中国东部第四纪自然环境演化及庐山“冰碛层”堆积时期的自然环境研究

根据第四纪地层内孢粉组合和动物群等新资料恢复了我国东部各大区域第四纪各个时期的自然环境特征,其温暖期与干冷期的交替与深海沉积O~(18)温度变化趋势大致对应。庐山三次“冰期冰碛层”内孢粉组合表明均为温暖湿润针阔叶混交林景观,而不是寒冷的冰川环境。     

流体包裹体成分测定的低温相变和显微拉曼光谱分析技术研究进展

论述了包裹体低温分析技术的原理以及进展。传统的流体包裹体低温分析技术是以显微冷冻测温测定无机盐体系为主,目前已发展到应用低温原位拉曼光谱技术对包裹体中的阳离子和阴离子进行定量-半定量分析。油气包裹体原位低温分析技术也取得了较大的突破,对不同成分油气包裹体低温下的相变过程取得了一定的认识,据此对油气包裹体进行分类,推测其主要成分,为油气包裹体计算提供基础参数。     

藏南白垩系黑-红层沉积岩有机质组成分布特征

对藏南江孜县床得剖面白垩系黑层和红层沉积岩进行的有机地球化学研究表明,黑层有机碳含量高于红层5～10倍,红层和黑层饱和烃主峰碳数分别为nC25和nC23;黑层和红层沉积有机质的母质来源都以水生植物和菌藻类等低等生物为主,陆源有机质的输入非常有限;但饱和烃的分布和主峰碳数的差异可能反映了有机母源物质在种群方面的差异,而这种差异可能主要是水体温度存在差异造成的,即红层发育时期水体温度可能高于黑层沉积时期.而在高温度条件下,水生生物和陆生植物的生长发育受到限制,造成原始有机质产率和有机质沉积保存量低可能是红层沉积岩形成的主要原因.     

Stable isotope study of the Archaean rocks of the Vredefort impact structure,central Kaapvaal Craton,South Africa

The Vredefort dome in the Kaapvaal Craton was formed as a result of the impact of a large meteorite at 2.02 Ga. The central core of Archaean granitic basement rocks is surrounded by a collar of uplifted and overturned strata of the Witwatersrand Supergroup, exposing a substantial depth section of the Archaean crust. Orthogneisses of the core show little variation in whole-rock δ ¹⁸O value, with the majority being between 8 and 10‰, with a mean of 9.2‰ (n = 35). Quartz and feldspar have per mil differences that are consistent with O-isotope equilibrium at high temperatures, suggesting minimal interaction with fluids during subsequent cooling. These data refute previous suggestions that the Outer Granite Gneiss (OGG) and Inlandsee Leucogranofels (ILG) of the core represent middle and lower crust, respectively. Granulite-facies greenstone remnants from the ILG have δ ¹⁸O values that are on average 1.5‰ higher than the ILG host rocks and are unlikely, therefore, to represent the residuum from the partial melting event that formed the host rock. Witwatersrand Supergroup sedimentary rocks of the collar, which were metamorphosed at greenschist-to amphibolite-facies conditions, generally have lower δ ¹⁸O values than the core rocks with a mean value for metapelites of 7.7‰ (n = 45). Overall, through an ∼20 km thick section of crust, there is a general increase in whole-rock δ ¹⁸O value with increasing depth. This is the reverse of what is normal in the crust, largely because the collar rocks have δ ¹⁸O values that are unusually low in comparison with metamorphosed sedimentary rocks worldwide. The collar rocks have δD values ranging from −35 to −115‰ (average −62‰, n = 29), which are consistent with interaction with water of meteoric origin, having a δD of about −25 to −45‰. We suggest that fluid movement through the collar rocks was enhanced by impact-induced secondary permeability in the dome structure. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

手掘式顶管在市政排水工程中的应用

从混凝土管材的选定、工作坑的设计及施工、顶管顶进中若干关键问题入手,介绍了手掘式顶管施工技术在成都市中心城水环境综合整治工程G标段管道排水工程中的应用。     

试论东海陆架盆地的基底构造演化和盆地形成机制

本文主要根据东海陆架盆地和周边的地质、地球物理资料,分析盆地的基底岩性特征、结构特征。认为东海陆架盆地的基底除元古界片麻岩外,还分布有一定范围的中生界及古生界。基底构造特征是纵向上多层次,横向上不均一,南北有别,东西分带。构造演化上经历了张、合、压、扭等复杂过程。     

Marine Ecology - A Century of Changes

Abstract. The major changes within the concepts of marine ecology are investigated, with the aim to design this new journal's scientific format. Four phases of marine sciences are distinguished: the phase of seafarers, of oceanographic expeditions, of marine stations, and of field research. The changes in the latter two are discussed in detail. The changes are described as occurring along three axes. First, as a movement towards the object; accomplished by fieldwork, scientific diving, remote controlled equipment, and by underwater experimentation. Second, the cooperation between several disciplines that led towards bridging gaps. And lastly, how the discovery of unifying principles in ecology (the development of an ecological theory) led the approach in marine ecology towards increasing complexity.     

0421号热带风暴"海马"登陆前后环境场对其移向和强度影响的分析

0421号热带风暴“海马(Haima)”于2004年9月13日12:00在浙江省温州市沿海登陆,登陆后迅速减弱为热带低压,20:00在浙江境内消失.本研究采用物理量诊断分析法,探讨该热带风暴登陆前后涡度场、湿焓场变化对其移向和强度的影响.结果表明,该热带风暴登陆后,涡度(ξ)明显减弱.涡度局地变化(ξ/t)值分布显示,风暴移动方向的后方,涡度减弱的趋势比前方涡度增大的趋势更剧烈;风暴有向其外围(ξ/t)正值中心(即涡度增幅最大)移动的趋势.该热带风暴登陆前、后,湿焓都增大,但登陆后湿焓增大趋势已大大减弱;风暴有向湿焓局地变化(E/t)正值中心移动的趋势,即向能量增强最大的方向移动.     

西太平洋暖池变异及其对西太平洋次表层海温场的影响

应用热带太平洋上层XBT温度资料,分析研究了西太平洋暖池区(0°～16°N,125°～145°E)上层海洋的变化特征以及与西太平洋次表层海温场之间的关系.研究表明,西太平洋暖池区的垂向温度存在显著的年际变化,尤其在次表层(120～200m)的变化最为明显.西太平洋暖池区的次表层冷暖信号明显早于西太平洋次表层的海温异常.分析发现,西太平洋暖池区的海温异常是导致整个西太平洋次表层海温场变异的关键区,当西太平洋暖池区的次表层冷暖信号加强时,3～4个月后西太平洋海温场出现大范围的冷暖异常.