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响度是人耳接收到声音信号后的一种感觉量,它并非一个物理量,与人类的听觉特征和主观感受直接相关,一般用单位宋(Sone)来度量.响度评定值不是直接由接收端收到的实际声音测试信号计算出响度,而是采用插入到中间参考语音通道和待测语音通道、与频率无关的传输损耗值来表示. 相似文献
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α-含氧取代酞菁的聚集性质研究 总被引:2,自引:0,他引:2
以3-硝基邻苯二腈为原料分别与苯酚和甲醇反应合成3-苯氧基邻苯二腈和3-甲氧基邻苯二腈, 这些α-取代的邻苯二腈以二甲氨基乙醇为溶剂, 在有无醋酸锌条件下环合, 分别形成α-四苯氧基锌酞菁、α-四苯氧基无金属酞菁、α-四甲氧基锌酞菁、α-四甲氧基无金属酞菁, 对产物结构进行了表征. 光谱分析结果表明, 此类锌酞菁在氯仿等非配位溶剂中能自发形成J型聚集体, 其Q带出现一个红移吸收带, 经UV-Vis光谱、荧光光谱及MALDI-TOF质谱分析表明, 该聚集体的形成机理为基于酞菁分子间的锌-氧自配位相互作用. 相似文献
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Nonlinear Optical Properties of Novel Polymeric Rare Earth Phthalocyanine Studied Using Picosecond Z-Scan Technique 下载免费PDF全文
Three novel tri-dimensional phthalocyanine polymers, with lanthanum (LaPPc), gadolinium (GdPPc) and ytterbium (YbPPc) as centric atoms, have been synthesized from a tetranuclear phthalonitrile. Third-order optical nonlinearities of these compounds in DMF solution are measured by a picosecond Z-sacn technique at 532 nm. It is found that all the compounds show reverse saturation absorption and nonlinear self-focus refraction effect. The second-order molecular hyperpolarizabilities are calculated to be 1.82×10^-23, 1.48×10^-23 and 1.45×10^-23 esu for LaPPc, GdPPc and YbPPc, respectively. The differences among their nonlinear optical properties are attributed to the special tri-dimensional structure and the variation in rare earth atoms. 相似文献
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