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131.
132.
The grafting of acrylic acid onto electron beam‐irradiated polypropylene was carried out using preirradiation method. The stability of peroxy radicals was investigated by electron spin resonance. It was found that the decay of peroxy radicals is much faster at 70°C than at 40°C and ambient temperature. The grafting has been observed to be strongly dependent on the monomer dilution in the reaction medium. The grafting was ascertained by attenuated total reflectance (ATR). The distribution of grafts across the samples was monitored by infrared microscopy. It was found that the graft management is considerably influenced by composition of the grafting medium. The grafting involving pure monomer leads to the surface enrichment with the polyacrylic acid chains. The samples grafted in pure monomer led to much lower contact angles as compared to the diluted monomer solution. The swelling of the grafted samples also showed a trend that was governed by the graft management. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 546–553, 2006 相似文献
133.
Guo Dong Zhu Jing Xu Xue Jian Yan Jie Li Zhi Gang Zeng Miao Shen Li Zhang 《Thin solid films》2006,510(1-2):181-183
This paper introduces the Force Modulation technique to the study of crystallization process in ferroelectric vinylidene fluoride and trifluoroethylene copolymer films. Using this technique we have successfully visualized ferroelectric crystalline domains and observed that these ferroelectric domains grow out from amorphous phase, unite into strip-like structures, and finally congregate into a union. Force Modulation can weaken the influence of topography on imaging of ferroelectric domains, and reveal more details, which are difficult to be observed in topographical image. 相似文献
134.
135.
Qing YangKaibin Tang Chunrui WangJian Zuo Daoyuan ZhangYitai Qian 《Thin solid films》2003,436(2):203-207
SnS2 films have been deposited on glass and alumina plate substrates by the reactions between an organotin precursor [tetrabuyltin, (CH2CH2CH2CH3)4Sn] and carbon disulfide in n-hexane at the temperature range 180-200 °C for 10-40 h. The reaction system was oxygen free and applied at a moderate temperature. The films so prepared were characterized by techniques of X-ray diffraction, Scanning electron microscopy, Raman and Mössbauer spectroscopies. The films deposited on glass as well as on alumina plate have an average thickness of 30 μm, but have different rose-like morphologies, which are influenced by both the anisotropic growths of crystals and the different substrate structures. Photoluminescence measurements show that the films have an emission peak at approximately 590 nm. 相似文献
136.
Fluorescence microscopy techniques have become important tools in mitosis research. The well-known disadvantages of fluorescence microscopy, rapid bleaching, phototoxicity and out-of-focus contributions blurring the in-focus image are obstacles which still need to be overcome. Confocal fluorescence microscopy has the potential to improve our capabilities of analyzing cells, because of its excellent depth-discrimination and image processing power. We have been using a confocal fluorescence microscope for the study of the mechanism of poleward chromosome movement, and report here (1) a cell preparation technique, which allows labeling of fixation sensitive spindle antigens with acceptable microtubule preservation; (2) the use of image processing methods to represent the spatial distribution of various labeled elements in pseudocolour; (3) a novel immunoelectron microscopic labeling method for microtubules, which allows the visualization of their distribution in semithin sections at low magnification; and (4) a first attempt to study microtubule dynamics with a confocal fluorescence microscope in living cells, microinjected with rhodamine labeled tubulin. Our experience indicates that confocal fluorescence microscopy provides real advantages for the study of spatial colocalization of antigens in the mitotic spindle. It does not, however, overcome the basic limits of resolution of the light microscope. Therefore, it has been necessary to use an electron microscopic method. Our preliminary results with living cells show that it is possible to visualize the entire microtubule network in stereo, but that the sensitivity of the instrument is still too low to perform dynamic time studies. It will be worthwhile to further develop this new type of optical instrumentation and explore its usefulness on both fixed and living cells. 相似文献
137.
138.
通过对L520型智能中子仪测定农田土壤含水量的标定研究,在试验区草甸土类型的土壤中,在0~100cm的土层中得到了一条标定土壤含水量的回归直线,用此法测定土壤含水量较重量法快捷方便且误差小。 相似文献
139.
报道了以茈为荧光探针,探讨小剂量~(60)Co γ射线照射后小鼠胸腺细胞膜流动性的变化。结果表明,剂量在0.25-1.00Gy范围,胸腺细胞膜流动性降低与剂量之间呈明显线性关系。从0.50Gy起,辐照组荧光强度比值I_1/I_2与I_3/I_2与对照组的比较存有显著差异(P<0.05)。提示淋巴细胞膜流动性的变化可作为小剂量辐照早期效应的敏感指标。 相似文献
140.
A possible structure of the casein micelle based on high-resolution field-emission scanning electron microscopy 总被引:2,自引:0,他引:2
Douglas G. Dalgleish Paul A. Spagnuolo H. Douglas Goff 《International Dairy Journal》2004,14(12):1025-1031
New electron micrographs, produced using the technique of Field Emission Scanning Electron Microscopy, showing the details of the micellar surface, are presented. The images show the micellar surfaces without any coating, and suggest that the surface of the micelle may have a much more complex structure than has previously been demonstrated. Although there appear to be no spherical subunits (submicelles), there is evidence for the organization of the caseins into tubular structures within the micelle. The surface is not smooth, and contains gaps between the substructures. The observations are discussed in terms of published models of micellar structure, where is it suggested how the depiction of the micellar surface can be used to explain certain factors of its reactivity and behaviour. 相似文献