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THE EVOLUTION Of.SMALL LAKE BASINS IN THE GOBI dESERT IN MONGOLIA

第四纪研究 2009年第4期29卷 678-686页

作者： J. Grunert c. Stolz N. Hempelmann A. Hilgers d. Htille f. Lehmkuhl T. f.lauer d. dasch Universitat Mainz Geographisches Institut Becherweg 21 55128 Mairtz Germany Universltat Koln Geographlsehes InstitutAlbertus-Magnus-Platz50923 Koln Germany RWTH Aachen Geographisehes Institut WullnerstraBe 52056 Aachen Germany Mongolian Academy of.Science Sect. GeoecologyUlan BatorMongolia

In order to investigate pluvial lakes in the Gobi two places were selected f.r f.eld studies: Khongoryn Els inSouth- and Mongol Els in West-Mongolia. In the eastern and central parts of.Khongoryn Els two small endorheic basins,Bayan Tukhem and Khongoryn Gol depressions were studied. Pluvial lake deposits and beach ridges both supposedly mid-Holocenein age give evidence of.a 9m and a 15m deep f.eshwater lake,respectively. Today both depressions are nearlydried out and exposed to wind def.ation. A dif.erent situation was f.und at Uujin Sair river valley which cuts through thedune f.eld at its lowest and narrowest (3 km) part. Here, a 22.5 m thick f.ssil accumulation of.at least 20 layers of.f.ne sand(dune sand)alternating with silt(f.uvial playa sediment)was exposed and OSL dated. 12 dates ranging between 14ka and17ka reveal the accumulation as Late Glacial which correlates well with the aridity at that time reported f.r central Asia byseveral authors. Interpreting the dates it seems obvious that the whole sediment was quickly deposited in a period of.about16ka,and shortly af.er dissected by the Uujin Sair during a similar short time due to increasing humidity of.the *** situation was f.und at the eastern rim of.Mongol Els. Two rivers,Shurgiyn Gol and Zavran Gol are impinging hereon the high dunes which have damed both rivers in the past. A younger, shallow lake existed during mid-Holocene( ^(14)c-dated to some 5.5ka)and a large, 17m deep lake( ^(14)c -- dated to some 39ka) probably during stage 4. Expected OSLdates will hopef.lly support this hypothesis. Anyhow, the palaeogeography of.the dune f.eld was dif.erent f.om today; itmoved eastward daming the large river Shurgiyn Gol.

关键词： mid-Holocene late-Glacial playa stage 4(?)-lake

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f.ST Pulsar *** Prof.les of.682 Pulsars

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Research in Astronomy and Astrophysics 2023年第10期23卷 71-175页

作者： P.f.Wang J.L.Han J.Xu c.Wang y.yan W.c.Jing W.Q.Su d.J.Zhou T.Wang National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of.Astronomy University of Chinese Academy of SciencesBeijing 100049China

Pulsar polarization prof.les f.rm a very basic database f.r understanding the emission processes in a pulsar *** caref.l polarization calibration of.the 19-beam L-band receiver and verif.cation of.beamof.set observation results,we obtain polarization prof.les of.682 pulsars f.om observations by the f.ve-hundredmeter Aperture Spherical radio Telescope(f.ST)duringthe Galactic Plane Pulsar Snapshot survey and other normal f.ST *** them,polarization prof.les of.about 460 pulsars are observed f.r the f.rst *** prof.les exhibit diverse *** pulsars have a polarization position angle curve with a good S-shaped swing,some with orthogonal modes;some have components with highly linearly polarized components or strong circularly polarized components;some have a very wide prof.le,coming f.om an aligned rotator,and some have an interpulse f.om a perpendicular rotator;some wide prof.les are caused by interstellar *** derive geometric parameters f.r 190 pulsars f.om the S-shaped position angle curves or with orthogonal *** f.nd that the linear and circular polarization or the widths of.pulse prof.les have various f.equency *** with a large f.action of.linear polarization are more likely to have a large Edot.

关键词： polarization (stars:)pulsars:general astronomical databases:miscellaneous

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Oxidation behavior and microstructural evolution of.f.coNiTicu f.ve-element high-entropy alloy nanoparticles

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Journal of.Materials Science & Technology 2024年第10期177卷 133-141页

作者： H.Bai R.Su R.Z.Zhao c.L.Hu L.Z.Ji y.J.Liao y.N.Zhang y.X.Li X.f.Zhang Key Laboratory f.r Anisotropy and Texture of.Materials(MOE) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China Institute of.Advanced Magnetic Materials College of Materials and Environmental EngineeringHangzhou Dianzi UniversityHangzhou310012China

High-entropy alloys(HEAs)have attracted extensive attention ascribed to their unique physical and chemical properties induced by the cocktail ***,their oxidation behaviors,in particular at nanoscale,are still lack because of.multi-element complexity,which could also be completely dif.er-ent f.om the bulk *** this work,we synthesized f.coNiTicu f.ve-element HEA nanopar-ticles(NPs)with unif.rm elemental distribution by arc-discharging approach,and f.rther investigated their oxidation behaviors at 250 ℃,and 350 ℃.The morphology,structure and element distribution of.NPs were analyzed by transmission electron microscopy(TEM),energy dispersive spectroscopy(EdS)and electron energy loss spectroscopy(EELS).The surf.ce oxidation in f.coNiTicu NPs during the high-temperature process can induce nanoscale pores at core/shell interf.ces by Kirkendall ef.ect,and even the eventual coalescence into a single ***,the oxidation states of.NPs with diameters(d)varying f.om 60 to 350 nm were analyzed in detail,revealing two typical conf.gurations:hollow(dd yolk-shell structures(d>150 nm).The experimental results were complemented by f.rst-principles calculations to investigate the dif.usion behaviors of.f.ve elements,evidencing that the surf.ce oxidation strongly alters the surf.ce segregation pref.rences:(1)in the initial stage,cu and Ni appear to pref.r segregating on the surf.ce,while co,Ti and f. tend to stay in the bulk;(2)in the oxidation process,cu pref.rs to stay in the center,while Ti segregates to the surf.ce ascribed to the reduced po-tential *** study gives new insights into oxidation of.nanoscale HEA,and also provides a way f.r f.brication of.high-entropy oxides with controllable architectures.

关键词： High-entropy alloy Nanoparticles Oxidation Kirkendall ef.ect Exchange bias ef.ect

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High black carbon and ozone concentrations during pollution transport in the Himalayas: f.ve years of.continuous observations at NcO-P global GAW station

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Journal of.Environmental Sciences 2013年第8期25卷 1618-1625页

作者： A. Marinoni P. cristof.nelli P. Laj R. duchi d. Putero f. calzolari T. c. Landi E. Vuillermoz M. Maione P. Bonasoni Institute f.r Atmospheric Sciences and climate National Research Council of Italy Laboratoire de Glaciologie et Géophysique de l'Environnement Université Grenoble 1 CNRS EV-K2-cNR committee Urbino University DiSBeF

To study the inf.uence of.polluted air-mass transport carrying ozone （O3） and black carbon （Bc） in the high Himalayas, since March 2006 the Nepal climate Observatory at Pyramid （NcO-P） GAW-WMO global station （Nepal, 5079 m a.s.l.） is operative. during the f.rst 5-year measurements, the O3 and Bc concentrations have shown a mean value of.48 ± 12 ppb （± standard deviation） and 208 ± 374 ng/m3, respectively. Both O3 and Bc showed well def.ned seasonal cycles with maxima during pre-monsoon （O3 ： 61.3 ± 7.7 ppbV; Bc： 444 ± 433 ng/m3） and minima during the summer monsoon （O3 ： 40.1 ± 12.4 ppbV; Bc： 64 ± 101 ng/m3）. The analysis of.the days characterised by the presence of.a signif.cant Bc increase with respect to the typical seasonal cycle identif.ed 156 days af.ected by ＂acute＂ pollution events, corresponding to 9.1% of.the entire data-set. Such events mostly occur in the pre-monsoon period, when the O3 diurnal variability is strongly related to the transport of.polluted air-mass rich on Bc. On average, these ＂acute＂ pollution events were characterised by dramatic increases of.Bc （352%） and O3 （29%） levels compared with the remaining days.

关键词： ozone black carbon Himalayas pollution biomass burning troposphere

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Ef.ect of.Palm Oil By-pass f.t on Milk composition of.Early Lactation Holstein cows f.d Whole Plant corn Silage during dry Season

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Journal of.Agricultural Science and Technology(A) 2011年第8期1卷 1144-1149页

作者： y. Han R Paengkoum d. f. Wang Guizhou Institute of.Animal husbandry and Veterinary Science Guiyang 550005 Guizhou Province P R. China School of.Animal Production Technology Suranaree University of Technology Muang Ditrict Nakhon Ratchasima 30000 Thailand

The objective of.this study was to investigate the ef.ect of.Palm Oil By-pass f.t （POBf. on milk composition of.early lactation Holstein during dry season, 24 postpartum Holstein （1 d-14 d） were selected and align to two groups according to cRd experimental design; each group included 12 Holstein cows. The control received by-pass f.t 0 g/h.d, the experimental group received by-pass f.t 300 g/h.d. The results shown, dMI and yield of.milk did not be af.ected with supplementation of.by-pass f.t, however, milk protein increased by 6.71%, milk f.t increased by 8.16%, lactose increased by 0.22%, SNf.increased by 1.98%, TS increased 4.08%; digestibility of.diet protein decreased by 6.62%, digestibility of.EE decreased by 7.96%, digestibility of.Ndf.and AdL decreased by 1.36%, 8.97% respectively, digestibility of.dM and OM decreased by 4.42, 3.07 percentage units; amount of.c4-c17 milk f.tty acids showed a decreased tendency, that of.cIs-c22 showed an increased tendency, the milk cLA increased signif.cantly （P 〈 0.01）. To sum up, supplementation of.by-pass f.t f.r early lactation Holstein is an important measure to balance energy and sustain milk yield and quality.

关键词： By-pass f.t milk yield milk f.t milk protein milk composition.

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Study of.the structural,f.rroelectric,dielectric,and pyroelectric properties of.the K0.5Na0.5NbO3 system doped with Li+,La3+,and Ti4+

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Journal of.Advanced ceramics 2020年第3期9卷 329-338页

作者： c.MONTERO-TAVERA M.d.dURRUTHy-ROdRiGUEZ f.d.cORTES-VEGA J.M.yANEZ-LIMON center f.r Research and Advanced Studies of.IPN Campus QueretaroMexico National Evangelical University Paseo de los Periodistas#54Ensanche MirafloresSanto DomingoDistrito NacionalRepiblica Dominicana

Pure *** sNbO3(KNN)and KNN doped with Lit(6%mole),Lat(1.66%,5%,6%mole),and Ti+t(10%mole)were prepared by mixture of.oxides using high-energy milling and conventional solid-state *** ef.ects of.the dopant on the physical properties of.pure KNN have been evaluated based on the structural,f.rroelectric,pyroelectric,and dielectric *** XRd measurements show that KNN pure sample contains a mixture of.monoclinic and orthorhombic crystalline phases,with a slightly higher concentration of.monoclinic *** contrast,all doped samples show a higher concentration of.the orthorhombic phase,as well as the presence of.a secondary phase(K6Nb10.8O3o),also detected by Raman *** samples with a higher concentration of.this secondary phase,also present greater dielectric losses and lower values of.remnant *** dielectric measurements allowed us to detect temperatures of.structural transitions(orthorhombic-tetragonal,O-T)previous to the f.rroelectric paraelectric transition(tetragonal-cubic,T-c),and also in this set of.samples,a direct correlation was f.und between the values of.remnant polarization and the corresponding pyroelectric signal response.

关键词： K0.5Na0.5NbO3(KNN) lead-f.ee solid-state reaction structural properties pyroelectric properties dielectric properties Li,La,Ti doping elements

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Perf.uoroalkane acids in human milk under the global monitoring plan of.the Stockholm convention on Persistent Organic Pollutants(2008-2019)

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f.ontiers of.Environmental Science & Engineering 2022年第10期16卷 91-104页

作者： Heidelore f.edler Mohammad Sadia thomas Krauss Abeer Baabish Leo W.y.yeung School of.Science and Technology MTM Research Centre(O)rebro UniversitySE-70182(O)rebroSweden f.nda(c)ao Oswaldo cruz(f.OcRUZ) Instituto Nacional de Controle de Qualidade em Saúde(INCQS)Avenida Brasil4365-Manguinhos EP 21.040-900Rio de Janeiro-RJBrazil

Within the global monitoring plan(GMP)established by article 16 of.the Stockholm convention on Persistent Organic Pollutants,perf.uorooctane sulf.nic acid(Pf.S),perf.uorooctanoic acid(Pf.A),and perf.uorohexane sulf.nic acid(Pf.xS)are recommended f.r analysis in core matrices to assess occurrence and changes geographically and with *** 101 samples consisting of.86 national pools and 15 pools f.om States in Brazil obtained between 2008 and 2019,Pf.xS was detected in 17%of.the national pools and none in *** and Pf.S had a detection f.equency of.100%and 92%,*** perf.uoroalkane substances(Pf.S)had either low detection f.equencies and median values of.zero(carboxylic acids c4-c11;except Pf.A)or could not be quantif.ed in any sample(sulf.nic acids,c4-c10,and long-chain carboxylic acids,c_(12)-c_(14)).correlation between Pf.A and Pf.S was moderately(r=0.58).Whereas median values were almost identical(18.9 pg/g *** Pf.S;18.6 pg/g *** Pf.A),Pf.S showed larger ranges(f.w.-212 pg/g f.w.)than Pf.A(f.w.-63.4 pg/g f.w.).It was shown that wealthier countries had higher Pf.A concentrations than poorer *** dif.erence in concentrations was f.und f.r samples collected in countries having or not having ratif.ed the Stockholm convention amendments to list Pf.S or *** goal to achieve 50%decrease in concentrations within ten years was met by Antigua and Barbuda,Kenya,and Nigeria f.r Pf.S and by Antigua and Barbuda f.r *** a f.w cases,increases were observed;one country f.r Pf.S,f.ur countries f.r Pf.A.

关键词： Human biomonitoring Human breast milk Lc-MS/MS analysis Lif.style parameters

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Total Phenols,f.avonoids and Antioxidant Activity in Annona muricata and Annona purpurea callus culture

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Phyton-International Journal of.Experimental Botany 2019年第2期88卷 139-147页

作者： M.y.Ovando-domínguez M.c.Luján-Hidalgo d.González-Mendoza A.A.Vargas-díaz N.Ruiz-Lau f.A.Gutiérrez-Miceli c.A.Lecona-Guzmán Laboratorio de cultivo de Tejidos Vegetales.Tecnológico Nacional de México/Instituto Tecnológico de Tuxtla Gutiérrez Carretera Panamericana Km.1080.Tuxtla GutiérrezChiapasC.P.29050México Instituto de ciencias Agrícolas de la Universidad Autónoma de Baja calif.rnia(IcA-UABc).carretera a delta s/n c.P.21705 Ejido Nuevo LeónBaja CaliforniaMéxico cONAcyT-colegio de Postgraduados Campus CampecheCarretera Federal Haltunchén-Edzna km 17.5.SihochacChampotónCampecheCP 24450México cONAcyT-Tecnológico Nacional de México/Instituto Tecnológico de Tuxtla Gutiérrez.carretera Panamericana Km.1080.Tuxtla Gutiérrez ChiapasC.P.03940México

callus cultures of.Annona muricata and Annona purpurea were induced in Murashige and Skoog(MS)medium supplemented with dif.erent concentrations of.1-naphthylacetic acid(NAA),6-benzyladenine(BA)and 2,4-dichlorophenoxyacetic acid(2,4-d)utilized hypocotyls with *** highest percentage of.callus f.rmation was the treatment supplemented with 3 mg L-1 NAA f.r ***(100%)while f.r *** in lower percentage(75%).BA stimulated the f.rmation of.shoots in all the evaluated concentrations,being the concentration of.2 mg L-1 the one that induced the greater f.rmation of.shoots f.r ***(23 shoots/explant)and ***(28 shoots/explant).The content of.total phenols,f.avonoids and antioxidant activity was measured in the callus obtained f.om both *** results showed that a higher content of.total phenols was quantif.ed in callus of.***(27.8 mg g-1 dw)compared to ***(23.2 mg g-1 dw).The highest content of.total f.avonoids was observed in the callus of.***(8.0μg g-1 dw).Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydracil radical *** concentration required f.r 50%inhibition(Ic50)of.the 2,2-diphenyl-1-picrylhydracil radicals were 4.22μg mL-1 in methanolic extracts of.callus of.***,while in extracts of.callus of.*** was 2.86μg mL-1,in both cases was greater than that f.und f.r *** culture of.the species studied in this work represents an alternative f.r the production of.natural antioxidants.

关键词： Annonaceae antioxidant activity 6-benzyladenine secondary metabolites tissue culture

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The relation between ductility at high temperature and solid solution in Mg alloys

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Journal of.Magnesium and Alloys 2022年第1期10卷 241-256页

作者： d.f.Shi c.M.cepeda-Jiménez M.T.Pérez-Prado IM dEA Materials Institute C/Eric Ka ridel228906 GetafeMadridSpain department of.Materials Science Polytechnic University of Madrid/Universidad Politecnica de MadridE.T.S.de Ingenieros de Caminos28040MadridSpain department of.Physical Metallurgy CENIMCSICAv.Gregorio del Amo 828040 MadridSpain

This work investigates the ef.ect of.solid solution on ductility and on the activation of.individual def.rmation mechanisms at moderate temperatures and at quasi-static strain rates in Mg-Zn and Mg-Al alloys. With that aim, f.ur solid solution Mg-Zn and Mg-Al binary alloy ingots containing 1 and 2 wt.% solute atoms were subjected to hot rolling and subsequent annealing to generate polycrystals with similar average grain size and basal-type texture f.r each composition. The activity of.the dif.erent slip systems af.er tensile testing at 150°c and at 250°c was evaluated in pure Mg and in the alloys by EBSd-assisted slip trace analysis. In addition, segregation of.Zn and Al atoms at grain boundaries during the thermo-mechanical processing was characterized by HAAdf.STEM and EdX. It was f.und that while the addition of.Al and Zn atoms to pure Mg does not lead to major changes in the mechanical strength at the investigated temperatures, it does enhance ductility signif.cantly, especially at 250℃. Our results show that this increase in ductility cannot be attributed to a higher activation of.non-basal systems in the alloys, as reported earlier, as the incidence of.non-basal systems is indeed considerably higher in pure Mg. This work suggests, on the contrary, that the ductility increase may be attributed to the presence of.a more homogenous basal activity in the alloys due to a lower degree of.orientation clustering, to grain boundary solute segregation, and to a higher slip dif.usivity at grain interiors.

关键词： Magnesium Solute segregation Slip trace analysis ductility def.rmation mechanisms

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Larger f.oods reduce soil cO_(2)ef.lux during the post-f.ooding phase in seasonally f.ooded f.rests of.Western Amazonia

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Pedosphere 2021年第2期31卷 342-352页

作者： Emma M.dOcHERTy Andrew d.thomas department of.Geography and Earth Sciences Aberystwyth UniversityAberystwyth SY233DB(UK) School of.Geography University of LeedsLeeds LS29JT(UK)

Seasonally f.ooded várzea f.rests of.Western Amazonia are one of.the most productive and biodiverse wetland f.rests in the ***,data on their soil cO_(2)emissions,soil organic matter decomposition rates,and soil c stocks are *** is a concern because hydrological changes are predicted to lead to increases in the height,extent,and duration of.seasonal f.oods,which are likely to have a signif.cant ef.ect on soil c stocks and ***,with no empirical data,the impact of.altered f.ood regimes on várzea soil c cycles remains *** study quantif.ed the ef.ects of.maximum annual f.ood height and soil moisture on soil cO_(2)ef.lux rate(R_(s))and soil organic matter decomposition rate(k)in the várzea f.rests of.Pacaya Samiria National Reserve,*** study was conducted between May and August *** results showed that R_(s)(10.6–182.7 mg c m^(-2)h^(-1))and k(0.016–0.078)varied between and within sites,and were considerably lower than the values reported f.r other tropical *** addition,R_(s)was negatively af.ected by f.ood height(Pd soil moisture(Pd it decreased with decreasing river levels post f.ooding(Pcontrast,k was not af.ected by any of.the above-mentioned *** moisture was the dominant f.ctor inf.uencing R_(s),and it was signif.cantly af.ected by maximum f.ood height,even af.er the f.oods had subsided(Pconsequently,we concluded that larger f.oods will likely lead to reduced R_(s),whilst k could remain unchanged but with decomposition processes becoming more anaerobic.

关键词： c cycle climate change greenhouse gas soil cO_(2)emissions soil moisture soil organic matter decomposition rate tropical f.rest

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