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theoretical and experimental investigations on an X-shaped vibration isolator with active controlled variable stiffness

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1371-1386页

作者： Zeyu CHAI J.t.HAN Xuyuan SONG Jian ZANG Yewei ZHANG Zhen ZHANG College of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China Jacobs School of Engineering University of California San DiegoSan Diego CA 92122U.S.A. Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of EducationNortheastern UniversityShenyang 110819China

A novel X-shaped variable stiffness vibration isolator(X-VSVI)is *** Runge-Kutta method,harmonic balance method,and wavelet transform spectra are introduced to evaluate the performance of the X-VSVI under various *** layer number,the installation angle of the X-shaped structure,the stiffness,and the active control parameters are systematically *** addition,a prototype of the X-VSVI is manufactured,and vibration tests are carried *** results show that the proposed X-VSVI has a superior adaptability to that of a traditional X-shaped mechanism,and shows excellent vibration isolation performance in response to different amplitudes and forms of ***,the vibration isolation efficiency of the device can be improved by appropriate adjustment of parameters.

关键词： bionic vibration isolation X-shaped structure variable stiffness structure nonlinear dynamics prototype experiment

An MPI parallel DEM-IMB-LBM framework for simulating fluid-solid interaction problems

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2219-2231页

作者： Ming Xia Liuhong Deng Fengqiang Gong tongming Qu Y.t.Feng Jin Yu Hunan Key Laboratory of Geomechanics and Engineering Safety Xiangtan UniversityXiangtan411105China School of Civil Engineering Southeast UniversityNanjing211189China Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyHong KongChina Zienkiewicz Centre for Computational Engineering Swansea UniversitySwanseaSA18ENUK Fujian Research Center for tunneling and Urban Underground Space Engineering Huaqiao UniversityXiamen361021China

the high-resolution DEM-IMB-LBM model can accurately describe pore-scale fluid-solid interactions,but its potential for use in geotechnical engineering analysis has not been fully unleashed due to its prohibitive computational *** overcome this limitation,a message passing interface(MPI)parallel DEM-IMB-LBM framework is proposed aimed at enhancing computation *** framework utilises a static domain decomposition scheme,with the entire computation domain being decomposed into multiple subdomains according to predefined processors.A detailed parallel strategy is employed for both contact detection and hydrodynamic force *** particular,a particle ID re-numbering scheme is proposed to handle particle transitions across sub-domain *** benchmarks are conducted to validate the accuracy and overall performance of the proposed ***,the framework is applied to simulate scenarios involving multi-particle sedimentation and submarine *** numerical examples effectively demonstrate the robustness and applicability of the MPI parallel DEM-IMB-LBM framework.

关键词： Discrete element method(DEM) Lattice Boltzmann method(LBM) Immersed moving boundary(IMB) Multi-cores parallelization Message passing interface(MPI) CPU Submarine landslides

Evaluation of periglacial landforms and formation of soil properties on the Mount Honaz,SW türkiye

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Journal of Mountain Science 2024年第9期21卷 3047-3067页

作者： SERİN Soner UNCU Levent DEDE Volkan tÜRKEŞMurat Institute of Social Sciences İstanbul Universityİstanbul 34119Türkiye Department of Geography BilecikŞeyh Edebali UniversityBilecik 11234Türkiye Department of Geography Ardahan UniversityArdahan 75002Türkiye Center for Climate Change and Policy Studies Boğaziçi Universityİstanbul 34342Türkiye

the main aim of this study is to explain periglacial processes on the summits of Mount Honaz(2571 m a.s.l.),define periglacial landforms,and determine the relationships between morphometric features and topographic *** circles,stony earth circles,non sorted steps,and non sorted stripes were identified on the summits of Mount ***'s correlation coefficient(r)and linear regression analyses were performed by taking metric measurements from 125 periglacial landforms to describe their morphometric features(length,width,height)of periglacial landforms and explain the relationships between them and topographic factors(elevation,slope).to explain the relationships between periglacial landforms and soil properties,soil samples from 11 periglacial landforms were taken and *** landforms,which continue to develop on the summits of Mount Honaz today,have been evaluated with present climate *** of soil samples indicates a notable impact of parent material on the genesis of periglacial *** high ratio of organic matter in mud circle and non sorted step landforms and the high lime ratio in stony earth circle landforms prove a strong relationship between the formation mechanisms of landforms and the soil ***,it is consistent with the findings obtained from the analysis that severe periglacial processes and washing and scavenging events are experienced more on the northern slopes.

关键词： Periglacial processes and geomorphology Soil analysis Morphometric analysis Mount Honaz türkiye

HI in High Gas-phase Metallicity Dwarf Galaxy WISEA J230615.06+143927.9

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Research in Astronomy and Astrophysics 2024年第1期24卷 292-299页

作者： Yan Guo C.Sengupta t.C.Scott P.Lagos Y.Luo Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China Institute of Astrophysics and Space Sciences(IA Porto) Rua das Estrelas4150-762PortoPortugal

We present resolved Giant Metrewave Radio telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a tidal Dwarf Galaxy(tDG) candidate. tDGs are observed to have higher metallicities than normal dwarfs. J2306 has an unusual combination of a blue g-r color of 0.23 mag, irregular optical morphology and high-metallicity(12 +log(O/H) = 8.68 ± 0.14), making it an interesting galaxy to study in more detail. We find J2306 to be an H I rich galaxy with a large extended, unperturbed rotating H I disk. Using our H I data we estimated its dynamical mass and found the galaxy to be dark matter(DM) dominated within its H I radius. the quantity of DM, inferred from its dynamical mass, appears to rule out J2306 as an evolved tDG. A wide area environment search reveals J2306 to be isolated from any larger galaxies which could have been the source of its high gas metallicity. Additionally, the H I morphology and kinematics of the galaxy show no indication of a recent merger to explain the *** detailed optical spectroscopic observations of J2306 might provide an answer to how a seemingly ordinary irregular dwarf galaxy achieved such a high level of metal enrichment.

关键词： galaxies:abundances galaxies:dwarf galaxies:irregular radio lines:galaxies radio lines:ISM

Molecular phylogeny and taxonomy of Phlomoides(Lamiaceae subfamily Lamioideae)in China:Insights from molecular and morphological data

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Plant Diversity 2024年第4期46卷 462-475页

作者： Yue Zhao Ya-Ping Chen Bryan t.Drew Fei Zhao Maryam Almasi Orzimat t.turginov Jin-Fei Xiao Abdul G.Karimi Yasaman Salmaki Xiang-Qin Yu Chun-Lei Xiang CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau&Inner Mongolia Key Laboratory of Grassland Ecology School of Ecology and EnvironmentInner Mongolia UniversityHohhot 010000Inner MongoliaChina Department of Biology University of Nebraska at KearneyKearneyNE 68849USA CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization&Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province Chinese Academy of SciencesChengdu Institute of BiologyChengdu 610042SichuanChina Center of Excellence in Phylogeny of Living Organisms Department of Plant ScienceCollege of ScienceUniversity of TehranP.O.Box 14155-6455TehranIran Institute of Botany Academy of Sciences of the Republic of UzbekistanTashkent 100047Uzbekistan Faculty of Biology Department of Botany and Plant PhysiologyNational University of Uzbekistan named after Mirzo UlugbekTashkent 100174Uzbekistan Faculty of Pharmacy Kabul University1006 KabulAfghanistan

Phlomoides,with 150-170 species,is the second largest and perhaps most taxonomically challenging genus within the subfamily Lamioideae(Lamiaceae).With about 60 species,China is one of three major biodiversity centers of *** some Phlomoides species from China have been included in previous molecular phylogenetic studies,a robust and broad phylogeny of this lineage has yet to be ***,given the myriad new additions to the genus,the existing infrageneric classification needs to be evaluated and ***,we combine molecular and morphological data to investigate relationships within Phlomoides,with a focus on Chinese *** observed that plastid DNA sequences can resolve relationships within Phlomoides better than nuclear ribosomal internal and external transcribed spacer regions(nrItS and nrEtS).Molecular phylogenetic analyses confirm the monophyly of Phlomoides,but most previously defined infrageneric groups are not *** addition,morphological analysis demonstrates the significant taxonomic value of eight characters to the *** on our molecular phylogenetic analyses and morphological data,we establish a novel section Notochaete within Phlomoides,and propose three new combinations as well as three new *** study presents the first molecular phylogenetic analyses of Phlomoides in which taxa representative of the entire genus are included,and highlights the phylogenetic and taxonomic value of several morphological characters from species of Phlomoides from *** study suggests that a taxonomic revision and reclassification for the entire genus is necessary in the future.

关键词： Lamioideae Molecular phylogenetics Morphology Phlomideae taxonomy

Morphological and molecular description of a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii ***.(Diptera:Psychodidae)from Western Ghats,India

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Asian Pacific Journal of tropical Medicine 2024年第5期17卷 226-234页

作者： Prasanta Saini Harish Kumar Shah Mathew Jessu Sonia t tom Anns KP Amju ICMR-Vector Control Research Centre(Field Station) KottayamKeralaIndia

Objective:to report a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii ***.(Diptera:Psychodidae)from Western Ghats,***:A systematic sandfly survey was conducted in the thrissur and Kollam districts of Kerala,India using mechanical aspirators,light and sticky traps,both indoor and outdoor habitats,for a period of one *** acid barcoding of samples was performed targeting mitochondrial cytochrome oxidase I(COI)gene and sequence generated was subjected to phylogenetic ***:Sergentomyia(Neophlebotomus)ashwanii,a new sandfly species is recorded and described in this communication.A single row of 10-12 pointed teeth in the cibarium with 4-6 small denticles or fore-teeth are the key characteristics that is distinctive from other members of the subgenus *** COI barcode followed by phylogenetic analysis of the nucleotide sequence confirms that specimens of the species belong to the same taxonomic group while the genetic distance(14.2%)with the congeners established it to be a different ***:the Western Ghats'being an important biodiversity hotspot and has dearth of systematic entomological surveys on *** current study tried to fill the void and also report a new sandfly species.

关键词： Sergentomyia(Neophlebotomus)ashwanii COI barcode Western Ghats Phlebotomine sandflies

Low crude protein formulation with supplemental amino acids for its impacts on intestinal health and growth performance of growing-finishing pigs

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Journal of Animal Science and Biotechnology 2024年第4期15卷 1590-1606页

作者： Marcos Elias Duarte Wanpuech Parnsen Shihai Zhang Marvio L.t.Abreu Sung Woo Kim Department of Animal Science North Carolina State UniversityRaleighNC 27695USA

Background Low crude protein(CP)formulations with supplemental amino acids(AA)are used to enhance intestinal health,reduce costs,minimize environmental impact,and maintain growth performance of ***,extensive reduction of dietary CP can compromise growth performance due to limited synthesis of non-essential AA and limited availability of bioactive compounds from protein supplements even when AA requirements are ***,implementing a low CP formulation can increase the net energy(NE)content in feeds causing excessive fat *** supplementation of functional AA,coupled with low CP formulation could further enhance intestinal health and glucose metabolism,improving nitrogen utilization,and growth *** experiments were conducted to evaluate the effects of low CP formulations with supplemental AA on the intestinal health and growth performance of growing-finishing *** In Exp.1,90 pigs(19.7±1.1 kg,45 barrows and 45 gilts)were assigned to 3 treatments:CON(18.0%CP,supplementing Lys,Met,and thr),LCP(16.0%CP,supplementing Lys,Met,thr,trp,and Val),and LCPt(16.1%CP,LCP+0.05%SID trp).In Exp.2,72 pigs(34.2±4.2 kg BW)were assigned to 3 treatments:CON(17.7%CP,meeting the requirements of Lys,Met,thr,and trp);LCP(15.0%CP,meeting Lys,thr,trp,Met,Val,Ile,and Phe);and VLCP(12.8%CP,meeting Lys,thr,trp,Met,Val,Ile,Phe,His,and Leu).In Exp.3,72 pigs(54.1±5.9 kg BW)were assigned to 3 treatments and fed experimental diets for 3 phases(grower 2,finishing 1,and finishing 2).treatments were CON(18.0%,13.8%,12.7%CP for 3 phases;meeting Lys,Met,thr,and trp);LCP(13.5%,11.4%,10.4%CP for 3 phases;meeting Lys,thr,trp,Met,Val,Ile,and Phe);and LCPG(14.1%,12.8%,11.1%CP for 3 phases;LCP+Glu to match SID Glu with CON).All diets had 2.6 Mcal/kg *** In Exp.1,overall,the growth performance did not differ among *** LCPt increased(Pthe duodenum and *** LCP and LCPt increased(Pt-1,4F2hc,and B0At exp

关键词： Amino acids Growing-finishing pigs Growth performance Intestinal health Low crude protein formulation Net energy

Decision and Coordination of an E-commerce Supply Chain Considering Returns and Network Externalities

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JOURNAL OF SYStEMS SCIENCE AND SYStEMS ENGINEERING 2024年第5期33卷 552-575页

作者： Shen, Liang Lin, Fei Wang, Yuyan Ding, Luping Cheng, t. C. E. Wang, Dexia Shandong Univ Finance & Econ Sch Publ Finance & Taxat Jinan 250014 Peoples R China Shandong Univ Finance & Econ Sch Management Sci & Engn Jinan 250014 Peoples R China Hong Kong Polytech Univ PolyU Business Sch Hung Hom Kowloon Hong Kong 999077 Peoples R China

Considering the large number of returns in online sales and the network externalities of e-platforms, we develop a decentralized model and a centralized model to explore the impacts of returns and network externalities on e-commerce supply chain (ECSC) decisions. We show that in the decentralized model, the service level, price, market demand, and ECSC members' profits increase with the network externality strength. However, the service level and price increase, while the market demand and ECSC members' profits decrease with the product return rate. the centralized model is the optimal operating mode when it is properly coordinated. We design the "commission and return cost-sharing" contract to optimize ECSC, in which the proportion of the e-platform's sharing of the return handling cost is exactly equal to the proportion of the system profit after coordination. Based on the decentralized model, we develop two extended models in which we endogenize the impacts of the service level and return rate on the network externality strength. through comparisons between the extended and decentralized models, we show that high-quality service can improve ECSC's profitability, while a high return rate hurts its economic performance.

关键词： E-commerce supply chain coordination mechanism network externalities return products POLICY COMPAtIBILItY PERFORMANCE COMPEtItION REtAILER IMPACt tIME

tensile deformation of fine-grained Mg at 4K,78K and 298K

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Journal of Magnesium and Alloys 2024年第6期12卷 2534-2556页

作者： M.Walag A.Kula P.Noga t.tokarski G.Cios M.Niewczas AGH University of Krakow Faculty of Non-Ferrous MetalsKrakowPoland AGH University of Krakow Academic Centre for Materials and NanotechnologyKrakowPoland Materials Science and Engineering McMaster UniversityHamiltonCanada

the impact of grain size, ranging from 0.9 μm to 9 μm, on the mechanical properties of commercially pure Mg is investigated at temperatures of 4K, 78K, and 298K. the mechanisms governing plastic flow are influenced by both grain size and temperature. At 4K and 78K, dominant deformation modes in Mg involve dislocation glide and extension twinning, regardless of grain size. the interactions between basal and non-basal dislocations and dislocations with grain boundaries promote an unusually high rate of work hardening in the plastic regime, leading to premature failure. the yield stress follows the Hall-Petch relationship σy~ k/√d, with the slope k increasing with decreasing temperature. At 298K, in addition to dislocation glide and twinning, grain boundary sliding(GBS) becomes significant in samples with grain sizes below 3 μm, considerably enhancing the material's deformability. GBS activation provides an additional recovery mechanism for dislocations accumulating at grain boundaries, facilitating their absorption during sliding and rotation. Analysis of σ Θ relationship suggests that the basal slip is the dominant dislocation mode in Mg at 298K. Decreasing grain size suppresses dislocation activity and twinning and increases GBS, resulting in lower Θ and σ Θ values. Suppressing conventional deformation modes coupled with enhanced GBS yields stress softening, breaking down the Hall-Petch relationship in Mg below 3 μm grain size, leading to an inverse Hall-Petch behaviour. the work reports new data on the strength, ductility, work hardening and fracture behaviour, and their variations with Mg grain size across different temperature regimes.

关键词： Polycrystalline Mg Mechanical properties Deformation mechanisms Work-hardening texture evolution Cryogenic temperatures Hall-Petch relationship