一种用于检测薄膜均匀性的光谱方法

介绍了一种新的简单有效的薄膜均匀性信息获取方法,该方法基于我们先前提出的纳米薄膜厚度精确测量方法,它通过检测镀制在含有过渡层的衬底上不同位置的薄膜的光谱,并由其干涉峰间的差异获取薄膜的均匀性信息.与传统方法相比,该方法无需直接测量薄膜的厚度,减少了测量膜厚带来的误差和影响,因而可以快速得出薄膜均匀性结论.该方法操作方便...     

以Na2TeO3为碲源制备CdTe纳米晶及其表征

本文以巯基乙酸作为稳定剂,在水相中制备了CdTe纳米晶。以亚碲酸钠作为碲源,从而避免了以H2Te或NaHTe（用碲粉和硼氢化钠合成）作为碲源时,需要氮气或其它气体作为保护气体的过程,简化了制备工艺,并且提高了CdTe纳米晶的产量。用X射线衍射仪（XRD）、透射电镜（SEM）和荧光分光光度计对其进行了表征。分析表明CdTe纳米晶为立方相,并且有较窄的荧光发射峰。详细探讨了反应时间、pH值及前驱物浓度对CdTe纳米晶荧光性能的影响。     

跨孔透射法在灌注桩检测中的应用

介绍了跨孔透射法检测灌注桩桩身完整性的原理、方法和现场检测技术.通过现场检测实例,利用声波曲线判定桩身混凝土质量及缺陷的可疑位置,并采用PSD判据法进行辅助分析,从而达到判别桩身缺陷性质及范围的目的.结果表明:跨孔透射法判断基桩完整性,其检测过程简单、结果直观可靠,为桩身混凝土质量提供了一种有效的检测方法.     

光折变光子晶格带隙展宽的实验研究

本文利用振幅掩模的傅里叶变换法在LiNbO3:Fe晶体中制作了一维光子晶格,通过连续旋转晶体,由功率探测器测得透射率,绘出Bragg带隙曲线.分析了用两孔振幅掩模制作的光子晶格的带宽、位置,讨论了在孔间距为6mm条件下,振幅掩模孔的数目由3个增加到5个的带隙情况,由实验观察发现了奇特的现象:衍射光的数目由2个增加到4个...     

APT和萃取复型研究压力容器模拟钢中富Cu团簇的析出

用原子探针层析技术(APT)和萃取复型方法研究了核反应堆压力容器模拟钢中富Cu原子团簇的析出.提高了Cu含量的压力容器模拟钢经过880℃水淬,再经过660℃/10 h调质处理,随后在370℃进行不同时间的时效处理,利用APT对时效4500 h的样品分析结果显示,样品中富Cu原子团簇的数量密度达到3.1×1023m-3....     

高速列车变截面铸钢件的X射线数字成像检测

变截面铸钢件是高速列车常见零部件,应用X射线照相法检测难度很大。采用450kVX射线数字平板成像检测系统（DR）,采用光栏限束准直器、叠加曝光或连续透射以降低图像噪声;屏蔽散射线以提高信噪比;利用软件调节以增强图像细节,达到充分利用数字成像动态范围大、宽容度良好的特性,成功地检测了高速列车变截面铸钢件中的各种缺陷。     

纳米MnFe2O4的制备及其对高氯酸铵热分解的催化性能（英文）

Nano-MnFe2O4 particles were synthesized by co-precipitation phase inversion method and low-temperature combustion method respectively, using MnCl2, FeCl3, Mn(NO3)2, Fe(NO3)3, NaOH and C6H8O7. X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravim-etry-differential thermal analysis (TG-DTA) and differential scanning calorimetry (DSC) were used to characterize the structure, morphology, thermal stability of MnFe2O4 and its catalytic performance to ammonium perchlorate. Results showed that single-phased and uniform spinel MnFe2O4 was obtained. The average particle size was about 30 and 20 nm. The infrared absorption peaks appeared at about 420 and 574 cm-1, and the particles were stable below 524 ℃. Using the two prepared catalysts, the higher thermal decomposition temperature of ammonium perchlorate was decreased by 77.3 and 84.9 ℃ respectively, while the apparent decomposition heat was increased by 482.5 and 574.3 J?g?1. The catalytic mechanism could be explained by the favorable electron transfer space provided by outer d orbit of transition metal ions and the high specific surface absorption effect of MnFe2O4 particles.     

Al-Mg-Si合金和Al-Mg-Si-0.6%Cu合金的内耗研究

采用低频力学谱仪对Al-Mg-Si合金和Al-Mg-Si-0.6%Cu合金的内耗进行了研究。结果表明:两种合金的内耗在加热过程先升高后降低。利用TEM对Al-Mg-Si合金和Al-Mg-Si-0.6%Cu合金的微观结构进行观察,显示合金内耗的变化是合金中的析出相和位错相互作用的结果。     

Chemical solution route to synthesize claw-like ZnO nanorod array and its optical properties

By using a low-cost and facile hydrothermal method, a peculiar claw-like ZnO nanorod array is successfully synthesized. The hydrothermal growth is done in an aqueous solution with equimolar zinc acetate （ZAc, Zn（CH_3COO）2·2H20） and hexa methylenetetramine （HMTA, C_6H_12N_4）. The obtained ZnO nanorod array is characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results indicate that the nanorods are high-quality monocrystals. The photoluminescence （PL） spectrum is performed to investigate the optical properties of this product.     

Enhancement of nonlinear optical phenomena from crown-like nanostructure zinc oxide based on whispering gallery mode

Whispering gallery mode （WGM）-enhanced nonlinear optical phenomena from crown-like nanostructure zinc oxide （ZnO） samples are observed. The samples are synthesized by vapor-phase transport method. The morphology and crystal struc- ture are examined and characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and high-resolution transmission electron microscopy （HRTEM）, and they are excited by femtosecond laser pulses with cen- tral wavelengths of 355 nm, 800 nm and 1150 nm, respectively. The typical stimulated emission presents a red shift com- pared with spontaneous emission, which is observed under the excitation of 355 nm with a relatively low threshold. The ultraviolet （UV） frequency up-conversion emission is obtained when the excitation pulse wavelengths are selected as 800 nm and 1150 nm, respectively. The peak position and the relationship between the emission intensity and excitation inten- sity demonstrate that the UV up-conversion photoluminescence （PL） is induced by two- and three-photon absorptions. The PL characteristics and their WGM-enhanced mechanism are investigated.