简介:Thisstudyexaminesmechanismsforprovidingnucleitoequiaxedgrainsintheweldsofpureferriticstainlesssteel(FSS).TheadditionofthealloyelementTitopureFSS439causestheprecipitationofTiN,whichcanbenefitthecolumnar-to-equiaxedtransition(CET)ofgastungstenarcwelding(GTAW).Meanwhile,theinitialmorphologyoftheprecipitates,theconcentrationmultiplicationsofTi,N,etc.ofFSS439shouldbecontrolledtoinducetheformationofCETduringtheshortweldingprocess.
简介:Ti-dopedW03filmswerepreparedbythemid-frequencydual-targetmagnetronsputteringmethod.ThestructureandelectrochromicpropertiesoftheTi-dopedWO3filmswereanalysedbyX-Raydiffraction(XRD),Ramanspectroscopy,spectrophotometer,cyclicchronoam-perometryandatomicforcemicroscopy(AFM).Theresultsindicatethatthecrystallinitydecreaseafterthedopingoftitanium,thechannelsforioninjectionandextractionincrease,therespondingspeedwith5.1%titaniumdopedbecomesfaster,anditscirclelifeincreasesmorethanfourtimescomparedwiththeundopedWOafilm.Inthecolouredstate,theW-O-Wbondsdecrease,buttheW=Obondsincrease.SincetheW-O-WbondsbreakdownforLi~+ions'injectionandmoreW=Obondsform,itismoreconvenienttoinjectLi~+ionsintotheTi-dopedfilmthanundopedfilmbecausemoreW-O-Wbondsbreakdowninthecolouredstate.
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简介:目的探讨成骨细胞在细菌纤维素/聚乳酸/羟基磷灰石复合支架中的生长和增殖情况。方法将成骨细胞以5×104/ml的密度接种于细菌纤维素(BC)、细菌纤维素/聚乳酸(BC/PLA)、细菌纤维素/聚乳酸/羟基磷灰石(BC/PLA/HA)三种支架中,进行体外培养。采用MTT比色法测定1、3、5、7d的成骨细胞增殖情况;碱性磷酸酶活性测定法检测3、6、9d的碱性磷酸酶活性变化,并通过扫描电镜观察细胞在复合支架中的形态变化。结果实验组与对照组比较1、3、5、7d细胞的增殖量(OD值)有统计学差异(p〈0.05),其中BC/PLA/HA组的OD值高于其他实验组;第3d至第9d三组细胞的ALP分泌量均呈上升趋势,各组间比较均有统计学差异(p〈0.05);复合培养6dSEM观察可见三组材料中均有细胞的粘附,BC/PLA/HA组的细胞生长状态好于其他两组材料。结论BC/PLA/HA较BC/PLA和BC有利于成骨细胞的增殖和生长。
简介:采用射频磁控溅射法在医用钛表面制备羟基磷灰石(HA)涂层,研究HA涂层的形貌、物相、力学性能、细胞相容性和在机体内的组织相容性,分析其在骨修复中应用的可能性。结果表明:射频磁控溅射法制备的钛基HA生物涂层呈粗糙岛屿状结构,HA平均粒径为(40?2)nm、厚度为1.0~1.6μm的涂层力学性能最好,其纳米硬度高于11GPa,弹性模量大于136GPa;HA涂层可促进成骨细胞增殖,成骨细胞粘附于HA涂层表面并形成伪足铺展生长;植入实验动物体内4周后材料表面被结缔组织覆盖,血管形成;植入12周后,骨小梁形成,其内部可见破骨细胞;植入12周后与植入前相比,涂层的结合强度未发生显著变化。说明该HA涂层具有较高的成骨活性和稳定性,在骨修复方面具有良好的应用前景。
简介:摘要目的探讨丹参酮IIA治疗慢性肺心病急性加重期的疗效观察。方法将118例慢性肺心病急性加重期患者随机分为对照组和治疗组,对照组采用常规基础治疗,给予患者依拉普利治疗,治疗组在对照组基础上给予丹参酮IIA治疗,对比两组患者疗效情况及治疗前后心功能改善情况。结果治疗组患者治疗后总有效率为94.92%,对照组患者治疗后总有效率为81.36%,两组总有效率对比差异有统计学意义(P<0.05);治疗组治疗后RVP、LVEF、Mpvp指标显著优于治疗前及对照组治疗后,且差异有统计学意义(P<0.05)。结论丹参酮IIA治疗慢性肺心病急性加重期的疗效显著,能显著改善患者心功能。
简介:Er^3+-dopedSrBi4Ti4O15-Bi4Ti3O12(SBT-BIT-xEr^3+,x=0.00,0.05,0.10,0.15and0.20)inter-growthceramicsweresynthesizedbythesolid-statereactionmethod.Structural,electricalandup-conversionpropertiesofSBT-BIT-xEr^3+wereinvestigated.Allsamplesshowedasinglephaseoftheorthorhombicstructure.RamanspectroscopyindicatedthattheEr^3+substitutionforBi^3+atAsitesofthepseudo-perovskitelayerincreasesthelatticedistortionofSBT-BIT-xEr^3+ceramics.ThesubstitutionofBi^3+byEr^3+leadstoadecreaseofdielectriclosstanδandanincreaseofconductivityactivationenergy.Piezoelectricconstantd33wasslightlyimproved,butdielectricconstantwasdecreasedwiththeEr^3+doping.TheSBT-BIT-xEr^3+ceramicwithx=0.15exhibitstheoptimizedelectricalbehavior(d33~17pC/N,tanδ~0.83%).Moreover,twobrightgreen(532and548nm)andonered(670nm)emissionbandswereobservedunderthe980nmexcitation.Optimizedemissionintensitywasalsoobtainedwhenx=0.15fortheSBT-BIT-xEr^3+ceramic.Therefore,thiskindofceramicsoughttobepromisingcandidatesformultifunctionaloptoelectronicapplications.