Tschebyscheff 函数在大气模式垂直离散问题中的应用   总被引：2，自引：0，他引：2       下载免费PDF全文

廖洞贤  朱艳秋 《应用气象学报》1995,6(2):213-219

文章就常用全球谱模式中的垂直离散问题进行了讨论，给出了用Tschebyscheff函数积分静力方程、连续方程，以及计算垂直平流、垂直扩散等的方法。还对某些气象要素在垂直方向微商呈现间断的问题进行了分析，指出了其中存在的问题和应采取的措施。  相似文献   

桂北四堡群火山岩形成环境及构造意义   总被引：2，自引：0，他引：2  

廖宗廷  张起钻 《上海国土资源》1994,(2):1-10,18

通过野外地质、岩石化学、稀土配分、微量元素等的综合分析表明,桂北四堡群火山岩形成于火山岛弧的构造环境,由四堡群组成的地质体是中元古代位于扬子大陆边缘以南的岛弧地体,中元古代末期该地体与扬子大陆边缘发生碰撞拼贴造山作用,这一作用决定了中、晚元古代桂北及邻区的大陆边缘构造及其演化过程。  相似文献   

黄河源区新构造运动对生态环境恶化的影响     

张森琦  李永国  尚小刚  辛元红  王占昌  石维栋  庄永成  周金元 《地质通报》2006,(Z1)

基于黄河源区1∶25万生态环境地质调查新获得的大量实际资料,通过分析和研究发现,黄河源区早更新世—中更新世处于走滑伸展的大陆动力学背景,在整体隆升中,形成断块山与拉分盆地,湖泊广布;晚更新世,大陆动力学机制过渡为挤压收缩,在整体抬升中,断块山显著崛起,湖盆萎缩、变形;全新世,大陆动力学环境反转为走滑挤压,持续隆升,黄河扩展源头到达本区,扎陵湖、鄂陵湖外泄,闭流盆地水环境转向开放。近代,特别是20世纪70年代以来,新构造活化与寒冻风化岩屑坡扩大、沙质荒漠化蔓延、湖泊和沼泽湿地萎缩、区域地下水位下降、源区黄河频繁断流、生态环境日益恶化响应关系密切。因此,新构造运动在黄河源区生态环境恶化中起主导作用,而其他因素则起到促进与加速的作用。  相似文献   

柴达木盆地东部石炭系烃源岩评价     

段宏亮  钟建华  王志坤  马锋  尹成明  温志峰 《地质通报》2006,(Z2)

柴达木盆地东部地区石炭系暗色泥岩、碳酸盐岩、煤及炭质泥岩均发育。大量区域地质调查及有机地球化学分析表明,石炭系烃源岩主要以暗色泥岩和碳酸盐岩为主,炭质泥岩和煤可能具有生烃能力。暗色泥岩有机碳含量平均为1.13%,有机质类型以Ⅲ型和Ⅱ2型为主,为中等—好的烃源岩;碳酸盐岩有机碳含量低,平均为0.26%,有机质类型为Ⅱ1与Ⅱ2型,属中等—差的烃源岩。除都兰地区有机质成熟度过高、处于过成熟的生干气阶段外,其他地区有机质成熟度中等,正处于生、排烃高峰期,具有良好的油气勘探前景。石灰沟地区烃源岩厚度大、丰度高,暗色泥岩和碳酸盐岩分别达到了好烃源岩和中等烃源岩的标准,有机质成熟度中等,生烃潜力较大。  相似文献   

石太客运专线特长隧道地区水文地质研究 及隧道开挖环境影响效应^*   总被引：6，自引：0，他引：6       下载免费PDF全文

邓清海  马凤山  袁仁茂  李国庆  赵海军 《第四纪研究》2006,26(1):136-143

文章在充分分析已有地质和水文地质资料的基础之上,综合大面积水文地质调绘和多种勘探成果,对石太客运专线太行山隧道和南梁隧道所在区域的水文地质条件进行了系统分析。将隧道区域划分为娘子关泉域系统、威州泉域系统和散泉系统三大地下水含水系统,同时将太行山隧道区划分为5个水文地质单元,将南梁隧道区划分为两个水文地质单元。另外,论述了隧道开挖对地下水和地表水环境的影响,主要表现在对断层或岩脉与隧道相交地段的水位、水量产生影响,这为进一步解决特长隧道施工过程中的突水、涌水等问题提供了可靠的基础性资料,加深了对河北、山西两省交界处水文地质条件薄弱地带的了解。  相似文献   

南岳雨凇分析     

朱明辉 王琪刘甜甜  廖春花禹伟 邓晓春 《气象科技》2006,34(4):436-440

分析了南岳雨凇与冷冬及西太平洋副热带高压的关系。结果表明,在冷冬年份,南岳雨凇日数偏多;在暖冬年份,南岳雨凇日数偏少。西太平洋副热带高压与南岳冬季气温密切相关。副热带高压偏弱时,南岳冬季偏冷;副热带高压偏强时,南岳冬季偏暖。副热带高压的588线北界偏北时,南岳冬季偏暖,反之偏冷。副热带高压的西伸脊点偏东时,南岳雨凇日数偏多,反之偏少,而且西太平洋副热带高压的变化超前于冷暖冬的变化。  相似文献   

关于东昆仑地区前寒武纪地质的几点认识   总被引：13，自引：3，他引：13  

王国灿  魏启荣  贾春兴  张克信  李德威  朱云海  向树元 《地质通报》2007,26(8):929-937

以1∶25万区域地质调查资料为基础,对东昆仑造山带前寒武纪地质演化的几个关键问题进行了探讨。东昆仑地区3206Ma±14Ma的锆石207Pb/206Pb年龄信息表明,该区存在古太古代基底。代表东昆仑地区基底的"金水口岩群"可以解体为太古宙—古元古代的白沙河岩群和中元古代的小庙岩群,两者是2个不同构造旋回的产物。东昆仑地区万宝沟群的时代应限定在中元古代,而不能延续到新元古代。东昆仑地区的年代构造格架显示,前寒武纪存在3次强烈的区域性构造热事件,分别发生在2400～2500Ma、1800～1900Ma和大约1000Ma。1000Ma左右的聚合事件导致中元古代分隔的不同小陆块的有限裂解小洋盆闭合,陆块聚合形成"西域板块",并可能是整个Rodinia超大陆的组成部分。  相似文献   

The petrochemistry characteristics and petrogenesis of peraluminous granite in Tibet     

Liao Zhongli  Mo Xuanxue  Pan Guitang  Zhu Dicheng  Wang Liquan  Zhao Zhidan  Geng Quanru  Xiong Xingguo  Dong Guochen 《Frontiers of Earth Science》2007,1(2):194-205

There are 61 major peraluminous granitic bodies in Tibet (TPGs) along the south of the Bangong Co-Gêrzê-Amdo-Nujiang suture, whose lithology includes tourmaline granite, muscovite granite and two-mica granite. The TPGs have SiO₂ = 65.7%−79.52%, K₂O + Na₂O = 2.20%−12.51%, K₂O/Na₂O = 0.49−1.04 and A/CNK = 1.04−1.38. Al₂O₃ gradually decreases and the other oxides disperse with the increase in SiO₂. The rock series is mainly calc-alk series with high potassium. It has typical characteristics of strongly peraluminous granite. Based on the aluminum saturation index and QAP plots, the peraluminous granite plot is mostly within the continental collision granite (CCG) field, indicating that the peraluminous granites in Tibet formed in a continental collisional setting. Ab-Or-Q-H₂O phase diagram indicates the pressure of 0.5 × 10⁸−2 × 10⁸ Pa in TPGs, from which it can be deduced that the forming temperature was under 700°C. The TPGs mainly occurred at the collision stage between two continental crust plates, and the original magma is rooted in the remelting from the upper crust. It is the S-type granite in petrogenesis. The South Gandise belt and the Lhagoi Kangri belt have similar characteristics, suggesting that the two belts have the same magma source and the same tectonic setting. Translated from Acta Geologica Sinica, 2006, 80(9): 1329–1341 [译自: 地质学报]  相似文献   

Geochemical processes controlling the elevated fluoride concentrations in groundwaters of the Taiyuan Basin,Northern China   总被引：1，自引：0，他引：1  

Qinghai Guo  Yanxin WangTeng Ma  Rui Ma 《Journal of Geochemical Exploration》2007

High fluoride groundwater with F⁻ concentration up to 6.20 mg/L occurs in Taiyuan basin, northern China. The high fluoride groundwater zones are mainly located in the discharge areas, especially in places where shallow groundwater occurs (the groundwater depth is less than 4 m). Regional hydrogeochemical investigation indicates that processes including hydrolysis of silicate minerals, cation exchange, and evaporation should be responsible for the increase in average contents of major ions in groundwater from the recharge areas to the discharge areas. The concentration of F⁻ in groundwater is positively correlated with that of HCO₃⁻ and Na⁺, indicating that groundwater with high HCO₃⁻ and Na⁺ contents help dissolve some fluoride-rich minerals. The water samples with high F⁻ concentration generally have relatively higher pH value, implying that alkaline environment favors the replacement of exchangeable F⁻ in fluoride-rich minerals by OH⁻ in groundwater. In addition, the mixing of karst water along the western mountain front and the evaporation may also be important factors for the occurrence of high fluoride groundwater. The inverse geochemical modeling using PHREEQC supports the results of hydrogeochemical analyses. The modeling results show that in the recharge and flow-through area of the northern Taiyuan basin, interactions between groundwater and fluoride-rich minerals are the major factor for the increase of F⁻ concentration, whereas in the discharge area of the northern basin, the evaporation as well as the mixing of karst water has greater contribution to the fluoride enrichment in groundwater.  相似文献   

Analytic stage–discharge formulae for flow in straight trapezoidal open channels     

Huasheng Liao  Donald W. Knight 《Advances in water resources》2007

Analytic stage–discharge formulae are derived for flow in straight trapezoidal channels, based on the 2D analytic velocity distribution in open channels given by Shiono and Knight [Shiono K, Knight DW, Turbulent open-channel flows with variable depth across the channel. J Fluid Mech 1991;222:617–46]. A simple hand-calculation method is provided. Legendre incomplete elliptic integrals of the first and second kinds and a binomial series expansion are used in the derivation of these analytic formulae, together with physically based hydraulic parameters, such as local friction factor (f), dimensionless eddy viscosity (λ) and secondary flow (Γ). The stage–discharge results obtained from the formulae are shown to be in good agreement with experimental data, as are the corresponding analytic velocity and boundary shear stress distributions. The influences of f, λ and Γ on the stage–discharge relationship are also discussed.  相似文献