or fixed by developers). It is not a trivial task for developers to find actionable warnings(i.e., warnings that are acted on and fixed by developers) in all reported warnings. Hence,the excessive unactionable warnings seriously impede the usability of SATs [2].

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Hexokinase 1 and 2 mediates glucose utilization to regulate the synthesis of kappa casein via ribosome protein subunit 6 kinase 1 in bovine mammary epithelial cells

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Animal Nutrition 2024年第1期16卷 338-349页

作者： Tianyu Yang jia Guo Han Song Osmond Datsomor Yuhang Chen Maocheng jiang Kang Zhan Guoqi zhao Institute of Animal Culture Collection and Application College of Animal Science and Technology Yangzhou University Yangzhou 225009 China

Glucose plays a vital part in milk protein synthesis through the mTOR signaling pathway in bovine mammary epithelial cells (BMEC). The objectives of this study were to determine how glucose affects hexokinase (HK) activity in BMEC and investigate the regulatory effect of HK in kappa casein (CSN3) synthesis via the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway in BMEC. For this, HK1 and HK2 were knocked out in BMEC using the CRISPR/Cas9 system. The gene and protein expression, glucose uptake, and cell proliferation were measured. We found that glucose uptake, cell proliferation, CSN3 gene expression levels, and expression of HK1 and HK2 increased with increasing glucose concentrations. Notably, glucose uptake was significantly reduced in HK2 knockout (HK2KO) BMEC treated with 17.5 mM glucose. Moreover, under the same glucose treatment conditions, the proliferative ability and abundance of CSN3 were significantly diminished in both HK1 knockout (HK1KO) and HK2KO BMEC compared with that in wild-type BEMC. We further observed that the phosphorylation levels of ribosome protein subunit 6 kinase 1 (S6K1) were reduced in HK1KO and HK2KO BMEC following treatment with 17.5 mM glucose. As expected, the levels of glucose-6-phosphate and the mRNA expression levels of glycolysis-related genes were decreased in both HK1KO and HK2KO BMEC following glucose treatment. These results indicated that the knockout of HK1 and HK2 inhibited cell proliferation and CSN3 expression in BMEC under glucose treatment, which may be associated with the inactivation of the S6K1 and inhibition of glycolysis.

关键词： Glucose Hexokinase Milk protein Mechanistic target of rapamycin complex 1 signaling pathway Bovine mammary epithelial cell Kappa casein

Lidar-Based Action-Recognition Algorithm for Medical Quality Control

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激光与光电子学进展 2024年第12期61卷 306-314页

作者： Wang Yuanze Zhang Haiyang Wu Xuan Kong Chunxiu ju Yezhao zhao Changming School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Photoelectronic Imaging Technology and System Ministry of EducationBeijing 100081China Key Laboratory of Information Photon Technology Ministry of Industry and Information TechnologyBeijing 100081China

Medical-action recognition is crucial for ensuring the quality of medical *** advancements in deep learning,RGB camera-based human-action recognition made huge ***,RGB cameras encounter issues,such as depth ambiguity and privacy *** this paper,we propose a novel lidar-based action-recognition algorithm for medical quality ***,point-cloud data were used for recognizing hand-washing actions of doctors and recording the action’s *** improved anchor-to-joint(A2J)network,with pyramid vision transformer and feature pyramid network modules,was developed for estimating the human *** addition,we designed a graph convolution network for action classification based on the skeleton ***,we evaluated the performance of the improved A2J network on the open-source ITOP and our medical pose estimation ***,we tested our medical action-recognition method in actual wards to demonstrate its effectiveness and running *** results show that the proposed algorithm can effectively recognize the actions of medical staff,providing satisfactory real-time performance and 96.3% action-classification accuracy.

关键词： ambient intelligence lidar human action recognition deep learning medical care

Linearized waveform inversion for vertical transversely isotropic elastic media:Methodology and multi-parameter crosstalk analysis

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Petroleum Science 2024年第1期21卷 252-271页

作者： Ke Chen Lu Liu Li-Nan Xu Fei Hu Yuan Yang jia-Hui Zuo Le-Le Zhang Yang zhao National Key Laboratory of Petroleum Resources and Engineering Unconventional Petroleum Research InstituteChina University of Petroleum(Beijing)Beijing102249China Aramco Beijing Research Center Aramco AsiaBeijing100102China University of Lausanne LausanneCH-1015Switzerland Bureau of Geophysical Prospecting China National Petroleum CorporationZhuozhou 072750HebeiChina

Seismic migration and inversion are closely related techniques to portray subsurface images and identify hydrocarbon *** migration aims at obtaining structural images of subsurface geologic *** specifically,seismic migration estimates the reflectivity function(stacked average reflectivity or pre-stack angle-dependent reflectivity)from seismic reflection *** the other hand,seismic inversion quantitatively estimates the intrinsic rock properties of subsurface *** seismic inversion methods are applicable to detect hydrocarbon reservoirs that may exhibit lateral variations in the inverted *** there exist many differences,pre-stack seismic migration is similar with the first iteration of the general linearized seismic ***,seismic migration and inversion techniques assume an acoustic or isotropic elastic *** reservoirs such as shale and tight sand formation have notable anisotropic *** present a linearized waveform inversion(LWI)scheme for weakly anisotropic elastic media with vertical transversely isotropic(VTI)*** is based on two-way anisotropic elastic wave equation and simultaneously inverts for the localized perturbations(ΔVp_(0)/Vp_(0)/Vs_(0)/Vs_(0)/,Δ∈,Δδ)from the long-wavelength reference *** proposed VTI-elastic LWI is an iterative method that requires a forward and an adjoint operator acting on vectors in each *** derive the forward Born approximation operator by perturbation theory and adjoint operator via adjoint-state *** inversion has improved the quality of the images and reduces the multi-parameter crosstalk comparing with the adjoint-based *** have observed that the multi-parameter crosstalk problem is more prominent in the inversion images for Thomsen anisotropy ***,the Thomsen parameter is the most difficult to *** also analyze the multi-parameter crosstalk using scattering radiation patte

关键词： Elastic Anisotropy Least-squares imaging Waveform inversion Computational geophysics

Model reduction of fractional impedance spectra for time–frequency analysis of batteries, fuel cells, and supercapacitors

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Carbon Energy 2024年第1期6卷 108-141页

作者： Weiheng Li Qiu-An Huang Yuxuan Bai jia Wang Linlin Wang Yuyu Liu Yufeng zhao Xifei Li Jiujun Zhang Institute for Sustainable Energy/College of Sciences Shanghai UniversityShanghaiChina Shanxi Key Laboratory of Nanomaterials and Nanotechnology School of Mechanical and Electrical EngineeringXi'an University of Architecture and TechnologyXi'anShaanxiChina Xi'an Key Laboratory of New Energy Materials and Devices School of Materials Science and EngineeringInstitute of Advanced Electrochemical EnergyXi'an University of TechnologyXi'anShaanxiChina

Joint time–frequency analysis is an emerging method for interpreting the underlying physics in fuel cells,batteries,and *** increase the reliability of time–frequency analysis,a theoretical correlation between frequency-domain stationary analysis and time-domain transient analysis is urgently *** present work formularizes a thorough model reduction of fractional impedance spectra for electrochemical energy devices involving not only the model reduction from fractional-order models to integer-order models and from high-to low-order RC circuits but also insight into the evolution of the characteristic time constants during the whole reduction *** following work has been carried out:(i)the model-reduction theory is addressed for typical Warburg elements and RC circuits based on the continued fraction expansion theory and the response error minimization technique,respectively;(ii)the order effect on the model reduction of typical Warburg elements is quantitatively evaluated by time–frequency analysis;(iii)the results of time–frequency analysis are confirmed to be useful to determine the reduction order in terms of the kinetic information needed to be captured;and(iv)the results of time–frequency analysis are validated for the model reduction of fractional impedance spectra for lithium-ion batteries,supercapacitors,and solid oxide fuel *** turn,the numerical validation has demonstrated the powerful function of the joint time–frequency *** thorough model reduction of fractional impedance spectra addressed in the present work not only clarifies the relationship between time-domain transient analysis and frequency-domain stationary analysis but also enhances the reliability of the joint time–frequency analysis for electrochemical energy devices.

关键词： battery,fuel cell,supercapacitor fractional impedance spectroscopy model reduction time-frequency analysis

High-entropy oxide-supported platinum nanoparticles for efficient hydrogen evolution reaction

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Rare Metals 2024年第4期43卷 1537-1546页

作者： Ming-Yu Fan jia-jun Wang jun zhao Hong Zhang Tian-Yi Ma Xiao-Peng Han Wen-Bin Hu School of Materials Science and Engineering Tianjin Key Laboratory of Composite and Functional Materials Key Laboratory of Advanced Ceramics and Machining TechnologyTianjin UniversityTianjin300350China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou350207China School of Science RMIT UniversityMelbourneVIC3000Australia

High-entropy oxides(HEOs)are a new class of single-phase structures with unique electronic and catalytic properties;therefore,it is worthwhile to explore their applications in *** this study,a Pt/(FeCoNiCrAl)_(3)O_(4)nanohybrid using HEO as a support was developed as an efficient catalyst for the hydrogen evolution reaction(HER).Pt/(FeCoNiCrAl)_(3)O_(4)exhibited high HER activity with a low overpotential of 22 mV at10 mA·cm^(-2),outperforming other binary,ternary,and quaternary *** HER activity of Pt/(FeCoNiCrAl)_(3)O_(4)was higher than that of a commercial Pt/C with a significantly lower Pt *** catalyst exhibited good activity and long-term stability(60 h)in an electrolytic water-splitting *** good activity can be attributed to the fact that the introduction of Pt effectively facilitates electronic interactions between Pt and the *** addition,the HEO substrate was more favorable for dispersing Pt particles,optimizing the electrochemical specific surface area,and significantly reducing the charge resistance of the *** study extends the application of HEOs in electrocatalysis and demonstrates the promising prospects of HEOs as supports for electrocatalysts.

关键词： High-entropy oxides Hydrogen evolution reaction Nanohybrid Water electrolysis

Naturally occurring PA^(E206K)point mutation in 2009 H1N1 pandemic influenza viruses impairs viral replication at high temperatures

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Virologica Sinica 2024年第1期39卷 71-80页

作者： Mengmeng Cao Qiannan jia Jinghua Li Lili zhao Li zhu Yufan Zhang Shan Li Tao Deng National Institute of Pathogen Biology Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing100730China CAS Key Laboratory of Pathogen Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing100101China

The emergence of influenza virus A pandemic H1N1 in April 2009 marked the first pandemic of the 21st *** this study,we observed significant differences in the polymerase activities of two clinical 2009 H1N1 influenza A virus isolates from Chinese and Japanese *** comparison of the three main protein subunits(PB2,PB1,and PA)of the viral RNA-dependent RNA polymerase complex and subsequent mutational analysis revealed that a single amino acid substitution(E206K)was responsible for the observed impaired replication *** in vitro experiments showed that presence of PAE206K decreased the replication of influenza A/WSN/33 virus in mammalian cells and a reduction in the virus’s pathogenicity in *** studies revealed that PAE206K is a temperature-sensitive mutant associated with the inability to transport PB1–PA complex to the nucleus at high temperature(39.5℃).Hence,this naturally occurring variant in the PA protein represents an ideal candidate mutation for the development of live attenuated influenza vaccines.

关键词： H1N1 Influenza A virus Polymerase acidic protein Point mutation Viral replication

Nitrite-catalyzed economic and sustainable bromocyclization of tryptamines/tryptophols to access hexahydropyrrolo[2,3-b]indoles/tetrahydrofuroindolines in batch and flow

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Chinese Chemical Letters 2024年第7期35卷 247-252页

作者： Xiao Xiao Biao Chen jia-Wei Li jun-Bo Zheng Xu Wang Hang zhao Fen-Er Chen Institute of Pharmaceutical Science and Technology Collaborative Innovation Center of Yangtze River Delta Region Green PharmaceuticalsZhejiang University of TechnologyHangzhou 310014China College of Chemistry and Chemical Engineering Jiangxi Normal UniversityNanchang 330022China Engineering Center of Catalysis and Synthesis for Chiral Molecules Department of ChemistryFudan UniversityShanghai 200433China Shanghai Engineering Center of Industrial Asymmetric Catalysis for Chiral Drugs Shanghai 200433China

A highly efficient and concise bromocyclization has been successfully achieved,in which tryptamine/tryptophol derivates can be transformed to valuable HPI/TFI scaffolds with economic and green ***,a controllable cascade transformation of bromocyclization and aromatic bromination has also been smoothly achieved to form dibrominated HPIs and *** could be successfully scaled up under both the batch process and a continuous flow *** most remarkable peculiarity of our process over all previous methods is that the generated water is the major ***,successful application of this new protocol has been demonstrated by the pharmaceutical and natural products syntheses.

关键词： Tryptamines and tryptophols Nitrite Economic and sustainable bromocyclization HPI and TFI structures Bath and flow

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