126 resultados para 1995_01202302 TM-36 4301703


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beta, beta-1, 3-Piopylenedithio-alpha, beta-unsaturated arylketones 2 via chemoselective 1,2-addition with allyl or benzyl Grignard reagents afforded the corresponding carbinols 3 and 4. Catalysed by silica gel, the carbinols 3 and 4 were converted to the beta,gamma-unsaturated arylketones 5, 6. The mechanism and reaction condition were discussed.

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研究了水热法合成晶体,浓度配比、生长温度对晶体生长习性的影响.合成了一系列化学计量比的Y_(1-x-0.3)Er_(0.3)Tm_xP_5O_(14)(x=0.01~0.1)晶体,观察和分析了晶体的缺陷及成因,测定和讨论了晶体结构.

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[目的]探索从虎耳草科植物中提取DNA的有效方法.[方法]采用改进的CTAB法,从11种虎耳草科植物中提取DNA.以提取的DNA为模板,利用通用引物"psb AF"和"trnHR"对虎耳草科植物叶绿体DNA psb A-trn H片段进行PCR扩增.[结果]通过该方法提取的DNA纯度较高,质量较好.用所得DNA进行psb A-trn H扩增的产量高,可用于后续的测序等分析.对山地虎耳草的PCR产物纯化后进行测序,得到262 bp的序列.将其与CenBank中的虎耳草属其他植物的psb A-tm H序列进行比对分析,证实该序列为目标psb A-trn H片段的区域.[结论]该方法可有效去除次生物质对DNA的干扰,提取的基因组DNA可用于叶绿体psb A-trn H测序分析和其他遗传学分析.