Combination of atomic force microscopy and chemical hydrolysis to characterize degradable regions in polymer blends

In this study, we demonstrate the usefulness of chemical‐based method in combination with atomic force microscopy (AFM) to characterize the degradable regions in a wide range of polymer blends. This approach is based on selective hydrolysis of one of the components in a multiple‐phase system, and the ability of AFM to provide nanoscale lateral information about the different phases in the polymer system. Composite films containing different percentage of hydrolyzable polymer were either melt processed or solution casted and then exposed to a hydrolytic acidic environment. Tapping mode AFM was used to analyze the samples before and after hydrolysis. Dramatic topographic changes such as pits were observed on the acid exposed samples, indicating that the degradation was localized and the more susceptible component in the blend was hydrolyzed. Additionally, the progressive hydrolysis of the composites was studied by attenuated total reflection FTIR (ATR‐FTIR) analyses to confirm the AFM results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 726–733, 2006     

合成孔径雷达目标自动识别研究

讨论了基于物理光学和几何绕射理论的散射中心理论模型,对散射中心模型的各个参数在图像域进行了估计,详细分析了基于散射中心理论的SAR图像目标特征提取算法,采用了先估计目标方位后识别目标类型的目标识别方法以提高目标识别的效率,并利用Delaunay三角化技术提高了目标方位的估计精度.实测MSTAR SAR图像中目标的识别结果表明了该方法的准确性和有效性.     

自动识别系统ATR的测角精度研究

介绍了TCA2003全站仪的自动目标识别(ATR)系统及其功能，研究了自动识别系统在实际应用中的测角精度及其可靠性。基于试验的目的，选择了不同的试验场地和方法，详细分析了ATR的测角精度以及环境对测角质量的影响，比较了传统的人工测角与ATR测角的可靠性，获得了有益的结论，对开拓ATR测量仪器的应用范围具有指导作用。     

红外光谱技术的进展及其应用

对漫反射、衰减全反射傅里叶变换红外光谱和差谱等技术及其应用进行了简单介绍     

聚氨酯脲的表面组成及结构

用ＡＴＲ－ＦＴ－ＩＲ和ＸＰＳ研究了聚氨酯脲以及聚二甲硅氧烷改性聚氨酯脲的表面组成和结构,发现与空气接触面和与模板接触面含有的ＰＤＭＳ和聚四亚甲基醚软段浓度远远大于其体体浓度,并且与空气接面比与模板接触面含有更多的ＰＤＭＳ和ＰＴＭＯ段。将聚酯脲水合至３个星期,其表面组成和氢键未发生任何变化。     

Molecular structure characteristics,functional parameters and in vitro protein digestion of pressure‐cooked soya bean flours with different amounts of water

When a food product is cooked at high temperature with different proportions of water, the differential degradation that occurs in the molecular structure promotes changes in their functional characteristics. In this study, water and soya bean flour (dry base) were mixed in different ratios (3:1, 2:1, 1:1, 0.25:1 and 0:1) and pressure cooked at 130 °C, 1.5 kg cm^?2 for 30 min, cooled down to 40 °C and air dried for 24 h. Protein changes due to thermal process were determined with the ATR‐FTIR, as well as some functional parameters and in vitro protein digestibility. At higher water:soya bean flour ratios (3:1 and 2:1), the protein digestibility increased due to denaturation of tertiary structures, while urease activity (UA) and the functional characteristics of water absorption index (WAI) and water solubility index (WSI) decreased. Pearson's correlation analysis revealed that molecular changes on amide I, II and in α‐helix: β‐sheet ratios were directly related with the amount of added water.     

Effects of Atmospheric Pressure Plasmas on Isolated and Cellular DNA—A Review

Atmospheric Pressure Plasma (APP) is being used widely in a variety of biomedical applications. Extensive research in the field of plasma medicine has shown the induction of DNA damage by APP in a dose-dependent manner in both prokaryotic and eukaryotic systems. Recent evidence suggests that APP-induced DNA damage shows potential benefits in many applications, such as sterilization and cancer therapy. However, in several other applications, such as wound healing and dentistry, DNA damage can be detrimental. This review reports on the extensive investigations devoted to APP interactions with DNA, with an emphasis on the critical role of reactive species in plasma-induced damage to DNA. The review consists of three main sections dedicated to fundamental knowledge of the interactions of reactive oxygen species (ROS)/reactive nitrogen species (RNS) with DNA and its components, as well as the effects of APP on isolated and cellular DNA in prokaryotes and eukaryotes.     

Characterization of marama bean (Tylosema esculentum) by comparative spectroscopy: NMR, FT-Raman, FT-IR and NIR

The marama bean from Southern Africa has proven to be a source for production of various healthy food products. In order to exploit its commercial potential, it is important to know its chemical composition in more detail. In this study, marama beans from different geographical sites and harvest years were analyzed by use of infrared, near infrared, Raman, and ¹H as well as ¹³C nuclear magnetic resonance spectroscopy. These techniques can measure single beans in a rapid and non-destructive manner. By comparative application, the qualitative composition of the marama bean was explored in detail, revealing large amounts of protein, dietary fiber and unsaturated fat. The carbohydrate fraction was largely present as pectins and a minor fraction of smaller water soluble carbohydrates were tentatively assigned to raffinose. It is characteristic that the beans do not contain starch or ??-glucans and that the water soluble part of the proteins/peptides have a high content of the aromatic amino acid tyrosine.     

硅酮耐划伤剂对车用聚丙烯内饰材料性能的影响

采用衰减全反射红外光谱(ATR)研究了硅酮耐划伤剂改性的车用聚丙烯材料表面和内部的含量分布。ATR及十字划格实验结果表明:硅酮耐划伤剂能均匀地分散在材料的表面和内部。随着硅酮耐划伤剂用量的增大,材料耐划伤性能相应提高。ATR及扫描电镜(SEM)证明车用聚丙烯耐划伤注塑材料成皮芯结构,严重划伤样品的划痕破坏了材料表层,出现黏滑现象,而加入硅酮耐划伤剂的改性材料划痕深度较浅,添加量超过4.5%时,材料划伤前后的色差△L<1。     

单波长光激励SPW测定金属膜厚度与介电常数

采用衰减全反射（ＡＴＲ）技术，单波长激励金属膜表面等离子激元波（ＳＰＷ）的共振吸收峰，在考虑金属膜表面粗糙度的情况下，用非线性最小二乘曲线拟合同时确定出了金属膜厚度与介电常数，并在另一波长下获得验证。