Mobility Sequence of Chemical Elements During Loess Weathering—Pedogenesis,Weinan,Shaanxi Province,China

The distribution of chemical elements in the Weinan loess section shows that: (1) carbonate is the critical constituent affecting loess chemistry. The leaching of carbonates may cause “apparent” enrichment of some other constituents. (2) CaCO₃, SiO₂, FeO, MgO, K₂O and Na₂O are mobile while Al₂O₃, Fe₂O₃ and TiO₂ are inert components. The mobility sequence may follow the order of CaCO₃>FeO>MgO>Na₂O>K₂O>SiO₂>Al₂O₃>TiO₂>Fe₂O₃. (3) No obvious migration is noticed of iron, except changes in valence and forms, during the pedogenic process. Little iron has been supplied to paleosol from precipitation. (4) Carbonates and, to a lesser extent, iron are most sensitive to, and can be therefore used as good indicators of, environmental changes. This research project was financially supported by the National Natural Science Foundation of China (Grant No. 49672137).     

地-井电磁成像的灵敏度分析

本文着重讨论地—井电磁成像的灵敏度,包括不同观测分量、不同观测位置和不同工作频率的灵敏度函数的分布,为成像系统的布置和数据解释提供理论上的指导     

基于粗糙集和遗传算法的超光谱波段集合整体缩减

提出一种对高光谱遥感影像波段集合进行整体缩减的方法。该方法首先根据模糊集和粗糙集理论,对原光谱波段集会进行近似等价波段区间的自动划分。对于每个近似等价波段区间,在考虑其他区间合成影像数据影响的情况下,利用遗传算法进行合成权系数的优化。实验表明,整体迭代线性合成方法不仅具有较高的计算效率,而且可以获得比独立线性合成方法明显优化的结果。     

中国西部大尺度流域建立分带式融雪径流模拟模型

针对中国西部大尺度流域利用遥感信息进行的融雪径流模拟模型建立过程,提供以数字地形因子分析为手段的分区,分带方法。在ＮＯＡＡ／ＡＶＨＲＲ卫星云图为主要监测信息源的前提下,应用支持软件,解决了图像纠正,图形转为图像后再与图像匹配等问题。同时,根据研究得出雪象元之阈值,使用监督分类的训练样本方法统计出流域内雪盖面积及各带的雪盖面积百分比。作为应用和检验,对黄河上游的曲什安流域进行样本操作,分３个垂直带各     

鄂尔多斯盆地下奥陶统碳酸盐岩有机相类型及生烃潜力

对鄂尔多斯盆地下奥陶统马家沟组碳酸盐岩的各种沉积环境的有机相特征进行了研究,结果表明平均有机碳丰度最高的是陆缘斜坡相碳酸盐岩(0.26%),其次是膏盐湖(0.22%)、膏云坪(0.21%),而开阔海、云坪和滩等环境的碳酸盐岩有机碳平均含量较低(<0.20%);碳酸盐岩干酪根样品多数为富氧、贫氢,显示其有机质类型较差;岩石地球化学特征和生物化石特征反映出陆缘斜坡处于相对还原的环境,而其他沉积环境则为氧化环境。鄂尔多斯盆地下奥陶统的大部分碳酸盐岩处于生烃潜力较差的C～D相。从有机质数量、有机相类型来判断,鄂尔多斯盆地下奥陶统碳酸盐岩不是好烃源岩,难以形成具有一定规模的气田。     

一次冷涡过程降水的微物理机制分析

该文分析了一次冷涡天气过程中云微物理量的分布特征、降水粒子的增长机制及云下雨滴的蒸发效应。主要结果为:云系由低层暖性Sc云和冷性主体As云组成。As云底高2 km,云顶高大于5 km,云中存在比较大的过冷水区,–11.2 ℃时的过冷水含量0.21 g·m-3,但过冷水的含量分布极不均匀,大于0.05 g·m-3的过冷水区连续分布的宽度87%小于2.4 km,不利于云中冰晶的连续凇附增长;同时云下雨滴的蒸发效应大,直径小于1.0 mm的雨滴难以落到地面,因此本次过程只产生弱的降水。     

材料研究与制备过程中的几个矿物学岩石学问题

在材料的研究与制备过程中往往会遇到很多有趣的矿物学、岩石学问题。这些问题有些是矿物学工作者和材料研究者所熟悉的,是材料研究者直接利用了矿物学工作者的研究成果。而有些问题是材料研究者首先发现,并将其中的某些条件加以利用,但缺少深入的矿物学理论研究;还有些工作是矿物学工作者得到的矿物学纯理论研究成果,但却不知如何应用到材料的开发与研究中。这就造成了介于矿物学与材料学之间的一个薄弱环节。这个薄弱环节为矿物、岩石工作者提供了一个广阔的研究领域和很多富有诱惑力的崭新的研究课题。于是一个新的分支学科———矿…     

Coupling between metallogenesis of the Cryogenian Datangpo-type manganese deposit in South China and major geological events

The exploration of the Cryogenian manganese deposits in the Datangpo Formation of South China has achieved great progress in recent years. It is concern in the long term there are many studies on this manganese deposits due to its particularity in the temporal and spatial distribution and the mineralization background. In this paper,we systematically summarize the previous achievements on the Datangpo-type manganese deposits. Besides,we also review current findings of Neoproterozoic global geotectonics,palaeoclimate evolution,ancient marine chemistry,and microbial evolution etc. The possible linkage between the massive metallogenesis of the Cryogenian Datangpo manganese deposits in the South China and Neoproterozoic major geological events is established. The break-up of Rodinia supercontinent led to the widespread rift basin systems in the world since the Middle Neoproterozoic. The Nanhua Basin in South China,which is a manganese-forming sedimentary basin,developed from the rift basin. The rift basin provided space for manganese deposits and controlled the distribution of manganese deposit. The hydrothermal activities at the bottom of the basin provided favorable manganese source. During the Neoproterozoic ice period(“Snowball Earth”event),global ice-sheets cut off or hindered exchanges of mass and energy between different spheres of Earth,which may lead to the widespread anoxic condition in the ice age ocean. The palaeoclimate changes during the glacial-interglacial period led to the disappearance of ice-sheets and the triggering of mass and energy exchanges between different sub-systems of Earth,followed by the variation of redox condition of the ancient sea. For the Nanhua Basin,the oxidation of surface water and the oxygen-bearing base flow provided the oxidation environment for the precipitation of manganese. Besides,new evidence indicated that manganese microbiological mineralization was the potential mechanism for manganese deposit under the microbial resuscitation condition during the interglacial period. All these major geological events have complicated connections and they provided essential metallogenic conditions for the sedimentary mineralization of “Datangpo”manganese deposit. It is believed that there is a coupling between the sedimentary metallogenesis of the Cryogenian Datangpo-type manganese deposit in South China and Neoproterozoic major geological events.     

云南5月降雨量与前期季节内振荡活动相互关系的分析研究

云南地处低纬高原,受南亚季风影响,其5月降雨量的多寡基本表征了这一地区雨季开始的早晚,对该地区的农业生产有着重要的影响,本文利用TBB（黑体辐射温度）资料及云南地区的降水资料,分析研究了该地区5月降雨量与前期印度洋赤道地区季节内振荡活动的关系。分析结果表明,冬季印度洋赤道地区季节内振荡活动的强弱与次年5月云南地区的降雨量有着密切的联系,即,当冬季印度洋赤道地区季节内振荡活动较强时,次年云南地区5月降雨量较常年偏多;反之,则偏少。     

Permo-Carboniferous Sequence Stratigraphy and Sea Level Changes in North China Platform

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