Solid non-conjugated polymers have long been regarded as insulators due to deficiency of delocalizedπelectrons along the molecular chain framework.Up to date,origin of insulating polymer regulated charge transfer has...Solid non-conjugated polymers have long been regarded as insulators due to deficiency of delocalizedπelectrons along the molecular chain framework.Up to date,origin of insulating polymer regulated charge transfer has not yet been uncovered.In this work,we unleash the root origin of charge transport capability of insulating polymer in photocatalysis.We ascertain that insulating polymer plays crucial roles in fine tuning of electronic structure of transition metal chalcogenides(TMCs),which mainly include altering surface electron density of TMCs for accelerating charge transport kinetics,triggering the generation of defect over TMCs for prolonging carrier lifetime,and acting as hole-trapping mediator for retarding charge recombination.These synergistic roles contribute to the charge transfer of insulating polymer.Our work opens a new vista of utilizing solid insulating polymers for maneuvering charge transfer toward solar energy conversion.展开更多
采用单一变量法研究了激光功率和温度对激光沉积制造Ti65钛合金高周疲劳性能的影响,通过光学显微镜、超声波探测仪和扫描电镜(scanning electron microscope,SEM)对试样的显微组织、内部缺陷和断口形貌进行了分析.结果表明,不同功率试...采用单一变量法研究了激光功率和温度对激光沉积制造Ti65钛合金高周疲劳性能的影响,通过光学显微镜、超声波探测仪和扫描电镜(scanning electron microscope,SEM)对试样的显微组织、内部缺陷和断口形貌进行了分析.结果表明,不同功率试样的显微组织均为网篮组织,α相的含量明显高于β相的含量,高温下网篮组织中的α相发生粗化,晶粒内部出现一些块状α相,组织的均匀性下降.室温和高温条件下高功率和低功率试样的疲劳极限分别为454,398.5,371.5 MPa和336.25 MPa,同一温度下,高功率试样的疲劳极限要比低功率试样的疲劳极限高10%以上;同一功率下,室温试样的疲劳极限要比高温试样的疲劳极限高18%以上,温度对于高周疲劳的影响更大.激光沉积制造Ti65钛合金试样内部存在气孔缺陷,低功率试样中气孔的数目多且直径大,其疲劳源均形核于气孔缺陷处,气孔直径越大,距离表面距离越近,裂纹萌生的越快,疲劳寿命越低,高功率试样中气孔的数目少且直径小,其疲劳源均萌生于表面裂纹,缺陷的存在对裂纹的萌生存在很大影响.展开更多
文摘Solid non-conjugated polymers have long been regarded as insulators due to deficiency of delocalizedπelectrons along the molecular chain framework.Up to date,origin of insulating polymer regulated charge transfer has not yet been uncovered.In this work,we unleash the root origin of charge transport capability of insulating polymer in photocatalysis.We ascertain that insulating polymer plays crucial roles in fine tuning of electronic structure of transition metal chalcogenides(TMCs),which mainly include altering surface electron density of TMCs for accelerating charge transport kinetics,triggering the generation of defect over TMCs for prolonging carrier lifetime,and acting as hole-trapping mediator for retarding charge recombination.These synergistic roles contribute to the charge transfer of insulating polymer.Our work opens a new vista of utilizing solid insulating polymers for maneuvering charge transfer toward solar energy conversion.
文摘采用单一变量法研究了激光功率和温度对激光沉积制造Ti65钛合金高周疲劳性能的影响,通过光学显微镜、超声波探测仪和扫描电镜(scanning electron microscope,SEM)对试样的显微组织、内部缺陷和断口形貌进行了分析.结果表明,不同功率试样的显微组织均为网篮组织,α相的含量明显高于β相的含量,高温下网篮组织中的α相发生粗化,晶粒内部出现一些块状α相,组织的均匀性下降.室温和高温条件下高功率和低功率试样的疲劳极限分别为454,398.5,371.5 MPa和336.25 MPa,同一温度下,高功率试样的疲劳极限要比低功率试样的疲劳极限高10%以上;同一功率下,室温试样的疲劳极限要比高温试样的疲劳极限高18%以上,温度对于高周疲劳的影响更大.激光沉积制造Ti65钛合金试样内部存在气孔缺陷,低功率试样中气孔的数目多且直径大,其疲劳源均形核于气孔缺陷处,气孔直径越大,距离表面距离越近,裂纹萌生的越快,疲劳寿命越低,高功率试样中气孔的数目少且直径小,其疲劳源均萌生于表面裂纹,缺陷的存在对裂纹的萌生存在很大影响.
