简介:CAFIUVice-PresidentAiPingdeliveredaspeechattheOxfordUniversityChinaCentreduringhisvisittotheUnitedKingdomfrom16to19ofMarchattheinvitationofthe48GroupClub.Thefollowingisthefulltextofthespeech.
简介:Attheendof2015,athree-memberdelegationofyoungscholarsfromAlexanderGorchakovPublicDiplomacyFund(AGPDF)visitedBeijingandTianjinfromDecember7to11attheinvitationoftheChineseAssociationforInternationalUnderstanding(CAFIU).
简介:Thenasogastrictube(NGT)hasbecomeafrequentlyuseddevicetoalleviategastrointestinalsymptoms.Nasogastrictubesyndrome(NTS)isanuncommonbutpotentiallylife-threateningcomplicationofanindwellingNGT.NTSischaracterizedbyacuteupperairwayobstructionduetobilateralvocalcordparalysis.Wereportacaseofa76-year-oldmanwithNTS,inducedbyanindwellinglongintestinaltube.Hewasadmittedtoourhospitalfortreatmentofsigmoidcoloncancer.Heunderwentsigmoidectomytoreleaseabowelobstruction,andhadalongintestinaltubeinsertedtodecompresstheintestinaltract.Hepresentedacutedyspneafollowingprolongedintestinalintubation,andbronchoscopyshowedbilateralvocalcordparalysis.TheNGTwasremovedimmediately,andtracheotomywasperformed.Thepatientwasfinallydischargedinafullyrecoveredstate.NTSbeconsideredinpatientscomplainingofacuteupperairwayobstruction,notonlywithaNGTinsertedbutalsowithalongintestinaltube.
简介:ForagraphG,wedenotebyp(G)andc(G)thenumberofverticesofalongestpathandalongestcycleinG,respectively.ForavertexvinG,id(v)denotestheimplicitdegreeofv.Inthispaper,weobtainthatifGisa2-connectedgraphonnverticessuchthattheimplicitdegreesumofanythreeindependentverticesisatleastn+1,theneitherGcontainsahamiltonianpath,orc(G)≥p(G)-1.
简介:Haze-to-fogtransformationduringalonglasting,lowvisibilityepisodewasexaminedusingtheobservationsfromacomprehensivefieldcampaignconductedinNanjing,Chinaduring4-9December2013.Inthisepisode,hazewastransformedintofogandthefoglastedfordozensofhours.Theimpactsofmeteorologicalfactorssuchaswind,temperature(T)andrelativehumidity(RH)onhaze,transitionandfogduringthisepisodewereinvestigated.Resultsrevealedsignificantdifferencesbetweenhazeandfogdays,duetotheirdifferentformationmechanisms.Comparisonwasmadeforboundary-layerconditionsduringhazydays,haze-to-fogdaysandfoggydays.DistributionsofwindspeedandwinddirectionaswellassynopticweatherconditionsaroundNanjinghaddeterminativeimpactsontheoccurrencesandcharacteristicsofhazeandfog.WeakenedsoutherlywindinsouthernNanjingresultedinhighconcentrationofpollutants,andhazeeventsoccurredfrequentlyduringthestudyperiod.Thewindspeedwaslessthan1ms-1inthehazeevent,whichresultedinastableatmosphericconditionandweakdispersionofthepollutants.Theheightofthetemperatureinversionwasabout400mduringtheperiod.Theinversionintensitywasweakandthetemperature-differencewas4℃km-1orlessinhaze,whiletheinversionwasstronger,andtemperature-differencewasabout6℃km-1,approachingtheinversionlayerintensityinthefogevent.HazeeventisstronglyinfluencedbyambientRH.RHvaluesincreased,whichresultedinhazedaysevidentlyincreased,suggestingthatanincreasingfractionofhazeeventsbecausedbyhygroscopicgrowthofaerosols,ratherthansimplybyhighaerosolloading.WhenRHwasabove90%,hazeaerosolsstartedtobetransformedfromhazetofog.Thisstudycallsformoreeffortstocontrolemissionstopreventhazeeventsintheregion.
简介:Anultrasensitivebiosensorbasedonhybridstructureandcomposedoflong-rangesurfaceplasmonpolariton(LRSPP)anddielectricplanarwaveguide(PWG)modesisproposed.BothPWGandLRSPPmodeshavestrongresonancestoformstrongcouplingbetweenthetwomodes,andthetwomodescancoupletoenhancesensitivityofsensors.Inthehybridstructure,PWGiscomposedofcytop–Si–cytopmultilayersandtheLRSPPconfigurationiscomposedofcytop–metal–sensingmediummultilayerslabs.Thehighestimagingsensitivitiesof2264and3619RIU-1wererealizedintheproposedsensorsbasedonAuandAl-monolayergraphene,respectively,whicharenearly1.2and1.9timeslargerthanthe1910RIU-1sensitivityoftheconventionalLRSPRsensor(LRSPPsensor).Moreover,itisdemonstratedthatthePWG-coupledLRSPPbiosensorisapplicabletothesensingmedium,withrefractiveindexinthevicinityof1.34.
简介:Background:InWesternNorthAmerica,increasingwildfireandoutbreaksofnativebarkbeetleshavebeenmediatedbywarmingclimateconditions.Bioclimaticmodelsforecastthelossofkeyhighelevationspeciesthroughouttheregion.Thisstudyusesretrospectivevegetationandfirehistorydatatoreconstructthedriversofpastdisturbanceandenvironmentalchange.Understandingtherelationshipamongclimate,antecedentdisturbances,andthelegacyeffectsofsettlement-eraloggingcanhelpidentifythepatternsandprocessesthatcreatelandscapessusceptibletobarkbeetleepidemics.Methods:Ouranalysisusesdatafromlakesedimentcores,standinventories,andhistoricalrecords.Sedimentcoresweredatedwithradiometrictechniques(~(14)Cand~(210)Pb/~(137)Cs)andsubsampledforpollenandcharcoaltomaximizethetemporalresolutionduringthehistoricalperiod(1800CEtopresent)andtoprovideenvironmentalbaselinedata(last10,500years).Pollendataforsprucewerecalibratedtocarbonbiomass(Ct/ha)usingstandardallometricequationsandatransferfunction.Charcoalsampleswereanalyzedwithstatisticalmodelstofacilitatepeakdetectionanddeterminefirerecurrenceintervals.Results:TheWasatchPlateauhasbeendominatedbyEngelmannspruceforestsforthelast~10,500years,withsubalpinefirbecomingmoreprominentsince6000yearsago.Thislandscapehasexperiencedadynamicfireregime,whereburningeventsaremorefrequentandofhighermagnitudeduringthelast3000years.TwoimportantdisturbanceshaveimpactedEngelmannspruceinthehistoricalperiod:1)high-gradeloggingduringthelate19~(th)century;and(2)ahighseveritysprucebeetleoutbreakinthelate20~(th)centurythatkilled>90%ofmaturespruce(>10cmdbh).Conclusions:Ourstudyshowsthatspruce-dominatedforestsinthisregionareresilienttoarangeofclimateanddisturbanceregimes.Severallinesofevidencesuggestthat19~(th)centuryloggingpromotedalegacyofsimplifiedstandstructureandcompositionsuchthat,whencli
简介:Wedemonstratedlong-periodgrating(LPG)inscriptiononpolymerfunctionalizedopticalmicrofibersanditsapplicationsinopticalsensing.Opticalmicrofiberswerefunctionalizedwithultraviolet-sensitivepolymethylmethacrylatejacketsand,thus,LPGscouldbeinscribedonopticalmicrofibersviapoint-by-pointultravioletlaserexposure.Fora2mmlongmicrofiberLPG(MLPG)inscribedonopticalmicrofiberswithadiameterof5.4μm,aresonantdipof15dBat1377nmwasobserved.ThisMLPGshowedahighsensitivityofstrainandaxialforce,i.e.,-1.93pm∕μεand-1.15pm∕μN,respectively.AlthoughtheintrinsictemperaturesensitivityoftheLPGsisrelativelylow,i.e.,-12.75pm∕°C,itcanbeincreasedtobe-385.11pm∕°Cbyappropriatesealing.Benefitingfromthesmallfootprintandhighsensitivity,MLPGscouldhavepotentialapplicationsinopticalsensingofstrain,axialforce,andtemperature.
简介:
简介:Background:Thispaperexploredthelong-term,ceteris-paribuseffectsofpotentialCO,fertilizationontheglobalforestsector.BasedonthefindingsofNorbyetal.(PNAS2005,102(50))aboutforestresponsetoelevated[CO_2].Methods:ForestproductivitywasincreasedintheGlobalForestProductsModel(GFPM)inproportiontotherising[CO.,]projectedintheIPCCscenarioA1B,A2,andB2.Projectionsoftheforestareaandforeststockandoftheproduction,consumption,prices,andtradeofproductsrangingfromfuelwoodtopaperandpaperboardwereobtainedwiththeGFPMforeachscenario,withandwithoutCO_2fertilizationbeginningin2011andupto2065.Results:C02fertilizationincreasedwoodsupply,leadingtolowerwoodpriceswhichinturninducedmodestlowerpricesofendproductsandhigherglobalconsumption.However,productionandvalueaddedinindustriesdecreasedinsomeregionsduetotherelativecompetitiveadvantagesandtothevaryingregionaleffectsofCO_2fertilization.Conclusion:ThemaineffectofCO,fertilizationwastoraisetheleveloftheworldforeststockin2065by9to10%forscenariosA2andB2andby20%forscenarioA1B.Theriseinforeststockinducedbyfertilizationwasinpartcounteractedbyitsstimulationofthewoodsupplywhichresultedinlowerwoodpricesandincreasedharvests.
简介:Tosystematicallystudythevehicle–bridgecoupleddynamicresponseanditschangerulewithdifferentparameters,avehiclemodelwithsevendegreesoffreedomwasbuiltandthetotalpotentialenergyofvehiclespacevibrationsystemwasdeduced.Consideringthestimulationofroadroughness,thedynamicresponseequationofvehicle–bridgecoupledsystemwasestablishedinaccordancewiththeelasticsystemprincipleoftotalpotentialenergywithstationaryvalueandthe‘‘set-in-right-position''rule.Onthebasisoftheself-compiledFortranprogramandbridgeengineering,thedynamicresponseoflongspancontinuousgirderbridgeundervehicleloadwasstudied.Thisstudyalsoincludedthecalculationofvehicleimpactcoefficient,evaluationofvibrationcomfort,andanalysisofdynamicresponseparameters.Resultsshowtheimpactcoefficientchangeswithlanenumberandislargerthanthevaluecalculatedbythe‘‘generalcodefordesignofhighwaybridgesandculverts(China)''.TheDieckmannindexofbridgevibrationisalsorelatedtolanenumber,andthevibrationcomfortevaluationisgoodinnormalconditions.Therelevantconclusionsfromparametricanalyseshavepracticalsignificancetodynamicdesignanddailyoperationoflong-spancontinuousgirderbridgesinexpressways.Safetyandcomfortareexpectedtoimprovesignificantlywithfurthercontrolofthevibrationofvehicle–bridgesystem.
简介:Inthispaper,weinvestigatetheglobalexistenceandlongtimebehaviorofstrongsolutionsforcompressiblenematicliquidcrystalflowsinthreedimensionalwholespace.TheglobalexistenceofstrongsolutionsisobtainedbythestandardenergymethodundertheconditionthattheinitialdataareclosetotheconstantequilibriumstateinH~2-framework.IftheinitialdatasinL~1-normarefiniteadditionally,theoptimaltimedecayratesofstrongsolutionsareestablished.WiththehelpofFouriersplittingmethod,onealsoestablishesoptimaltimedecayratesforthehigherorderspatialderivativesofdirector.