简介：很多人认为法国人很臭、很懒、很粗鲁、拒绝说英语,但真相到底如何？

简介：AbstractBackground:Delivery room resuscitation assists preterm infants, especially extremely preterm infants (EPI) and extremely low birth weight infants (ELBWI), in breathing support, while it potentially exerts a negative impact on the lungs and outcomes of preterm infants. This study aimed to assess delivery room resuscitation and discharge outcomes of EPI and ELBWI in China.Methods:The clinical data of EPI (gestational age [GA] <28 weeks) and ELBWI (birth weight [BW] <1000 g), admitted within 72 h of birth in 33 neonatal intensive care units from five provinces and cities in North China between 2017 and 2018, were analyzed. The primary outcomes were delivery room resuscitation and risk factors for delivery room intubation (DRI). The secondary outcomes were survival rates, incidence of bronchopulmonary dysplasia (BPD), and risk factors for BPD.Results:A cohort of 952 preterm infants were enrolled. The incidence of DRI, chest compressions, and administration of epinephrine was 55.9% (532/952), 12.5% (119/952), and 7.0% (67/952), respectively. Multivariate analysis revealed that the risk factors for DRI were GA <28 weeks (odds ratio [OR], 3.147; 95% confidence interval [CI], 2.082-4.755), BW <1000 g (OR, 2.240; 95% CI, 1.606-3.125), and antepartum infection (OR, 1.429; 95% CI, 1.044-1.956). The survival rate was 65.9% (627/952) and was dependent on GA. The rate of BPD was 29.3% (181/627). Multivariate analysis showed that the risk factors for BPD were male (OR, 1.603; 95% CI, 1.061-2.424), DRI (OR, 2.094; 95% CI, 1.328-3.303), respiratory distress syndrome exposed to ≥2 doses of pulmonary surfactants (PS; OR, 2.700; 95% CI, 1.679-4.343), and mechanical ventilation ≥7 days (OR, 4.358; 95% CI, 2.777-6.837). However, a larger BW (OR, 0.998; 95% CI, 0.996-0.999), antenatal steroid (OR, 0.577; 95% CI, 0.379-0.880), and PS use in the delivery room (OR, 0.273; 95% CI, 0.160-0.467) were preventive factors for BPD (all P < 0.05).Conclusion:Improving delivery room resuscitation and management of respiratory complications are imperative during early management of the health of EPI and ELBWI.

简介：TheinfluencesofboththevolumeofPS/toluenesolutionintheUbbelohdeviscometerandtheprecisionofthetimemeasuringontheviscositybehaviorindiluteandextremelydiluteconcentrationregionareinvestigatedItwasfoundthattheinfluenceoftheformercanneglect,butthatofthelatterissoprominentthatthedatafluctuatebitterlyandlinearityofthecurveofthereducedviscosityvs.Concentration(ηsp/c～c)becomestoobadtoobeytheHugginsequationdowntotheextremelydiluteregion,despitetheerroroftheflowtimes△t≤0.2s,whichispermittedbytheconventionalmethodofviscositymeasurement.Throughstrictmathematicalanalyses,itwasfoundthatthcerror(E)ofthereducedviscosityisinproportionandinverseproportionto△tandconcentrationc,respectively.Sothelesstheconcentration,themoretheerroris.Consequently,alowestconcentrationlimitcLcorrespondingtogivenexperimentalerrormayexistanditwillbemeaninglessforfurtheroperationbelowcLbecauseofthegreatfluctuationofthedata.Therefore,itneedstoseriouslyreconsidertheapplicationoftheconventionalmethodofUbbelohdeviscositymeasurementintheextremelydilutepolymersolutionundertraditionalconditionsbecauseofthegreatinfluenceoftheexperimentalerror.

简介：Atheoreticalstudywasconductedtocharacterizehydraulicjumpoflaminarcircularliquidjets.Theobjectiveofthisresearchwastodeterminethejumplocationinasimpleexplicitform,Theeffectsofmanyfactorswereinvestigatedincludingnozzlediameter,jetexitpressure,nozzle-to-platespacing,jetvelocityandReynoldsnumber,ItwasfoundthatthetheoreticaldatacollapsedwellovertherangeofjetReynoldsnumber500≤Re≤1800withpreviousdata.

简介：Theself-assembledInAs/GaAsquantumdots(QDs)withextremelylowdensityof8×10~6cm~(-1)areachievedusinghighergrowthtemperatureandlowerInAscoveragebylow-pressuremetal-organicchemicalvapourdeposition(MOVCD).Asaresultofmicro-photoluminescence(micro-PL),forextremelylowdensityof8×10~6cm~(-1)InAsQDsinthemicro-PLmeasurementsat10K,onlyoneemissionpeakhasbeenachieved.ItisbelievedthattheInAsQDshaveagoodpotentialtorealizesinglephotonsources.

简介：Quantumeffectsplayanenhancementroleinp-pchainreactionsoccurringwithinstars.Suchanenhancementisquantifiedbyawavepenetrationfactorthatisproportionaltothedensityoftheparticipatingfuelparticles.Thisleadstoaninnovativetheoryfordenseplasma,anditsresultshowsgoodagreementwithindependentdataderivedfromthesolarenergyoutput.AnanalysisofthefirstZ-pinchmachineinmankind’shistoryexhibitingneutronemissionleadstoaderiveddeuteriumplasmabeamdensitygreaterthanthatofwater,withplasmavelocitiesexceeding10000km/s.Fusionpowercouldbeachievedbytheintersectionoffoursuchpinchedplasmabeamswithpowerfulhead-oncollisionsintheircommonfocalregionduetothebeamandtargetenhancedreaction.

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简介：KueishanTao(24°51'N,121°55′E)islocatedatatectonicjunctionofthefaultsystemextensionofTaiwanandthesouthernriftingendoftheOkinawaTrough.Aclusterofover30vents,atawaterdepthofabout10～20mofftheeasterntipofthetaoemitshydrothermalfluidsandvolcanicgasessuchasH2S.Asulfurchimneyormound,formedbycondensationofthesulfurcontainedinthehydrothermalfluid,canusuallybeseenaroundthevents.Thetallestchimneyreaches6m.Ventsdischargingayellowishfluidhavetemperaturesbetween92and116℃andflowratesashighas158t/h;ventsdischargingawhitishfluidhavelowertemperaturesofbetween48and62℃andlowerflowratesofabout7.0t/h.Theseworld-record,breakinglowpH(aslowas1.52)fluidsaretotallydifferentfromthosefoundintheblackandwhite-chimneysofthemid-oceanridges.MagnesiumandSiO2dataindicatethatthesehydrothermalfluidsprobablyoriginatefromadepthof915～1350mbelowthesurface.Whiletheratiosofmajorionsrelativetothesodiumofthesehydrothermalfluidsarequitesimilartoopenoceanwater,theratiosofSO4andchloridetosodiumseemtobehigherforsomeofthevents.ItissuggestedthatthevolcanicgasescontributeSO4andohlorinetothefluids,henceincreasingtheirratiosrelativetosodium.Somehydrothermalfluids,however,arefoundtobedepletedofthemajorelementswhichcanhavebeencausedbyphaseseparation.Theconcentrationsofironandmanganeseinthefluidsaremuchlowerthanthosefoundinthemid-oceanridges,whilethealuminiumcontentishigher.Fourspeciesofbenthos(Xenograpsustestudinatus,asnail,aseaanemone,andaSipuncala),1speciesofalgae(Corallinaceae),and1speciesoffish(Siganusfusescens)wererecordednearthehydrothermalvents.AmitoehondriaDNAsequencecomparisonofXenograpsustestudinatuswith6otherdecapodspeciesshowsthegreatestnumberofnitrogenbasedifferencesintheDNAfragmentsfrom225to270.Thegenediversit

简介：Low-frequencychorusemissionshaverecentlyattractedmuchattentionduetothesuggestionthattheymayplayimportantrolesinthedynamicsoftheVanAllenBelts.However,themechanism(s)generatingtheselow-frequencychorusemissionshavenotbeenwellunderstood.Inthisletter,wereportaninterestingcaseinwhichbackgroundplasmadensityloweredthelowercutofffrequencyofchorusemissionsfromabove0.1fce(typicalordinarychorus)to0.02fce(extremelylow-frequencychorus).Thoseextremelylow-frequencychoruswaveswereobservedinaratherdenseplasma,wherethenumberdensityNewasfoundtobeseveraltimeslargerthanhasbeenassociatedwithobservationsofordinarychoruswaves.Forsuprathermalelectronswhosefreeenergyissuppliedbyanisotropictemperatures,lineargrowthrates(calculatedusingin-situplasmaparametersmeasuredbytheVanAllenProbes)showthatwhistlermodeinstabilitycanoccuratfrequenciesbelow0.1fcewhenthebackgroundplasmadensityNeincreases.EspeciallywhenNereaches90cm^-3ormore,thelowestunstablefrequencycanextendto0.02fceorevenless,whichisconsistentwithsatelliteobservations.Therefore,ourresultsdemonstratethatadensebackgroundplasmacouldplayanessentialroleintheexcitationofextremelylowfrequencychoruswavesbycontrollingthewavegrowthrates.

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简介：Adirectsynthesisofmethyllevulinatefromcellulosealcoholysisinmethanolmediumundermildcondition(180210C)catalyzedbyextremelylowconcentrationsulfuricacid(0.01mol/L)andtheproductisolationweredevelopedinthisstudy.Effectsofdifferentprocessvariablestowardsthecatalyticperformancewereperformedasafunctionofreactiontime.Theresultsindicatedthatsulfuricacidconcentration,temperatureandinitialcelluloseconcentrationhadsignificanteffectsonthesynthesisofmethyllevulinate.Anoptimizedyieldofaround50%wasachievedat210Cfor120minwithsulfuricacidconcentrationof0.01mol/Landinitialcelluloseconcentrationbelow100g/L.Theresultingproductmixturewasisolatedbyadistillationtechniquethatcombinesanatmosphericdistillationwithavacuumdistillationwheren-dodecanewasaddedtohelpdistilltheheavyfraction.Thelightfractionincludingmainlymethanolcouldbereusedasthereactionmediumwithoutanysubstantialchangeintheyieldofmethyllevulinate.ThechemicalcompositionandstructuraloflowerheavyfractionwerecharacterizedbyGC/MS,FTIR,1H-NMRand13C-NMRtechniques.Methyllevulinatewasfoundtobeamajoringredientoflowerheavyfractionwiththecontentover96%.Thispathwayisefficient,environmentallybenignandeconomicalfortheproductionofpurelevulinateestersfromcellulose.

简介：根据Anderson亲爱原则，为极其重的降雨(缩短的同样极端的降雨/降水)的预报的一个方法基于中国气象学的管理(CMA)的T213全球整体预言系统(EPS)的整体预报数据被开发。在20072010期间使用T213预报降水数据并且在20012010的JuneAugust的观察降雨数据，累积分发功能(CDF)的特征观察，T213EPS预报降水被分析。因此，根据在模型之间的CDF的连续差别，气候和EPS预报，极端降水预报索引(EPFI)的一个数学模型被建立并且适用在17312011年7月期间在中国预报几个极端降雨事件的实验。结果证明EPFI利用了模型的尾巴信息气候的CDF和极端降雨的提供的令人喜悦的的预报。EPFI为预先发给极端降雨的早警告37天基于T213EPS是有用的。与预报铅时间的扩展，EPFI变得不太熟练。结果也证明模型气候CDF的合理性具有到EPFI的技巧的重要重要性。

简介：有逐渐变细的节STTS的一个看台波浪试管与其突然的节被逐渐变细的节代替的突然的节STAS从一个standingwave试管被发展。研究被打算STAS把声学的性质和STTS的极其非线性的纯站波浪与那些作比较。STTS的声学的性质与转移矩阵被学习。它被证明，象STAS一样，STTS是刺耳的standingwave试管。与它的刺耳的性质，181dB极其非线性的纯站波浪在在它的第一回声频率激动的STTS被获得。然后，极其非线性的站波浪的浸透性质上的比较试验性的研究与一样的长度在STTS和STAS被执行。STTS能压制泛音并且同时更有效地减少站的波浪的精力损失，这被发现。与STAS相比，在扬声器的一样的电压下面，STTS获得了一个更高的极其非线性的纯站波浪。而且，它被作出对有利的裁决第三回声频率的第三泛音接近了的STTS健全来源阻抗，健全压力水平转移功能的山谷价值对应于的第七回声频率。因为这，第三泛音随基本波浪的增加很快增加了并且趋于浸透。

简介：Thusfar,measurementsandestimationsofactualevapotranspiration(ET)inextremelyaridareasarestillinsufficient.BasedonsuccessiveobservationsfromJune–September2014,wesimulatedETofaPopuluseuphraticaOliv.forestduringthegrowingseasoninanextremelyaridregionofnorthwestChinausingtheShuttleworth–Wallace(S–W)model.SimulatedETvalueswerecomparedtothoseoftheeddy-covariance(EC)methodona1hinterval.Witharootmeansquareerror(RMSE),relativeerror(RE)andmeanabsoluteerror(MAE)of0.192,3.100and0.165mmh-1,respectively,modelperformancewasnotsatisfactory.Inparticular,ondayswithstrongwinds(Sep.11–13),deviationsbetweensimulatedandobservedETvaluesincreasedto0.275,0.878and0.251mmh-1,RMSE,REandMAErespectively.Thesevaluesweresignificantlygreaterthanthoseinotherstudyperiodsandweremostlikelyowingtosharpincreasesinwindspeed.Asaresult,thereweresubstantialadvectiveeffects,whichisnotconsistentwiththeassumptionoftheS–Wmodelthattherearenoadvectiveeffectsormesoscalecirculationpatternsinducedbysurfacediscontinuities.