300mm硅片CMP设备装载技术研究

定位装载机构是硅片化学机械抛光（CMP）设备的一个重要组成部分。本文通过对目前CMP设备中硅片定位装载机构的介绍、分析与比较,介绍了一种新型定位装载机构的功能、结构原理及控制原理,并最终通过在工艺试验中的实际应用确定了该机构已基本达到设计要求。     

Highly (1 0 0)-oriented Pb(Zr0.20Ti0.80)O3/(Pb1−xLax)Ti1−x/4O3 multilayered thin films prepared by RF magnetron sputtering

The Pb(Zr_0.20Ti_0.80)O₃/(Pb_1−xLa_x)Ti_1−x/4O₃ (x = 0, 0.10, 0.15, 0.20) (PZT/PLT_x) multilayered thin films were in situ deposited on the Pt(1 1 1)/Ti/SiO₂/Si(1 0 0) substrates by RF magnetron sputtering technique with a PbO_x buffer layer. With this method, all PZT/PLT_x multilayered thin films possess highly (1 0 0) orientation. The PbO_x buffer layer leads to the (1 0 0) orientation of the multilayered thin films. The effect of the La content in PLT_x layers on the dielectric and ferroelectric properties of the PZT multilayered thin films was systematically investigated. The enhanced dielectric and ferroelectric properties are observed in the PZT/PLT_x (x = 0.15) multilayered thin films. The dielectric constant reaches maximum value of 365 at 1 KHz for x = 0.15 with a low loss tangent of 0.0301. Along with enhanced dielectric properties, the multilayered thin films also exhibit large remnant polarization value of 2P_r = 76.5 μC/cm², and low coercive field of 2E_c = 238 KV/cm.     

视觉系统在超声打孔机中的应用

超声加工给工具或工件沿一定方向施加超声频振动进行振动加工,可以完成传统工艺不能进行的加工.超声打孔机解决了基板的加工问题.由于视觉系统的引入,使得基板的加工能够得到精确定位及检测,极大地提高了生产效率和产品质量.介绍了视觉系统在超声打孔机中的工作原理及应用.     

发芽糙米研究现状与未来发展方向

介绍了发芽糙米中的主要功能性成分及其生理功能,综述了发芽糙米中γ-氨基丁酸的富集研究现状和我国发芽糙米的研究情况,总结了发芽糙米发展中存在的问题和未来发展的方向.     

食品包装材料中酯类化学物质QSRR应用研究

采用气相色谱-氢火焰离子化检测器(GC-FID)同时测定食品包装材料中21种酯类添加剂的色谱保留时间(tR),并采用分子电性距离矢量(MEDV)和定位基指数(T)表征酯类添加剂的分子结构,然后运用多元线性回归(multiple linearregression,MLR)建立酯类添加剂结构与其气相色谱保留值的定量结构- 色谱保留关系(quantitative structure retention relationship,QSRR)模型,建模相关系数R=0.9840,留一法交互检验(leave-one-out,LOO)相关系数RLOO=0.9747,同时采用外部验证的方法对所建模型的稳定性能进行分析和验证,外部样本预测值的相关系数Qext 为0.9789,并且考察所建模型的实际应用性。结果表明,该模型具有良好的稳定性和预测能力,能够为食品包装材料中酯类化学物质向内装食品中的迁移行为研究以及分离、检测方法的建立,提供有效的理论依据。     

创作与定位──内蒙古大学文体馆的设计思考

“定位分析”是建筑创作过程的起点和设计理念产生的基础。结合内蒙古大学文体馆的设计思考,从主客体两个方面阐述了它的意义和个人的创作体会。     

Amplification effect of platelet type nanoparticles on the orientation behavior of injection molded nylon 6 composites

The effect of platelet type nanoparticles and processing conditions; mold temperature and injection speed, on the development of local microstructure in injection molded nylon 6 parts was investigated. The molded parts exhibit two crystal forms (α and γ) of nylon 6 in varying proportions from skin to core. The γ crystals preferentially grow near the surface regions and α crystal fraction increases with distance from the surface in all molded parts. However, the spatial variation of crystal phases across the thickness in nanocomposites differs from that of unfilled nylon 6. Nanoplatelets induce high levels of orientation of the polymer matrix throughout the thickness of the molded part even at high mold temperatures where nonisothermal effects are highly suppressed and confined to very close proximity of surfaces. These high chain orientation levels observed in nanoparticle filled systems is a result of the shear amplification effect that occurs in small spaces between adjacent nanoparticles of differing velocity. The local preferential crystalline orientation of nylon 6 resin and nanoparticles across the thickness of the molded parts are investigated using a series of structure characterization techniques including microbeam wide angle X-ray, SAXS and TEM.     

Effect of flow on solutions of rod-coil block co-polymers

An elongational flow field is imposed on a solution of block copolymers consisting of semirigid macromolecules with rigid, rodlike sequences of units in combination with random coil (flexible) units. The problem is formulated according to the lattice treatment of Matheson and Flory. In this formulation, the system consists of rigid blocks whose lengths and locations are fixed by the structure within each macromolecule. These blocks are separated by random coiled units. An excess free energy other than the equilibrium Gibbs free energy of the quiescent solution has to be considered due to the flow field that tends to align the rods. This excess free energy is calculated from the potential energy of rods when a steady-state, homogeneous and irrotational flow field is applied to the solution. The effects of composition, polymer-solvent interaction, size of the co-polymer and flow rates are investigated. Depending on the size and number of rods, some of the chains studied exhibit a biphasic region at equilibrium that shifts to lower concentrations with increasing flow. Longer chains with shorter rods that are isotropic at equilibrium, exhibit a biphasic region at finite values of flow. The degree of orientation increases sharply when the system is biphasic. For larger flows, the orientation function is very close to unity which is perfect orientation.     

Measurement of the size, shape and orientation of convex bodies

Different types of solid bodies (particles) with specific shape and size are needed for industrial processes. For spherical particles, ‘sizer’ measurements are usually reported as sphere diameters. For non-spherical particles, particle shape and especially orientation must be taken into account. Particles of a specific shape will present different views when looked at from different directions.We have employed a Camsizer^® instrument to measure the distribution of projected area under different physical conditions for solid cylindrical particles:

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Under ‘ideal’ conditions, corresponding to a uniform distribution of particle orientation, measurements agreed with predictions. The celebrated theorem of Cauchy applies only to this case.

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For two other situations, measured and predicted results differed. However, from the experimental data it was possible to infer the particle orientations and hence theoretically predict the projected area distribution. Excellent agreement between theory and practice was then restored.

     

WiNDOW 3.0单晶体取向分析系统

该软件提供了对单晶体取向的快速分析方法。对于背射劳厄法、透射劳厄法和衍射仪法都适用。最后取向结果以极射赤面投影表示,可以长期保存。该软件用C语言(Microsoft C6.0)编写,在窗口环境(Microsoft Windows 3.0)下运行,有优良的用户界面。