利津洼陷沙四上亚段深部砂岩的成岩环境演化

为研究利津洼陷沙四上亚段深部砂岩成岩环境,对岩心样品进行偏光、荧光、阴极发光显微镜和扫描电镜观察,辅以粘土矿物含量、元素含量测试.识别出酸性和碱性2种成岩环境,酸性环境以硅质沉淀、碳酸盐矿物溶解、长石溶解或蚀变为高岭石等现象组合为标志,碱性环境以碳酸盐矿物沉淀、长石次生加大、石英溶解等现象组合为标志.总体演化为:同生期,原始沉积流体造成碱性环境;早成岩期,未熟有机质演化形成短期的酸性环境,继承流体形成主体的碱性环境;中成岩A1期(埋深约2700～3200m),有机质成熟形成酸性环境;中成岩A2期(埋深约3200～4200m),深部断裂活动形成碱性环境;中成岩B期(埋深约4200～4400m),第二期充注油气的热演化形成酸性环境.     

C_4植物的出现与全球环境变化

C4 光合作用途径 (C4 植物 )的出现和随后的扩展 ,是发生在新生代晚期的重大事件。这一事件是晚新生代全球环境演化的产物。C4 植物在某些生态系统中占据主导地位 ,又通过食物链 ,影响了动物 ,特别是食草动物的演化。以C4 植物为主的干草原环境甚至与人类的起源有着某种成因上的联系。C4 植物的出现对中新世以来全球环境变化和现代环境格局形成过程具有特殊的意义。文中就C4 植物出现和扩展的时间、C4 植物的分布和生态特征、C4 植物出现的环境背景、构造运动 ,特别是印度和欧亚板块碰撞以及由青藏高原强烈隆升引发的侵蚀作用和大气组分变化及其与C4 植物出现的联系等问题作了较为系统的综述。文章还介绍了中国北方现代草本植物的δ13 C值的最新研究结果 ,并就草本植物δ13 C值与环境参数之间可能的关系进行了初步讨论。     

四维地震资料处理及其关键

四维地震利用时延三维地震资料的差异来解释地下储层流体的变化，时延地震资料的差异除了受地下储层流体因素的影响外，还受采集和处理因素的影响。为了尽可能的减少或消除由非储层因素所引起的差异，四维地震资料处理总的要求是相对振幅保持处理，高信噪比处理和一致性处理，一致性处理是四维地震资料特有的处理，其一般处理原则是：（１）调查影响四维地震资料非穗生的原因；（２）保持处理流程的一致性；（３）尽量保持相同的偏移     

Conceptual design studies of the 5 m terahertz antenna for Dome A,Antarctica

As the highest, coldest and driest place in Antarctica, Dome A provides exceptionally good observing conditions for ground-based observations over terahertz wavebands. The 5 m Dome A Terahertz Explorer （DATES） has been proposed to explore new terahertz windows, primarily over wavelengths between 350 and 200 pm. DATE5 will be an open-air, fully-steerable telescope that can function by unmanned operation with remote control. The telescope will be able to endure the harsh polar environment, including high altitude, very low temperature and very low air pressure. The unique specifications, including high accuracies for surface shape and pointing and fully automatic year-around remote operation, along with a stringent limit on the periods of on-site assembly, testing and maintenance, bring a number of challenges to the design, construction, assembly and operation of this telescope. This paper intro- duces general concepts related to the design of the DATE5 antenna. Beginning from an overview of the environmental and operational limitations, the design specifications and requirements of the DATE5 antenna are listed. From these, major aspects on the conceptual design studies, including the antenna optics, the backup structure, the pan- els, the subreflector, the mounting and the antenna base structure, are explained. Some critical issues of performance are justified through analyses that use computational fluid dynamics, thermal analysis and de-icing studies, and the proposed approaches for test operation and on-site assembly. Based on these studies, we conclude that the specifications of the DATE5 antenna can generally be met by using enhanced technological approaches.     

A critical review of groundwater budget myth, safe yield and sustainability

The principle of water balance is well known, but its application often causes controversy. One recent debate is the use of the water balance equation to determine the safe yield and sustainable yield. Two extreme opinions exist on natural groundwater recharge. One misconception is that the development of groundwater is considered to be safe if the pumping rate does not exceed the rate of natural recharge. Another is that the sustainable pumping rate has nothing to do with natural recharge, but depends on the increased recharge and decreased discharge (called capture) induced by pumping. The truth is that both the natural recharge and dynamic development of the capture determine the safe yield or sustainable yield of a groundwater basin. This paper clarifies the water budget controversy and uses the water balance equation to critically analyse the concepts of safe yield and sustainable yield. Numerical simulation of a hypothetical case was used to demonstrate the natural groundwater balance, effects of pumping and the dynamic development of the capture.     

哈萨克斯坦卡帕尔-阿拉善4号井氦气（He）含量映震特征

介绍了哈萨克斯坦卡帕尔-阿拉善4号井的水文地球化学环境,分析其17年氦气（He）含量变化映震特征,氦气（He）变化的地震前兆异常表现为：上升（或下降）幅度、速率变化超出正常范围,具有较好的重复性,测值遵循的是,背景值－趋势性上升（或突升）,趋势性下降（或突降）－恢复至背景值的变化过程。将该井氦气（He）观测数据经过滤波、差分处理后,以3倍均方差作为异常识别标准,结果表明：氦气（He）对监测点周围300km范围5级地震、400km范围6级地震的对映率分别为100％、66．7％,是较好的地震前兆手段之一。     

Molecular fossil and paleovegetation records of paleosol S4 and adjacent loess layers in the Luochuan loess section, NW China

Using gas chromatography-mass spectrometry (GC-MS) technique, a series of biomarkers were identi- fied, including n-alkanes, n-alkane-2-ones, isoprenoid etc. from the loess-paleosol samples collected from the S4 and adjacent L5, L4 of the Luochuan loess section, Northwestern China. Based on these data, especially n-alkanes and high-resolution magnetic susceptibility and grain size data, the pa- leoenvironment and paleovegetation history during S4 was reconstructed. The CPI (Carbon Predomi- nance Index) and correlation between n-alkanes and magnetic susceptibility and grain size data dem- onstrated that the molecular fossils in paleosol and loess layers can reflect the vegetation condition during the loess-paleosol formation, if the allochthonous organic inputs could be excluded reasonably. The ACL (average chain length) index is correlated well with paleomagnetic susceptibility and grain size variations, displaying their good synchrony with warm and humid climate. However, it relatively lagged behind the paleomagnetic susceptibility and the grain size variations when the climate began to deteriorate. During the formation period of paleosol, the n-alkanes was dominated by C31 homologue, indicating that the primary organic input originated from herbs. Our study also demonstrated that the herbs were more flourish than wood plants in Loess Plateau, especially in the Luochuan area during the warm and humid phase, and there was no typical forest vegetation developed in the studied period.