Distribution and Comparison of Steranes From Blue-Green Algae Under Different Simulated Conditions

Two remarkably opposite distribution patterns of sterane series are revealed from living blue-green alga (or cyanobacterium) under different simulated conditions. The organic matter derived from hydrous-pressure pyrolysis of the blue-green alga is characterised by the predominance of C_(27) sterane over C_(29) sterane; this is coincident with traditional thought. On the contrary, the organic matter derived from artificially silicified microfossils of the blue-green alga is characterised by the predominance of C_(29) sterane over C_(27) sterane; this appears to be an unusual distribution pattern. Such kind of unusual steranedistribution also has been foundin the samples of Precambrian cherts with abundant well-preserved microfossil algae. All these imply that the special source of organisms and the medium, procedure or conditions of simulated pyrolysis may result in the different distribution patterns of sterane biomarkers.     

不同模拟条件下蓝藻甾烷化合物的分布及其对比

现代蓝藻(又称蓝细菌)水压热解生成的有机质与现代蓝藻模拟硅化转化为人工化石生成的有机质,表现出两种相反的甾烷系列化合物分布特征,前者C_(27)甾烷多于C_(29)甾烷,与传统的认识吻合;后者C_(29)甾烷多于C_(27)甾烷,属异常分布,在前寒武纪富藻燧石层样品中也发现C_(29)甾烷多于C_(27)甾烷,特殊的生物来源和热解实验的介质,方法与条件可能是甾烷类生物标志化合物分布特征差异的原因。     

New Discoveries in Study on Hydrocarbons From Thermal Degradation of Heterotrophically Yellowing Algae

Green autotrophic alga Chlorella protothecoides contains a very small quantity of hydrocarbons. Heterotrophic culture of this alga results in the cells yellowing, chlorophyll disappearing, protein decreasing and lipid increasing remarkably. The quantities of hydrocarbons from them directly and from the thermal degradation of the cells at or below 200℃ are very low. These hydrocarbons are characterized by predominance of high molecular weight normal alkanes with maximum at C23-C25. When these heterotrophi-cally yellowing cells are thermally degraded at 300℃ , the aliphatic hydrocarbons increase greatly, 32 times that of the green autotrophic ones at the same temperature. Meanwhile, the low molecular weight normal alkanes with C17 as the peak become predominant instead of the original ones of high molecular weight. The actual potential of microplanktonic algae in producing hydrocarbons should be much greater than what people have recognized before.     

采用旋转圆盘－圆环电极研究4－甲基咪唑的缓蚀作用

采用旋转圆盘－圆环电极研究４－甲基咪唑的缓蚀作用吴庆余钮淦襄（武汉汽车工业大学化工系４３００７０）关键词旋转电极缓蚀作用工业锅炉使用一段时间后要进行酸洗除垢，以便有效地利用热能，避免意外爆炸事故发生。各种钢铁件在电镀、涂装及其他表面处理之前也经常要利...     

傅里叶变换红外光谱法研究HL-60细胞的分化过程

利用傅里叶变换红外光谱法(FTIR)研究了人白血病细胞HL-60在全反式维甲酸(ATRA)作用下向粒细胞分化的过程。结果表明,分化后的HL-60细胞FTIR图谱发生了显著变化,体现在与蛋白质、脂类、核酸和多糖等生物大分子相关的特征性谱带上。细胞内脂类物质烃链增长,含量增加。指纹图谱区域(900～1 300 cm-1)的谱带随着分化进程呈现规律性的变化。其中,核酸含量相对增加,并在1 052和1 153 cm-1附近出现了新的谱峰,二阶导数谱进一步发现在1 022 cm-1处出现新峰,这说明蛋白糖基化,磷酸化以及核酸氢键加强作用在HL-60细胞分化的过程中起着重要作用。通过计算一些图谱参数,并与硝基四唑氮蓝(NBT)还原实验相比较,证明红外图谱的变化与分化程度成正相关。     

异养黄化藻类产烃研究新发现

浮游藻类Chlorella protothecoides经过异养黄化后细胞内叶绿素消失,脂类含量成倍增加。异养黄化藻热解前和200℃以下较低温热解时,产烃量很低,且以C_(23)—C_(25)为主峰的高碳数正烷烃占优势:热解温度达300℃时其饱和烃产量迅速增加,是相同热解温度时绿色自养藻饱和烃产量的32倍。这时原先以高碳数占优势的正烷烃分布特征飞跃地转变为以C_(17)为主峰的低碳数正烷烃占优势的分布特征,原异养细胞内大量的十八碳一烯酸是C_(17)正烷烃的直接分子来源。用异养黄化藻类热模拟产烃符合自然界藻类生烃的实际过程,研究结果发现水生浮游藻类实际的产烃潜力应比人们过去的认识还大得多。     

变通公式 巧妙解题

变通公式巧妙解题２５１７００山东惠民县一中吴庆余等差数列（ａｎ）：ａｎ＝ａ１十（ｎ－１）ｄ公式可巧妙地将ａｎ与Ｓｎ转换，用此公式处理ａｎ与Ｓｎ关系思路清新，功效独到．例１等差数列ａｎ前ｎ项和Ｓ。一５；ｌ’＋３ｎ求通项ａ。（例２在等差数列｛ａ。｝中，前...