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Effects of layer interactions on instantaneous stability of finite Stokes flows

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 69-84页

作者： Chen ZHAO Zhenli CHEN C.t.MUtASA Dong li School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

the stability analysis of a finite Stokes layer is of practical importance in flow control. In the present work, the instantaneous stability of a finite Stokes layer with layer interactions is studied via a linear stability analysis of the frozen phases of the base flow. the oscillations of two plates can have different velocity amplitudes, initial phases, and frequencies. the effects of the Stokes-layer interactions on the stability when two plates oscillate synchronously are analyzed. the growth rates of two most unstable modes when δ t equal, and δ = δ*/h*, where δ*and h*are the Stokes-layer thickness and the half height of the channel, respectively. However, their vorticities are different. the vorticity of the most unstable mode is symmetric, while the other is asymmetric. the Stokes-layer interactions have a destabilizing effect on the most unstable mode when δ tabilizing effect when δ > 0.68. However, the interactions always have a stabilizing effect on the other unstable mode. It is explained that one of the two unstable modes has much higher dissipation than the other one when the Stokes-layer interactions are strong. We also find that the stability of the Stokes layer is closely related to the inflectional points of the base-flow velocity profile. the effects of inconsistent velocity-amplitude, initial phase, and frequency of the oscillations on the stability are analyzed. the energy of the most unstable eigenvector is mainly distributed near the plate of higher velocity amplitude or higher oscillation frequency. the effects of the initial phase difference are complicated because the base-flow velocity is extremely sensitive to the initial phase.

关键词： finite Stokes layer instantaneous stability Stokes-layer interaction asynchronous oscillation

Preliminary Evaluation of Injecting Brown Coalsin Ironmaking Blast Furnace

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Preliminary Evaluation of Injecting Brown Coalsin Ironmaking...

Physics-informed deep learning for fringe pattern analysis

“第十届中国钢铁年会”暨“第六届宝钢学术年会”

作者： Shen y S liao J H yu A B li y t Zhu J M Department of Chemical Engineering Monash University Ironmaking Baosteel

Pulverized coal injection(PCI)iswidely practised in ironmaking industry due to many benefits in particular the reduction of production cost,where black coal was largely used at *** brown coal with aneven lower cost has a great potential to be used in PCI technology and further reduce the cost by replacing the black *** brown coal needs upgrading before burning in the furnace aiming for removing the massive moisture0%,usually by briquetting or *** is unclear whether the brown coal products can be used in ironmaking blast furnace(BF)and replicate the performance of black coal in aspects of aerodynamic and physicochemical *** this study,an industry-scale three-dimensional CFD PCI model is used to preliminarily study the feasibility of using brown coals in PCI operation by comparing the coal combustion efficiency of brown coalsupgraded by briquetting andpyrolysis with one given black coal under typical PCI conditions,in terms of flow,temperature,gas composition and coal combusts *** simulation results indicate that the brown coal upgraded by briquettingshowsquite different coal burnoutat the raceway end while the brown coal upgraded by pyrolysis shows similar burnout at the raceway end,compared to the given black *** modelling offers a cost-effective way to optimize and control the injection of different brown coals upgraded by different methods under PCI conditions.

关键词： blast furnace brown coal PCI CFD

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Opto-Electronic Advances 2024年第1期7卷 4-15页

作者： Wei yin yuxuan Che Xinsheng li Mingyu li yan Hu Shijie Feng Edmund y.Lam Qian Chen Chao Zuo Smart Computational Imaging Laboratory(SCILab) School of Electronic and Optical EngineeringNanjing University of Science and TechnologyNanjing 210094China Smart Computational Imaging Research Institute(SCIRI)of Nanjing University of Science and technology Nanjing 210019China Jiangsu Key Laboratory of Spectral Imaging&Intelligent Sense Nanjing 210094China Department of Electrical and Electronic Engineering The University of Hong KongPokfulamHong Kong SAR 999077China

Recently,deep learning has yielded transformative success across optics and photonics,especially in optical *** neural networks (DNNs) with a fully convolutional architecture (e.g.,U-Net and its derivatives) have been widely implemented in an end-to-end manner to accomplish various optical metrology tasks,such as fringe denoising,phase unwrapping,and fringe ***,the task of training a DNN to accurately identify an image-to-image transform from massive input and output data pairs seems at best naive,as the physical laws governing the image formation or other domain expertise pertaining to the measurement have not yet been fully exploited in current deep learning *** this end,we introduce a physics-informed deep learning method for fringe pattern analysis (PI-FPA) to overcome this limit by integrating a lightweight DNN with a learning-enhanced Fourier transform profilometry (Le FtP) *** parameterizing conventional phase retrieval methods,the Le FtP module embeds the prior knowledge in the network structure and the loss function to directly provide reliable phase results for new types of samples,while circumventing the requirement of collecting a large amount of high-quality data in supervised learning *** by the initial phase from Le FtP,the phase recovery ability of the lightweight DNN is enhanced to further improve the phase accuracy at a low computational cost compared with existing end-to-end *** results demonstrate that PI-FPA enables more accurate and computationally efficient single-shot phase retrieval,exhibiting its excellent generalization to various unseen objects during *** proposed PI-FPA presents that challenging issues in optical metrology can be potentially overcome through the synergy of physics-priors-based traditional tools and data-driven learning approaches,opening new avenues to achieve fast and accurate single-shot 3D imaging.

关键词： optical metrology deep learning physics-informed neural networks fringe analysis phase retrieval

Spatiotemporal mapping of(ultra‐)mafic magmatic mine areas:Implications of economic and political realities in China

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Deep Underground Science and Engineering 2024年第1期3卷 91-102页

作者： Heling li liang tang tim t.Werner Zhengmeng Hou Fan Meng Jingjing li College of Earth Sciences Chengdu University of TechnologyChengduChina Institute of Subsurface Energy Systems Clausthal University of TechnologyClausthal ZellerfeldGermany School of Geography Earth and Atmospheric SciencesFaculty of ScienceThe University of MelbourneMelbourneVictoriaAustralia

the spatiotemporal extension/expansion of mine areas is affected by multiple *** far,very little has been done to examine the interaction between mine areas and political or economic ***(ultra‐)mafic magmatic mines in China played a specific role in supporting national development and providing an ideal research subject for monitoring their *** this study,remote sensing and mining‐related GIS data were used to identify and analyze 1233(ultra‐)mafic magmatic mine area polygons in China,which covered approximately 322.96 km2 of land and included a V–ti–Fe mine,a copper–nickel mine,a chromite mine,an asbestos mine,and a diamond *** was found that(1)the areal expansion of mines is significantly related to the mine types,perimeter,topography,and population density.(2)the mine area variation also reflects market and policy *** temporal expansion of the mine area from 2010 to 2020 followed an S‐shaped pattern(with the turning point occurring in 2014),closely related to iron overcapacity and tightened mining policies.(3)the complexity(D)of the mine area may reflect mine design and excavation *** be specific,lower D indicates early‐stage or artisanal/small‐scale mining,whereas higher D represents large‐scale *** study demonstrates that the detailed mapping of mine land can serve as an indicator to implement miningrelated market and policy ***(ultra‐)mafic mines area data set can be accessed at https://***/record/7636616#.y-p0uXaZOa0.

关键词： complexity mine area mining and socioeconomic interaction spatiotemporal distribution (ultra‐)mafic magmatic mine

Food security amid the COVID-19 pandemic in Central Asia:Evidence from rural tajikistan

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Journal of Integrative Agriculture 2024年第8期23卷 2853-2867页

作者： yuhan Zhao Chen Qian yumei Zhang Xiande li Kamiljon t.Akramov Institute of Agricultural Economics and Development Chinese Academy of Agricultural SciencesBeijing 100081China Academy of Global Food Economics and Policy College of Economics and ManagementChina Agricultural UniversityBeijing 100083China International Food Policy Research Institute(IFPRI) WashingtonD.C.20005USA

Food security has been long understudied in the context of Central *** present an analysis examining household-level food demand for tajikistan and assessing the magnitude of its food security changes during the COVID-19 *** on an extensive household survey data set from tajikistan,we estimate the expenditure,income,and price elasticities for nine food categories using the QUAIDS ***,we develop a microsimulation model using the estimated elasticities to assess the dual impact of declining remittance income and rising food prices stemming from the pandemic *** are significant differences in demand elasticities across food groups,with high elasticities observed for nutritious foods,such as meat,fruit,eggs,and milk,in rural ***,our findings show that changes in remittance income and food prices significantly negatively affected food security for rural households during the COVID-19 *** findings have important implications for policymakers concerned about rural livelihoods and food security in remittance-receiving economies during the post-pandemic period.

关键词： international remittances food security COVID-19 tajikistan Central Asia

Reply to the note by li Piani et al.

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Defence technology（防务技术） 2024年第1期31卷 603-606页

作者： t.li Piani J.Weerheijm L.J.Sluys tU Delft Stevinweg 12628 CNDelftthe Netherlands tNO PO Box 452280 AARijswijkthe Netherlands NLDA Faculty of Military Sciences1781 CADen Helderthe Netherlands

In 2017,a ballistic phenomenological model was proposed by the authors of Ref.[1] to numerically simulate the experimental depths of small caliber projectiles impacting walls made of *** opportunity for a new model in the field revealed from the observation that two older models recently used by the authors of Ref.[2] shared a linear relationship between the penetration depth P and the impacting velocity v_(O).

关键词： Penetration Adobe Modeling

Microstructure evolution and shape memory behaviors of Ni_(47)ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

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Journal of Materials Science & technology 2024年第4期171卷 80-93页

作者： y.H.Zhang H.li Z.W.yang X.liu Q.F.Gu State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of High-Performance Precision Forming technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)ti_(44)Nb_(9)shape memory alloy(SMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SMA ***,microstructure evolution and deformation mechanisms of Ni_(47)ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory behaviors of Ni_(47)ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the Niti matrix andβ-Nb *** stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density of{114}austenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(t)upon heating increases first and then ***ε_(re)^(t)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(t)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(t)is mainly associated with the irrecoverable strain by{20−1}martensite *** effe

关键词： Ni_(47)ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis thermomechanical loading Microstructure evolution Shape memory behaviors Stress-induced martensitic transformation Deformation twinning

Comparative analyses of mitogenomes in the social bees with insights into evolution of long inverted repeats in the Meliponini

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Zoological Research 2024年第1期45卷 160-175页

作者： yu-Ran li Zheng-Wei Wang Richard t.Corlett Wen-Bin yu yunnan Key Laboratory for the Conservation of tropical Rainforests and Asian Elephants&Center for Integrative Conservation Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303China CAS Key Laboratory of tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303China Southeast Asia Biodiversity Research Institute Chinese Academy of SciencesMenglaYunnan 666303China University of Chinese Academy of Sciences Shijingshan DistrictBeijing 100049China

the insect mitogenome is typically a compact circular molecule with highly conserved gene ***,mitogenome structural variations have been reported in specific taxa,and gene rearrangements,usually the tRNAs,occur in different *** synapomorphies of mitogenome organizations can provide information for phylogenetic inferences,comparative analyses of mitogenomes have been given increasing ***,most studies use a very few species to represent the whole genus,tribe,family,or even order,overlooking potential variations at lower taxonomic levels,which might lead to some incorrect *** provide new insights into mitogenome organizations and their implications for phylogenetic inference,this study conducted comparative analyses for mitogenomes of three social bee tribes(Meliponini,Bombini,and Apini)based on the phylogenetic framework with denser taxonomic sampling at the species and population *** analyses revealed that mitogenomes of Apini and Bombini are the typical type,while those of Meliponini show diverse variations in mitogenome sizes and *** inverted repeats(IRs)cause significant gene rearrangements of protein coding genes(PCGs)and rRNAs in Indo-Malay/Australian stingless bee *** evolution analyses showed that the lineage with IRs have lower dN/dS ratios for PCGs than lineages without IRs,indicating potential effects of IRs on the evolution of mitochondrial *** finding of IRs and different patterns of gene rearrangements suggested that Meliponini is a hotspot in mitogenome *** conserved PCGs and rRNAs whose rearrangements were found only in the mentioned lineages within Meliponini,tRNA rearrangements are common across all three tribes of social bees,and are significant even at the species level,indicating that comprehensive sampling is needed to fully understand the patterns of tRNA rearrangements,and their implications for phylogenetic inference.

关键词： Social bees Phylogeny Mitogenome structure Gene rearrangement Inverted repeats

Decoding human brain functions: Multi-modal, multi-scale insights

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the Innovation 2024年第1期5卷 17-18页

作者： Camilla t.Erichsen Deying li lingzhong Fan Sino-Danish Center University of Chinese Academy of SciencesBeijing 100190China Brainnetome Center Institute of AutomationChinese Academy of SciencesBeijing 100190China Core Centre for Molecular Morphology Section for Stereology and MicroscopyDepartment of Clinical MedicineAarhus University8200 Aarhus NDenmark School of Health and life Sciences University of Health and Rehabilitation SciencesQingdao 266000China

Unraveling the intricate relationship between the structure and function of the human brain remains a central and unresolved question in *** considerations impose significant constraints on invasive techniques in human neuroscience ***,knowledge about human brain function often relies on animal models to provide valuable discoveries and ***,caution is warranted,as findings from animal studies may not always be directly translatable to humans,especially when investigating higher cognitive functions.

关键词： functions insight modal