被子植物起源于买麻藤目的相关证据

综述了买麻藤目与被子植物关系的经典分类学、化学分类学、古植物学和现代分子生物学等方面的证据,结合买麻藤目与被子植物的基部类群中2类关键性成分:菧类和异喹啉类生物碱,对买麻藤目在被子植物演化中的地位进行了讨论,认同买麻藤目为被子植物姊妹群地位合理性,并认为被子植物应该起源于买麻藤目植物。

Paleophytochemical Constituents from the Pliocene Fossil Wood of Pinus Armandii from Longling,Yunnan

Specimens of fossil wood preserved lignified in Pliocene brown coal and identified as Pinus armandii Francher come from an opencast coalmine at Longling in western Yunnan Province, China. Phytochemical investigation of the fossil wood isolated using liquid column chromatography seven compounds （1-7） including a new fluorene derivative named 11,11-dimethyl-11H-benzo[b]fluorene. A further 28 volatiles were detected by gas chromatography-mass spectrometry （GC-MS）. Spectroscopic investigation methods, including MS and 1D and 2D-NMR techniques elucidated the structure of the seven compounds. Two types of natural products, isopimara and stilbene commonly occuring in extant and Pliocene fossil P. armandii indicate phytochemical fidelity during burial under certain circumstances in sediments. Discovery of stilbenes that can inhibit the activities of wood-destroying fungi in the Pliocene P. armandii prompts the assumption that the chemical preservation of this Pliocene fossil wood of P. armandii in brown coal might contribute to the presence of inner natural inhibitors against wood-destroying fungi.

适合致密油藏的低伤害可回收清洁压裂液体系

为了降低致密砂岩油藏压裂施工的成本和环境污染风险,提高压裂液的利用效率,以脂肪酸、二甲氨基丙二胺、二氯异丙醇、非离子表面活性剂、多组分有机溶剂等为原料,制得新型复合表面活性剂(GEMR-2),将其与有机酸盐调节剂复配制得适合致密油藏的低伤害可回收清洁压裂液体系。室内对压裂液的携砂性、破胶性、对岩心的伤害性、可回收等综合性能进行了评价,并成功进行了现场应用。结果表明,该压裂液体系的耐温抗剪切性能良好,在80℃、170 s^(-1)的条件下剪切120 min后的黏度仍能达到50 mPa·s以上。压裂液的携砂能力较强,并且可以迅速破胶,破胶液的残渣含量低于1.5 mg/L,界面张力较低。该压裂液破胶后对储层天然岩心渗透率的伤害率低于5%,具有低伤害的特点。使用破胶液重复配制的压裂液仍然具备较强的耐温抗剪切性能,具有良好的可回收重复利用性能。在ZM-12井使用低伤害可回收清洁压裂液体系的施工过程顺利,压裂增产效果显著,现场返排液重复配液性能较好,节约了大量的水资源。