2024剑桥雅思讲义Labelling_a_Diagram 1.docx

上传人:p** 文档编号:672574 上传时间:2024-01-08 格式:DOCX 页数:3 大小:52.64KB
下载 相关 举报
2024剑桥雅思讲义Labelling_a_Diagram 1.docx_第1页
第1页 / 共3页
2024剑桥雅思讲义Labelling_a_Diagram 1.docx_第2页
第2页 / 共3页
2024剑桥雅思讲义Labelling_a_Diagram 1.docx_第3页
第3页 / 共3页
亲,该文档总共3页,全部预览完了,如果喜欢就下载吧!
资源描述

《2024剑桥雅思讲义Labelling_a_Diagram 1.docx》由会员分享,可在线阅读,更多相关《2024剑桥雅思讲义Labelling_a_Diagram 1.docx(3页珍藏版)》请在第壹文秘上搜索。

1、ZQ国国PaSSaHe1TheLayersoftheSunConsidertheearth,themoon,andalltheotherplanetsinoursolarsystem.Thinkaboutthemassthatallthoseobjectsmusthavewhentheyarealladdedtogether.Counter-intuitively,addedalltogethertheyaccountforonly0.2%ofthetotalmassofthesolarsystem.Thesunmakesuptheremaining99.8%ofallthemassinthe

2、solarsystem!Thesunisthecenterofthesolarsystemandthelargestobjectinthesolarsystem.OursunisastarthatprovideslightandheatandsupportsalmostalllifeonEarth.Thesunisasphere,butunliketheearthandthemoonzitisnotsolid.Mostatomsinthesunexistasplasmazorafourthstateofmattermadeupofsuperheatedgaswithanelectricalch

3、arge.Oursunconsistsalmostentirelyoftheelementshydrogenandheliumzandbecausethesunisnotsolid,itdoesnothaveadefinedouterboundary.Itdoes,however,haveadefiniteinternalstructure.Thereareseveralidentifiablelayersofthesun:Thecoreistheinnermostorcentrallayerofthesun.Thecoreisplasmazbutmovessimilarlytoagas.It

4、stemperatureisaround27milliondegreesCelsius.Inthecore,nuclearreactionscombinehydrogenatomstoformhelium,releasingvastamountsofenergyintheprocess.Theenergyreleasedthenbeginstomoveoutwardztowardstheouterlayersofthesun.Justoutsidethecoreistheradiativezone,whichhasatemperatureofabout7milliondegreesCelsiu

5、s.Theenergyreleasedinthecoretravelsextremelyslowlythroughtheradiativezone.Particlesoflightcalledphotonscanonlytravelafewmillimetersbeforetheyhitanotherparticleinthesun,areabsorbedandthenreleasedagain.Itcantakeaphotonaslongas50millionyearstotravelallthewaythroughtheradiativezone.Surroundingtheradiati

6、vezoneistheconvectionzone.Here,hotmaterialfromnearthesunscenterrises,coolsatthesurface,andthenplungesbackdownwardtoreceivemoreheatfromtheradiativezone.Thismovementhelpstocreatesolarflaresandsunspots.Thesefirstthreelayersmakeupwhatwewouldactuallycallthesun.Thenextthreelayersmakeupthesunsatmosphere.Of

7、course,therearenosolidlayerstoanypartofthesun,sotheseboundariesarefuzzyandindistinct.Thevisiblesurfaceofthesunisknownasthephotosphere.Thisistheregionofthesunthatemitssunlight.Itsalsooneofthecoolestlayersofthesun-onlyabout6700oC.Lookingataphotographofthesunssurface,youcanseethatithasseveraldifferentc

8、olors:oranges,yellowandredszgivingitagrainyappearance.Wecannotseethiswhenweglancequicklyatthesunasoureyescantfocusthatquicklyandthesunistoobrightforustolookatformorethanabriefmoment.Lookingatthesunforanylengthoftimecancauseblindness,sodonttryit!Sunlightisemittedfromthesunsphotosphere.Afractionofthel

9、ightthattravelsfromthesunreachesEarth.Ittravelsaslightinarangeofwavelengths,includingvisiblelight,ultraviolet,andinfraredradiation.Visiblelightisallthelightwecanseewithoureyes.Wecantseeultravioletorinfraredradiation,buttheireffectscanDD国BIstillbedetected.Forexample,sunburniscausedbyultravioletradiat

10、ionwhenyouspendtoomuchtimeinthesun.Thechromosphereisthezoneabout2,000kilometersthickthatliesdirectlyabovethephotosphere.Thechromosphereisathinregionofthesunsatmospherethatglowsredasitisheatedbyenergyfromthephotosphere.Temperaturesinthechromosphererangefromabout4000oCtoabout10,000oC.Jetsofgasfireupth

11、roughthechromosphereatspeedsupto72,000kilometersperhour;reachingheightsashighas10,000kilometers.Theoutermostlayerofthesunzandtheoutermostpartofitsatmosphere,iscalledthecorona.Itisthesunshaloorcrown.Ithasatemperatureof2to5milliondegreesCelsiusandismuchhotterthanthevisiblesurfaceofthesunzorphotosphere

12、.Thecoronaextendsmillionsofkilometersintospace.Ifyoueverhavethechancetoseeatotalsolareclipse,youwillbeabletoseethesunscorona,shiningoutintospace.Toconclude,inthesunscore,nuclearfusionreactionsgenerateenergybyconvertinghydrogentohelium,andtherestofthesunisheatedbythemovementofthisenergyoutwardfromthe

13、core.Lightenergyfromthesunisemittedfromthephotosphere,andittravelsthroughspace,andsomeofitreachestheearth.ThesunisthesourceofalmostalltheenergyonEarthandsunlightpowersphotosynthesis,aswellaswarmingandilluminatingourEarth.Adaptedfrom:https:en.wikibooks.orq/Wiki/HiqhSChOOlEarthSCienCe/TheSUcSS国IELTSADVANTAGEDailySkillsClinic:LabellingaDiagramPracticeQuestions1-4Labelthediagrambelowwiththenamesofthelayersofthesun.ChooseNOMORETHANTWOWORDSfromthereadingpassageforeachanswer.

展开阅读全文
相关资源
猜你喜欢
相关搜索

当前位置:首页 > 外语学习 > 雅思/LSAT

copyright@ 2008-2023 1wenmi网站版权所有

经营许可证编号:宁ICP备2022001189号-1

本站为文档C2C交易模式,即用户上传的文档直接被用户下载,本站只是中间服务平台,本站所有文档下载所得的收益归上传人(含作者)所有。第壹文秘仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。若文档所含内容侵犯了您的版权或隐私,请立即通知第壹文秘网,我们立即给予删除!