中国恐龙蛋化石及其生态地层浅析

文章系统地对中国恐龙蛋化石的地理分布作了总结,并将恐龙蛋化石类型归纳为９科,１３属,２１种。在此基础上,着重分析了恐龙蛋化石古生态特征,分别从蛋化石的排列方式,恐龙产蛋的方式,不同类型蛋化石间及蛋化石与骨骼化石共生几方面作了探讨,并进一步阐述恐龙蛋化石在晚白垩世地层划分对比所具有的直接指示意义     

高分辨率层序地层学

高分辨率层序地层学覃建雄田景春（成都理工学院沉积所）图１容纳空间与沉积物供给之间的关系由此产生的地层叠置型式描绘在容纳空间与沉积物供给的比较图中。图中相应的位置配有横剖面,说明单一沉积层序的各不同发展阶段。当容纳空间的增加是正值时,地层格架由沉积供给...     

综合地层学在山东省中生代地层研究中的应用

本文利用综合地层学理论,在研究过程中选用了多门类生物地层学、同位素年龄地层学和火山地层学、生态地层学和岩石地层学及沉积地层学、地震地层学和测井地层学等手段,对鲁北区,鲁西南区、鲁中区和鲁东区中生代地层进行了划分和对比。     

含煤岩系沉积学和层序地层学研究现状和展望

在对含煤岩系沉积系研究历史进行回顾的基础上,论述了含煤岩系层序地层学方法以及海平面变化与聚煤作用的关系。注重强调分布广泛的厚煤层实际上是在基准面或海平面的抬升过程中堆积的,煤层底面代表海泛面。     

A simplified fragility analysis of fan type cable stayed bridges

A simplified fragility analysis of fan type cable stayed bridges using Probabilistic Risk Analysis (PRA) procedure is presented for determining their failure probability under random ground motion. Seismic input to the bridge support is considered to be a risk consistent response spectrum which is obtained from a separate analysis. For the response analysis, the bridge deck is modeled as a beam supported on springs at different points. The stiffnesses of the springs are determined by a separate 2D static analysis of cable-tower-deck system. The analysis provides a coupled stiffness matrix for the spring system. A continuum method of analysis using dynamic stiffness is used to determine the dynamic properties of the bridges .The response of the bridge deck is obtained by the response spectrum method of analysis as applied to multidegree of freedom system which duly takes into account the quasi - static component of bridge deck vibration. The fragility analysis includes uncertainties arising due to the variation in ground motion, material property, modeling, method of analysis, ductility factor and damage concentration effect. Probability of failure of the bridge deck is determined by the First Order Second Moment (FOSM) method of reliability. A three span double plane symmetrical fan type cable stayed bridge of total span 689 m, is used as an illustrative example. The fragility curves for the bridge deck failure are obtained under a number of parametric variations. Some of the important conclusions of the study indicate that (i) not only vertical component but also the horizontal component of ground motion has considerable effect on the probability of failure; (ii) ground motion with no time lag between support excitations provides a smaller probability of failure as compared to ground motion with very large time lag between support excitation; and (iii) probability of failure may considerably increase for soft soil condition.     

宁镇山脉孔山地区栖霞组底部之新观察

本文论述的地层，系1961年在宁镇山脉之首次发现。我们将其划分为“独立”的地层小单元，其理论根据是：①地层中所含生物群独具特色，有Schwagerina tschernyschewi化石带；②沉积建造别具一格，以粉砂质页岩或石灰质页岩为主，并夹有灰岩层或透镜体，与其上覆、下伏地层均迥乎不同；③与下伏地层船山群之间，具有一明显的侵蚀面，与上覆栖霞组灰岩段之间为连续沉积，     

PCR引物设计

多聚酶链式反应（ＰｏｌｙｍｅｒａｓｅＣｈａｉｎＲｅａｃｔｉｏｎ，ＰＣＲ）又称无细胞分子克隆系统，是一种体外扩增特异ＤＮＡ片断的技术，１９８５年由美国Ｃｅｔｕｓ公司和加利福尼亚大学联合创建，是９０年代分子生物学领域的一项革命性突破，很快地在分子克隆、遗传病的基因诊断、法医学、考古学等方面得到了广泛应用。ＰＣＲ技术实际上就是在模板ＤＮＡ（ＴｅｍｐｌｅｔｅＤＮＡ）引物（Ｐｒｉｍｅｒ）和４种脱氧核糖核苷酸（ｄＡＴＰ，ｄＧＴＰ．ｄＣＴＰ，ｄＴＴＰ）存在的条件下依赖于ＤＮＡ聚合酶（Ｔａｑｓｅ）的酶促合成反应…     

文蛤属(Meretrix)16S rRNA基因及ITS1序列的系统学分析

利用线粒体16SrRNA基因片段及核糖体DNA转录间隔区ITS1序列分析的方法,以近缘属的青蛤(Cyclinasinensis)为外群,对文蛤属的文蛤(M.meretrix)、丽文蛤(M.lusoria)、帘文蛤(M.lyrata)和斧文蛤(M.lamarckii)4种贝类进行了系统学研究。经ClustalX多重比对及DNAsp软件分析后,用PAUP4.0分析软件,计算出种间序列的碱基转换/颠换频率,利用邻接法NJ构建系统发育树。结果表明,帘文蛤与该属其他三种的分歧时间较早,两类序列与其他种类间的相对遗传距离分别在0.25866—0.28218和0.15644—0.20104之间。文蛤与丽文蛤间的16SrDNA及ITS1序列间的遗传距离仅为0.04805和0.04201,拓扑结构图显示关系很近,并且二者的分布区大面积重叠,其序列间的转换/颠换频率接近种内单元型(haplotype)间的序列变化,鉴于它们的贝壳形态有一定差别,应归为同一个种内的不同地理亚种比较恰当。