贵州施秉白云岩溶蚀特性及孔隙特征实验研究

以贵州施秉白云岩为研究对象,从宏观和微观角度分析白云岩的溶蚀特性及孔隙特征,结果显示:(1)在众多影响施秉喀斯特发育的因素中,矿物成分是最基本的内因,水是最关键的外因,孔隙结构起辅助作用。(2)极细晶白云岩的单位表面积溶蚀量一般大于细晶白云岩的,在晶粒相同的情况下,白云岩的溶蚀量与Ca O和Mg O的含量分别成正比,且Mg O的含量影响较Ca O大。(3)施秉白云岩溶蚀速率不仅受岩石矿物颗粒粒径大小的控制,还受岩石内部孔隙结构特征的影响,颗粒粒径越大,孔隙度越高,连通性越好,越有利于水溶液进入,溶蚀量也就越大。(4)施秉白云岩的溶蚀特性是多种因素综合作用的结果,必须把各个因素分离开来,从宏观和微观角度逐个作详细的分析研究,然后综合起来,才能对喀斯特发育规律有更深入的了解。     

热带海气相互作用波及其不稳定性

本文利用一个简单的海气耦合模式,讨论了热带海洋和大气中Rossby波的相互作用。结果指出,海洋和大气中向西传播的Rossby波耦合后,不仅存在着向西传播的波动,而且还可以产生一类向东传的新波。这种向东传播的波动出现在波长较长的波段范围内,这个范围的大小受海气相互作用强度的制约。另外,波动可以出现不稳定性,向西和向东传的波均有不稳定现象发生,不稳定增长率也受海气相互作用强度的制约。最后,根据所得到的海气相互作用波,对ENSO现象作了一个可能的解释。     

琼东南盆地华光凹陷天然气水合物稳定带厚度的影响因素

为了探讨琼东南盆地华光凹陷海底天然气水合物稳定带的分布规律,定量研究了静水压力、底水温度、地温梯度和气源组分对水合物稳定带的影响程度。在此基础上,分析了华光凹陷现今甲烷水合物稳定带的厚度分布。最后,综合各因素的历史演化过程,初步探讨了华光凹陷1.05 Ma BP以来天然气水合物稳定带的演化。结果表明:(1)气源组分和海底温度的变化对研究区内水合物稳定带的影响较大;水合物稳定带厚度与海底温度呈良好的线性负相关性。(2)水深超过600 m的海域具备形成天然气水合物的温压条件;超过600 m水深的海域水合物稳定带厚度大部分超过 100 m,其中西北部稳定带的最大厚度超过300 m,是有利的水合物勘探区。(3)华光凹陷1.05 Ma BP以来天然气水合物稳定带厚度经历了快速增厚–窄幅变化–快速减薄和恢复的过程。麻坑群与水合物稳定变化敏感区在空间上具有较好的叠合关系。结合前人的研究成果,推测其形成与天然气水合物的分解释放有关。     

A DIAGNOSTIC ANALYSIS OF AIR TEMPERATURE ANOMALY MODE OVER CHINA IN 2009/2010 WINTER BASED ON GENERALIZED EQUILIBRIUM FEEDBACK ASSESSMENT (GEFA) METHOD

By using the observed monthly mean data over 160 stations of China and NCAR/NCEP reanalysis data, the generalized equilibrium feedback assessment(GEFA) method, combined with the methods of EOF analysis, correlation and composite analysis, is used to explore the influence of different SST modes on a wintertime air temperature pattern in which it is cold in the northeast and warm in the southwest in China. The results show that the 2009/2010 winter air temperature oscillation mode between the northern and southern part of China is closely related to the corresponding sea surface temperature anomalies(SSTA) and its associated atmospheric circulation anomalies. Exhibiting warming in Northeast China and cooling in Southwest China, the mode is significantly forced by the El Nio mode and the North Atlantic SSTA mode, which have three poles. Under the influence of SSTA modes, the surface northerly flow transported cold air to North and Northeast China, resulting in low temperatures in the regions. Meanwhile, the mid-latitude westerlies intensify and the polar cold air stays in high latitudes and cannot affect the Southwest China, resulting in the warming there.     

计算机互联网上时间传递的一种设计方案

目前,国内外时间传递方式主要有长波授时、短波地、电话授时、双星比对、ＧＰＳ时间信息等。信息产业的不断发展,使得互联网络已成为一种新的信息传递手段和资源共享方式 。通过计算机网络传输标准时间、频率将是授时领域的新课题,也是时间同步的新手段。讨论了计算机互联网上时间传递的一种设计方案,给出利用计算机网络系统实现标准时间的传递的具体方法,并介绍一种计算机互联网时间传递软件的使用方法等。     

沉积物中硬质粘土层的研究进展

大量的钻孔资料表明,平原地区及其海域沉积物中普遍有硬质粘土层的存在。硬质粘土层在工程地质、地理学研究等方面具有重要的价值,它不仅是高层建筑的持力层,而且是研究全球环境变化事件、古气候演变的良好载体。该文阐述了硬质粘土层的一般特征、成因以及在粒度、地球化学元素、年代学、沉积环境等方面的研究进展,并展望了硬质粘土层在年代、物质来源和沉积环境等方面的研究方向,认为黄河三角洲硬质粘土层研究较少,需要开展大范围的、系统深入的、多学科的宏观和微观综合分析,挖掘硬质粘土层蕴含的古环境意义和应用价值。     

基于移动网络的端到端密钥协商协议

虽然3G网络的安全机制扩展到核心网络,但是并没有实现端到端安全.基于自生成证书公钥密码体制,设计一种端到端密钥协商协议,只需要一个消息交换就可以建立安全的三方会话密钥.安全性分析结果表明:基于移动网络的端到端密钥协商协议能够解决密钥管理及第三方无举证窃听,与其他密钥协商协议相比,具有较好的安全性,为端到端加密在移动通信系统中的大规模应用提供基础.     

Microbial Diversity in Nankai Trough Sediments at a Depth of 3,843 m

Dense populations of bivalves, primarily Calyptogena sp., were observed at cold seeps of the Nankai Trough. Bacterial input to the sediment was estimated through determination of phospholipid ester-linked fatty acid (PLFA) and DNA profiles. Results indicated a bacterial biomass of 10⁹ cells (g dry wt)^-1 while individual fatty acid profiles revealed a predominance of monounsaturated fatty acids, mainly 18:1 isomers. The presence of these fatty acids can be interpreted to reflect a response to low temperature and a predominance of psychrophilic bacteria. DNA fragments encoding bacterial ribosomal RNA small-subunit sequences (16S rDNA) were amplified by the polymerase chain reaction method using DNA extracted directly from the sediment samples. From the sequencing results, at least 19 kinds of bacterial 16S rDNAs related to mostly the Proteobacteria and a few gram-positive bacteria were identified. These results suggest that the bacterial community in the Nankai Trough sediments consists of mainly bacteria belonging to the Proteobacteria , , and subdivisions. Bacteria belonging to the and subdivisions, which are known to include epibiont and sulfate reducing bacteria, respectively, were mostly detected in the sediment obtained from inside the area of the Calyptogena community, and the -Proteobacteria may function to supply reduced sulfur to bacterial endosymbionts of Calyptogena.     

Rock magnetic properties and palaeomagnetic results of sediments from a stone implement layer in the Bose Basin,Guangxi

Directional samples were taken to study rock magnetism and palaeomagnetic records from the Dong- sheng profile, which is 5 m thick and on the northwest edge of the Bose Basin. Mineralogy and rock magnetism of typical samples indicate that coarse granular titanomagnetite, and fine-grained hematite, superparamagnetic maghemite formed by pedogenesis are in the sediment, which has undergone many transformative processes during different stages of pedogenesis. Parallel samples were taken for thermal demagnetization (TH) (0 to 680℃) and alternating field (AF) demagnetization (0 to 80 mT) respectively. Experimental results of these two kinds of demagnetization illustrate that there are two or more magnetic components in the samples. Intensity of NRM decreases by almost 60% to 90% rapidly when the temperature ranges from 100℃ to 350℃, with a steady magnetic component. It is impossible to analyze the magnetic components at high temperature because those fluctuate widely when the temperature is higher than 400℃. Steady magnetic components from 100℃ to 350℃ indicate that the remanence was mainly carried by fine-grained hematite formed by pedogenesis, reflecting a change in the geomagnetic field while the magnetite was being oxidized into hematite by chemical weathering after deposition. The formative age of the sediments cannot be obtained by magnetic methods in this profile.     

Mid-Late Neoproterozoic rift-related volcanic rocks in China: Geological records of rifting and break-up of Rodinia

Early Cambrian and Mid-Late Neoproterozoic volcanic rocks in China are widespread on several Precambrian continental blocks,which had aggregated to form part of the Rodinia supercontinent by ca.900 Ma....