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简介：正如一句俗语，“天有不测风云”，自然灾害贯穿着人类发展的整个进程。面对强大的大自然，我们无法消极逃避，只能努力去面对。我们应该尊重自然、研究自然、掌握规律、趋利避害、力争最大限度地与大自然和谐相处。

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简介：THEBeijingNaturalHistoryMuseumwasthefirstnaturalsciencemuseumestablishedafterthefoundingofthePeople’sRepublic.Itencompassesspecimencollection,preservation,and

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简介：Aftermajornaturaldisasters,suchastherecentearthquake-tsunamieventinSouthAsia,reportsappearaboutthemysteriousabilityofanimalstoanticipateandtoescapetheimpendingdanger.Thisisanopportunitytorecallthelonghistoryofthisphenomenoninthetraditionsofdifferentcivilizations,toevaluateChineseefforts,30-40yearsago,tousethisphenomenonforearthquakeprediction,andtojudgeitsstateofacceptanceinmodernscience.Aneffortismadetointroducethisphenomenonasaresearchfieldofmodernbionics.Thetimingisfavorablesince,increasingly,infraredthermalanomalies,monitoredfromsatellite,suggestinglitho-atmosphericprocesses,arefoundtoprecedeearthquakes.Theywereunexpectedbyseismologistsandareheresuggestedtoessentiallyreflecttheenergyconversionpatternsresponsibleforthesignalsmonitoredbyanimals.Theaimistolearnfromanimalsinthelongtermhownaturaldisasterscanbetterbeanticipated,andhowsimpletechnicalwarningsystemscanbedeveloped.Somechallengesareanalyzed.Oneisinterpretationofthenatureofenergyreleasepriortothemainearthquakedisasterresultingin"macro-anomaly"precursors,anotherisbettertounderstandtheeffectonanimalsenses.Theroleofnon-linearcooperativephenomenaincludingtsunamitypewavesisemphasized.

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简介：DiamondfromLiaoning,Chinawasstudiedbysynchrotronradiationandinfraredspectrum.Thedistributionofdislocationsinthespecimenthasbeenrevealed.Anewmethodtodeterminetheorientationofcrystaldefectshasbeenproposedandtheorientationindexesofthedislocationsinthespecimenwerecalculatedbythismethod.Ithasbeenfoundthatthedislocationsinthespecimentarenearbutnotpreciselyparallelto{111}planes,Themaximumanglebetweendislocationand{111}planeisabout16°.AlmostallthedislocationsinthespecimenthavethesameBurgersvector1/2[101]andimplythesamenessoftheirorigination.

简介：1TechnologyofnaturalmaterialsEarlymanusedconvenientlyshapedstonesastools."Workshop"areashavebeenfoundwithlargenumbersofstones,someshowingsignsofbeingworked[1].However,organicmaterialslikewoodwilldecayundernormalwetconditionsinthepresenceofoxygen,sowewon'tfindthesamesortofevidenceforwoodentools.Itissafetoassumethatearlymanusedsticksasprobesandclubs,andmaybeevenformakingsomesortofnestlikeprotectionagainsttheelementsandpredators,sinceweseechimpanzeesandotheranimalsdoingthissortofthing.Sowood,andalmostcertainlyotherplantmaterialssuchasfibrousleaves,andboneandothermaterialsgleanedfromdeadanimals,wouldbeusedfromtheearliesttimes.WeneedtoknowthisinordertoestablishtheideathatMancanbeexpectedtohavealonghistoryoftheuseandmanipulationofnaturalmaterials.Thisneedsskillsinchoosingmaterialsforcertainusesonthebasisoftheirmechanicalproperties,whetherthosepropertiesaretodowiththeeaseofshapingthematerialortheeffectivenessofthatmaterialinuse.Occasionallythematerialwaschosensimplybecauseitwasreadilyavailable.Ifwefindthataparticularmaterialwasalwaysusedforacertainjob,it'sreasonabletodeducethatManwasexertingmaterialsselectioncriteriathroughexperience.

简介：HIVisablood-bomevirustransmittedviasexualintercourseorpercutaneousexposuretoinfectedblood,orfromaninfectedmothertoherchildduringthebirthprocess.Followinginfection,thetimebeforeonsetofclinicaldiseasevariesfrommonthstoyears;thedurationisinfluencedbyage(therateofprogressionincreaseswithage)andHLAtype(A1,B8,DR3areassociatedwithrapidprogressionandB27withslowprogression),butnotbygenderorriskactivity.Althoughmostpatientsinitiallyhavenocharacteristicsymptoms,thereisusually(90%)agradualdeclineinimmunefunction.

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简介：最近的学习建议了那个天生的免疫系统可能在怀孕前进起一个重要作用。在这研究，调查而不是T房间，NK房间和NKT房间是否是在早怀孕的外部血的主导的人口，流动cytometry被用来检测百分比和T房间的细胞内部的cytokine表情，NK房间，在非怀孕的女人和早怀孕的women.In的外部血的NKT房间我们的结果，NK房间的百分比和NKT房间显著地与非怀孕相比在怀孕被增加。然而，T房间的百分比没被改变。我们没在早怀孕的女人的外部血检测全部的淋巴细胞或T房间的Th2优势，也在NK和NKT房间没有在T房间，而是IFN-生产的类型1和类型2cytokines的重要变化在早怀孕被减少。这些结果建议包括NK房间和NKT房间的天生的免疫系统应该在怀孕前进起一个枢轴的作用。在天生的免疫系统的2移动机制应该在人的早怀孕期间被付更多的注意的类型1/type。

简介：ThispaperreportsthephotochemicaldegradationofMethyleneBlue(MB)innaturalseawater(NSW).Thephotode-gradationreactionconformedtothefirst-orderreactionkineticswiththerateconstant0.0158min-1.MBwasphotochemicallyde-gradatedfasterunderhigh-pressuremercurylamp(HPML)thanundersunlight.WhenMBwasinlowerconcentrations,salinitycouldinhibitthephotoreactionwhereasMBinhigherconcentration,salinitycouldacceleratethephotoreaction.Humidacidcouldalsoinhibitthephotoreactions.ToxicitytestswithmarinephytoplanktonSkeletonemacostatum(Sk)andHeterosigmaakashiwoHada(Ha)showeddecreasedacutetoxicityafterphotodegradation.

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简介：Overthepastthousandsofyears,humansocietyhasexperiencedevolutionfromtheprimitivecivilization,theagriculturalcivilization,theindustrialcivilizationandtotheecologicalcivilization,whichisahistoryfromlow-leveltoadvanceddevelopment.Thecoreoftheecologicalcivilizationis"respectingnature,complyingwithnatureandprotectingnature",whichisessentialtoharmoniousco-existencebetweenmanandnature.Thisharmoniousco-existencerequiresconstantlyimprovingsystemandmechanismforthedevelopmentofnationalspace,naturalresourceconservationandutilization,andecologicalenvironmentprotection,torealizethewin-winofresourcedevelopmentandenvironmentalprotection.Itisathousand-yearplafftoachieveecologicalcivilizationbasedonunifiedmanagementofnaturalresources.

简介：Digitrecognitionfromanaturalscenetextinvideosurveillance/broadcastingapplicationsisachallengingresearchtaskduetoblurred,fontvariations,twisted,andnon-uniformcolordistributionissueswithadigitinanaturalscenetoberecognized.Inthispaper,tosolvethedigitnumberrecognitionproblem,aprincipal-axisbasedtopologycontourdescriptorwithsupportvectormachine(SVM)classificationisproposed.Thecontributionsofthispaperinclude:a)alocaldescriptorwithSVMclassificationfordigitrecognition,b)higheraccuracythanthestate-of-theartmethods,andc)lowcomputationalpower(0.03second/digitrecognition),whichmakethismethodadoptabletoreal-timeapplications.

简介：Accordingtothestructure-basedforestmanagementtheory,theappraisalindicessystemofnaturalforestmanagementefficiencywasestablishedfromspatialutilization,speciesdiversity,constructivespeciescompetitionandtreecomposition,whichcouldbeusedtodepictstandstatus,anditsmetewandwasgiven.RelativeweightwasendowedbyTheAnalyticHierarchyProcess(AHP),andthentheconceptionofnaturalforestmanagementefficiencycomprehensiveappraisalindexwasputforwardforthefirsttimeandappliedtofourdifferentsamplingplotsofnaturalforest,threeofthemfromDongdapoforestregion,Jiaohe,Jilinprovince,andonefromBaihuaforestarea,Xiaolongshan,Gansuprovince,China.Theresultsareasfollowing:thestandstatuswasobviouslyimprovedafterbeingmanagedandplotA,Bgotamarkof"medium"whileCandDwere"perfect".Fromhightolow,thearrangementofforestmanagementefficiencycomprehensiveappraisalindexwasC>D>A>B.Thisappraisalresultabidedbythephenomenondetectedinthepracticalfield.Theforestmanagementefficiencycomprehensiveappraisalindexbroughtupinthispapercouldbetakenasawayofcomprehensivequantitativechangeofstandstatewhichdirectlyreflectstheeffortofforestmanagementandaffordsscientificbasisofnaturalforestmanagementeffort.