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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 0.9μm to 9μm,on the mechanical properties of commercially pure mg is investigated at temperatures of 4K,78K,and *** mechanisms governing plastic flow are influenced by both grain size and *** 4K and 78K,dominant deformation modes in mg involve dislocation glide and extension twinning,regardless of grain *** 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 *** yield stress follows the Hall-petch relationshipσ_(y)∼k/√d,with the slope k increasing with decreasing *** 298K,in addition to dislocation glide and twinning,grain boundary sliding(GBS)becomes significant in samples with grain sizes below 3μm,considerably enhancing the material’s *** activation provides an additional recovery mechanism for dislocations accumulating at grain boundaries,facilitating their absorption during sliding and *** ofσrelationship suggests that the basal slip is the dominant dislocation mode in mg at *** grain size suppresses dislocation activity and twinning and increases GBS,resulting in lowerandσ*** conventional deformation modes coupled with enhanced GBS yields stress softening,breaking down the Hall-petch relationship in mg below 3μm grain size,leading to an inverse Hall-petch *** 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

Superplasticity of fine-grained mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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Journal of magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.t.Jeong S.w.Lee w.J.Kim Department of materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

the superplastic behavior and associated deformation mechanisms of a fine-grained mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCpαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

the CCD instrument background of the SmILE SXI

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Earth and planetary physics 2024年第1期8卷 15-24页

作者： m.w.J.Hubbard O.Hetherington D.J.Hall t.w.Buggey S.parsons t.Arnold A.Holland C.pagani S.Sembay Centre for Electronic Imaging The Open UniversityMilton KeynesMK76AAUK X-ray and Observational Astronomy Group Department of Physics&AstronomyUniversity of LeicesterLE17RHUK

the ESA and CAS SmILE mission orbit is highly elliptical and will pass through multiple radiation *** Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is *** shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen ***,two radiation environments can be approximated based on the shutter door position:open and *** instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two *** to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two *** results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar *** is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.

关键词： instrument background X-ray astronomy space radiation

multi-scale habitat influences sprainting and group size of a freshwater-obligate smooth-coated otter(Lutrogale perspicillata) in tungabhadra Otter Conservation Reserve, India

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Ecological processes 2024年第1期13卷 159-175页

作者： Ankit moun p.Ramesh Kumar m.malathi priya t.Ramesh Riddhika Kalle Sálim Ali Centre for Ornithology and Natural History Deputy Conservator of Forests Bellary Territorial Forest Division Deputy Conservator of Forests Working Plan and Survey and Research WingBellary Territorial Forest Division Centre for Functional Biodiversity University of Kwa Zulu-Natal

Background the impact of changing land-use patterns and associated anthropogenic threats on scale-dependent habitat use of semi-aquatic mustelids in scent-marking and social behaviour can provide important insights into the habitat ecology of smooth-coated otters(Lutrogale perspicillata).methods we sampled 180 stream segments(100–400 m) as spatial replicates of 60 1-km2 sites to record indirect evidence(i.e. spraints and mass latrine sites) and group sizes of smooth-coated otters along the tungabhadra Otter Conservation Reserve(tOCR) during the dry season. to quantify habitat, we recorded stream characteristics, riparian vegetation, and anthropogenic disturbances at the local scale, and hydro-environmental characteristics and land uses at the landscape scale. Using markovian-chain detection and occupancy models, we assessed the multi-scale habitat use of otters in their selection of suitable areas for scent-marking based on repeated presence-absence data on spraint/latrine locations along the tOCR. we further used linear regression techniques to explore relationships between the number of individuals in smooth-coated otter group and hydro-environmental characteristics, spraint/latrine encounter rate, anthropogenic pressure, land cover, topography, and *** At the local scale, the probability of spraint deposition and group size decreased with anthropogenic disturbance while the probability of spraint detections decreased with grass cover. At the landscape scale, the probability of otter site use for spraint deposition and group sizes increased in southeast flowing streams. Spraint deposition increased with the proportion of sugarcane fields, whereas in contrast, group size decreased with proportion of sugarcane *** Our findings highlight the first empirical evidence on multi-scale habitat use of a southern Indian population of smooth-coated otters in an inland freshwater ecosystem surrounded by the scrub jungle–agriculture matrix. we sug

关键词： presence-absence modelling Inland river Freshwater ecosystem Semi-aquatic mammal Smooth-coated otter

Radiative decays D*(s)→ D(s)γ in covariant confined quark model

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Chinese physics C 2024年第2期48卷 45-56页

作者： C.t.tran m.A.Ivanov p.Santorelli Q.C.Vo Department of physics HCMC University of Technology and EducationVo Van Ngan 1700000 Ho Chi Minh CityVietnam Bogoliubov Laboratory of theoretical physics Joint Institute for Nuclear Research141980 DubnaRussia Dipartimento di Fisica"E.pancini" Universitàdi Napoli Federico ⅡComplesso Universitario di Monte S.AngeloVia CintiaEdificio 680126 NapoliItaly Istituto Nazionale di Fisica Nucleare Sezione di Napoli80126 NapoliItaly University of Science 700000 Ho Chi Minh CityVietnam

Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢ*** radiative couplings gD*Dγencoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by *** compare our results with other theoretical studies and experimental *** couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).the most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QCD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QCD sum rules.

关键词： covariant quark model radiative decay charmed meson

A novel approach to study generalized coupled cubic Schrödinger-Korteweg-de Vries equations

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Journal of Ocean Engineering and Science 2024年第1期9卷 13-24页

作者： Lanre Akinyemi p.Veeresha m.t.Darvishi Hadi Rezazadeh mehmet Senol Udoh Akpan Department of mathematics Lafayette CollegeEastonPAUSA Department of mathematics Christ Deemed to be UniversityBengaluru 560029India Department of mathematics Razi UniversityKermanshah 67149Iran Faculty of Engineering technology Amol University of Special Modern TechnologiesAmolIran Department of mathematics Nev¸s ehir HacıBekta¸s Veli UniversityNev¸s ehirTurkey Drexel University Department of MathematicsPhiladelphiaPAUSA

the Kortewegde Vries(KdV)equation represents the propagation of long waves in dispersive media,whereas the cubic nonlinear Schrödinger(CNLS)equation depicts the dynamics of narrow-bandwidth wave packets consisting of short dispersive waves.A model that couples these two equations seems in-triguing for simulating the interaction of long and short waves,which is important in many domains of applied sciences and engineering,and such a system has been investigated in recent *** work uses a modified Sardar sub-equation procedure to secure the soliton-type solutions of the generalized cubic nonlinear Schrödinger-Korteweg-de Vries system of *** various selections of arbitrary parameters in these solutions,the dynamic properties of some acquired solutions are represented graph-ically and *** particular,the dynamics of the bright solitons,dark solitons,mixed bright-dark solitons,w-shaped solitons,m-shaped solitons,periodic waves,and other soliton-type *** re-sults demonstrated that the proposed technique is highly efficient and effective for the aforementioned problems,as well as other nonlinear problems that may arise in the fields of mathematical physics and engineering.

关键词： CNLS equation modiﬁed Sardar sub-equation method KdV equation Solitons Long and short waves

Evaluation of a hepatic biomarker of nutritional imbalance in juvenile red drum(Sciaenops ocellatus) fed 60% soybean meal-based diets using NmR-based metabolomics

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Animal Nutrition 2024年第1期16卷 45-61页

作者： Fabio Casu Aaron m.watson Justin Yost t.Gibson Gaylord Daniel w.Bearden michael R.Denson marine Resources Research Institute South Carolina Department of Natural Resources Bozeman Fish technology Center United States Fish and Wildlife Service marine Biochemical Sciences Group Chemical Sciences Division National Institute of Standards and Technology Hollings Marine Laboratory

A 12-week feeding trial with juvenile red drum(Sciaenops ocellatus) fed high-soybean meal(SBm) diets was conducted to investigate a putative biomarker of nutritional imbalance, N-formimino-L-glutamate(FIGLU). three fishmeal-free, 60% SBm pelleted diets(named B12, Fol, and met, respectively) were tested to evaluate the effects on growth performance and tissue metabolite profiles of supplementation of vitamin B12(0.012 mg/kg), folate(10 mg/kg), methionine(1 g/kg) respectively, above basal supplementation levels. A fourth SBm-based diet(named B12/Fol/met) was formulated with a combination of B12, folate, and methionine to attain the above-mentioned target concentrations. A fifth 60% SBm diet(named FwS) with methionine supplementation(1 g/kg above basal supplementation levels), enriched with taurine, lysine and threonine as well as minerals, was also tested. this diet contained formulation targets and additives which have allowed for replacing fishmeal with plant proteins in rainbow trout feeds. Control diets included a fishmeal-based diet(named Fm), an unsupplemented basal 60% SBm diet(named SBm60), and a “natural” diet(named N) made up of equal parts of fish(cigar minnows), squid and shrimp as a positive reference for growth performance. Formulated feeds contained approximately 37% total crude protein, approximately 14% total crude lipid and were energetically balanced. Standard growth performance metrics were measured, and tissues(liver, muscle) were collected at week 12 to evaluate diet-induced metabolic changes using nuclear magnetic resonance(NmR)-based *** results show that the FwS diet outperformed all other SBm diets and the Fm diet under all performance metrics(pwas not detected in fish fed the N diet but was detected in those fed the SBm diets and the Fm diet. Fish fed the FwS diet and the met diet showed lower hepatic levels of FIGLU compared with the other SBm-based diets(pting that among the different supplementatio

关键词： Aquaculture metabolomics Nuclear magnetic resonance Red drum Soybean meal N-Formimino-L-glutamate

胸部Ct对弥漫性特发性骨肥厚的诊断:观察者间一致性

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国际医学放射学杂志 2017年第2期 230-231页

作者： S.F.Oudkerk p.A.de Jong m.Attrach t.Luijkx C.F.Buckens w.p.t.m.mali 杜倩妮 Department of Radiology and Nuclear medicine University Medical Center Utrecht

摘要目的评估和改善基于Ct对弥漫性特发性骨肥厚(DISH)诊断观察者间的一致性。方法将600例接受Ct检查行肺癌筛查的病人随机分为2组。根据Resnick对X线表

关键词：弥漫性特发性骨肥厚病人胸部躯干 Ct

利用常规胸部Ct偶发异常影像辨识未来心血管事件高危个体

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国际医学放射学杂志 2014年第6期 573-574页

作者： p.m.Jairam m.J.A.Gondrie D.E.Grobbee w.p.t.m.mali p.C.A.Jacobs Y.van der Graaf 杨君 Julius Center for Health Sciences and primary Care and Department of Radiology University Medical Center UtrechtUniversiteitsweg 100PO Box 85500Room E 1163584 CG Utrechtthe Netherlands

摘要目的推导并验证基于Ct影像的预测规则,研究胸部Ct偶发异常影像对发现心血管病(CVD)高危病人的作用。材料与方法本研究经伦理审查委员会的批准,免除签署

关键词：胸部躯干心血管 Ct