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MgO-attached graphene nanosheet(MgO@GNs)reinforced magnesium matrix nanocomposite with superior mechanical,corrosion and biological performance

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2062-2076页

作者： s.Abazari A.shamsipur H.R.Bakhsheshi-Rad M.s.soheilirad F.khorashadizade s.s.Mirhosseini Department of Materials and Metallurgical Engineering Amirkabir University of TechnologyTehran ***Iran Iranian National standards Organization of Hormozgan HormozganIran Advanced Materials Research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran Department of Materials and Metallurgical Engineering Iran University of Science and TechnologyTehranIran

Magnesium(Mg)alloys are gaining great consideration as body implant materials due to their high biodegradability and ***,they suffer from low corrosion resistance and antibacterial *** this research,semi-powder metallurgy followed by hot extrusion was utilized to produce the magnesium oxide@graphene nanosheets/magnesium(MgO@GNs/Mg)composite to improve mechanical,corrosion and cytocompatibility *** have revealed that the incorporation of MgO@GNs nanohybrids into Mg-based composite enhanced microhardness and compressive *** vitro,osteoblast cell culture tests show that using MgO@GNs nanohybrid fillers enhances osteoblast adhesion and apatite *** presence of MgO@GNs nanoparticles in the composites decreased the opening defects,micro-cracks and micro-pores of the composites thus preventing the penetration of the corrosive solution into the *** demonstrated that the MgO@GNs/Mg composite possesses excellent antibacterial properties because of the combination of the release of MgO and physical damage to bacterium membranes caused by the sharp edges of graphene nanosheets that can effectively damage the cell wall thereby facilitating penetration into the bacterial lipid ***,the MgO@GNs/Mg composite with high mechanical strength,antibacterial activity and corrosion resistance is considered to be a promising material for load-bearing implant applications.

关键词： metal matrix composites MgO@GNs nanohybrid strengthening mechanisms antibacterial activity biocompatibility

Direct microwave leaching conditions of rare earth elements in fluorescent wastes

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Journal of Rare Earths 2024年第6期42卷 1165-1174,I0007页

作者： A.Bilen B.Birol M.N.saridede s.s.kaplan M.s.sonmez Department of Metallurgical and Materials Engineering Yildiz Technical UniversityIstanbulTurkey Department of Chemical Engineering and Materials science Stevens Institute of TechnologyNew JereyUSA Department of Metallurgical and Materials Engineering Istanbul Technical UniversityIstanbulTurkey

The luminescent phosphor powder in the fluorescent lamp constitutes 2%of the lamp’s *** can be mentioned that fluorescent wastes are a crucial raw material to produce rare earth *** the present study,microwave leaching process was conducted to dissolve rare earth elements yttrium(Y),europium(Eu),and remaining rare earth elements(REEs)present in the phosphor powder of the fluorescent *** the yields were *** the microwave leaching process,the effects of the temperature(80-160℃),acid type(hydrochloric acid(HCl),nitric acid(HNO_(3)),sulphuric acid(H_(2)sO_(4))),acid concentration(0.5-6 mol/L),solid to liquid ratio(0.1:10-0.5:10)and reaction time(5-90 min)parameters on leaching efficiencies of varying rare earth elements and calcium were *** highest yield was obtained in the direct microwave leaching of fluorescent waste with the experimental conditions of 6 mol/L HCl,160℃,0.1:10 solid-to-liquid ratio(s:L),and 90 *** energy calculations were made,and kinetic models of the reactions were obtained,and it is observed that Y and Eu dissolution is diffusion-controlled,on the other hand,lanthanum(La),cerium(Ce),and terbium(Tb)were examined to be chemical reaction ***,calcium(Ca)and gadolinium(Gd)seem coherent with the mixed ***,mathematical models of all experimental studies are created with the response surface Box-Behnken method and the correlation coefficients of all the models are over 90%.

关键词： Rare earth elements(REEs) Direct microwave leaching Fluorescent waste kinetic models Response surface method

Heating of nanoparticles and their environment by laser radiation and applications

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Nanotechnology and Precision Engineering 2024年第1期7卷 78-115页

作者： Victor k.Pustovalov Belarusian National Technical University Pr.Independency65Minsk 220013Belarus

This review considers the fundamental dynamic processes involved in the laser heating of metal nanoparticles and their subsequent *** particular interest are the absorption of laser energy by nanoparticles,the heating of a single nanoparticle or an ensemble thereof,and the dissipation of the energy of nanoparticles due to heat exchange with the *** goal is to consider the dependences and values of the temperatures of the nanoparticles and the environment,their time scales,and other parameters that describe these *** results and analytical studies on the heating of single metal nanoparticles by laser pulses are discussed,including the laser thresholds for initiating subsequent photothermal processes,how temperature inﬂuences the optical properties,and the heating of gold nanoparticles by laser *** studies of the heating of an ensemble of nanoparticles and the results of an analytical study of the heating of an ensemble of nanoparticles and the environment by laser radiation are *** methods for nanoparticles under laser heating are considered,including changes in the refractive indices of metals and spectral thermometry of optical scattering of nanoparticles,Raman spectroscopy,the thermal distortion of the refractive index of an environment heated by a nanoparticle,and thermochemical phase transitions in lipid bilayers surrounding a heated *** the sequence of events after radiation absorption and their time scales underlies many applications of *** applicationﬁelds for the laser heating of nanoparticles are reviewed,including thermochemical reactions and selective nanophotothermolysis initiated in the environment by laser-heated nanoparticles,thermal radiation emission by nanoparticles and laser-induced incandescence,electron and ion emission of heated nanoparticles,and optothermal chemical *** of the laser heating of nanoparticles in la

关键词： Nanoparticles Laser Heating Modeling Nanothermometry Applications

soil resilience assessment using soil profile descriptions and Analytic Hierarchy Process in Mediterranean mountains considering diverse fire occurrences

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Journal of Mountain science 2024年第8期21卷 2517-2532页

作者： Jesús RODRIGO-COMINO Departamento de Análisis Geográfico Regional y Geografía Física Facultad de Filosofía y LetrasCampus Universitario de CartujaUniversidad de GranadaGranada 18071Spain

Wildfires are complex natural phenomena that exert significant impacts on landscapes,societies,and *** the concept of resilience is crucial in mitigating its possible negative impacts,as it involves preparing for,responding to,and recovering from *** research aims to demonstrate the utility of in situ soil profile description in assessing land use resilience using an Analytic Hierarchy Process(AHP)through an expert panel *** study examines a catchment located in the Balearic Islands,considering two fire occurrences(once and twice),comparing abandoned agricultural terraces and natural *** results demonstrated that the priority ranking of variables to assess soil profile resilience against wildfires,determined by a panel of 10 experts,identified horizon depth(25.1%),slope inclination(21.5%),and hydrological connectivity(16.6%)as the most crucial *** variables,such as number and size of roots,structure of pedal soil material,size class structure,and rock fragments,also contributed to resilience but to a lesser extent,with scores ranging from 5.7%to 9.6%.Analyzing the priorities established by the experts using AHP,the results showed that the least resilient soil horizon was H1 of the control hillslope,especially under high and low connectivity processes,which aligned with the loss of superficial soil horizons after one and two *** showed greater changes in resilience after occurring wildfires compared to terraces,with the most significant alterations occurring after the second wildfire *** study addresses a significant knowledge gap in the field by highlighting the interconnectedness of wildfires,resilience,and land use,providing insights into land management strategies for wildfire-prone regions.

关键词： soil profiles soil geography Wildfires AHP Land management Expert panel survey

Litterfall production modeling based on climatic variables and nutrient return from stands of Eucalyptus grandis Hill ex Maiden and Pinus taeda L.

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Journal of Forestry Research 2024年第5期35卷 26-36页

作者： Andrés Baietto Andrés Hirigoyen Jorge Hernández Amabelia del Pino Forest Department Faculty of AgronomyUniversity of the Republic12900 MontevideoUruguay National Research Program of Forest Production National Agriculture Research InstituteINIA97000 TacuarembóUruguay soil and Water Department Faculty of AgronomyUniversity of the Republic12900 MontevideoUruguay

Native grasslands in the Pampas of south America are increasingly being replaced by Eucalyptus and Pinus *** short rotation regimes used for the stands require high nutrient levels,with litterfall being a major source of nutrient *** model the litterfall production using climatic variables and assess the nutrient return in 14-year-old Eucalyptus grandis and Pinus taeda stands,we measured litter production over 2 years,using conical litter traps,and monitored climatic *** temperature,accumulated precipitation,and mean maximum vapor pres-sure deficit at the seasonal level influenced litterfall produc-tion by ***;seasonal accumulated precipitation and mean maximum temperature affected litterfall by *** regression tree modeling based on these climatic vari-ables had great accuracy and predictive power for ***(N=33;MAE(mean absolute error)=0.65;RMsE(root mean square error)=0.91;R^(2)=0.71)and ***(N=108;MAE=1.50;RMsE=1.59;R^(2)=0.72).The nutrient return followed a similar pattern to litterfall deposition,as well as the order of importance of macronutrients(***:Ca>N>k>Mg>P;***:N>Ca>k>Mg>P)and micronutrients(*** and ***:Mn>Fe>Zn>Cu)in both *** study constitutes a first approximation of factors that affect litterfall and nutrient return in these systems.

关键词： Afforestation Litterfall Nutrient recycling Climate modeling Myrtaceae Pinaceae

A new perspective on intervertebral disc calcification—from bench to bedside

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Bone Research 2024年第1期12卷 50-61页

作者： Emanuel J.Novais Rajkishen Narayanan Jose A.Canseco koen van de Wetering Christopher k.kepler Alan s.Hilibrand Alexander R.Vaccaro Makarand V.Risbud Department of Orthopaedic surgery Sidney Kimmel Medical CollegeThomas Jefferson UniversityPhiladelphiaPAUSA Unidade Local de saúde do Litoral Alentejano Orthopedic DepartmentSantiago do CacémPortugal Rothman Orthopedic Institute at Thomas Jefferson University PhiladelphiaPAUSA

Disc degeneration primarily contributes to chronic low back and neck ***,there is an urgent need to understand the spectrum of disc degeneration phenotypes such as fibrosis,ectopic calcification,herniation,or mixed *** these phenotypes,disc calcification is the least *** calcification,by definition,is the pathological mineralization of soft tissues,widely studied in the context of conditions that afflict vasculature,skin,and ***,disc calcification is associated with poor surgical outcomes and back pain refractory to conservative *** is frequently seen as a consequence of disc aging and progressive degeneration but exhibits unique molecular and morphological characteristics:hypertrophic chondrocyte-like cell differentiation;TNAP,ENPP1,and ANk upregulation;cell death;altered Pi and PPi homeostasis;and local *** studies in mouse models have provided a better understanding of the mechanisms underlying this *** is essential to recognize that the presentation and nature of mineralization differ between AF,NP,and EP ***,the combination of anatomic location,genetics,and environmental stressors,such as aging or trauma,govern the predisposition to ***,the systemic regulation of calcium and Pi metabolism is less important than the local activity of PPi modulated by the ANk-ENPP1 axis,along with disc cell death and differentiation *** there is limited understanding of this phenotype,understanding the molecular pathways governing local intervertebral disc calcification may lead to developing disease-modifying drugs and better clinical management of degeneration-related pathologies.

关键词： degeneration metabolism intervertebral

Cross-method Analysis of Corotation Radii Data set for spiral Galaxies

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Research in Astronomy and Astrophysics 2024年第7期24卷 95-110页

作者： V.s.kostiuk A.A.Marchuk A.s.Gusev sternberg Astronomical Institute Lomonosov Moscow State UniversityUniversitetsky pr.13119234 MoscowRussia Central(Pulkovo)Astronomical Observatory Russian Academy of SciencesPulkovskoye chaussee 65/1196140 St.PetersburgRussia saint Petersburg state University Universitetsky pr.28198504 St.PetersburgRussia

A corotation radius is a key characteristic of disk galaxies that is essential to determine the angular speed of the spiral structureΩ_p,and therefore understand its *** the literature,there are plenty of methods to estimate this value,but do these measurements have any consistency?In this work,we collected a data set of corotation radius measurements for 547 galaxies,300 of which had at least two *** initial analysis reveals that most objects have rather inconsistent corotation radius ***,a significant fraction of galactic disks is distinguished by a large error coverage and almost uniform distribution of *** findings do not have any relation to spiral type,Hubble classification,or presence of a *** other reasons,obtained results could be explained by the transient nature of spirals in a considerable part of *** have made our collected data sample publicly available,and have demonstrated on one example how it could be useful for future research by investigating a winding time value for a sample of galaxies with possible multiple spiral arm patterns.

关键词： galaxies fundamental parameters-galaxies kinematics and dynamics-galaxies structure

Atomistic Investigation of shock-Induced Amorphization within Micro-shear Bands in Hexagonal Close-Packed Titanium

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Acta Metallurgica sinica(English Letters) 2024年第9期37卷 1590-1600页

作者： Z.C.Meng k.G.Wang T.Ali D.Li C.G.Bai D.s.Xu s.J.Li A.H.Feng G.J.Cao J.H.Yao Q.B.Fan H.Wang R.Yang Institute of Metal Research Chinese Academy of SciencesShenyang 110016China school of Materials science and Engineering University of Science and Technology of ChinaShenyang 110016China Interdisciplinary Centre for Additive Manufacturing(ICAM) School of Materials and ChemistryUniversity of Shanghai for Science and TechnologyShanghai 200093China school of Materials science and Engineering Tongji UniversityShanghai 201804China key Laboratory for Light-Weight Materials Nanjing Tech UniversityNanjing 210009China National key Laboratory of science and Technology on Materials Under shock and Impact School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401135China

The mechanical response of a single crystal titanium sample against(0001)α surface impact was investigated using molecular dynamics ***,non-uniform plastic deformation was observed in the *** high strain rates,amorphization occurred near the edge of the contact region where severe shear strain induced a large number of stacking faults(sFs)and *** contrast,the central part of the contact region underwent less deformation with significantly fewer ***,instead of amorphization by consuming sFs and dislocations,there was a gradual increase in the density of dislocations and sFs during the process of *** local amorphous regions eventually grew into shear bands.

关键词： shock compression Amorphization shear band Titanium Molecular dynamics

Exploring van der Waals materials with high anisotropy:geometrical and optical approaches

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Light(science & Applications) 2024年第4期13卷 645-653页

作者： Aleksandr s.slavich Georgy A.Ermolaev Mikhail k.Tatmyshevskiy Adilet N.Toksumakov Olga G.Matveeva Dmitriy V.Grudinin kirill V.Voronin Arslan Mazitov konstantin V.kravtsov Alexander V.syuy Dmitry M.Tsymbarenko Mikhail s.Mironov sergey M.Novikov Ivan kruglov Davit A.Ghazaryan Andrey A.Vyshnevyy Aleksey V.Arsenin Valentyn s.Volkov kostya s.Novoselov Moscow Center for Advanced studies Kulakova str.20Moscow 123592Russia. Emerging Technologies Research Center XPANCEOInternet CityEmmay TowerDubaiUnited Arab Emirates. Donostia International Physics Center(DIPC) Donostia/San-Sebastián 20018Spain. Institute of Materials Ecole Polytechnique Federale de Lausanne1015 LausanneSwitzerland. Department of Chemistry Lomonosov Moscow State UniversityMoscow 119991Russia. Laboratory of Advanced Functional Materials Yerevan State UniversityYerevan 0025Armenia. National Graphene Institute(NGI) University of ManchesterManchester M139PLUK. Department of Materials science and Engineering National University of SingaporeSingapore 03-09 EASingapore. Institute for Functional Intelligent Materials National University of Singapore117544 SingaporeSingapore

The emergence of van der Waals(vdW)materials resulted in the discovery of their high optical,mechanical,and electronic anisotropic properties,immediately enabling countless novel phenomena and *** success inspired an intensive search for the highest possible anisotropic properties among vdW ***,the identification of the most promising among the huge family of vdW materials is a challenging quest requiring innovative ***,we suggest an easy-to-use method for such a survey based on the crystallographic geometrical perspective of vdW materials followed by their optical *** our approach,we found As2s3 as a highly anisotropic vdW *** demonstrates high in-plane optical anisotropy that is~20%larger than for rutile and over two times as large as calcite,high refractive index,and transparency in the visible range,overcoming the century-long record set by *** these benefits,As2s3 opens a pathway towards nextgeneration nanophotonics as demonstrated by an ultrathin true zero-order quarter-wave plate that combines classical and the Fabry–Pérot optical phase ***,our approach provides an effective and easy-to-use method to find vdW materials with the utmost anisotropic properties.

关键词： anisotropy anisotropic high