简介:DuringGHtherapyfor2.3-9.6years,maleadult-onsetGH-deficientpatientswithadiagnosisofanonfunctioningadenomahavenoincreasedall-causemortality.However,womenwithadult-onsetGHdeficiency(GHD)arestillatslightlyhigherrisk.Thisgeneralimprovementinmortalityisduetoamorecontemporaryregimenofcardiovasculardrugs,arefinementofsurgicalprocedures,besidestheintroductionofGHtherapyimprovedhormonereplacementregimenswithloweredglucocorticoidreplacement,updatedapproachesofsexsteroidsforwomen,andlessuseofcranialradiotherapy.Theunderlyingdiseaseisthemostimportantpredictorformortality:eg,acraniopharyngioma,malignantcausesofhypopituitarism,previousCushing'sdisease,andthepresenceofdiabetesinsipidus/
简介:摘要针对陶瓷刀具WG300车削高温合金GH4169,设计了车削加工实验,利用扫描电镜(SEM)图对产生的切屑的形态进行研究,得到了切削速度对切屑的影响规律,观察到随着切削速度的增加,切屑出现显著的锯齿状。该研究对陶瓷刀具加工过程中的切削速度的选择具有指导和参考意义。
简介:Usingmetallographicobservationandmechanicalmeasurement,themicrostructureandmechanicalpropertiesofGH4169Galloyhasbeeninvestigated.Theeffectofthephosphorus,borontraceelementsonmechanicalpropertiesoftheGH4169Galloyarecomparedandanalyzed.Theresultsshowedthatthehot-workabilityoftheGH4169Galloyisverygood.ThestressrupturespropertiesofGH4169Galloyisover3timesthanthetraditionalGH4169alloy.
简介:Thedisplacementfieldsux,uyatgrowingcracktipofLYI2-Mspecimenswithdoubleedgecracksaremeasuredusingmoiremethod.TheexperimentalsingularityfieldsarecomparedwithGHtheoreticalfield[12-14].ThesizeandshapeoftheexperimentalGHsingularityfieldsareobtained.Theerrorinboththeexperimentalandtheoreticalevaluationsiscontrolledwithin±10%.Theexperimentsshowthatthereis(InA/r)+1singularitydominantaroundagrowingcracktip.Theshapeofthisdominantregionrangesfrombutterflywingtooblateandcircular.InsideGH-field,thereisa3-DdeformeddamagezonewherenoGHsin-gularityexists.
简介:摘要:金属增材制造作为一种新兴的智能加工技术,具有材料利用率高、加工周期短、成本低等显著优势。如今已广泛应用于航空航天、核电和石油化工等领域。疲劳断裂是许多承力结构的主要失效形式之一。如航空发动机涡轮叶片,在频繁起停的服役工况中,容易引起疲劳失效,需要对疲劳裂纹的扩展行为进行研究,包括裂纹扩展机理及扩展速率模型方面的研究,使用修正后的扩展模型对疲劳寿命进行评估和预测更为合适。
简介:Inthispaper,theGH-congruencecanonicalformsofpositivesemidefiniteanddefinteiniteanddefinite(neednotbeself-conjugate)quaternionmatricesaregiven,andaneccessaryandsufficientconditionofGH-congruencefortwopositivesemidifinite(definite)quaternionmatricesisgivenalso.ThensimultaneousGH-congruencereducedformsfortwoself-conjugatematri-cesandsomeresultaboutthesimultaneousGH-congruencediagonalizationofquaternionmatricesareobtained.
简介:摘 要:本文针对GH3030合金锻件低倍检查面上出现沿流线分布的黑色条纹缺陷,在分析的基础上,结合质量复查,并通过解剖确认,确定了问题产生的原因。