江汉平原钟桥遗址地层揭示的史前洪水事件

通过野外考古调查研究,利用对钟桥遗址疑似古洪水层和研究区现代洪水沉积物的锆石微形态、粒度、磁化率、Rb/Sr等地球化学指标的比较、AMS14C技术和考古器物断代,发现钟桥遗址在4800~4597 cal. a BP、4479~4367 cal. a BP和4168~3850 cal. a BP分别经历了三次古洪水事件并相应堆积了古洪水沉积层;结合江汉平原及其周边地区众多遗址的古洪水沉积层时代对比证据,揭示了屈家岭文化中晚期（4900~4600 cal. a BP）和石家河文化末期至夏代（4100~3800 cal. a BP）两次大洪水事件在江汉平原地区非常普遍。对史前洪水发生环境背景的进一步分析,反映江汉平原在5000~4500 a BP及4000 a BP前后的时段气候表现得不稳定,古洪水事件与气候环境变化驱动的江汉平原湖群扩张存在一定的联系,并影响区域新石器文化兴衰过程。同时,其它证据也表明该区社会发展过程和环境变化过程特别是古水文过程的矛盾在石家河文化末期已特别突出,发现具有全球意义的4000 a BP前后气候异常引起的大洪水事件是江汉平原地区石家河文化消亡的重要环境因素;而石家河文化末期该区内部或同中原以及其它地区间的冲突,都加速了石家河文化的崩溃。这些研究成果,提供了可靠的大禹时代史前洪水证据来说明其对新石器文化兴衰的社会影响,对于揭示4000 a BP气候事件中区域气候水文变化的响应规律,亦具有重要的科学意义。</p

海南岛不同油茶主产区油茶籽油营养成分分析及品质综合评价Nutritional components analysis and comprehensive quality evaluation of oil-tea camellia seed oil from different main

海南岛油茶籽油品质独特，为促进海南岛油茶资源开发利用并为油茶籽油品质性状育种提供参考依据，选取海南岛不同油茶主产区的油茶籽，对油茶种仁含油率及油茶籽油理化指标、无机元素含量、脂肪酸组成和生物活性物质含量进行测定，并对考察指标进行相关分析、品质综合评价和聚类分析。结果表明：海南岛油茶籽种仁平均含油率为49.13%；油茶籽油无机元素含量丰富，不饱和脂肪酸含量在90%左右，角鲨烯含量为78.33~96.23 mg/kg,茶多酚含量为64.78~77.36 mg/kg,维生素E含量为430.7~484.4 mg/kg;某些考察指标之间存在显著或极显著的相关性；定安和海口产油茶籽油综合得分较高，琼海油茶籽油综合得分最低；通过聚类分析，海南岛油茶籽油主产区可分为3类，其中定安为一类，屯昌、琼海、澄迈、临高为一类，海南中部山区、海口为一类。综上，海南岛油茶籽油品质较高，各油茶主产区油茶籽油有其自身特点。 The quality of oil-tea camellia seed oil originated from Hainan Island is unique. To promote the development and utilization of oil-tea camellia resources and further provide a reference for the quality traits breeding of oil-tea camellia seed oil in Hainan Island, oil-tea camellia seed samples from the main oil-tea camellia producing areas in Hainan Island were collected. The oil content in oil-tea camellia seed kernel, the physicochemical indexes, contents of inorganic elements, fatty acid composition and bioactive substances contents in oil-tea camellia seed oil were determined. Subsequently, data on these traits were submitted to do correlation analysis, comprehensive quality evaluation and cluster analysis. The results showed that the average oil content in oil-tea camellia seed kernel was 49.13%. The oil-tea camellia seed oil was rich in inorganic elements, and the contents of unsaturated fatty acid, squalene, tea polyphenol and vitamin E were about 90%, and 78.33-96.23, 64.78-77.36, 430.7-484.4 mg/kg, respectively. Significant or extreme significant correlations were found between some traits. The comprehensive scores of oil-tea camellia seed oil originated from Ding′an and Haikou were relatively higher, while that from Qionghai was the lowest. According to cluster analysis, the main producing areas of oil-tea camellia seed oil in Hainan Island could be divided into three categories, Ding′an into one category, Tunchang, Qionghai, Chengmai and Lingao into one category, and the central mountains and Haikou into one category. In conclusion, the quality of oil-tea camellia seed oil originated from Hainan Island is high, and the oil-tea camellia oil in each main producing area has its own characteristics