简介:ChinaCommemoratesT.R.MalthusTocommemoratethe200thanniversary(1798-1998)ofthepublicationoftheESSAYONTHEPRINCIPLEOFPOPULATIO...
简介:摘要文章主要介绍了利用低氮燃烧技术实现对燃煤锅炉氮氧化物排放的控制,并以某热电厂为例,详细阐述了低氮燃烧器加空气分级燃烧技术在130t/h燃煤锅炉上的工程应用。通过低氮燃烧器改造,降低NOx排放≤280mg/Nm3(6%O2),达到了很好的环保效益。
简介:摘要义东油田大81-4块复杂断块油田,以稳产、上产、经济效益为中心,以强化工况管理为主线,不断提高油井技术管理水平,努力实现油田高效长寿开发,为完成全年的生产经营指标奠定了坚实的基础。
简介:TheRelationshipbetweensexratioatage0to4andaltitudeinChinaisquantitativelyinvestigatedbyusingGeographicalInformationSystem(GIS)technologyinthispaper.Theresultsshowthatthecountieswithhighsexratioatage0to4in1990and2000aremainlydistributedontheeastofthewell-knownChinesepopulationdivision,Anhui-Tengchongline,andthereishighnegativecorrelationbetweensexratioatage0to4andaltitudeinChinesecounties.Therearehighestsexratioatage0to4intheregionsunder100meters,butthisratioover3200metersfallsintothenormalrange.Andthesexratioatage0to4continuestofalldownwhenthealtituderises.Sothegeographicalenvironmentevidentlyaffectsthesexratioatbirth.Thereishighersexratioatbirthinlower-altituderegions.Theeffectwithaltitudemaybeassociatedwiththeambienttempeture.