简介:摘要CD17弹簧操作机构推杆零件的结构工艺特点是直径小、长度较长,加工刚性较差,以及不锈钢不易切削性,给加工带来一定的难度。针对这些特点,选择合理的刀具和合理的几何角度,确定合理的切削参数。以及工件合理装夹。给出解决问题的具体方法,克服了加工难点,取得了良好的加工效果。
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.