论党的第二代领导集体对政治民主化的贡献

政治文明是社会主义社会政治现代化建设的重要目标,而政治民主化是政治文明发展的重要体现。党的第二代领导集体在社会主义政治民主化方面作出了重要贡献,即健全与完善了人民代表大会制度、党内民主制度以及基层民主制度,积极推动了中国社会主义政治文明的发展进程。     

原子荧光光度法测定植物样品中的铋

植物样品经硝酸-高氯酸1次湿法消解后,用氢化物发生-原子荧光光谱法测定铋。测定时加入消泡剂磷酸三丁酯,可有效消除泡沫,降低记忆效应,提高精密度。方法精密度(RSD=12)铋1.50%。经加标回收试验和国家一级标准物质验证,测定结果与标准值吻合。     

微波消解-氢化物发生原子荧光光谱法测定粉煤灰中的硒

粉煤灰中含有的硒元素较高,有综合利用价值.由于基体的复杂性,并未形成成熟可靠的测定技术.本文参考煤炭样品和土壤样品中硒的原子荧光光谱分析方法,采用氢化物发生-原子荧光光谱法测定粉煤灰中的硒.样品经氢氟酸-硝酸-双氧水体系微波消解得到清亮、透明的消解液,消解液经浓盐酸还原后,加入三价铁盐消除共存元素的干扰,所加的铁盐量不干扰硒的测定.方法检出限为0.020 μg/g;平行测定5份粉煤灰样品,相对标准偏差低于4.2％;加标回收率为94.0％～105.0％.应用建立的方法对煤飞灰标准物质进行分析,测定值与标准值基本相符;对不同地区的实际粉煤灰样品进行分析,证实方法可靠,可用于粉煤灰中硒元素的测定.     

微波消解-氢化物发生原子荧光光谱法测定茶园土壤中的铅

样品用王水微波消解浸提,氢化物发生-原子荧光光谱法测定茶园土壤中痕量铅的含量。对样品浸取方法、实验条件、增感剂和共存元素进行了条件实验。结果表明,王水微波消解浸取,铅浸出量最大,减少了试剂用量和环境污染;铁氰化钾-盐酸羟胺体系有显著的增感作用,铁氰化钾在配制溶液时用米糠除去试剂中可能存在的铅,降低了空白;钴、锌、砷、镉等共存离子不干扰铅的测定,通过加入邻菲啰啉-硫氰酸钠消除铁和铜的干扰,提高了铅的回收率。方法检出限为0.65 μg/L,精密度(RSD,n=10)为1.89%,回收率在86.8%~110.4%之间。用土壤标准物质验证,测定值与标准值相符,方法快速准确,适合于大批量样品的分析检测。     

Assessment of generation temperatures of crude oils

Biological marker maturity parameters were used to estimate the minimum HC generation temperatures of crude oils from Eastern Hungary. More than 50 oils and oil shows were analysed. Molecular- and homologous-ratios of biological marker compounds (triterpanes, steranes, mono- and triaromatic steroid hydrocarbons) were used as maturation parameters. The oils have at least five maturity stages, i.e. they have been generated under different thermal conditions. The highest reservoir temperature in each group was chosen as the best estimate of the groups' temperature just below the generation temperature, i.e. reservoirs of the group might be expected to be at shallower depths (lower temperatures) than those of the generation zone due to vertical migration into pools. For each maturation level, a threshold temperature range for genesis was inferred from reservoir temperatures; they are from 130–135°C for the least mature oils to 210–215°C for the most mature oils. In the least mature oils cracking was not observed, hence carbon–carbon cracking reactions had not taken place during their genesis. The most mature oils are intensively cracked oils; they are almost condensates. Two major genetic groups (families) of oils were found in the area. Both are present in each maturation level. The effects of migration were checked, and no influence on maturation was found. A number of the oils are in overpressured reservoirs within, or just above, the zone of the present-day active oil generation, hence the present-day temperatures of the pools must have been maximum temperatures. Contrary to the traditionally accepted temperature range for petroleum generation–maturation reactions (50–150°C), there is strong evidence from this study that the onset of oil generation requires temperatures higher than 130°C and is still proceeding above 215°C.     

Practical kinetic modeling of petroleum generation and expulsion

Models for petroleum generation used by the industry are often limited by (a) sub-optimal laboratory pyrolysis methods for studying hydrocarbon generation, (b) over-simple models of petroleum generation, (c) inappropriate mathematical methods to derive kinetic parameters by fitting laboratory data, (d) primitive models of primary migration/expulsion and its coupling with petroleum generation, and (e) insufficient use of subsurface data to constrain the models. Problems (a), (b) and (c) lead to forced compensation effects between the activation energies and frequency factors of reaction kinetics that are wholly artificial, and which yield poor extrapolations to geological conditions. Simple switch or adsorption models of expulsion are insufficient to describe the residence time of species in source rocks. Yet, the residence time controls the thermal stresses to which the species are subjected for cracking to lighter species.     

氢化物原子荧光法测定天然水中痕量砷

水样经王水分解,在酸度10％—25％介质中,As(v)用硫脲-抗坏血酸预还原,使As(Ⅱ)与硼氢化钾溶液生成气态氢化物(AsH_3),在原子荧光光度计上测定砷量。方法简便、快速、灵敏。方法检出限为0.08μg/l,相对标准偏差(R.S.D.)为5.05％,回收率为94.3％—105.4％。     

海洋纤毛虫巨大拟阿脑虫的实验生态学研究:初始密度及食物对其种群生长的影响

采用实验生态学方法，就不同初始种群密度及食物密度等因素对海洋纤毛虫巨大拟阿脑虫（隶属纤毛门，盾纤目）的种群自然增长率（r)及世代时间（G）的影响进行了探讨。结果表明，初始种群密度与r值呈负相关，与G则呈正相关，初始密度为1ind/ml时，r值达最大值2．61/d，G值则为最小值为0．29d;r值随食物密度的增大而增大，当食物密度为2．8E＋08ind/ml时，r值达最大值为2．07。同时讨论了种群自然增长率和世代时间之计算方法在实验中的应用。     

微量砷,锑,铋流动注射在线还原氢化物发生原子吸收连续测定法

本文采用了流动注射分析技术，用氢化物发生原子吸收分光光度法直接连续测定砷、锑、铋。在稀盐酸介质中，试样溶液中以不同氧化态存在的待测元素被硫脲、碘化钾、抗坏血酸混合还原抑制剂溶液在线还原为易生成氢化物的形式，与硼氢化钠反应生成氢化物，经我们自制的带雾化器的气液分离器分离后进入原子化器。方法稳定灵敏，再现性好，一次溶样可直接连续测定地质样品中砷、锑、铋３种元素。用本方法测定地质标样结果吻合很好，其检出限（３σ）分别为８．８４，６．９１，１２．２９×１０￣（－８）ｇ／Ｌ。相对标准偏差小于２％。     

氢化物原子荧光法测定含铀岩石中微量硒

本文介绍了氢化物原子荧光法测定含铀岩石中微量硒的方法。测定下限为０．０１μｇ／ｇ，测量精度（２×１０－７）ＲＳＤ为６．６３％。方法灵敏度高、快速、操作简便。本方法也适用于一般岩石样品中微量硒的测定。