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金属蛋白结构和功能关系的研究,是生物无机化学的一个重要研究课题。随着研究的深入,各种现代实验技术逐渐被应用这一领域中,穆斯堡尔谱作为一种吸引人的技术已经被广泛地应用。随着穆斯堡尔谱技术上的改进和发展,将会使其在此领域方面的应用更加广泛。本文着重介绍穆斯堡尔谱的一些重要参数以及其在金属蛋白尤其是在铁蛋白中应用的特点。 相似文献
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Characterization of Superfine Sr2CeO4 Powder Prepared by Microemulsion-Heating Method 总被引:2,自引:0,他引:2
Powder phosphor of Sr2CeO4 is prepared by microemulsion-heating method and a film of the phosphor on ITO glass is formed by electrophoretic deposition. Field emission scanning electron microscopy (FE-SEM) images show that the powder fired at 850 ℃ for 4 h has a spherical shape with an average diameter of 70 ~ 80 nm whereas the powder sintered at 900 ℃ for 4 h and 1000 ℃ for 4 h have shuttle-like and spherical shapes, respectively, with both sizes less than 1 μm.X-ray diffraction (XRD) patterns indicate that the superfine Sr2CeO4 exhibits an orthorhombic crystal structure. Roomtemperature photoluminescence (PL) measurements show that there are three excitation peaks located at around 262, 280and 341 nm, and all the Sr2CeO4 samples display an intense blue emission at 470 nm with CIE coordinate of (x, y) =(0.176, 0.283). The quantum yield of phosphor is high up to 0.47 ± 0.04. Compared with Sr2CeO4 samples prepared with traditional high-temperature heating, the phosphor synthesized with this method has a smaller size, lower calcination temperature, and shorter calcination time, and the main excitation and emission bands are blue shifted about 30 and 12 nm respectively. The startup voltage for Sr2CeO4 film on ITO glass shifts from 2700 to 4000 V with increasing thickness of the film. 相似文献
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介绍一种应用于巷道照明的隔爆型LED驱动电路的设计与计算方法。在设计电路中采用了一款型号为RM2603的恒流恒压集成控制电路,以RM2603为核心的驱动电路所用外围器件少,而且价格低廉,适用电压范围宽,性价比高,免维护,适合煤矿巷道照明大范围使用。 相似文献
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麦草碱木素酚化改性及其制备LPF胶粘剂工艺研究 总被引:2,自引:0,他引:2
利用碱性条件下酚化改性的麦草碱木素代替部分苯酚制备了高木质素/苯酚比例和胶粘强度高的木质素酚醛树脂(LPF)胶粘剂.利用傅立叶红外光谱(FT-IR)和凝胶色谱(GPC)研究了麦草碱木素在碱性条件下酚化改性前后的结构变化.FT-IR分析表明,麦草碱木素发生了酚化反应,伴随着酯基的断裂和甲氧基的脱落;GPC结果显示,木质素平均分子量降低,分子量分布范围变宽.接着,研究了木质素/苯酚比例、氢氧化钠浓度、甲醛/木质素比例、酚化温度、酚化时间、缩聚温度、缩聚时间等反应工艺参数对LPF胶粘剂性能的影响,优化了麦草碱木素酚化改性制备LPF胶粘剂的反应工艺参数.最后,比较了反应工艺参数优化的LPF胶粘剂与传统PF胶粘剂的各项性能,结果显示,麦草碱木素酚化改性后代替70 % 的苯酚制备得到的LPF胶粘剂的胶粘强度与传统PF胶粘剂相近. 相似文献
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