Microstructure characteristics of laser forming repaired Ti60 alloy

The microstructure characteristics of laser forming repaired (LFR) Ti60 (Ti-5.6Al-4.8Sn-2Zr-1Mo-0.35Si-0.3Nb) as-deposited and annealed samples are analyzed. The microstructure of as-deposited repaired zone (RZ) consists of epitaxial columnar prior β grains, in which fine woven α laths and β-phase between α laths exist. The heat-affected zone (HAZ) experiences a continuous microstructural transition from duplex microstructure of the base metal zone (BMZ) to the microstructure of RZ. The presence of silicide precipitates is observed in both RZ and BMZ in an annealed sample by transmission electron microscopy. They are identified as (Ti, Zr) 6 Si 3 distributed mainly at the α/β interface with the size of 100 300 nm. The fine αprecipitates are detected in BMZ by electron diffraction; there was no α detected in RZ.     

基于反谐振空芯光纤的中红外TDLAS系统设计及应用实验研究

针对燃烧诊断在2～3μm波长的光谱测量需求，设计并搭建了基于反谐振空芯光纤的可调谐半导体吸收光谱（TDLAS）测量装置，开展了高温水汽在2.5μm波长吸收光谱的定标与测量研究。在2～5μm中红外波段，反谐振空芯光纤可实现低损、单模长距离传输，能够有效解决商用氟化物光纤多模干涉造成的TDLAS测量精度下降的问题。经所提TDLAS系统准直后光束的直径低至2.5 mm，发散角为0.004 rad，系统信噪比为31 dB，相比基于氟化物光纤的TDLAS系统，所提系统的性能得到了极大提升。进一步分析了反谐振空芯光纤中痕量水蒸气对于4029.52 cm-1谱线测量的影响，并通过抽真空的方式降低其影响，从而提高了系统的测量精度。     

超疏水性三维银纳米树SERS基底的制备及用于阿奇霉素检测

制备了一种超疏水性三维银纳米树表面增强拉曼散射(SERS)基底，利用扫描电子显微镜(SEM)、能量色散X射线光谱(EDS)及X射线衍射(XRD)对三维银纳米树进行表征，利用接触角(CA)分析其疏水性能。以罗丹明B(RB)为拉曼探针进行条件优化，并考察阿奇霉素(AZM)在该基底上的SERS性能，发现该SERS基底对AZM具有较强的拉曼增强效应，在1.0×10^-11～1.0×10^-9 mol/L范围内，AZM浓度的对数值与拉曼峰强度I_SERS呈良好的线性关系，线性拟合方程为I_SERS=4098logc+47769(R²=0.987)，检出限为4 pmol/L。使用该方法检测AZM分散片、人血清及猪血清中的AZM，加标回收率在91.2%～118.1%之间，相对标准偏差为1.1%～6.2%。