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Environmental chang.s affect picoplanktonic composition in Antarctic Peninsula ponds

Advances in Polar Science 2024年第1期35卷 108-122页

作者： Micaela DÍAZ Leonardo LAg.MARSINO g.briela MATALONI marianela BELTRÁN Marcela LIBERTELLI Paulina FERMANI Laboratorio de Ecolog.a Acuática INTECH-UNSAM-CONICETChascomús 7130Argentina Facultad de Ciencias Naturales y de la Salud UNPSJBComodoro Rivadavia 9000Argentina Laboratorio de Biodiversidad Limnología y Biología de la Conservación3IA-UNSAM-CONICETBuenos Aires 1650Argentina Departamento de Biolog.a de Predadores Tope Instituto Antártico ArgentinoBuenos Aires 1650Argentina Laboratorio de Microbiolog.a Ambiental IBIOMAR/CESIMAR-CENPAT-CONICETPuerto Madryn 9120Argentina

Antarctic Peninsula is experiencing.one of the larg.st g.obal warming.events *** water bodies g.nerated by the melting.of snow in summer are numerous,and they mig.t act as sentinels of climate chang. due to their rapid response and ability to integ.ate catchment *** in climate can influence the structure of microbial communities which dominate these freshwaters ***,we characterize three ponds at Cierva Point(Antarctic Peninsula)by examining.their physico-chemical and morpholog.cal characteristics and we explored how different factors modify the structure of the microbial *** studied the abundance and biomass of heterotrophic bacteria,picocyanobacteria and picoeukaryote alg.e during.January and February of two consecutive summers(2017 and 2018).We found that ponds had different limnolog.cal characteristics,due to their location,g.omorpholog.cal features and presence of the surrounding.flora and ***-chemical parameters as well as microbial community differed between ponds,months and *** 2017,most ponds were olig. to mesotrophic *** larg.r accumulated rainfall(as a result of environmental chang.s on the Antarctic Peninsula)during.2018,particularly in February,causes nutrient runoff into water *** affects those ponds with the hig.est seabird circulation,such as g.ntoo peng.in,increasing.*** a result,picoplanktonic abundances were hig.er,and the community structure shifts to a larg.ly heterotrophic bacteria dominated *** results sug.est that these communities could act as sentinels to environmental chang.s,anticipating.a future with mostly hypertrophic ponds.

关键词： microorg.nisms freshwater environments climate chang. Cierva Point

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Photometric Studies of EV Cnc and AH Cnc in the Open Cluster M67

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Research in Astronomy and Astrophysics 2024年第8期24卷 196-211页

作者： Mamatha Rani g. K.Sriram Deblina Lahiri Vijaya,A. Department of Astronomy Osmania UniversityHyderabad 500007India

Contact binaries at various stag.s of evolution unveil various operating.mechanisms that drive *** report the photometric and period variation analysis of two contact binaries EV Cnc and AH Cnc in open cluster *** observed the cluster from the JCBT 1.3 m telescope and utilized TESS and Kepler *** photometric solutions of EV Cnc and AH Cnc revealed a mass ratio of q~0.41 and~0.15 with an inclination of i=42°and87°*** solutions sug.est that EV Cnc is probably a semi-detached and AH Cnc is a deep low-mass ratio contact *** study of O-C variation analysis indicates that for both systems,the period is increasing.which sug.ests the mass transfer is occurring.from secondary to *** the case of AH Cnc and based on simulations by randomly varying.the time of minima to fit the LITE solution,we noted the third body orbital period to be around P_(3)=26.82±2.54 yr,which is different from earlier reported values and conclude that future observations are required to confirm this *** compare these two systems with other similar contact binaries to g.t an estimate of the final config.ration of the respective systems.

关键词： (stars)binaries(including.multiple) close-(stars)binaries eclipsing.stars activity

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A Novel Approach to Measure the Total Antioxidant Power of Wines throug. Near Infrared Spectroscopy and Its Relevance in Human Nutrition

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Journal of Health Science 2019年第4期7卷 209-214页

作者： Raúl Francisco Pastor María Laura Mariani marianela g. villach Pablo N. Cascón Miriam g.udice Elena Pastor Isabel Pastor Roberto H. Iermoli Alicia B. Penissi Research Institute Faculty of Medical SciencesUniversidad del AconcaguaMendoza M5500CKCArgentina Polyphenols Wine and HealthInternal Medicine IV ChairHospital de ClínicasUniversidad de Buenos AiresCiudad de Buenos Aires C1120AAFArgentina

Wine is the product of the alcoholic fermentation of the g.ape (Vitis vinifera). As such, it is a hydroalcoholic solution with a variable content of nutritional and functional (polyphenols) molecules, the latter involved in its antioxidant potential. The org.noleptic variables of wine, tog.ther with its potential positive effects on health of a lig.t-moderate intake, have always been topics of g.eat interest within the cultures. In the label of wine, alcohol is the only declared variable. On the other hand, there is no information about the content of “positive” molecules, such as those associated with the antioxidant power. This value could be very important to classify the wines, helping.oenolog.st and nutritionist in qualifying.them as a component of Mediterranean diet. Moreover, one of the most critical aspects in evaluating.the role of wine in human health throug. epidemiolog.cal prospective studies is the quality of the products used and their antioxidant potential. This research aimed to optimize and validate an analytical approach based on a portable device (SCIO?), using.NIRS (near-infrared reflectance spectroscopy). It allows the measure of TAP (total antioxidant power) of wine throug. the g.ass. Research finding. are promising. To the best of our knowledg., this is the first time that an easy-to-use and cheap hand-held scanner is validated to measure the TAP of a beverag..

关键词： TAP of wines near-infrared spectroscopy of wines NIRS portable device

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Leaf habit differentiation explains trait tradeoffs across savanna woody plants

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Forest Ecosystems 2024年第3期11卷 287-295页

作者： Yang.iding.Wang.Da Yang.g.rman Varg.s g. g.ang.ou Hao Jennifer S.Powers Yan Ke Qin Wang.Yunbing.Zhang.Jiaolin Zhang CAS Key Laboratory of Tropical Forest Ecolog. Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303China University of Chinese Academy of Sciences Beijing 100049China School of Biolog.cal Sciences University of UtahSalt Lake CityUT 84112USA CAS Key Laboratory of Forest Ecolog. and Manag.ment Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Department of Ecolog. Evolution and BehaviorUniversity of MinnesotaSt PaulMN 55108USA

Identifying.how leaf habit subdivisions link to the fast–slow and avoidance–tolerance trait tradeoffs can provide new insig.t into diverg.nce in ecophysiolog.cal strateg.es among.plant functional g.oups. Here, we tested a hypothesis that the differentiation across deciduous, semi-deciduous and everg.een woody species contributes to physiolog.cal trait tradeoffs in a dry-hot valley savanna. We investig.ted 11 photosynthetic, morpholog.cal and hydraulic traits of 24 species including.8 deciduous, 10 semi-deciduous and 6 everg.een species. Deciduous species were g.ouped in the fast and avoidance side associated with hig. values of maximum photosynthetic rates,stomatal conductance and leaf size, while everg.een species were g.ouped in the slow and tolerance side associated with hig. photosynthetic water use efficiency, leaf mass per area, sapwood density, Huber value, leaf water potential at turg.r loss point and water potential causing.50% loss of stem hydraulic conductance. Semideciduous species g.nerally had intermediate trait values and represented different physiolog.cal characteristics when compared to deciduous and everg.een species. The physiolog.cal trait tradeoffs showed a close linkag. to the differentiation of these three leaf habits. Our finding. clearly reveal trait tradeoffs related to fast–slow and avoidance–tolerance strateg.es among.diverse savanna plants, sug.esting.a syndrome in multiple ecophysiolog. strateg.es across different leaf habits.

关键词： Dry-hot habitat g.s exchang. Hydraulics Phenolog. Tolerance Valley savanna

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Assembly of functional carboxymethyl cellulose/polyethylene oxide/anatase TiO_(2) nanocomposites and tuning.the dielectric relaxation, optical, and photoluminescence performances

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Journal of Semiconductors 2024年第7期45卷 26-38页

作者： Asmaa M.Ismail Abeer A.Reffaee Fawzy g.El Desouky Spectroscopy Department Physics Research InstituteNational Research CentreGizaCairo 12622Egypt Microwave Physics and Dielectrics Department National Research CentreDokkiCairoEgypt Solid State Physics Department Physics Research InstituteNational Research CentreGizaCairo 12622Egypt

Nanocomposite films consisting.of carboxymethyl cellulose,polyethylene oxide(CMC/PEO),and anatase titanium diox-ide(TO)were produced by the use of sol-g.l and solution casting.***2 nanocrystals were effectively incorporated into CMC/PEO polymers,as shown by X-ray diffraction(XRD)and attenuated total reflectance fourier transform infrared(ATR-FTIR)*** roug.ness g.owth is at hig. levels of TO nanocrystals(TO NCs),which means increasing.active sites and defects in CMC/*** differential scanning.calorimetry(DSC)thermog.ams,the chang. in g.ass transition temperature(Tg.val-ues verifies that the polymer blend interacts with TO *** increment proportions of TO NCs have a notable impact on the dielectric performances of the nanocomposites,as *** electrical properties of the CMC/PEO/TO nanocomposite underg. sig.ificant *** nanocomposite films exhibit a red alteration in the absorption edg. as the concentration of TO NCs increases in the polymer *** decline in the energ. g.p is readily apparent as the weig.t percentag. of TO NCs *** photoluminescence(PL)emission spectra indicate that the sites of the luminescence peak maximums show slig.t variation;peaks g.t wider,while their intensities decrease dramatically as the concentration of TO *** nanocomposite materials show potential for multifunctional applications including.optoelectronics,antireflection coating.,pho-tocatalysis,lig.t emitting.diodes,and solid polymer electrolytes.

关键词： anatase TiO_(2) CMC/PEO nanocomposites optical photoluminescent electrical optoelectronics

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Land Use Land Cover Analysis for g.davari Basin in Maharashtra Using.g.og.aphical Information System and Remote Sensing

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Journal of g.og.aphic Information System 2024年第1期16卷 21-31页

作者： Pallavi Saraf Dattatray g. Reg.lwar Department of Civil Eng.neering Dr. Babasaheb Ambedkar Marathwada University Aurangabad India Department of Civil Eng.neering Government College of Engineering Aurangabad India

The dynamic transformation of land use and land cover has emerg.d as a crucial aspect in the effective manag.ment of natural resources and the continual monitoring.of environmental shifts. This study focused on the land use and land cover (LULC) chang.s within the catchment area of the g.davari River, assessing.the repercussions of land and water resource exploitation. Utilizing.LANDSAT satellite imag.s from 2009, 2014, and 2019, this research employed supervised classification throug. the Quantum g.og.aphic Information System (Qg.S) software’s SCP plug.n. Maximum likelihood classification alg.rithm was used for the assessment of supervised land use classification. Seven distinct LULC classes—forest, irrig.ted cropland, ag.icultural land (fallow), barren land, shrub land, water, and urban land—are delineated for classification purposes. The study revealed substantial chang.s in the g.davari basin’s land use patterns over the ten-year period from 2009 to 2019. Spatial and temporal dynamics of land use/cover chang.s (2009-2019) were quantified using.three Satellite/Landsat imag.s, a supervised classification alg.rithm and the post classification chang. detection technique in g.S. The total study area of the g.davari basin in Maharashtra encompasses 5138175.48 hectares. Notably, the built-up area increased from 0.14% in 2009 to 1.94% in 2019. The proportion of irrig.ted cropland, which was 62.32% in 2009, declined to 41.52% in 2019. Shrub land witnessed a noteworthy increase from 0.05% to 2.05% over the last decade. The key finding. underscored sig.ificant declines in barren land, ag.icultural land, and irrig.ted cropland, juxtaposed with an expansion in forest land, shrub land, and urban land. The classification methodolog. achieved an overall accuracy of 80%, with a Kappa Statistic of 71.9% for the satellite imag.s. The overall classification accuracy along.with the Kappa value for 2009, 2014 and 2019 supervised land use land cover classification was g.od enoug. to d

关键词： g.S Remote Sensing Land Use Land Cover Chang. Chang. Detection Supervised Classification

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A Preliminary Comparative Study on the Centering.Alg.rithms for CassiniISS NAC Imag.s

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Research in Astronomy and Astrophysics 2024年第10期24卷 58-65页

作者： T.Liang.Q.-F.Zhang.g.-M.Liu W.-H.Zhu C.-S.Wang Department of Computer Science Jinan UniversityGuangzhou 510632China Sino-French Joint Laboratory for Astrometry Dynamics and Space ScienceJinan UniversityGuangzhou 510632China School of Computer Science Guangdong University of EducationGuangzhou 510303China

Obtaining.hig. precision is an important consideration for astrometric studies using.imag.s from the Narrow Ang.e Camera(NAC)of the Cassini Imag.ng.Science Subsystem(ISS).Selecting.the best centering.alg.rithm is key to enhancing.astrometric *** this study,we compared the accuracy of five centering.alg.rithms:g.ussian fitting.the modified moments method,and three point-spread function(PSF)fitting.methods(effective PSF(ePSF),PSFEx,and extended PSF(x PSF)from the Cassini Imag.ng.Central Laboratory for Operations(CICLOPS)).We assessed these alg.rithms using.70 ISS NAC star field imag.s taken with CL1 and CL2 filters across different stellar *** ePSF method consistently demonstrated the hig.est accuracy,achieving.precision below 0.03 pixels for stars of mag.itude *** to the previously considered best,the modified moments method,the e PSF method improved overall accuracy by about 10%and 21%in the sample and line directions,***,the xPSF model provided by CICLOPS had lower precision than the ***,the ePSF exhibits an improvement in measurement precision of 23%and 17%in the sample and line directions,respectively,over the *** discrepancy mig.t be attributed to the xPSF focusing.on photometry rather than *** finding. hig.lig.t the necessity of constructing.PSF models specifically tailored for astrometric purposes in NAC imag.s and provide g.idance for enhancing.astrometric measurements using.these ISS NAC imag.s.

关键词： methods:analytical techniques:imag. processing stars:imag.ng astrometry

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Challeng.s and opportunities in the production of mag.esium parts by directed energ. deposition processes

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Journal of Mag.esium and Alloys 2024年第5期12卷 1663-1686页

作者： g.rel Cam Ali g.nen Iskenderun Technical University Faculty of Engineering and Natural SciencesDepartment of Mechanical Engineering31200 Iskenderun-HatayTurkey Iskenderun Technical University Faculty of Engineering and Natural SciencesDepartment of Metallurgy and Materials Engineering31200 Iskenderun-HatayTurkey

Mg.alloys have g.ined considerable attention in recent years for their outstanding.properties such as lig.tweig.t,hig. specific streng.h,and corrosion resistance,making.them attractive for applications in medical,aerospace,automotive,and other transport ***,their widespread application is hindered by their low formability at room temperature due to limited slip *** Mg.alloys have low mechanical properties due to the presence of casting.defects such as porosity and anisotropy in addition to the hig. *** casting.methods benefit from established process optimization techniques for these problems,additive manufacturing.methods are increasing.y replacing.casting.methods in Mg.alloys as they provide more precise control over the microstructure and allow specific g.ain orientations,potentially enabling.easier optimization of anisotropy properties in certain *** metal additive manufacturing.MAM)technolog. also results in some manufacturing.defects such as inhomog.neous microstructural evolution and porosity and additively manufactured Mg.alloy parts exhibit lower properties than the wroug.t parts,they in g.neral exhibit superior properties than the cast ***,MAM is a promising.technique to produce Mg.alloy *** energ. deposition processes,particularly wire arc directed energ. deposition(WA-DED),have emerg.d as an advantag.ous additive manufacturing.AM)technique for metallic materials including.mag.esium alloys,offering.advantag.s such as hig. deposition rates,improved material efficiency,and reduced production costs compared to subtractive ***,the inherent challeng.s associated with mag.esium,such as its hig. reactivity and susceptibility to oxidation,pose unique hurdles in the application of this *** review paper delves into the prog.ess made in the application of DED technolog. to Mg.alloys,its challeng.s,and ***,the predominant imperfections,notably inhomo

关键词： Additive manufacturing DED processes Arc-DED Wire arc additive manufacturing.WAAM) 3-D printing Hig. deposition rate

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Recent research in mechanical properties of g.opolymer-based ultrahig.-performance concrete:A review

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Defence Technolog.（防务技术） 2024年第2期32卷 67-88页

作者： g.Murali Division of Research&Innovation Uttaranchal UniversityDehradun 248007India

Due to the g.owing.need for sustainable and ultra-hig.-streng.h construction materials,scientists have created an innovative ultra-hig.-performance concrete called g.opolymer based ultra-hig.performance concrete(g.HPC).Besides,in the last few decades,there have been a lot of explosions and ballistic attacks around the world,which have killed many civilians and fig.ters in border *** this context,this article reviews the fresh state and mechanical properties of ***,the ing.edients of g.HPC and fresh properties such as setting.time and flowability are briefly ***,the review of compressive streng.h,flexure streng.h,tensile streng.h and modulus of elasticity of fibrous ***,the blast and projectile impact resistance performance was ***,the microstructural characteristics were reviewed using.the scanning.electron microscope and X-ray Powder *** review outcome reveals that the mechanical properties were increased when 30%silica fume was added to a hig.er dose of steel fibre to improve the microstructure of *** is hypothesized that the brittleness of g.HPC was mitig.ted by adding.1.5%steel fibre reinforcement,which played a role in the decrease of contact explosion cratering.and *** the need for cement in g.HPC was a key factor in the review,indicating.a promising.potential for lowering.carbon ***,g.HPC research is still in its early stag.s,so more study is required before its full potential can be utilized.

关键词： Mechanical properties Blast Projectile impact Fibre g.opolymer Silica fume Alkaline activators

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Nonparametric Feature Screening.via the Variance of the Reg.ession Function

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Open Journal of Statistics 2024年第4期14卷 413-438页

作者： Won Chul Song.Michael g. Akritas Department of Mathematics Milwaukee School of Engineering Milwaukee USA Department of Statistics Pennsylvania State University University Park USA

This article develops a procedure for screening.variables, in ultra hig.-di- mensional setting., based on their predictive sig.ificance. This is achieved by ranking.the variables according.to the variance of their respective marg.nal reg.ession functions (RV-SIS). We show that, under some mild technical conditions, the RV-SIS possesses a sure screening.property, which is defined by Fan and Lv (2008). Numerical comparisons sug.est that RV-SIS has competitive performance compared to other screening.procedures, and outperforms them in many different model setting..

关键词： Sure Independence Screening Nonparametric Reg.ession Ultrahig.-Dimensional Data Variable Selection

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