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A single-mode polymer optical fiber (POF) with highly photosensitive core doped with benzil dimethyl ketal (BDK) is fabricated and used for writing Bragg grating through the two-beam interference method. The Bragg wavelength of the grating is about 1570 nm, while the full-width at half-maximum (FWHM) of the reflection peak is 0.3 nm. The temperature response of POF Bragg grating is theoretically analyzed and experimentally measured in contrast to silica optical fiber Bragg grating (FBG). The result shows that the temperature character of POF Bragg grating is negative, which is opposite to the silica optical FBG. The absolute value of the temperature response of POF Bragg grating is one order of magnitude higher than that of the silica optical FBG, making POF Bragg grating appear to be very attractive for constructing temperature sensors with high resolution. 相似文献
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黄酮类化合物研究(Ⅷ)——7-取代黄酮及2'''',4-二羟基-3-甲氧基-4''''-取代查尔酮的合成 总被引:1,自引:0,他引:1
3,4′,7-三羟基黄酮和3,3′,4′,7-四羟基黄酮是中草药舒冠通糖浆的主要成份,该药对冠心病、心绞痛、胸闷有一定疗效。为系统研究黄酮类化合物的构效关系,我们在前文基础上又合成了5个新的4′-羟基-7-取代黄酮及5个3′-甲氧基-4′-羟基-7-取代黄酮。在此过程中,又合成了4个新的2′,4-二羟基-3-甲氧基-4′-取代查尔酮。其合成路线如下: 相似文献
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