【摘要】 量热计测定结果表明,不同地区银杏(Ginkgo　biloba)叶热值(caloric　content,亦称等容燃烧热,Qv)不同,显示地域性条件对银杏叶能态具有较大影响。热分析研究结果显示,不同地区银杏叶的差热(differentialthermal　analysis,DTA)、热重(thermogravimetry,TG)和微分热重(differential　thermogravimetry,DTG)曲线及其特征相似,表明不同地区银杏叶的基本化学组成和结构具有共性,但其DTA、DTG曲线的特征参数、峰高、焓变、热解重量损失率等均存在一定差异,显示银杏叶DTA、DTG曲线主要参数可作为表征不同地域银杏叶性状差异的指标。红外光谱研究表明,供试银杏叶中含黄酮类化合物,银杏叶DTA曲线320℃放热峰主要与黄酮非核部分热解有关,DTA曲线500℃放热峰主要与黄酮环上羟基和残留集团热解有关。更多还原

【Abstract】 It is proved by determination of caloric meter that ginkgo leaves from different areas vary on their caloric content, which shows that local condition can affect greatly on the leaves’ energy state. Caloric analysis showes that ginkgo leaves located in various areas are resemble in DTA,TG and DTG curve and their characters, which indicate that they have common properties in basic chemical componient and structure, but have different specific parameters, peak height, enthalpy variation,weight lose ratio in pyrogenation of DTA and DTG curves, which showes that the main parameter of DTA and DTG could be used as a good index to tolken the character variation of ginkgo leaves. Infrared spectrum has proved that ginkgo leaves contain flavone compounds, heat release peak of DTA curve at 320℃ of ginkgo leaves is closely related to the fission of no-nuclear part of flavone, heat release peak of DTA curve at 500℃ of ginkgo leaves is closely related to the fission of -OH and other residual group on flavone chain.更多还原