学科分类
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4 个结果
  • 简介:经济新常态下资源消耗强度和再生资源价格下降、人口红利消失以及技术创新要求的提高,对再生资源管理和产业发展提出了严峻挑战。再生资源管理应体现其基本属性、价格和组织结构三方面的转轨特征,加快完善基本管理制度构建,具体包括统一监管制度、分类管理制度、生产者责任延伸制度和领跑着制度等。

  • 标签: 转轨期 再生资源 制度构建 循环经济 废弃物管理
  • 简介:对比研究一种新型三级时效制度(T76+T6)和常规回归再时效制度(RRAT77)对7150铝合金型材耐腐蚀性能的影响。选取三种腐蚀溶液(3.5%NaCl;10mmol/LNaCl+0.1mol/LNa2SO4;4mol/LNaCl+0.5mol/LKNO3+0.1mol/LHNO3),分别对7150铝合金型材进行开路电位、循环极化曲线以及电化学阻抗谱的表征。讨论自腐蚀电位、点蚀电位、点蚀转换电位以及电位差值等参数对铝合金腐蚀表征的适用性与局限性。电化学与扫描电镜(SEM)结果表明,相比于传统RRAT77制度,T76+T6时效制度处理的铝合金在没有强度损失的前提下,具备更好的耐点蚀、耐晶间腐蚀以及耐剥落腐蚀的能力。这是由于该新型三级时效制度处理的铝合金的晶界析出相进一步粗化和断续分布所致。

  • 标签: 7150铝合金 新型三级时效 循环极化曲线 电化学阻抗谱
  • 简介:TheeffectsoftheintroductionofCetoLa_(1-x)Ce_xFe_(11.5)Si_(1.5)alloyson1:13phaseformationmechanism,thefirst-ordermagneticphasetransitionstrengtheningcharacteristics,andmagnetocaloricpropertywerestudied,respectively.Theresultsshowthattheformationmechanismsof1:13andLaFeSiphasesinLa_(1-x)Ce_xFe_(11.5)Si_(1.5)alloysarethesameasthoseofCe_2Fe_(17)andCeFe_2phasesinCe–Febinarysystem,respectively.ThesubstitutionofCein1:13phasewhichislimitedcanmakethefirst-ordermagneticphasetransitioncharacteristicsstrengthen,whichcanmakethermalandmagnetichysteresisincrease,thetemperatureintervaloftemperatureinducedphasetransitiondecrease,andthecriticalmagneticfieldoffield-inducedmagneticphasetransition(HC)increase,respectively.Owingtothelatticeshrinkof1:13phasewiththeincreaseinCecontent,theCurietemperatures(TC)showalineardecrease.Themaximumchangeinmagneticentropygraduallyincreasesduetothedecreaseintemperatureintervaloftemperature-inducedphasetransition,buttherelativecoolingcapacitiesareallabout80Jákg-1atmagneticfieldof2T.

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  • 简介:Themicrostructuresofas-castandas-solutionMg–12Gd–2Er–1Zn–0.6Zralloyswereinvestigatedbyopticalmicroscopy(OM),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM),highresolutiontransmissionelectronmicroscopy(HRTEM)X-raydiffraction(XRD)andselected-areaelectrondiffraction(SAED)inthepresentinvestigation.TheresultsshowthattheprimaryeutecticphaseMg5(Gd,Er,Zn)andsomeflocculentfeaturesarefoundintheas-castalloy;theSAEDpatternindicatesthattheseflocculentfeaturesarethedenseareasofstackingfaults.The14H-LPSOstructureprecipitatesinthetemperaturerangeof673–793K,andthevolumefractionof14H-LPSOstructureincreaseswiththeextensionofheatingtime;however,thereisnoprecipitationof14H-LPSOstructurewhenthetemperaturereachesupto803K.Inaddition,theMg5(Gd,Er,Zn)phasedissolvesgraduallyalongwiththeprecipitationof14H-LPSOstructure.

  • 标签: 铸态合金 结构相 析出行为 扫描电子显微镜 透射电子显微镜 高分辨透射电镜