金属—PAN—S配合物的极谱研究——Ⅱ:Fe~(3+)—PAN—S—TEA—NH_3·H_2O—NH_4Cl体系配合吸附波

在NH_3·H_2O—NH_4Cl—三乙醇胺底液中Fe(Ⅲ)与PAN—S产生一灵敏的配合吸附波,峰电位在—0.50伏(vs.SCE)。峰电位与铁离子浓度在2.8×10~8～3.4×10~(-6)mol/L范围内线性良好,检出下限可达2.8×10~(-8)mol/L。该法用于乳粉、头发、血清等样品的测定,结果满意。     

Changes in polymer foils used in food packaging tested by using differential scanning calorimetry

This work is an experimental study of the differential scanning calorimetry characterisation of polymer materials used in food packaging materials, such as polypropylene (0.03 mm), polyethylene (0.1 and 0.03 mm), poly(D-(-)-Β-hydroxybutyrate) (powder), two-layered polypropylene (0.064 mm), and two-layered polypropylene with poly-vinylidene-chloride (0.012/0.021). The polymer stability was checked by simulation of conditions during food preparation in microwave ovens, sterilisation or rapid freezing. The materials were tested in the temperature range from 40 to 200‡C at different scan rates from 2 to 30°C min⁻¹ during heating or cooling. The enthalpies show a high correlation coefficient (0.964) with scan rate. All samples undergo phase change in the temperature range from 107 to 173°C during heating and enthalpies are in the range from 31.8 to 71.1Jg⁻¹. Upon subsequent cooling from 200°C, the temperature range of phase changes is shifted to lower temperatures from 86 to 102°C with enthalpies ranging from 30.4 to 57.8 J g⁻¹. Experiments with exposure of polymers to microwave radiation and freezing prove that the phase change considering the temperature range is very similar in all experiments.     

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。     

固定频率波束可调的多端口微带漏波天线

提出了一种崭新结构的多端口馈电微带漏波天线 ,实现了频率固定下的电控天线主波束逐级可调。在工作频率固定的情况下 ,通过控制双端口馈电微带天线上的中部馈电端口位置 ,使微带漏波天线主波束方向发生偏移。仿真结果表明 ,当工作频率固定为 7GHz的情况下 ,在H平面上 ,主波束扫描范围可以达到约 48°～ 88°。     

A study of the large strain deformation and failure behaviour of mixed biopolymer gels via in situ ESEM

A mixed biopolymer gel, consisting of a protein (gelatin) and polysaccharide (maltodextrin) mixture has been investigated. By controlling the composition it was possible to construct an ‘emulsion-like’ structure, with included spherical particles of one phase (maltodextrin) within a continuous matrix of the second (gelatin). Large strain deformation and failure behaviour of this system has been examined via in situ environmental scanning electron microscopy (ESEM). ESEM has been employed to explore the changes in the structure of the material, whilst allowing the sample to stay hydrated as it was subjected to tensile strain, thereby allowing simultaneous imaging and determination of stress-strain data of the native sample. Ductile behaviour was observed, which has been attributed to the stretching, tearing and fracture of gelatin ligaments and debonding at the interface between the maltodextrin particles and continuous gelatin matrix. Deformation and fracture of the maltodextrin particles during tensile testing was also observed. The interfacial fracture energy of the composite has been calculated following an elastomer composite-debonding model, although there are several limitations to this approach for the mixed gel. It was found in samples tested after different ageing times that the debonding stress and strain was decreasing with ageing leading to a lower interfacial fracture energy. Samples were also tested after successive loading cycles, which resulted in a mechanical strength decrease after each cycle.     

钨系延期药预点火反应机理研究

通过程控升温模拟点火条件，根据ＤＳＣ图谱分析，找出主要反应区的温度范围。研究结果表明，钨系延期药预点火反应是一个真正的固－固反应。     

Martha J. Farah.

Recognizes Martha J. Farah for rigorous empirical and theoretical analysis of visual cognition, in which understanding of normal function and analysis of neurological deficits illuminate and strengthen one another. Applying diverse experimental techniques within an integrated approach to the study of mind and brain, she has sharpened and helped to answer fundamental questions about how humans generate and manipulate visual images, recognize objects, and attend to positions in space. Along with a citation, a biography is presented for Farah, as well as a bibliography of her works. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Probabilistic linear models for multiresolution estimation in gray-level images

A multiresolution analysis of digital gray-level images is presented. A gray-level multi-scale framework is determined from two main assumptions: the gray scale is binary at the finest spatial resolution, and the gray levels of composed regions are obtained additively. In order to interrelate the gray-level histograms of the same image at different resolutions, probabilistic linear models are developed, which are then applied for estimation. Linear-optimization theory is used as a way of constructing such models. A general procedure for image processing is sketched, based on gray-level estimation. A versatile algorithm for nonlinear filtering is derived. Some examples of prospective applications are given.This work was partially supported by grant TIC91-646 from the DGYCIT of the Spanish Government.     

A snake for model-based segmentation of biomedical images

In this work we present a snake based approach for the segmentation of images of computerized tomography (CT) scans. We introduce a new term for the internal energy and another one for external energy which solve common problems associated with classical snakes in this type of images. A simplified minimizing method is also presented.