地学长江计划安徽实验中低频可控震源地震波信号提取方法评估

可控震源的激发过程精确可控、可重复性高。本文评估了重复激发形成的多道记录的信号增强方法,包括叠加方法和有效信号直接分离方法。相比线性叠加,加权叠加充分利用了有效信号的一致性,能进一步压制噪声,提高叠加记录的信噪比。相比时间域相位加权叠加,Semblance加权叠加更加稳定。时频域相位加权叠加能在时频域压制随机分散分布的噪声信号,叠加信号更加清晰。本文中,采用标准SVD分离获得的信号同线性叠加结果类似。本文利用密集分布的临时台阵评价地学长江计划安徽实验中低频可控震源在庐江第2激发点的激发效果。对比不同的处理流程发现,先互相关检测信号再进行时频域相位加权叠加能够取得最佳的处理效果,通过200多次重复激发,可以在50km范围内提取到较清晰的有效信号。     

Chemical weathering in Luzon, Philippines from clay mineralogy and major-element geochemistry of river sediments

Clay mineralogy and major-element geochemistry of 35 surface sediment samples collected in 21 major to moderate rivers of Luzon, Philippines are used to evaluate the present chemical weathering process. The clay mineral assemblage consists mainly of smectite (average 86%) with minor kaolinite (9%) and chlorite (5%) and very scarce illite (1%), and does not show strong island-wide differences. The major element results of both bulk and clay-fraction sediments indicate that the formation of clay minerals is accompanied by leaching of Ca and Na first and of Fe and Mn thereafter during the chemical weathering process. A low-moderate chemical weathering degree of bulk sediments and a moderate-intensive degree of clay-fraction sediments are obtained in Luzon rivers based on proxies of chemical index of alteration (CIA) and smectite crystallinity. It is suggested that the majority of andesitic–basaltic volcanic and sedimentary rocks along with the tectonically active geological setting and sub-tropical East Asian monsoon climate are responsible for the predominance of smectite in the clay mineral assemblage.     

基于CWSEI的地理信息系统课程教学改革探索

针对地理信息系统课程教学实践中表现出的“知识内化程度有待提高”,借鉴卡尔·韦曼科学教育改革理念与方法,探索以学生的“学习目标”为课程教学的出发点,反推教学设计的改革思路。立足“以生为本”理念,提出GIS课程改革五步法：可量测的学习目标—预期的学习效果—以促学为目的的阶段测试—有趣有效的课堂活动—精心设计的第一次课。以河南理工大学测绘工程专业的GIS课程为例,制定详细的教学改革方案,以期提升GIS课程教学效果,并为类似课程改革提供参考。     

西藏北部新生代大型逆冲推覆构造与唐古拉山的隆起

西藏北部唐古拉山地区新生代发育一大型逆冲推覆构造,推覆构造带走向与唐古拉山脉延伸方向一致,主体呈NW-SE向展布,由北部乌兰乌拉湖—巴庆构造带(锋带)、雀莫错—改纳构造带(中带)和南部各拉丹东—鄂碎玛构造带(根带)构成,构造样式上由根带到锋带表现为:高角度叠瓦逆冲构造、褶皱—逆冲构造和中低角度叠瓦逆冲构造,逆冲推覆运动方向由南西向北东,并在推覆构造带北侧发育新生代沱沱河前陆盆地。同构造岩浆侵入体同位素年代学和前陆盆地沉积充填序列演化表明,推覆构造形成时限为67.1～23.8Ma。推覆构造形成演化受控于印度—欧亚板块碰撞造山和其后印度板块持续向北俯冲动力学体制,并造成唐古拉山地区地壳在始新世—渐新世的强烈缩短、增厚和唐古拉山脉的隆起。     

Bioassay-guided extraction of crude fucose-containing sulphated polysaccharides from <Emphasis Type="Italic">Sargassum fusiforme</Emphasis> with response surface methodology

The response surface methodology (RSM) combined with bioassays was employed to optimize the extraction process of crude fucose-containing sulphated polysaccharides (cFCSP) from Sargassum fusiforme. The central composite design (CCD) was used with four variables, five levels, and four responses. The four variables were pH value of hydrochloric acid solution, extraction temperature (°C), ratio of liquid to raw material (mL g^?1), and extraction time (h), respectively. Chemical and bioassay indices were used in combination as the response parameters, which included the yield of cFCSP, fucose content, proliferation rate of spleen cells, and lipopolysaccharide-induced proliferation of splenocytes. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis, and examined using the appropriate statistical methods. The best extraction conditions were as follows: the pH value of hydrochloric acid solution was 3.50; the extraction temperature was 100°C; the ratio of liquid to raw material was 15.00 mL g^?1 and the extraction time was 2.50 h. The experimental yield was close to the predicted from the model. The extract could promote spleen lymphocyte proliferation, especially the lipopolysaccharide-induced lymphocyte proliferation in vitro, which suggested that its immunomodulatory effect on B lymphocytes. Therefore, cFCSP extracted from S. fusiforme could be utilized as an immunostimulant in functional foods and pharmaceutical industry in future.     

Origin, diversification, and relationships of Cambrian lobopods

As an extinct group, the origin, diversification and relationships of Cambrian lobopods have long been one of the most hotly-debated subjects. Lobopods used to be regarded as closely related to modern onychophorans and tardigrades, but the similarities are based on the few species of Cambrian lobopods and often on a fairly general level. With the discovery of new creatures and based on new observations on fossil lobopods, we consider that Cambrian lobopods show great diversity and reveal a close relationship between Cambrian lobopods and arthropods. In addition, comparison between the dorsal spines of Cambrian lobopods and small shelly fossils suggest that Cambrian lobopods might have originated from the Meishucun radiation and diversified in the Qiongzhusi radiation.     

底基三脚架在深海观测中的应用

底基三脚架是海底观测的平台之一,它能装备多种观测仪器,长期、稳定地立于海底,进行几乎无干扰的原位观测.底基三脚架已成功应用于深海化学、物理、生物和地质过程的现场观测,取得了大量的重要成果,但在我国的深海研究中还未开展.简述了底基三脚架的概念和发展历史、工作原理、应用及前景等,希望引起我国海洋工作者的兴趣和关注,推动底基三脚架在我国深海观测中的应用和发展.     

Distribution,Compositions and Significance of Oceanic Red Beds

Oceanic red beds are widely distributed in the global oceans and across the entire Phanerozoic period, which mostly appeared after oceanic anoxic events. They represent typical oxygen-rich sedimentary environment and play a significant role on ocean science research. Numerous studies have been carried out since the oceanic red beds were discovered. However, previous studies mainly focused on the Cretaceous oceanic red beds, and the understanding of the characteristics and scientific significance of oceanic red beds are not comprehensive. Therefore, we here summarized the global distribution characteristics and compared mineral and element compositions of various lithological oceanic red beds, including marly, clayey and cherty oceanic red beds. The main mineral and element components of oceanic red beds have no direct relationship with the color of the sediments, and mainly are affected by the regional environment and provenances. Therefore, the mineralogical and geochemical characteristics of oceanic red beds should be analyzed in combination with the regional background. The red coloration of oceanic red beds is controlled mainly by hematite, goethite and manganese-bearing calcite, which have two main mechanisms: ① Colored minerals formed in oxic conditions; ② Colored minerals formed due to low deposition rates. These two mechanisms are not completely independent, but complement one another with either dominance in most oceanic red beds. Lithological characteristics of oceanic red beds are controlled by three factors, including water depth, productivity and nutrients. Therefore, the formation of oceanic red beds should be considered with global changes and regional events. The unique origin mechanism and global distribution characteristics of long time-scale oceanic red beds can be used to indicate sedimentary paleoenvironment, paleo-oceanic current, and paleoclimate change. In addition, hydrothermal or magmatic activities on the ocean floor could also produce red-color deposits that are strongly different from sedimentary oceanic red beds. Based on the existing research, we also put forward the future in-depth studies on the oceanic red beds from multidisciplinary perspectives.     

宁东煤田红墩子矿区沉积环境对煤岩煤质的影响

为了揭示沉积环境对煤岩煤质的影响,以宁东煤田红墩子矿区为研究区,采用沉积学和煤岩学等方法对太原组和山西组层序进行了划分,结合煤岩煤质数据,探讨了沉积环境对煤岩煤质的影响。研究结果表明:层序Ⅰ、层序Ⅱ煤层受海水潮汐作用影响,整体上硫分含量较层序Ⅲ高,镜质组和惰质组含量较低,平面上,灰分、硫分呈现出南高北低的规律,镜惰比则出现南低北高的现象;层序Ⅲ煤层受河流及物源的共同影响,高灰煤、高硫煤主要集中在矿区的南北两端,镜惰比则由于河流作用导致沼泽水动力强弱及覆水稳定的变化,出现南高北低的现象。     

可可西里盆地瘭生代沉积演化历史重建

青藏高原北部可可西里盆地是高原腹地最大的第三纪沉积盆地，分布着厚度达5737.5m的新生代沉积。本文根据遍布整个盆地的野外实测剖面和地质观察点资料，采有典型剖面精确古地磁测年为基础的时间框架，开展沉积层序、岩笥特征、沉环境和古水流变化综合对比研究，将可可西里盆地新生代（约56Ma至约16Ma）划分为7个演化阶段，其中在30Ma至约23Ma期间盆地经历抬升变形，没有沉积作用发生。结果显示，前6个阶段（约56Ma至30Ma），盆地沉积中心逐渐向北、向东迁移，盆地南缘和西缘的构造逆冲作用逐步加强，而且在晚渐新世发生强烈南北向地壳缩短，反映青藏高原腹地早期隆升过程中依靠南北向地壳缩短和北东向逆冲扩展作用来实现的。在早中新世（约23Ma至约16Ma），盆地沉积物遭受低度变形，表明此期间高原以差异隆升为主。