检索结果-南通市图书馆

Highly divergent sympatric lineages of Leptotila verreauxi(Aves:Columbidae)suggest a secondary contact area in the isthmus of Tehuantepec,Mexico

在线全文

学校读者我要写书评

暂无评论

Avian Research 2024年第1期15卷 12-21页

作者： Orlando j.Espinosa-chávez Adolfo G.Navarro-Sigüenza Hernando Rodríguez-Correa Luis A.Sánchez-González Museo de Zoología“Alfonso L.Herrera” Depto.de Biología EvolutivaFacultad de CienciasUniversidad Nacional Autonoma de MexicoApdo.Postal 70-399CP 04510Ciudad de MexicoMexico Posgrado en Ciencias Biologicas Unidad de PosgradoEdificio D1◦PisoCircuito de PosgradosCiudad UniversitariaUniversidad Nacional Autonoma de MexicoCoyoacanCP 04510CDMXMexico Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autonoma de Mexico.Antigua Carretera a Patzcuaro No.8701 Col.Ex Hacienda de San Jose de la HuertaC.P.58190MoreliaMichoacanMexico

Due to a complex geological and biotic history,the isthmus of Tehuantepec(iT),has been long recognized as a driver for the evolutionary divergence of numerous lowland and highland *** distributed in the lowlands of the American continent,the White-Tipped Dove(Leptotila verreauxi)is a polytypic species with 13 recognized *** of these have been recorded in Mexico,and the distribution of three abuts at the iT,suggesting a contact *** estimate phylogenetic patterns,divergence times and genetic differentiation,we examined two mt DNA(ND2 and COi)and one n DNA(β-fibint 7)*** also used correlative ecological niche models(ENM)to assess whether ecological differences across the iT may have acted as a biogeographical *** estimated paleodistributions during the Middle Holocene,Last Glacial Maximum and Last interglacial,to evaluate the influence of climate changes on the distribution and demographic *** results showed genetically distinct lineages that diverged approximately 2.5 million years *** and ecological factors may have played a dual role in promoting differentiation,but also in the formation of a secondary contact zone in the southern *** ecological niche comparisons indicated that the ecological niche of sympatric lineages at the iT are not identical,suggesting niches divergence;in addition,environmental niche models across the region indicated no abrupt biogeographic barriers,but the presence of regions with low *** results suggest that genetic differentiation originated by a vicariant event probably related to environmental factors,favored the evolution of different ecological ***,the absence of a biogeographic barrier but the presence of less suitable areas in the contact regions,suggest that secondary contact zones may be also maintained by climatic factors for the eastern group,but also by biotic interactions for the western group.

关键词： Biogeographical boundary Humid and dry forests isthmus of Tehuantepec Phylogeography Secondary contact

Solid-liquid extraction for yttrium recovery using porous polymeric resin(XAD-7) functionalized with D_(2)EHPA

在线全文

学校读者我要写书评

暂无评论

j.urnal of Rare Earths 2024年第9期42卷 1764-1773,I0005页

作者： P.A.Martínez-Montoya R.G.Sanchez-Alvarado D.Y.Medina-Velazquez M.L.Carrera-j.ta P.Garnica-chávez A.de j.Morales-Ramirez Higher School of chemical Engineering and Extractive industries ESIQIEIPNDepartment of Metallurgical EngineeringUPALM S/NCol.LindavistaGustavo A.Madero Cd.de MéxicoC.P07738Mexico Metropolitan Autonomous University Department of MaterialsBasic Sciences and EngineeringAv.San Pablo No.180Col.Reynosa TamaulipasCd.de MéxicoC.P02200Mexico Center for Research and Technological innovation CIITECIPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P02250CDMXMexico

The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting *** extracting agents were supported on a macro porous polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with *** effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were *** most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHPA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping *** to 80% yttrium is extracted,while 75% yttrium is recovered in the striping *** all experiments,the reaction equilibrium is reached after 20 min,and the k.netics for the extraction stage was determined as a second-order ***,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is *** tests of extraction and discharge for yttrium ions show that the functionalized resin can work.at least five cycles without decreasing its ***,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.

关键词： Yttrium recovery Rare earth solid-liquid extraction XAD-7 resin Fluorescent lamps recycling Solid-liquid k.netics extraction

in vivo and in vitro study of resorbable magnesium wires for medical implants:Mg purity,surface quality,Zn alloying and polymer coating

在线全文

学校读者我要写书评

暂无评论

j.urnal of Magnesium and Alloys 2024年第6期12卷 2472-2488页

作者： k.Tesar j.Luňáck.vá M.j.x M.Žaloudk.vá R.Vrbová M.Bartoš P.k.ein L.Vištej.ová j.Dušk.vá E.Filová Z.Sucharda M.Steinerová S.Habr k.Balík.A.Singh Department of Materials Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueTrojanova 13Prague 12000Czech Republic institute of Physics Czech Academy of SciencesNa Slovance 2Prague 18221Czech Republic institute of Dental Medicine First Faculty of MedicineCharles University and General University Hospital in PragueKaterinská32Prague 12801Czech Republic Department of Physics Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueBrehová7Prague 11519Czech Republic Department of Composites and Carbon Materials Institute of Rock Structure and MechanicsCzech Academy of SciencesV Holešovickách 41Prague 18209Czech Republic institute of Anatomy First Faculty of MedicineCharles UniversityU Nemocnice 3Prague 12800Czech Republic Biomedical Center Faculty of Medicine in PilsenCharles UniversityAlej Svobody 76Pilsen 32300Czech Republic Department of Pathological Physiology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Department of Histology and Embryology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic institute of Pathology First Faculty of MedicineCharles University and General University Hospital in PragueStudnickova 2Prague 12800Czech Republic Department of Biomaterials and Tissue Engineering Institute of PhysiologyCzech Academy of SciencesVidenska 1083Prague 14200Czech Republic Research Center for Structural Materials National Institute for Materials Science1-2-1 SengenTsukuba 305-0047Japan

Magnesium is an excellent material in terms of biocompatibility and its corrosion products can serve as an active source for new bone ***,localized corrosion and H_(2)generation limit the potential of Mg-based *** low-alloyed Mg-Zn wires can strongly reduce problems with large H_(2)bubbles and improve the mechanical properties considerably while maintaining excellent long-term *** pick.ing and a polymer coating can be effectively used to lower the rate of in vivo *** this work.microstructural,mechanical,and in vitro characterization of 250μm and 300μm extruded wires made from ultra-pure Mg,commercially pure Mg,Mg-0.15Zn,Mg-0.4Zn and Mg-1Zn was ***,Mg-0.4Zn wires together with a variant coated with a copolymer of L-lactide andε-caprolactone were tested in vivo on artificially damaged Wistar rat *** on the observed Mg-induced osteogenesis,polymer-coated Mg wires with a small addition of Zn are a perspective material for bone-support applications,such as cerclage and fixation wires.

关键词： Magnesium Resorbable Mg wire Mg-Zn implant degradation Biocompatibility study Zn grain boundary segregation

Degradation and resynthesis of chlorophyll during increased oxidative stress and prolonged dark.ess differ between annual and perennial flax(Linum L.)

在线全文

学校读者我要写书评

暂无评论

Oil Crop Science 2024年第2期9卷 121-130页

作者： k.nyon j. Nisbett Abida Alok.zai Su Hyun Elizabeth k. G. Adam Mott j.son C.L. Browna Department of Biological Sciences University of Toronto ScarboroughTorontoONCanada Department of Cell&Systems Biology University of TorontoTorontoONCanada Centre for the Analysis of Genome Evolution&Function University of TorontoTorontoONCanada

Among plants,there is considerable variation in lifespan:annuals live less than one year,whereas perennials live for several years,with the longest-living perennial having survived 43,600 *** proposed by the Disposable Soma Theory,this lifespan variation among plants lik.ly reflects differential investment of limited energy and nutrient resources,with perennials investing more energy and nutrients into biomolecular maintenance compared to annuals in order to ensure persistence over multiple *** differential investment may be particularly important during periods of exogenous stress,which are k.own to accelerate biomolecular *** present study evaluated this hypothesis using annual and perennial flax(Linum L.)subj.cted to two exogenous stressors—increased oxidative stress(i.e.,foliar H2O2spraying)and complete prolonged *** chlorophyll has been shown to exhibit degradation in response to changes in environmental conditions,we utilized changes in chlorophyll levels during and after periods of exogenous stress to evaluate our *** predicted that i)perennials would exhibit a slower rate of chlorophyll degradation during exposure to exogenous stressors compared to annuals,and ii)perennials would exhibit a faster rate of chlorophyll resynthesis following such exposure compared to *** levels before,during,and after exposure to both exogenous stressors were measured in two separate trails,once using image colour analysis and once using *** chlorophyll degradation rates in response to oxidative stress did not differ between annuals and perennials,contrary to our predictions,chlorophyll resynthesis rates following such exposure were significantly higher in perennials,as *** plants were subj.cted to complete prolonged dark.ess,chlorophyll degradation rates were significantly lower in perennials than annuals,as predicted;however,when plants were subsequently reintroduced to natural photoperiod,ch

关键词： Ageing Life history Maximum lifespan Oxidative stress Somatic maintenance

Wettability,reactivity,and interface structure in Mg/Ni system

在线全文

学校读者我要写书评

暂无评论

j.urnal of Magnesium and Alloys 2024年第2期12卷 659-672页

作者： S.Terlick. N.Sobczak.Ł.Maj.P.Darłak.j.j.Sobczak institute of Metallurgy and Materials Science Polish Academy of Sciences25 Reymonta Str.KrakowPoland Faculty of Foundry Engineering AGH University23 Reymonta Str.KrakowPoland

The sessile drop method was applied to the experimental investigation of the wetting and spreading behaviors of liquid Mg drops on pure Ni *** comparison,the experiments were performed in two variants:(1)using the Capillary Purification(CP)procedure,which allows the non-contact heating and squeezing of a pure oxide-free Mg drop;(2)by classical Contact Heating(ch)*** high-temperature tests were performed under isothermal conditions(CP:760℃for 30 s;ch:715℃for 300 s)using Ar+5 wt%H_(2) *** the sessile drop tests,images of the Mg/Ni couples were recorded by CCD cameras(57 fps),which were then applied to calculate the contact angles of metal/substrate *** and transmission electron microscopy analyses,both coupled with energy-dispersive X-ray spectroscopy,were used for detailed structural characterization of the solidified *** was found that an oxide-free Mg drop obtained by the CP procedure showed a wetting phenomenon on the Ni substrate(an average contact angleθining and good wetting over the Ni substrate(θ_((CP))~20°in 5 s)to form a final contact angle ofθ_(f(CP))~18°.in contrast,a different wetting behavior was observed for the ch procedure,where the unavoidable primary oxide film on the Mg surface block.d the spreading of liquid Mg showing apparently non-wetting behavior after 300 s contact at the test ***,in both cases,the deep craters formed in the Ni substrates under the Mg drops and significant change in the structure of initially pure Mg drops to Mg-Ni alloys suggest a strong dissolution of Ni in liquid Mg and apparent values of the final contact angles measured for the Mg/Ni system.

关键词： Magnesium-based alloys Sessile drop tests Capillary purification procedure Wettability Reactivity Contact angle

Contrasting plant growth performance of invasive polyploid and native diploid Prosopis is mediated by the soil bacterial community

在线全文

学校读者我要写书评

暂无评论

Ecological Processes 2023年第1期12卷 193-203页

作者： Rishabh k.ushik.Meesha Sharma ch.V.Ramana ch.Sasik.la Maharaj.k.Pandit j.alott’s Hill international Research Centre WarfieldBracknell RG426EYEnglandUK Department of Environmental Studies University of DelhiDelhi 110007India Department of Plant Sciences School of Life SciencesUniversity of HyderabadP.O.Central UniversityHyderabad 500046India Bacterial Discovery Laboratory Centre for EnvironmentInstitute of Science and TechnologyJ.N.T.University HyderabadKukatpallyHyderabad 500085India j.ndal School of Environment&Sustainability OP Jindal Global UniversitySonipatHaryana 131001India

Back.round Soil microbial communities affect above-ground plant diversity and community composition by influencing plant growth *** studies have tested the effect of soil bacterial microbiome on growth performance of native and invasive plants,but the influence of specific bacterial isolates has not been ***,we investigated the effects of soil bacterial exclusion by soil sterilization and by inoculation of Streptomyces rhizobacterial isolates on the growth performance of native and invasive Prosopis *** Plant growth performance of invasive *** was significantly reduced when grown in sterilized soils,whereas native *** showed enhanced growth performance in the sterilized *** grown in the soil inoculated with the specific Streptomyces isolate from ***(Pj.),the growth performance of invasive *** was significantly enhanced while that of native *** seedlings was significantly ***,inoculation of *** and *** seedlings with Streptomyces isolate from the rhizosphere of native ***(PC1)had no significant effect on the growth performances either of *** or *** Our study reveals that invasive *** experiences positive feedback.from the non-native soil bacterial community,while the native *** experiences negative feedback.from its soil bacterial *** results provide fresh experimental evidence for the enemy release hypothesis,and further our understanding of the contrasting growth-promoting effects of differentially recruited microbial species belonging to the same genus(Streptomyces)in the rhizospheres of alien invasive and native plants.

关键词： Soil bacteria Streptomyces invasive Prosopis j.liflora Prosopis cineraria Soil microbiota

同方期刊数据库

The Soft X-ray imager(SXi)on the SMiLE Mission

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 5-14页

作者： S.Sembay A.L.Alme D.Agnolon T.Arnold A.Beardmore A.Belén Balado Margeli C.Bick.ell C.Bouldin G.Branduardi-Raymont T.Crawford j.P.Breuer T.Buggey G.Butcher R.Canchal j.A.Carter A.cheney Y.Collado-Vega H.Connor T.Crawford N.Eaton C.Feldman C.Forsyth T.Frantzen G.Galgóczi j.Garcia G.Y.Genov C.Gordillo H-P.Gröbelbauer M.Guedel Y.Guo M.Hailey D.Hall R.Hampson j.Hasiba O.Hetherington A.Holland S-Y.Hsieh M.W.j.Hubbard H.j.szenszk. M.j.nes T.k.nnedy k.k.ch-Mehrin S.k.gl S.k.uck.r k.D.k.ntz C.Lak.n G.Lak. O.Lylund A.Martindale j.Miguel Mas Hesse R.Nak.mura k.Ok.avik.N.Østgaard H.Ottacher R.Ottensamer C.Pagani S.Parsons P.Patel j.Pearson G.Peik.rt F.S.Porter T.Pouliantis B.H.Qureshi W.Raab G.Randal A.M.Read N.M.M.Roque M.E.Rostad C.Runciman S.Sachdev A.Samsonov M.Soman D.Sibeck.S.Smit j.Søndergaard R.Speight S.Stavland M.Steller TianRan Sun j.Thornhill W.Thomas k.Ullaland B.Walsh D.Walton C.Wang S.Yang School of Physics and Astronomy University of LeicesterLeicesterLE17RHUK Space Park.Leicester University of LeicesterLeicesterLE17RHUK Mullard Space Science Laboratory University College LondonDorkingRH56NTUK Centre for Electronic imaging Open UniversityMilton KeynesMK76 AAUK Birk.land Centre for Space Science Department of Physics and TechnologyUniv.of BergenN-5007 BergenNorway University of Vienna A-1010 ViennaAustria Space Research.institute Austrian Academy of SciencesA-8042 GrazAustria National institute of Aerospace Technology MadridSpain ESTEC European Space Agency2201 AZ NoordwijkNetherlands State k.y Laboratory of Space Weather National Space Science CentreBeijing 100190China University of Applied Sciences and Arts Northwestern Switzerland CH-5210 WindischSwitzerland k.egl Space GmbH CH-8157 DielsdorfSwitzerland Space Acoustics GmbH CH-8157 DielsdorfSwitzerland Zurich University of Applied Sciences 8400 WinterhurSwitzerland Genov Solutions N-5172 LoddefjordNorway STM Engineering N-5165 LaksevagNorway j.hn Hopk.ns University Applied Physics Laboratory MD 20723USA NASA/Goddard Space Flight Centre MD 20771USA Center for Space Physics Boston UniversityBostonMA 02215USA Department of Theoretical Physics and Astrophysics Masaryk University60177 BrnoCzech Republic institute of Physics E¨otvo¨s Lor´and University1053 BudapestHungary Aerospace information Research.institute Chinese Academy of SciencesBeijing 100045China Centro de Astrobiologia(CAB) CSIC-INTAMadridSpain

The Soft X-ray imager(SXi)is part of the scientific payload of the Solar wind Magnetosphere ionosphere Link.Explorer(SMiLE)*** is a j.int science mission between the European Space Agency(ESA)and the chinese Academy of Sciences(CAS)and is due for launch.in *** is a compact X-ray telescope with a wide field-of-view(FOV)capable of encompassing large portions of Earth’s magnetosphere from the vantage point of the SMiLE *** is sensitive to the soft X-rays produced by the Solar Wind charge eXchange(SWCX)process produced when heavy ions of solar wind origin interact with neutral particles in Earth’s *** provides a mechanism for boundary detection within the magnetosphere,such as the position of Earth’s magnetopause,because the solar wind heavy ions have a very low density in regions of closed magnetic field *** sensitivity of the SXi is such that it can potentially track.movements of the magnetopause on timescales of a few minutes and the orbit of SMiLE will enable such movements to be track.d for segments lasting many *** is led by the University of Leicester in the United k.ngdom(Uk.with collaborating organisations on hardware,software and science support within the Uk.Europe,china and the United States.

关键词： Soft X-ray imaging micropore optics large area CCD

Adaptive Signal Enhancement Unit for EEG Analysis in Remote Patient Care Monitoring Systems

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第5期67卷 1801-1817页

作者： ch.Srinivas k.chandrabhushana Rao Department of Electronics and Communication Engineering J.N.T.UniversityKakinada533003India Department of Electronics and Communication Engineering JNTUK-UCEVVizianagaram535003India

in this paper we propose an efcient process of physiological artifact elimination methodology from brain waves(BW),which are also commonly k.own as electroencephalogram(EEG)*** a clinical environment during the acquisition of BW several artifacts contaminates the actual BW *** leads to inaccurate and ambiguous *** the statistical nature of the EEG signal is more non-stationery,adaptive ltering is the more promising method for the process of artifact *** clinical conditions,the conventional adaptive tech.iques require many numbers of computational operations and leads to data samples overlapping and instability of the algorithm *** causes delay in diagnosis and decision *** overcome this problem in our work.we propose to set a threshold value to diminish the problem of round off *** resultant adaptive algorithm based on this strategy is Non-linear Least mean square(NL2MS)***,to improve this algorithm in terms of ltering capability we perform data normalization,using this algorithm several hybrid versions are developed to improve ltering and reduce computational *** the method,a new signal enhancement unit(SEU)is realized and performance of various hybrid versions of algorithms examined using real EEG signals recorded from the *** ability of the proposed schemes is measured in terms of convergence,enhancement and multiplications *** various SEUs,the MCN2L 2MS algorithm achieves 14.6734,12.8732,10.9257,15.7790 dB during the artifact removal of RA,EMG,CSA and EBA components with only two ***,this algorithm seems to be better candidate for artifact elimination.

关键词： Adaptive algorithms artifacts brain waves clipped algorithms signal enhancement unit wireless EEG monitoring

Geochemical studies of hybrid granite from Madugulapalli area, Eastern Dharwar Craton, Southern india: implications for crustal mixing

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

Acta Geochimica 2023年第1期42卷 9-23页

作者： Nagamma j.Ratnak.r j.Aj.y k.mar A Ashok.ch State Mines and Geology Department 508001 NalgondaIndia Department of Geology Osmania University500007 HyderabadIndia CSiR-National Geophysical Research.institute 500007 UppalHyderabadIndia

Magma produced by melting of continental crust and mantle at the Archean-Proterozoic boundary are compositionally variable and chemical compositions provide evidence for the mixing of two sources. Understanding the composition of hybrid magma is essential for determining the comparative infl uence of crust and mantle sources during orogenesis. The hybrid granites are less documented in indian cratons, especially less in Dharwar Craton. Here we present petrographic and whole-rock.geochemical data of Madgulapalli granitic rock. situated in the NE part of the Eastern Dharwar Craton(EDC), to elucidate their petrogenesis and role in crust formation. The Madugulapalli granites(MPG) are composed chiefl y of plagioclase, quartz, and alk.li feldspar with associated biotite showing alteration and inter-granular textures. Geochemically, they are metaluminous to peraluminous in nature with calc-alk.line hybrid granite. The hybrid granites exhibit both negative and positive europium anomalies;the lower Rb/Sr, Rb, Sr, and higher Sr/Y,(Dy/Yb)N ratios suggest that the interaction of older rock. with residual garnet source melted at high pressures. We hypothesize that hybrid granites are formed by interaction(e.g., metasomatism, mingling, or mixing) between parental magmas and pre-existing rock. with the infl uence of sanuk.toid melts(heat source) in a subduction environment. The genesis of the hybrid granites demonstrates the mixing coupled with diff erentiation in the petrogeny’s residue system in a syn-collision setting followed by continental crust stability in EDC during the Neoarchean period.

关键词： Madugulapalli granite Hybrid granite Crustal mixing Subduction