【正文】 其包羅萬象的應(yīng)用程序的通用性。在所有這些結(jié)構(gòu)的發(fā)展和建設(shè)的成功，是由于在材料技術(shù)的進(jìn)步不小的措施，特別是預(yù)應(yīng)力鋼，積累的知識(shí)，在估算預(yù)應(yīng)力部隊(duì)的短期和長期虧損二、譯文Buildingtypesanddesign Abuildingiscloselyboundupwithpeople，,buildingsaremainlyoftwotypes:,employment,insuchfieldsastheminingindustry,themetallurgicalindustry,machinebuilding,’,::alivingroom,culturalactivities,administrationworkandotherservices,suchasschools,officebuildings,parks,hospitals,shops,stations,theatres,gymnasiums,hotels,exhibitionhalls,bathpools,health,foodmarkets,schools,stores,thelibrary,amovietheater,’,manyfamiliespreferredtoliveasfaroutaspossiblefromthecenterofametropolitanarea,crowding,’,planshavetobedrawntoshowwhatthebuildingwillbelike,thelayoutmaybeconsideredunderthreecategories:“day”,“night”,and“services”.“day“roomsgenerallyincludeadiningroom,sittingroomandkitchen,butotherrooms,suchasastudy,maybeadded,whichisgenerallythelargest,oftenservesasadiningroom,too,“night““services“prisethekitchen,bathrooms,larder,however,oftenverydifficulttomeettheoptimumrequirements,itisalsonecessarytofollowthelocaltownplanningregulationswhichareconcernedwithpublicamenities,densityofpopulation,heightofbuildings,proportionofgreenspacetodwellings,buildinglines,thegeneralappearanceofnewpropertiesinrelationtotheneighborhood,afactorycanbegivena“shed”typeridgeroof, , ,thatspendabout80%oftheirtimeinsideofficesandhomes(Mullahetal.,1986。Paradesetal.,1987),(Papastefanouetal.,1988).Fromthenaturalriskpointofview,itisnecessarytoknowthedoselimitsofpublicexposureandtomeasurethenaturalenvironmentalradiationlevelprovidedbyground,air,water,foods,buildinginteriors,etc.,toestimatehumanexposuretonaturalradiationsources(UNSCEAR,1988).Lowlevelgammarayspectrometryissuitableforbothqualitativeandquantitativedeterminationsofgammarayemittingnuclidesintheenvironment(IAEA,1989).Theconcentrationofradioelementsinbuildingmaterialsanditsponentsareimportantinassessingpopulationexposures,asmostindividualsspend80%?.Indoorselevatedexternaldoseratesmayarisefromhighactivitiesofradionuclideinbuildingmaterials(ZikovskyandKennedy,1992).Greatattentionhasbeenpaidtodeterminingradionuclideconcentrationsinbuildingmaterialsinmanycountries(。Rizzoetal.,2001。Kumaretal.,2003。Tortoiseetal.,2003).,thepresentstudyaimsto:(1)Assessnaturalradioactivity(226Ra,232Thand40K)inrawandfinalproductsusedintheAssistcementfactoryandotherlocalfactoriesinEgypt.(2)Calculatetheradiologicalparameters(radiumequivalentactivityRead,levelindexIγr,externalhazardindexHexandabsorbeddoserate) (Limestone,Clay,Slag,Ironoxide,gypsum)whicharealltherawmaterialusedincementindustry,20samplesoffinalproductsweretakenfromAssistcement(Portland,ElMohandas,White,andSoleplateresistantcement()).Forparisonwithproductsfromotherfactories,8samplesweretakenfromtheordinaryPortlandcementfrom(Helena,Quean,Elkalmia,andTorah)and4samplesweretakenofwhitecement(SinaiandHelena).Eachsample,about1kginweightwaswashedindistilledwateranddriedinanovenatabout110176。Ctoensurethatmoistureispletelyremoved。thesampleswerecrushed,homogenized,andsievedthrougha200mesh, Activitymeasurementswereperformedbygammarayspectrometry,employinga3″3″(CanberraAccuses).%(100mmthick)(),(Genie2000fromCanberra) Thenaturalradionuclide226Ra,?1forradiumequivalentRae,1forlevelindexIγr,theexternalhazardindexHex≤1and59(nayh?1) Concreteisstronginpression,therebyrisingthebending,shear,.,togetherwithitsmagnitude,thetensilestressintheconcreteatthebottomofthebeamwillreachthetensilestrengthoftheconcrete,appliedwitheccentricityrelativetotheconcretecentric,willproducealongitudinalpressivestressdistributionvaryinglinearlyfromzeroatthetopsurfacetoamaximumofconcretestress,=,atthebottom,whereisthedistancefromtheconcretecentrictothebottombeam,andisthemomentoftheinertiaofthecrosssection,constructionmaterials(concreteandsteel),usedinliquidcontainmenttanks,pipes,andpressurereactorvessels,“hugging”stressonthecylindricalorsphericalstructure,,thepriestess’’,thedepthofapriestess’,thepriestess’smemberrequireslessconcrete,regardlessofthesystemused,prestressingoperationsthemselvesresultinanaddedcost:,ifalargeenoughnumberofprecastunitsaremanufactured,becauselessmaintenanceisneeded,alongerworkinglifeispossibleduetobetterqualitycontroloftheconcrete,(),thedeadweightofthebeambeesexcessive,resultinginheaviermembersand,consequently,forlargerspaces,datingbackto1872,anengineerfromCalifornia,Nebraska,recognizedtheeffectoftheshrinkageandcreep(transversematerialflow),prestressingoftanksandpipesdevelopedatanacceleratedpaceintheUnitedStates,withthousandsoftanksforwater,liquid,heintroducedthenowwellknownandwellacceptedFrey，,’39。sloadbalancingmethoddeservesparticularmentioninthisregard,asitconsiderablysimplifiedthedesignprocess,concreteofsubstantiallyhigherpressivestrengthisusedforpriestess’:(1),.(2)Inposttensionedconstruction,highbearingstressesresultattheendofbeamswheretheprestressingforceistransferredfromthetendonstotheanchoragefittings,’sconcreteisusedinbuilding,undergroundstructures,TVtowers,floatingstorageandoffshorestructures,powerstations,nuclearreactorvessels,particularlyprestressingsteel,andtheaccumulatedknowledgeinestimatingtheshortandlongtermlossesintheprestressingforces.第二篇：中英文翻譯Fundamentals This chapter describes the fundamentals of today’s wireless a detailed description of the radio channel and its modeling are presented, followed by the introduction of the principle of OFDM multicarrier addition, a general overview of the spread spectrum technique, especially DSCDMA, is given and examples of potential applications for OFDM and DSCDMA are introduction is essential for a better understanding of the idea behind the bination of OFDM with the spread spectrum technique, which is briefly introduced in the last part of this Radio Channel Characteristics Understanding the characteristics of the munications medium is crucial for the appropriate selection of transmission system architecture, dimensioning of its ponents, and optimizing system parameters, especially since mobile radio channels are consi