飞行时间二次离子质谱--强有力的表面、界面和薄膜分析手段

二次离子质谱（Secondary ion mass spectrometry，简称SIMS）是一种对表面灵敏的质谱技术，建立在表面各种类型带正、负电荷原子或分子发射的基础上。用飞行时间（Time of flight，简称TOF）仪器对这些二次离子进行质量分析，能确保并行质量登录、高质量范围、高流通率下的高分辨和精确质量测定这些优异性能。配合细聚焦扫描一次离子束，可在优于1nm的高深度分辨和优于50nm的横向分辨本领下，实现对表面优于单层ppm(百万分之一）量级的极高检测灵敏度。当今TOF－SIMS已发展为一种成熟且完善的表面分析技术。极高的灵敏度，再加上即使对大分子及不易挥发性分子都独具的敏感性，使它成为很多高技术领域不可缺少的分析手段，这些领域包括微电子学、化学和材料科学以至纳米技术和生命科学等。本文简述了TOF－SIMS的原理、仪器及其多方面的应用和展望。     

Centrifugal Casting of High Speed Steel/Nodular Cast Iron Compound Roll Collar

Ｈｉｇｈ ｓｐｅｅｄｓｔｅｅｌ (ＨＳＳ) ,ｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｅｘ ｃｅｌｌｅｎｔｈａｒｄｎｅｓｓ ,ｗｅａｒｒｅｓｉｓｔａｎｃｅ ,ａｎｄ ｇｏｏｄｒｅｄｈａｒｄｎｅｓｓ .Ｒｅｃｅｎｔｌｙ ,ＨＳＳｉｓａｐｐｌｉｅｄｔｏｍａｎｕｆａｃｔｕｒｅｈｏｔｒｏｌｌｉｎｇｒｏｌｌｓｔｏｐｒｏｄｕｃｅｓｔｒｉｐｓｏｆｇｏｏｄｓｈａｐｅａｎｄｓｍａｌｌｃｒｏｗｎｗｉｔｈｅｘｔｅｎｄｅｄｒｏｌｌｓｅｒｖｉｃｅｌｉｆｅ[1,2 ] .ＴｈｅＨＳＳｉｓａｐｐｌｉｅｄｔｏｍａｎｕｆａｃｔｕｒｅｒｏｌｌｃｏｌｌａｒｆｏｒ…     

Extracting Electron Densities in N-Type GaAs From Raman Spectra: Theory

In this paper, we present the theory for calculating Raman line shapes as functions of the Fermi energy and finite temperatures in zinc blende, n-type GaAs for donor densities between 10¹⁶ cm⁻³ and 10¹⁹ cm⁻³. Compared to other theories, this theory is unique in two respects: 1) the many-body effects are treated self-consistently and 2) the theory is valid at room temperature for arbitrary values of the ratio R = (Q²/α), where Q is the magnitude of the normalized wave vector and α is the normalized frequency used in the Raman measurements. These calculations solve the charge neutrality equation self-consistently for a two-band model of GaAs at 300 K that includes the effects of high carrier concentrations and dopant densities on the perturbed densities of states used to calculate the Fermi energy as a function of temperature. The results are then applied to obtain the carrier concentrations from Fermi energies in the context of line shapes in Raman spectra due to the coupling between longitudinal optical phonons and plasmons. Raman measurements have been proposed as a non-destructive method for wafer acceptance tests of carrier density in semiconductor epilayers. The interpretation of Raman spectra to determine the majority electron density in n-type semiconductors requires an interdisciplinary effort involving experiments, theory, and computer-based simulations and visualizations of the theoretical calculations.     

Development and evaluation of antimicrobial natamycin‐incorporated film in gorgonzola cheese conservation

Conservation of food products depends on product quality and packaging suitability. The objective of this work was to develop and evaluate the antimicrobial efficiency of natamycin‐incorporated film in the production process of Gorgonzola cheese. It aims to optimize the production process and increase shelf‐life and food safety for the consumer. Films with different concentrations of natamycin were produced and tested in Gorgonzola cheeses to evaluate its efficiency against Penicillium roqueforti on the cheese surface. Films with 2 and 4% natamycin presented satisfactory results for fungus inhibition and the amount of natamycin released to the cheese was below that allowed by the legislation. Copyright © 2006 John Wiley & Sons, Ltd.     

Imaging the domain pattern of the canted magnetization state in Co/Pt multilayer films

The exact magnetization pattern of magnetic films close to a spin-reorientation transition is difficult to analyze due to the intrinsically three-dimensional (3d) variation of the orientation of the local magnetization. We present a technique how this can be performed, based on the analysis of high quality 2d polarization maps from a single scanning electron microscope with polarization analysis (SEMPA) measurement with tilted sample. The key tool is the statistical distribution of all occurring polarization doublets, visualized in a 2d histogram plot. From the shape of the distribution the type of transition—canted-phase, or coexisting phases—can be inferred. For the canted-phase state, the canting angle can be accurately determined from geometrical considerations. With help of the histogram the image data can be analyzed and the three components of the magnetization can be calculated for most points of the image. For a Co/Pt multilayer film we found a cone state. The magnetization forms a complex pattern consisting of out-of-plane domains while the in-plane magnetization shows a maze pattern.     

晶体硅薄膜电池制备技术及研究现状

晶体硅薄膜太阳电池近些年来得到广泛的研究和初步的商业化探索。根据所采用的晶体硅薄膜沉积工艺中温度范围的不同，晶体硅薄膜电池研究可分为高温路线和低温路线两个不同发展方向。本文分别从这两个方向综述了目前国外晶体硅薄膜电池制备技术的最新进展，最新实验室研究结果。报导了晶体硅薄膜电池商业化进展状况，指出了晶体硅薄膜电池实现产业化必须解决的问题。     

Preparation of Compound Ultrafine CeO2 by Wet-Solid-Phase Mechanochemical Modification

To satisfy practical requirements from industrial applications, an alternate route for synthesis compound ultrafine CeO2 powders by wet-solid-phase mechanochemical modification using industrial grade hydrated cerium carbonate as raw material was proposed.The effect of modifier reaction percentage, reaction time, calcining temperature and modifier amount on particle size, density, suspensibility, and hardness of compound CeO2 powder was investigated.The phase evolutions of preparation process were characterized by XRD.SEM micrograph of the final product shows that compound CeO2 powders obtained are well-dispersed, spherically-shaped, uniformly-sized and submicron-sized particles.The method is readily available in raw material, low in cost, simple in process, and has great potential for industrialization.The compound CeO2 powders of different physical properties can be synthesized by controlling the above-mentioned influence factors in preparation process.     

主电机轴瓦异常情况分析解决办法

介绍南钢中板厂四辊轧机主电机轴瓦一种非典型故障现象，原因分析及解决办法，提出了对类似问题个人见解。     

聚氨酯-聚丙烯酸酯共聚乳液的成膜和性能

通过XPS和接触角测试研究了聚氨酯-聚丙烯酸酯共聚乳液在不同基材上的成膜情况，并对共聚胶膜的耐水性和附着力进行了考察．由于该共聚乳液同时存在着亲水组分和疏水组分，所以它在不同的基材上成膜可导致其膜表面的组成成分不同，因而导致其耐水性和附着力也随基材而异。结果表明，亲水性的聚氨酯组分均富集于胶膜内部，但胶膜底层聚氨酯组分的含量却随基材的不同而不同。在憎水且表面张力较高的基材上，共聚胶膜的耐水性良好；共聚胶膜的附着力在表面张力较高的基材上也良好。     

基于SPM技术的纳米信息存储薄膜的研究进展

扫描探针显微技术SPM可以在原子或分子尺度上对表面进行表征和修饰，应用SPM技术可以在薄膜表面形成纳米级的信息点阵，特别适合发展超高密度的信息存储，是一种非常有希望代替传统磁存储，光存储的纳米级存储技术，本文介绍了纳米信息存储薄膜的研究进展，并对其制备技术和读写机制进行了初步的探讨。