2. Makeapresentationononeofthealternativesourcesofenergysuccessfullyusedintheworld. Uniteleven

1. Readthefirstparagraphofthearticle.WhatkindofmaterialareengineersfromStanfordUniversityworkingon?

2. Readthewholearticleandmarkthestatementsastrue(t)orfalse(f).

1. Theresultingtransistorsarelessthanacentimeterthick._______

2. Organic transistors prove to be more efficient than their siliconanalogues._______

3. Ittakesjustalittlemorethantwomonthsforthetransistortodisappearinahumanorganism._______

4. Beingharmfulforapatient,silverwiresarenotusedinmakingmedicalelectronics._____

5. Thereisnoneedinconductinganyfurtherteststocreateworkingdevices.___

6. Beta-carotene(themoleculethatgivescucumberstheircolour)might,actasasemiconductor._________

Adesirablesolution

Biodegradableelectronicsformedicaldevicestakeastepcloser

Theideaofcreatingbiodegradableelectronicsforimplantationintothehumanbodyhasbeenaroundforacoupleofdecades,butnoonehasyetmanagedtodoit.However,ZhenanBaoandChristopherBettinger,whoarechemicalengineersatStanfordUniversity,havejustmadeastart.Theyhavecreatedtransistorsfromasulphur-containinghydrocarboncalledthiophene,apolyestercalledpolylactideco-glycolide(PLGA,forshort)andpolyvinylalcohol(PVA).AllofthesechemicalsareapprovedbyAmerica’sFoodandDrugAdministrationforhumanuse.

Tomaketheirtransistors,DrBaoandDrBettingerchoppedsheetsofPLGAinto1cmsquaresanddepositedthinsilvercontactsontothem.TheythencoatedthePLGAwiththiophene,whichactsasasemiconductor,interspersedwithPVA,whichactsasaninsulator.Theresultisaflexibletransistorafewmillimetresthick.

Suchorganictransistorsarenotasefficientandpowerfulassilicontransistors,noraretheyanythinglikeassmall.Buttheycanbemanufacturedcheaply.Moretothepoint,theybreakdownslowlyinwarm,saltyconditionsofthesortfoundinthebody.Inlaboratorytestsintendedtomimicthebody’sinterior,theydisappearedafter70days,leavingbehindonlythewires-which,beingmadeofsilver,arenottoxic.

Tocreateworkingdevicesitwillbenecessarytodouble-checkthattheotheringredientsarenottoxic,too,despitetheirFDAclearance,andalsotomaketheothercomponentsofelectricalcircuits,suchascapacitorsandresistors,inasimilarway.DrBaoisalsoinvestigatingothercompoundswithpotentialusesinthisarea,suchasbeta-carotene(themoleculethatgivescarrotstheircolour),whichshethinksmight,likethiophene,actasasemiconductor.Ifshesucceeds,itshouldbepossibletodeviseelectricalcontrolcircuitsforinstrumentssuchasdrug-deliverydevicesthatcouldbeimplantedandthenleftalonetodotheirthingforamonthortwobeforevanishing.

TheEconomist

3. Lookattheitalicizedwordsandwordcombinationsandexplainwhattheymeaninyourownwords.

4. Speakonthetechnologyofmakingabiodegradabletransistor.Usethewordsandwordcombinationsfromthebox.

biodegradableelectronicssulphur-containinghydrocarbonpolyestertochoptodepositsilvercontacttocoatsemiconductortointersperseinsulatortransistor

4.TranslatethearticlefromRussianintoEnglish.

Химия-этонаукаостроенииипревращениивеществ.Условно,химиюможноразделитьнадвеосновныхгруппы.Неорганическаяхимияизучаетсвойстваиреакциинеорганическихвеществ.Органическаяхимияисследуетвзаимодействиеорганическихвеществ,построенныхнаосновеуглероднойцепочки.Химияможетизучатьвеществаиреакции,протекающиевнутриживогоорганизма.Этимзанимаетсябиохимия,атакжемолекулярнаябиология.Таккакхимиязанимаетсяизучениемстроенияисвойстввеществ,тоонаоченьтеснопересекаетсясфизикой.Несколькоразделовхимииможнотакжерассматриватькакразделыфизики:квантоваяхимия,ифизическаяхимия.Аналитическаяхимиязанимаетсяанализомразличныххимическихвеществсцельюустановитьструктуруисследуемоговещества.

http://sci-lib.com/chemistry