1988年辽宁岫岩震群的某些特征

本文对1988年1、2月间岫岩震群进行了分析,发现该震群具有震源位置稳定集中、地震活动周期性明显、能量释放缓慢和振幅比线性关系好等特征。与海城地震前震相比两者之间存在明显差异,认为岫岩震群不属于前震性质的震群活动。     

再论A型花岗岩：对一种残余源模式的评价

0 绪言“A型”花岗岩这一术语是由Loiselle和Wones(1979)引入,用于描述沿大陆裂谷带产生(非造山)而具有弱碱性地球化学特点的花岗岩。一般将它解释为结晶于低水逸度条件下。与其它类型花岗岩相比,A型花岗岩具有高Fe/Mg、(Kq+Na)/Al、K/Na比值和高F、Zr、Nb、Ga及稀土元素(REE)和Y及Zn;具低Mg、Ca、Al、Cr、和Ni值(见Collins等,1982和Whalen等,1987)。因而A型花岗岩富集亲石元素而亏损那些I型、M型和S型花岗岩(解释为源于火成地壳、地幔和沉积源)有亲缘关系的耐熔(refractory)元素。Clemens等(1986)发现A     

Carbon isotopic fractionation associated with lipid biosynthesis by a cyanobacterium: relevance for interpretation of biomarker records

For the cyanobacterium Synechocystis UTEX 2470, grown photoautotrophically to a logarithmic stage of growth, the total lipid extract is depleted in 13C by 4.8% relative to average biomass. Depletions observed for acetogenic (straight-chain) lipids range from 7.6 (hexadecanoic acid) to 9.9% (a C16 n-alkyl chain bound in a polar-lipid fraction), with a mass-weighted average of 9.1%. Polyisoprenoid lipids fall into two isotopic groups, with phytol, diplopterol, and diploptene depleted by 6.4-6.9% and bishomohopanol (produced from the extracts by the preparative degradation of bacteriohopanepolyol) depleted by 8.4%. Analysis of the pattern of depletions indicates that two carbon positions in each C5 biomonomer leading to polyisoprenoid products are probably depleted in 13C relative to average biomass. The depletion of bacteriohopanepolyol relative to other polyisoprenoids can be ascribed to changes that occur over the life of each cell: (1) the 13C content of carbon flowing to lipid biosynthesis decreases as the cell size increases and (2) a greater proportion of the bacteriohopanepolyol which, unlike other polyisoprenoids, is present mainly in the cytoplasm rather than in membranes and is synthesized when cells are larger. Chlorophyll a is depleted relative to average biomass by O.7%. Given the observed depletion of 13C in phytol, the heteroaromatic, chlorophyllide portion of chlorophyll must be enriched in 13C by 2.7%. This enrichment is large relative to that in chlorophyllides produced by eukaryotes and may be related to a parallel enrichment of 13C in cyanobacterial glutamic acid. As in many previous investigations of cyanobacterial lipids, long-chain n-alkanes (C22-C29) are found in the extracts. They are, however, enriched in 13C relative to biomass and have isotopic compositions suggesting that they are contaminants of petrochemical origin. Available results indicate that cyanobacterial lipids will be depleted relative to dissolved CO2 that has served as a carbon source by 22-30% and that a wider range of depletions will be characteristic of eukaryotic products. The absence of long-chain n-alkanes in cyanobacteria reduces the possibility that petroleum ever formed from pre-eukaryotic sedimentary debris.     

辽宁省及邻近地区较大地震震级的测定方法

本文使用１９８６年至１９９１年期间沈阳遥测地震台网记录到的１４５３次地震的持续时间资料（２．０≤Ｍ＿Ｌ≤６．１级、５ｋｍ＜△＜１０００ｋｍ），求得了辽宁省及其邻近地区多台多幅度持时震级的经验公式，结果表明，这种震级误差小，应用范围为Ｍ＿Ｌ≤６．０级，解决了限幅地震无法计算震级的难题．     

赤道太平洋上厄尔尼诺的影响对大气二氧化碳聚集的贡献

在１９９２年北方的春季和秋季、１９９３年的春季、１９９４年的春季和秋季以及１９９６年的春季和秋季这两个野外季节,获得了一整套大气和海洋表层二氧化碳分压（ｐＣＯ２）测量结果及有意义的水文数据。１９９２～１９９４年的春季航次是在温暖的厄尔尼诺／南方波动事件期间进行的,秋季航次是在“冻舌”条件下进行的。东赤道太平洋具有高海水ｐＣＯ２和赤道底流上涌造成的高养分浓度的特征。这种水团由向西流动的南赤道流和上升的亚热带水混合而成,并由Ｅｋｍａｎ辐射沿着赤道向极地方向搬运。作为这些过程的结果,这个地区成为大洋内…     

夏威夷玄武岩的植物风化

含钙、镁硅酸盐矿物的风化是影响地质时期大气中ＣＯ２含量的一个重要过程。风化淅出的钙和镁在溶液中被搬运到海洋里,并在那里作为碳酸盐沉淀下来。不同地质时期化学风化作用受地壳运动引起的陆地面积、位置和地形的变化、全球气候的变化、岩石类型暴露的变化和生物进化...     

煤层气开发井网优化设计--以新集矿区为例

以新集矿区为例,系统地研究了煤层气开发井网设计的具体内容及工作程序。根据对新集矿区煤储层地质条件分析,确定了煤层气开发的目标煤层以及布井间距设计原则;通过煤储层数值模拟的产能预测,确定了煤层气开发的井网布置样式;在产能预测的基础上,结合经济分析,优化了煤层气开发的布井间距,进而提出了新集矿区首期煤层气开发布井方案,并进行了产能预测。指出新集矿区煤层气开发应采用地面垂直井、采动区煤层气开发以及井下瓦斯抽放等多种开发方式综合并举的形式。