英语小短文加翻译

英语小短文加翻译第一部分：英国文学短文(原文加中文翻译)Afernthathyperaccumulatesarsenic(这是题目，百度一下就能找到原文好，原文还有表格，我没有翻译)Ahardy,versatile,fast-growingplanthelpstoremovearsenicfromcontaminatedsoilsContaminationofsoilswitharsenic,whichisbothtoxicandcarcinogenic,iswidespread1.WehavediscoveredthatthefernPterisvittata(brakefern)isextremelyefficientinextractingarsenicfromsoilsandtranslocatingitintoitsabove-groundbiomass.Thisplant—which,toourknowledge,isthefirstknownarsenichyperaccumulatoraswellasthefirstfernfoundtofunctionasahyperaccumulator—hasmanyattributesthatrecommenditforuseintheremediationofarsenic-contaminatedsoils.WefoundbrakeferngrowingonasiteinCentralFloridacontaminatedwithchromatedcopperarsenate(Fig.1a).Weanalysedthefrondsofplantsgrowingatthesitefortotalarsenicbygraphitefurnaceatomicabsorptionspectroscopy.Of14plantspeciesstudied,onlybrakeferncontainedlargeamountsofarsenic(As;3,280–4,980p.p.m.).Wecollectedadditionalsamplesoftheplantandsoilfromthecontaminatedsite(18.8–1,603p.p.m.As)andfromanuncontaminatedsite(0.47–7.56p.p.m.As).Brakefernextractedarsenicefficientlyfromthesesoilsintoitsfronds:plantsgrowinginthecontaminatedsitecontained1,442–7,526p.p.m.Arsenicandthosefromtheuncontaminatedsitecontained11.8–64.0p.p.m.Thesevaluesaremuchhigherthanthosetypicalforplantsgrowinginnormalsoil,whichcontainlessthan3.6p.p.m.ofarsenic3.Aswellasbeingtolerantofsoilscontainingasmuchas1,500p.p.m.arsenic,brakeferncantakeuplargeamountsofarsenicintoitsfrondsinashorttime(Table1).Arsenicconcentrationinfernfrondsgrowinginsoilspikedwith1,500p.p.m.Arsenicincreasedfrom29.4to15,861p.p.m.intwoweeks.Furthermore,inthesameperiod,fernsgrowinginsoilcontainingjust6p.p.m.arsenicaccumulated755p.p.m.Ofarsenicintheirfronds,a126-foldeichment.Arsenicconcentrationsinbrakefernrootswerelessthan303p.p.m.,whereasthoseinthefrondsreached7,234p.p.m.Additionof100p.p.m.Arsenicsignificantlystimulatedferngrowth,resultingina40%increaseinbiomasscomparedwiththecontrol(datanotshown).After20weeksofgrowth,theplantwasextractedusingasolutionof1:1methanol:watertospeciatearsenicwithhigh-performanceliquidchromatography–inductivelycoupledplasmamassspectrometry.Almostallarsenicwaspresentasrelativelytoxicinorganicforms,withlittledetectableorganoarsenicspecies4.TheconcentrationofAs(III)wasgreaterinthefronds(47–80%)thanintheroots(8.3%),indicatingthatAs(V)wasconvertedtoAs(III)duringtranslocationfromrootstofronds.Aswellasremovingarsenicfromsoilscontainingdifferentconcentrationsofarsenic(Table1),brakefernalsoremovedarsenicfromsoilscontainingdifferentarsenicspecies(Fig.1c).Again,upto93%ofthearsenicwasconcentratedinthefronds.AlthoughbothFeAsO4andAlAsO4arerelativelyinsolubleinsoils1,brakefernhyperaccumulatedarsenicderivedfromthesecompoundsintoitsfronds(136–315p.p.m.)atlevels3–6timesgreaterthansoilarsenic.Brakefernismesophyticandiswidelycultivatedandnaturalizedinmanyareaswithamildclimate.IntheUnitedStates,itgrowsinthesoutheastandinsouthernCalifornia5.Thefernisversatileandhardy,andpreferssunny(unusualforafern)andalkalineenvironments(wherearsenicismoreavailable).Ithasconsiderablebiomass,andisfastgrowing,easytopropagate,andperennial.Webelievethisisthefirstreportofsignificantarsenichyperaccumulationbyanunmanipulatedplant.Brakefernhasgreatpotentialtoremediatearsenic-contaminatedsoilscheaplyandcouldalsoaidstudiesofarsenicuptake,translocation,speciation,distributionanddetoxificationinplants.*SoilandWaterScienceDepartment,UniversityofFlorida,Gainesville,Florida32611-0290,USAe-mail:[e-mail]?CooperativeExtensionService,UniversityofGeorgia,TerrellCounty,POBox271,Dawson,Georgia31742,USA?DepartmentofChemistry&SoutheastEnvironmentalResearchCenter,FloridaInternationalUniversity,Miami,Florida33199,1.Nriagu,J.O.(ed.)ArsenicintheEnvironmentPart1:CyclingandCharacterization(Wiley,NewYork,1994).2.Brooks,R.R.(ed.)PlantsthatHyperaccumulateHeavyMetals(CambridgeUniv.Press,1998).3.Kabata-Pendias,A.&Pendias,H.inTraceElementsinSoilsandPlants203–209(CRC,BocaRaton,1991).4.Koch,I.,Wang,L.,Ollson,C.A.,Cullen,W.R.&Reimer,K.J.Envir.Sci.Technol.34,22–26(2000).5.Jones,D.L.EncyclopaediaofFerns(Lothian,Melbourne,1987).积累砷的蕨类植物耐寒，多功能，生长快速的植物，有助于从污染土壤去除砷有毒和致癌的土壤砷污染是非常广泛的。我们已经发现，蕨类植物蜈蚣草（凤尾蕨）对从土壤中提取砷和转运到地上部生物量是非常有效的。据我们所知这种植物，是第一个已知的砷超富集植物以及也是第一种在已发现的蕨类中可以作为超富集植物，它有许多属性比如建议使用在砷污染土壤的修复。我们发现被铬砷酸铜污染的生长在佛罗里达州中部的一个站点的凤尾蕨图1a）。我们用石墨炉原子吸收法分析了在站点正生长植物叶子总砷的吸收光谱。对于14种研究植物物种中，只有凤尾蕨植物中含有大量的砷（含量；3280–4980ppm）。我们从受污染的站点（18.8–1603ppm）和未受污染的站点（0.47–7.56ppm）收集更多的植物和土壤样品。凤尾蕨从土壤中有效吸收砷转运到其叶子中，在受污染的站点生长的植物，含有1442–7526ppm的砷和那些未受污染的站点包含11.8–64ppm的这些值是比那些正常的土壤中生长的植物的高很多，其中包含小于3.6ppm的砷。对于含有高达1500ppm砷的疏松土壤中，凤尾蕨植物可以在很短的时间内吸收大量的砷进入它的叶子（表1）。在掺入1500ppm砷的土壤中蕨类叶子中砷浓度是不断增长的，在两周内砷含量从29.4增加到15861ppm。在蕨类叶子中的砷，是126倍的富集。凤尾蕨根的砷浓度小于303ppm，而那些在叶的浓度达到7234ppm。加入100ppm的砷显著刺激蕨类生长，导致在与对照相比，生物量增加了（数据未显示）。经过20周的增长，用1:1甲醇：水的方法提取该植物用高效液相色谱法–电感耦合等离子体质谱法来平衡砷。目前几乎所有的砷是相对无毒的无机形式，几乎没有检测到有机砷物种。作为（Ⅲ）的浓度叶（47-80％）与根（8.3％）相比更多，表示AS（V）被转换AS(III）在根转运到叶的过程中。以及从土壤中除去砷的植物含有不同浓度的砷（表1），从土壤中去除含砷的凤尾蕨也含有不同形态的砷（图1C）。再着，高达93%的砷主要集中在叶。虽然feaso4和AlAsO42H2O在土壤中的相对不溶，凤尾蕨富集的砷来自这些化合物进入它的叶状体（136–315ppm）在3级–6倍大于土壤砷。凤