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Annealing polyethylene terephthalate (PET)/polycarbonate (PC) blends enhance the transesterification reaction and increase the amount of copolymer at the interface of both polymers. The copolymer enhances the compatibility of PET with PC, because it contains both PET and PC blocks, which causes the interface between PET and PC to become fuzzy. When the PET/PC undergoes batch physical foaming with CO2, the copolymer significantly changes the resulting cell morphology, that is, the annealing time. Before annealing or in the absence of the copolymer, bubble nucleation occurs and dominates growth at the interface. When the PET/PC blends are annealed, the interface impedes bubble nucleation and growth. The polymer is stretched at the interface by bubble growth, forming fibril‐like structures connecting two polymer domains at the interface. Increased annealing time causes the interface to become more homogeneous and makes heterogeneous bubble nucleation difficult. At higher copolymer concentrations, the interface of PET and PC becomes fuzzy and the cell morphology becomes like those of foamed homogeneous polymers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献
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S. G. Li Q. Gong C. F. Cao X. Z. Wang J. Y. Yan Y. Wang H. L. Wang 《Optical and Quantum Electronics》2014,46(5):623-640
Since the external cavity quantum dot laser was first demonstrated, the performances have been improved in terms of operation temperature, output power, pulse generator and tuneability based on the naturally size fluctuation of quantum dot. Nowadays, the external cavity quantum dot sources have been successfully used in different absorption spectroscope techniques, in industry, biomedical and research. In this paper we reviewed the recent developments of quantum dot lasers operated in a grating-coupled external cavity system where a single frequency and wide tunable wavelength range were easily obtained by adjusting the grating angle. In all cases, we mainly stressed the significant progresses in understanding of basic optical and electronic properties to enable the importance steps forward. The prospects for further progress directed towards stability, mode-hoping-free tuning range, miniaturization and integration of the external cavity quantum dot lasers also reviewed. 相似文献
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A novel spectrofluorimetric method to determine abiraterone acetate and its active metabolite, abiraterone was developed, based on the fact that fluorescence intensity of abiraterone acetate and abiraterone could be enhanced in β-cyclodextrin (β-CD) due to the formation of the inclusion complex. The inclusion interaction of β-CD and abiraterone acetate and the β-cyclodextrin sensitized spectrofluorimetry was examined. The various factors influencing fluorescence were discussed in details. The results showed that under the optimized conditions, the linear range of calibration curve for the determination of biraterone acetate and abiraterone was 0.20?~?6.0 μg/mL, and the detection limit (LOD) was 6.8 (r?=?0.997) or 6.6 ng/mL (r?=?0.996), respectively. No interference was observed from common co-existing substances or pharmaceutical excipient. The method was successfully applied to the analysis of abiraterone acetate in pharmaceutical formulation and abiraterone in human serum/urine. 相似文献
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Inside Back Cover: Ultrathin WS2 Nanoflakes as a High‐Performance Electrocatalyst for the Hydrogen Evolution Reaction (Angew. Chem. Int. Ed. 30/2014) 下载免费PDF全文
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A novel fiber-optic sensor structure fabricated by cascading two optical microfiber knot resonators (MKRs) is proposed and demonstrated in this paper. A theoretical model for describing the principle of the sensing structure is given and its temperature responses are characterized experimentally. Experimental results show that high-precision and simultaneous multi-point temperature sensing in micro-scale can be achieved. Such a sensing structure also has the potential for achieving dual-parameter measurement to eliminate the cross-talk between two parameters in micro-scale. 相似文献
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