简介:Thispaperexaminestheimpactofforeignpenetrationonthepublicfirminamixedoligopolisticmarket.Throughtheestablishmentofamixeddoubleoligopolymarket,thispaperanalyzeshowtheshareofforeigninvestmentaffectstheenvironmentalpolicy,thepollutantemission,andthesocialwelfareundertheconditionofthestatetax.Theresultsshowthat:first,theintroductionofforeigninvestmenthassomecrowding-outeffectsonthesociallevelofoutput.Second,theentryofforeigninvestmentincreasestheprofitofthepublicfirmbyalargemargin,andthemaximumprofitoftheprivatefirmhasbeenreduced.Third,theincreaseofforeigninvestmentinpublicfirmdoesnotnecessarilyimprovetheenvironment.
简介:RodrigoRatosays“SotheAmericaneconomyneedstheworld,andtheworldneedstheAmericaneconomy”?.Forthat,itispossibletonotethattheshorthistoryofUSpolicyintheMiddleEast,includingthesuccessionofpresidential“doctrines”,fromTrumanthroughtoBushII,confirmedWashington’sappreciationofthestrategicroleoftheEasternMediterraneanandtheoilrichstatesoftheMiddleEastinthebroadercontextofUSpolicygoals.Thisinterestisduetothefactthatthisregion(MiddleEast)hasalargeofoilreservesandhugeeconomicrecourses.Thisregionholdsabout66%oftheworldoilreserves,andthisoilreservewillmaketheregiondominateforalongertimeontheglobaloilmarketandinternationaloil-producingorganizations,suchasOPEC,socontrolonthisregionhasbecomeafocusofattentiontodecision-makersintheworld,andthereisnodoubtthattheUnitedStateswasthemostprominentwhotriedtocontroltheregion.ThepurposeofthecurrentresearchistoshedlightontheUnitedStates’economicpresenceintheMiddleEastregiontounderstandhowUnitedStates’presencehasdevelopedintheregionandwhatmotiveswerebehinditspresence.
简介:摘要目的对行纤维支气管镜异物取出术的气道异物患儿胸部DR与螺旋CT诊断价值进行对比、分析。方法选取本院收治的60例行纤维支气管镜异物取出术的气道异物患儿作为本次的研究对象,收治时间为2016.02~2017.01,均行术前、术后胸部DR片,术前、后CT诊断。结果本文研究中,经CT诊断的阳性征象率为100.00%(60/60),阳性间接征象率为96.67%(56/60);经胸部DR诊断的阳性率为91.66%(55/60),阳性间接征象率为93.33%(56/60),对比无显著差异,P>0.05。结论临床中通过胸部DR、螺旋CT均可显示大部分气道异物患儿的直接征象,临床中可依据患儿的具体情况选择适应的诊断方案,对于较难的气管异物患儿,可优先采取螺旋CT诊断。