检索结果-南通市图书馆

Chebyshev polynomial-based Ritz method for thermal buckling and free vibration behaviors of metal foam beams

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 891-910页

作者： n.d.nGUYEn T.n.nGUYEn Faculty of Civil Engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City 71309Viet Nam Faculty of Engineering and Technology Kien Giang UniversityChau Thanh 92000Viet Nam

This study presents the Chebyshev polynomials-based Ritz method to examine the thermal buckling and free vibration characteristics of metal foam *** analyses include three models for porosity distribution and two scenarios for thermal *** material properties are assessed under two conditions,i.e.,temperature dependence and temperature *** theoretical framework for the beams is based on the higher-order shear deformation theory,which incorporates shear deformations with higher-order *** governing equations are established from the Lagrange equations,and the beam displacement fields are approximated by the Chebyshev *** simulations are performed to evaluate the effects of thermal load,slenderness,boundary condition(BC),and porosity distribution on the buckling and vibration behaviors of metal foam *** findings highlight the significant influence of temperature-dependent(Td)material properties on metal foam beams'buckling and vibration responses.

关键词： Ritz method Chebyshev function buckling vibration metal foam beam higher-order beam theory(HOBT)

Influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 563-580页

作者： n.HUMnEKAR d.SRInIVASACHARYA department of Mathematics National Institute of TechnologyWarangal 506004TelanganaIndia

The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is *** darcyBrinkman model is used to characterize the fluid flow dynamics in porous *** analytical solutions are obtained for the unidirectional and completely developed *** on a normal mode analysis,the generalized eigenvalue problem under a perturbed state is *** eigenvalue problem is then solved by the spectral ***,the critical Rayleigh number with the corresponding wavenumber is evaluated at the assigned values of the other flow-governing *** results show that increasing the darcy number,the Lewis number,the dufour parameter,or the Soret parameter increases the stability of the system,whereas increasing the inclination angle of the channel destabilizes the ***,the flow is the most unstable when the channel is vertically oriented.

关键词： nanofluid inclined channel variable viscosity linear stability double dif-fusion porous medium

Microscale shaping and rounding of ridge arrays and star pattern features on nickel mould via electrochemical polishing

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第2期12卷 207-226页

作者： Sana Zaki nan zhang Michael d.Gilchrist School of Mechanical and Materials Engineering University College DublinBelfieldDublin 4Ireland

High quality micro mould tools are critical for ensuring defect-free production of micro injection moulded *** demoulding stage of the micro injection moulding can adversely affect the surface integrity due to friction,adhesion and thermal stresses between the metallic mould and polymeric replicated *** the present work,we propose the use of precision electropolishing(EP)as a shaping and polishing process to control the draft angle and fillet radius of micro features in order to ease *** defects that occur in replicated polymer parts include cracks,burrs and distorted features.A nickel mould having multiple linear ridges and star shape patterns was designed for the present investigation to have characteristic dimensions ranging from 10μm to 150μm and with various aspect ratios to study the effect of electropolishing on modifying the shape of micro features and surface morphology.A transient 2d computational analysis has been conducted to anticipate the effect of shaping on the ni mould after electrochemical polishing with non-uniform material removal rates,based on the distribution of current *** experimental results indicate that after shaping using EP,the draft angle of star-patterns and linear patterns can be effectively increased by approximately 3.6°,while the fillet radius increases by up to 5.0μ*** controlling the electropolishing process,the surface roughness can be maintained under 50 *** work uses a green and environmental friendly nickel sulfamate electrolyte which can be effective for shaping of nickel micro features without causing any surface deposition.

关键词： Micro feature shaping and electropolishing Micro mould tools Green electrolyte demoulding micro patterns

Symmetry quantification and segmentation in STEM imaging through Zernike moments

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第8期33卷 39-48页

作者： Jiadong dan Cheng zhang 赵晓续 n.duane Loh department of Biological Sciences National University of SingaporeSingapore Center for Bioimaging Sciences(CBIS) National University of SingaporeSingapore department of Physics National University of SingaporeSingapore School of Materials Science and Engineering Peking UniversityBeijing 100871China

We present a method using Zernike moments for quantifying rotational and reflectional symmetries in scanning transmission electron microscopy(STEM)images,aimed at improving structural analysis of materials at the atomic *** technique is effective against common imaging noises and is potentially suited for low-dose imaging and identifying quantum *** showcase its utility in the unsupervised segmentation of polytypes in a twisted bilayer TaS_(2),enabling accurate differentiation of structural phases and monitoring transitions caused by electron beam *** approach enhances the analysis of structural variations in crystalline materials,marking a notable advancement in the characterization of structures in materials science.

关键词： scanning transmission electron microscopy(STEM) symmetry segmentation

Metagenomic analysis revealing the metabolic role of microbial communities in the free amino acid biosynthesis of Monascus rice vinegar during fermentation

在线全文

学校读者我要写书评

暂无评论

Food Science and Human Wellness 2024年第4期13卷 2317-2326页

作者： Hang Gao Jian zhang Li Liu Lijun Fu Yan Zhao Germán Mazza Xin zhang Beijing Academy of Food Sciences 100068 BeijingChina Institute for Research and development in Process Engineering Biotechnology and Alternative Energies(PROBIENCONICET-UNCo)8300 NeuquénArgentina

Free amino acid(FAA)is the important component of vinegar that infl uences quality perception and consumer *** is one of the major metabolites produced by microorganisms;however,the microbial metabolic network on FAA biosynthesis remains *** metagenomic analysis,this work aimed to elucidate the roles of microbes in FAA biosynthesis during Monascus rice vinegar *** profiles from functional analyses showed 14 dominant genera with high contributions to the metabolism *** metabolic network for FAA biosynthesis was then constructed,and the microbial distribution in different metabolic pathways was *** results revealed that 5 functional genera were closely involved in FAA *** study illuminated the metabolic roles of microorganisms in FAA biosynthesis and provided crucial insights into the functional attributes of microbiota in vinegar fermentation.

关键词： Monascus rice vinegar Metagenomic analysis Free amino acid synthesis Metabolic pathway Microbial distribution

Ion heat transport in electron cyclotron resonance heated L-mode plasma on the T-10 tokamak

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2024年第4期26卷 52-60页

作者： V.A.KRUPIn M.R.nURGALIEV A.R.nEMETS I.A.ZEMTSOV S.d.SUnTSOV T.B.MYALTOn d.S.SERGEEV n.A.SOLOVEV d.V.SARYCHEV d.V.RYJAKOV S.n.TUGARInOV n.n.nAUMEnKO national Research Centre“Kurchatov Institute” Moscow 123182Russia Bauman Moscow State Technical University Moscow 105005Russia Institution“Project Center ITER” Moscow 123098Russia JSC“SOLAR” Minsk 220034Belarus

Anomalous ion heat transport is analyzed in the T-10 tokamak plasma heated with electron cyclotron resonance heating(ECRH) in second-harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that in ECRH plasmas the calculated ion temperature could be overestimated, so an increase of anomalous ion heat transport is required. To study this effect two scans are presented: over the EC resonance position and over the ECRH power. The EC resonance position varies from the high-field side to the low-field side by variation of the toroidal magnetic field. The scan over the heating power is presented with on-axis and mixed ECRH regimes. discharges with high anomalous ion heat transport are obtained in all considered regimes. In these discharges the power balance ion heat conductivity exceeds the neoclassical level by up to 10 times. The high ion heat transport regimes are distinguished by three parameters: the ratio Te/Ti, the normalized electron density gradient R/■, and the ion–ion collisionality νii~*. The combination of high Te/Ti, high νii~*, and R/■=6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in the low transport scenario.

关键词： tokamak L-mode electron cyclotron resonance heating ion heat transport

Global patterns and ecological drivers of taxonomic and phylogenetic endemism in angiosperm genera

在线全文

学校读者我要写书评

暂无评论

Plant diversity 2024年第2期46卷 149-157页

作者： Hong Qian Brent d.Mishler Jian zhang Shenhua Qian Research and Collections Center Illinois State Museum1011 East Ash StreetSpringfieldIL 62703USA University and Jepson Herbaria Department of Integrative BiologyUniversity of CaliforniaBerkeleyCA 94720-2465USA Center for Global Change and Complex Ecosystems Zhejiang Tiantong Forest Ecosystem National Observation and Research StationSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment Ministry of EducationChongqing UniversityChongqing 400045China

Endemism of lineages lies at the core of understanding variation in community composition among geographic regions because it reflects how speciation,extinction,and dispersal have influenced current ***,we investigated geographic patterns and ecological drivers of taxonomic and phylogenetic endemism of angiosperm genera across the *** identify centers of paleo-endemism and neo-endemism of angiosperm genera,and show that they are mostly located in the Southern Hemisphere in tropical and subtropical regions,particularly in Asia and *** categories of phylogenetic endemism centers can be differentiated using current climate *** climate,historical climate change,and geographic variables together explained~80%of global variation in taxonomic and phylogenetic endemism,while 42-46%,1%,and 15%were independently explained by these three types of variables,*** our findings show that past climate change,current climate,and geography act together in shaping endemism,which are consistent with the findings of previous studies that higher temperature and topographic heterogeneity promote *** study showed that many centers of phylogenetic endemism of angiosperms,including regions in Amazonia,Venezuela,and west-central tropical Africa that have not previously been identified as biodiversity hotspots,are missed by taxon-based measures of endemism,indicating the importance of including evolutionary history in biodiversity assessment.

关键词： Angiosperm Current climate Endemism Historical climate change Topographic heterogeneity

Multifunctional SnO_(2) Qds/MXene Heterostructures as Laminar Interlayers for Improved Polysulfide Conversion and Lithium Plating Behavior

在线全文

学校读者我要写书评

暂无评论

nano-Micro Letters 2024年第11期16卷 156-169页

作者： Shungui deng Weiwei Sun Jiawei Tang Mohammad Jafarpour Frank nüesch Jakob Heier Chuanfang zhang College of Materials Science and Engineering Sichuan UniversityChengdu 610065People’s Republic of China Laboratory for Functional Polymers Swiss Federal Laboratories for Materials Science and Technology(EMPA)Überlandstrasse 1298600 DübendorfSwitzerland Institute of Materials Science and Engineering Ecole Polytechnique Fédérale de Lausanne(EPFL)Station 121015 LausanneSwitzerland Key Laboratory of Quantum Materials and devices of Ministry of Education School of PhysicsSoutheast UniversityNanjing 211189People’s Republic of China SEU‑FEI nano‑Pico Center Key Laboratory of MEMS of Ministry of EducationSoutheast UniversityNanjing 210096People’s Republic of China

Poor cycling stability in lithium–sulfur(Li–S)batteries necessitates advanced electrode/electrolyte design and innovative interlayer *** catalysis has emerged as a promising approach,leveraging the adsorption and catalytic performance on lithium polysulfides(LiPSs)to inhibit LiPSs shuttling and improve redox *** this study,we report an ultrathin and laminar SnO_(2)@MXene heterostructure interlayer(SnO_(2)@MX),where SnO_(2) quantum dots(Qds)are uniformly distributed across the MXene *** combined structure of SnO_(2) Qds and MXene,along with the creation of numerous active boundary sites with coordination electron environments,plays a critical role in manipulating the catalytic kinetics of sulfur *** Li–S cell with the SnO_(2)@MX-modified separator not only demonstrates superior electrochemical performance compared to cells with a bare separator but also induces homogeneous Li deposition during *** a result,an areal capacity of 7.6 mAh cm^(-2) under a sulfur loading of 7.5 mg cm^(-2) and a high stability over 500 cycles are *** work demonstrates a feasible strategy of utilizing a laminar separator interlayer for advanced Li–S batteries awaiting commercialization and may shed light on the understanding of heterostructure catalysis with enhanced reaction kinetics.

关键词： Lithium-sulfur battery Heterogeneous catalysis Heterostructure Redox kinetics Lithium dendrites

A core-satellite self-assembled SERS aptasensor containing a“biological-silent region”Raman tag for the accurate and ultrasensitive detection of histamine

在线全文

学校读者我要写书评

暂无评论

Food Science and Human Wellness 2024年第2期13卷 1029-1039页

作者： Chen Chen Yingfang zhang Ximo Wang Xuguang Qiao Geoffrey I.n.Waterhouse Zhixiang Xu Key Laboratory of Food Processing Technology and Quality Control in Shandong Province College of Food Science and EngineeringShandong Agricultural UniversityTai’an 271018China School of Chemical Sciences The University of AucklandAuckland 1142New Zealand

Herein,a novel interference-free surface-enhanced Raman spectroscopy(SERS)strategy based on magnetic nanoparticles(MnPs)and aptamer-driven assemblies was proposed for the ultrasensitive detection of histamine.A core-satellite SERS aptasensor was constructed by combining aptamer-decorated Fe_(3)O_(4)@Au MnPs(as the recognize probe for histamine)and complementary dnA-modified silver nanoparticles carrying 4-mercaptobenzonitrile(4-MBn)(Ag@4-MBn@Ag-c-dnA)as the SERS signal probe for the indirect detection of *** an applied magnetic field in the absence of histamine,the assembly gave an intense Raman signal at“Raman biological-silent”region due to *** the presence of histamine,the Ag@4-MBn@Ag-c-dnA SERS-tag was released from the Fe_(3)O_(4)@Au MnPs,thus decreasing the SERS *** optimal conditions,an ultra-low limit of detection of 0.65×10^(-3)ng/mL and a linear range 10^(-2)-10^5 ng/mL on the SERS aptasensor were *** histamine content in four food samples were analyzed using the SERS aptasensor,with the results consistent with those determined by high performance liquid *** present work highlights the merits of indirect strategies for the ultrasensitive and highly selective SERS detection of small biological molecules in complex matrices.

关键词： Surface-enhanced Raman spectroscopy Raman biological-silent region Aptamer Histamine detection Universal SERS-tag