TEM-based metrology for HfO2 layers and nanotubes formed in anodic aluminum oxide nanopore structures

Nanotubes are fabricated by atomic layer deposition (ALD) into nanopore arrays created by anodic aluminum oxide (AAO). A transmission electron microscopy (TEM) methodology is developed and applied to quantify the ALD conformality in the nanopores (thickness as a function of depth), and the results are compared to existing models for ALD conformality. ALD HfO2 nanotubes formed in AAO templates are released by dissolution of the Al2O3, transferred to a grid, and imaged by TEM. An algorithm is devised to automate the quantification of nanotube wall thickness as a function of position along the central axis of the nanotube, by using a cylindrical model for the nanotube. Diffusion-limited depletion occurs in the lower portion of the nanotubes and is characterized by a linear slope of decreasing thickness. Experimentally recorded slopes match well with two simple models of ALD within nanopores presented in the literature. The TEM analysis technique provides a method for the rapid analysis of such nanostructures in general, and is also a means to efficiently quantify ALD profiles in nanostructures for a variety of nanodevice applications.     

硅表面十六烯薄膜的制备与表征

利用机械与化学结合的方法实现了硅基底上的可控自组装（“割草种花”思想）,为纳米尺度结构的构筑提供了一定的实验基础．基于金刚石刀具切削的自组装加工技术,在氢终止的硅表面上制备了十六烯自纽装单分子膜,并利用原子力显微镜（AFM）和X射线光电子能谱（XPS）对自组装膜进行了检测和表征,证明这种方法能够方便快捷地实现硅基底上的可控自组装;并用AFM检测了十六烯薄膜的黏着力,分析了可能导致其变化的原因,根据黏着力的变化也说明切削区域生成了自组装膜。     

利用计量型原子力显微镜进行纳米台阶高度测量

计量型原子力显微镜纳米测量系统主要由扫描器、测针位置传感器和一体化微型激光干涉三维测量系统等部分构成．针对计量型原子力显微测量系统,采用三维激光干涉测量系统作为测量基准,以实现原子力测量系统的纳米尺度量值溯源和校准工作．建立了校准模型,分析了扫描器9项主要误差项,并将该模型应用到原子力显微镜扫描器的校准中．校准后的结果表明,除z轴位置误差不超过±2nm外,其他8项的残余误差均不超过±1nm．通过台阶高度国际比对,建立了台阶高度标准计算方法及不确定度分析模型．台阶高度国际比对的测量结果表明,计量型原子力显微镜的测量值与参考值相差均小于1．5nm．     

现代选矿过程粒度在线分析仪的研究进展

在线粒度分析仪是矿物加工连续生产过程中关键参数的自动检测装置。本文重点介绍了现代选矿过程中采用的几种不同类型之粒度在线分析仪的测量原理、仪器组成及其主要性能指标,并就它们各自的特点进行了对比介绍。     

混合表面活性剂增敏火焰原子吸收测定地质样品中的钼

研究了在火焰原子吸收光谱法中混合表面活性剂十二烷基硫酸钠和三乙醇胺对钼的增敏作用。在60g／L三乙醇胺和15g／L十二烷基硫酸钠的条件下,可使钼的灵敏度提高70％以上,且能消除多种共存元素的干扰。可用于一般地质样品中钼元素的测定。     

钨精矿中痕量汞的电化学冷蒸气发生-原子荧光光谱测定法

在断续流动条件下,采用自制的电化学流通池作为汞蒸气发生器,建立了电化学冷蒸气发生法-原子荧光光谱联用技术对汞的分析方法。在优化的实验条件下,汞的荧光强度在0～5.0μg/L范围内与浓度呈良好的线性关系,汞的检出限为1.3 ng/L。对1μg/L Hg测定的相对标准偏差为1.5%(n=11)。方法应用于钨精矿中汞的测定,样品加标回收率在97%～103%之间。方法准确可靠,灵敏度高。     

压缩感知合成孔径雷达射频干扰抑制方法

压缩感知合成孔径雷达成像技术能够利用少量采样数据恢复目标图像,大大减少数据存储系统的负担,但受到射频干扰时成像品质会严重下降;在目标场景稀疏条件下,分别构建目标回波信号原子库和射频干扰原子库,设计了压缩域合成孔径雷达成像射频干扰抑制算法,并对该算法进行理论分析,最终通过仿真实验验证了算法的有效性;仿真结果表明：该算法在较大干信比条件下,能有效抑制合成孔径雷达射频干扰,达到较好的成像效果。     

焦粉粒度对济钢烧结矿质量的影响

生产表明,在济钢二烧高碱度(R＝2.4)烧结矿生产的条件下,烧结矿RDI性能与其FeO含量有一定的相关关系.为了保证烧结矿中的FeO含量,又不致增加焦粉消耗,进行了焦粉粒度、混合料水分、风门开度等因素的相关试验.根据试验结果我们对焦粉粒度进行了优化, 并取得了良好的效果.     

Characterization of the effective atomic number for first row transition elements by the ratio of coherent to compton scattering intensities obtained by wavelength dispersive X-ray fluorescence

The effective atomic numbers of compounds of the first row transition elements were determined experimentally by a scattering method using wavelength dispersive X-ray fluorescence spectrometer. A calibration curve was created by using the intensity ratios of coherent to Compton scattered peaks of pure elements from atomic number 13–48. This relationship was employed to determine the effective atomic numbers of the compounds. The effective atomic numbers were also calculated by using empirical formulas from the literature. Mass attenuation coefficients were calculated using software. The experimentally measured values of the effective atomic numbers with the calculated values by empirical formulas were comparable.