Evolution of the luminosity function and colours of galaxies in a Λ cold dark matter universe

The luminosity function of galaxies is derived from a cosmological hydrodynamic simulation of a Λ cold dark matter universe with the aid of a stellar population synthesis model. At     , the resulting B -band luminosity function has a flat faint-end slope of     with the characteristic luminosity and the normalization in fair agreement with observations, while the dark matter halo mass function is steep with a slope of     . The colour distribution of galaxies also agrees well with local observations. We also discuss the evolution of the luminosity function, and the colour distribution of galaxies from     to 5. A large evolution of the characteristic mass in the stellar mass function as a result of number evolution is compensated by luminosity evolution; the characteristic luminosity increases only by 0.8 mag from     to 2, and then declines towards higher redshift, while the B -band luminosity density continues to increase from     to 5 (but only slowly at     .     

粗差发现和定位能力与相关系数的关系

根据粗差判断方程中的判断矩阵和两个统计检验量之间相关系数的函数式,论证了两种不同的研究方法所确定的粗差不能定位的数学模型实际上是相等的。通过算例,不仅说明两种研究方法对观测量不能定位粗差的判断是一致的,而且使用判断矩阵研究观测量的粗差发现和定位能力会更加方便简单。     

白云鄂博群中两个重要不整合界面特征及区域对比

白云鄂博群尖山组顶部的钙质风化壳和比鲁特组顶部的铁质风化壳分别代表长城系与蓟县系及蓟县系与青白口系的分界,并具较大区域上的一致性和可对比性。不整合界面的重新厘定,必然导致白云鄂博群的解体或改为白云鄂博超群。     

Application of extended distinct element method with lattice model to collapse analysis of RC bridges

This paper proposes a simple lattice model for collapse analysis of RC bridges subjected to earthquakes by using the extended distinct element method (EDEM). In the model, a concrete element consists of lumped masses connected to one another by springs, and a reinforcement bar is represented by a discrete model or an integrated model. The proposed lattice model is simple but its parameters are reasonably defined. It has fewer element nodes and connecting springs, which will be of benefit by shortening the CPU time. The processes to determine the initial stiffness of concrete and steel springs, the parameters of the constitutive model and the fracture criteria for springs are described. A re‐contact spring model is also proposed to simulate the re‐contact of the concrete after fracture of springs; and a general grid searching method is used to decrease the CPU time for judging re‐contact after fracture. The lattice model is assessed by numerical simulations and experiments. As an application, a damaged single‐column pier subjected to the Kobe Earthquake in 1995 is analysed by EDEM with the proposed model. The simulation results indicate that the proposed model predicts well qualitatively the collapse process of RC bridges. Copyright © 2003 John Wiley & Sons, Ltd.     

湘鄂赣二叠纪沉积盆地与层序地层

湘鄂赣二叠纪沉积盆地是在统一的陆愉－－华南陆块基础上发展而来的，根据晚古生代以来的地壳活动情况、沉积物充填序列、沉积相带及空间配置，该区可以划分为四种沉积盆地，即扬子克拉通盆地、扬子克拉通缘被动大陆边缘盆地、湘赣板内拉张盆地和华夏克拉能边缘盆地。由于没沉积盆地中层序发展的主控因素及上关效应的差异，从而决定了层序发育特点的差异，本文详细划分了各种沉积层序和沉积体系域，并进行了区域对比。在此基础上，探     

湘鄂赣二叠纪岩相古地理研究

湘鄂赣二叠纪沉积盆地是在华南陆块基础上发育而成，具有扬子克拉通北缘被动大陆边缘盆地，扬子克拉通盆地，湘赣板内拉张盆地和华夏克拉通边缘盆地等四类。根据古暴露等标志，建立了各类盆地的沉积层序，并进行了区域对比。     

甘肃敦煌-北山早前寒武纪岩石组合-构造初步框架

甘肃敦煌－北山地区广泛出露早前寒武纪岩石。这些岩石在早期的《甘肃省区域地质志》中被确定为前长城系、长城系、奥陶－志留系及部分石炭系。本文认为这些岩石应属太古宙和古元古代。据此，重新厘定了该区早前寒式纪岩石－构造框架。自南向北划分为敦煌太古宙杂岩区、北山南带古元古代剪切构造区和北山北带古元古代－太古宙杂岩区，并根据变形特点和岩石组合，进一步划分出次级带。     

藏南特提斯喜马拉雅带中段二叠纪-白垩纪的火山活动(Ⅰ):分布特点及其意义

在野外实地考察和追索的基础上，详细厘定了特提斯喜马拉雅带中段晚古生代以来火山岩的分布特点和迁移规律。结果表明，在特提斯喜马拉雅带中段晚古生代以来的地层系统中，从二叠纪→三叠纪→侏罗纪→白垩纪，共有11个层位含规模不等的火山岩，它们以透镜体、薄夹层或以块状玄武岩、玄武质安山岩等形式产出于不同地层系统中；从二叠纪→早中三叠世→晚三叠世→侏罗纪和白垩纪，具有由西向东、从南→北→南→北的迁移规律。这些火山活动的发现和厘定，对填补特提斯喜马拉雅带火山岩研究的空白，了解陆下岩石圈地幔和软流圈地幔之间的相互作用和新特提斯洋盆的形成演化都具有一定的指示意义。     

基于图形数据库NEO4J的政务空间信息融合研究

随着信息化测绘时代的快速发展,整个社会产生了大量的信息资源.从数据规模角度来说,政府拥有国内最为庞大的数据储量,掌握着大量的、权威的、关键的数据资源,是大数据时代的"财富"拥有者.整合图形数据库NEO4J自带的融合检索服务引擎,分析、整理、融合、统计这些数据,建立索引,提取有用信息,提供友好的查询服务界面,是在大数据时代背景下值得思考的问题.     

Geochemistry and Tectonic History of Seamount Remnants in the Xingshuwa Subduction Accretionary Complex of the Xar Moron Area,Eastern Margin of the Central Asian Orogenic Belt

This study focuses on the geology, geochemistry, zircon U-Pb geochronology and tectonic settings of the three types of seamount basalts from the Xingshuwa subduction accretionary complex in the Xar Moron area, eastern margin of the Central Asian Orogenic Belt(CAOB). The seamount remnants are composed of carbonate 'cap' sediments, large volumes of pillow and massive basalts, carbonate breccia slope facies and radiolarian cherts. Group 1 basalts are characterized by high contents of P2 O5 and TiO2 with alkaline affinity and LREE enrichment, indicating that they are derived from intraplate magma. Group 2 basalts display N-MORB LREE depletion patterns, indicating that they were formed at a mid-ocean ridge. Group 3 basalts have shown distinct Nb depletion and high Th/Yb ratios, indicating that they were generated in an island arc tectonic setting. The zircon U-Pb age of Group 1 basalt sample XWT18-131 is 576.4 ± 9.4 Ma, suggesting that the oceanic island seamount was the product of intraplate magmatism related to a mantle plume or 'hot spot' in the late Neoproterozoic. The zircon U-Pb age of Group 2 basalt sample XWT18-132 is 483 ± 22 Ma, indicating that the Paleo-Asian Ocean(PAO) was continuously expanding in the Early Ordovician. The zircon U-Pb age of Group 3 basalt sample XWT18-101 is 240.5 ± 8.2 Ma, suggesting that this area underwent the evolutionary path of ocean-continent transition, developing towards continentalization during the Middle Triassic. Thus, we believe that there was both mantle plume-related intraplate magmatism and intraoceanic subduction during the evolution of the PAO, the CAOB possibly being an evolutionary model of an intraoceanic subduction and mantle plume magmatism complex.