Helioseismology of Time-Varying Flows Through The Solar Cycle     

Laurent Gizon 《Solar physics》2004,224(1-2):217-228

Flows in the upper convection zone are measured by helioseismology on a wide variety of scales. These include differential rotation and meridional circulation, local flows around complexes of magnetic activity and sunspots, and convective flows. The temporal evolution of flows through cycle 23 reveals connections between mass motions in the solar interior and the large-scale characteristics of the magnetic cycle. Here I summarize the latest observations and their implications. Observations from local helioseismology suggest that subsurface flows around active regions introduce a solar-cycle variation in the meridional circulation.  相似文献   

Styles of back-arc extension in the Central Mediterranean     

Claudio Faccenna  Massimo Mattei  Renato Funiciello  & Laurent Jolivet 《地学学报》1997,9(3):126-130

In the Central Mediterranean two back-arc basins, the Liguro-Provençal (LPb) and the Tyrrhenian basin (Tb), opened progressively and consecutively from the late Eocene–Oligocene to the present. Evolution in space and time of rifting and drifting processes, along three different transects across these basins, shows differences in the style of extension: LPb opened with the formation of a narrow, single rift, while in the Tb deformation and magmatism is spread over a wide area. Moreover at the Northern end of the Tb the locus of extension progressively migrated towards the east whereas in the Southern Tb the locus of extension and magmatism migrated inside the basin, inducing continental break-up and drifting of the previously formed older conjugate basins. We propose that these different styles of back-arc extension depend upon internal conditions, such as prerift rheology linked with its geological heritage, and external conditions, e.g. the style of subduction.  相似文献   

风廓线雷达Cn2资料和L探空资料确定济南夏季边界层高度的对比研究     

王栋成  汤子东  邱粲  等. 《气象与环境科学》2021,44(2):96-105

  相似文献   

太原市冬季一次霾和沙尘“混合型污染”过程天气成因分析     

王小兰  闫世明  王雁  等. 《气象与环境科学》2021,44(4):43-52

  相似文献   

Salt crystallization in pores: quantification and estimation of damage     

Matthieu?AngeliEmail author  Jean-Philippe?Bigas  David?Benavente  Beatriz?Menéndez  Ronan?Hébert  Christian?David 《Environmental Geology》2007,52(2):205-213

The objective of this study is to understand and predict the alteration of porous rock by crystallization of salts. Samples of different rocks have been tested according to the EN 12370 standard test. Two parameters are proposed to evaluate the alteration of a rock during these tests. The alteration index AI represents the cycle in which the first damages occur. The alteration velocity AV represents the alteration rate at the end of the experiment, when the decay has become regular. These parameters can be estimated with the help of a microstructural study of the rocks. The most relevant intrinsic parameters of the stones for this estimation are capillary coefficient, evaporation coefficient, tensile strength and P-waves velocity. An evaluation of the alteration pattern is also proposed depending on the eventual heterogeneities and anisotropies of the rocks. The influence of the dimension and shape of the samples is also discussed.  相似文献   

塔河油田碳酸盐岩缝洞型油藏远井储集体定量化表征及动用技术     

梁健  王栋  张鑫 《江苏地质》2021,45(1):29-36

塔河油田奥陶系碳酸盐岩储层主要储集空间为溶洞和裂缝,直接钻遇溶洞比例达50%。针对目前远井储集体特征认识模糊、动用难度大等问题,基于物质平衡原理及注水指示曲线、液面恢复曲线等资料,对远井储集体的规模、裂缝导流系数、地层能量进行定量化研究,形成了一套远井储集体参数定量化表征技术。基于远井储集体特征,运用酸化、高压注水、复合措施等方法提高对远井储集体的动用,并在塔河油田推广应用,高效井占75%以上,有较好的应用前景。  相似文献   

湖南铅锌矿床地质特征与资源潜力评价     

李胜苗  于炳飞  田磊 《江苏地质》2021,45(3):262-270

铅锌是湖南优势矿产资源,成矿地质条件优越,资源潜力巨大。开展湖南铅锌资源潜力评价,预测铅锌矿产资源潜力,以更好地指导铅锌矿产资源的规划和利用。根据重要矿产预测类型划分方案,结合铅锌矿床地质特征和成矿模型,将湖南铅锌矿产预测类型划分为4类：碳酸盐型（李梅式、董家河式、江家垭式）、矽卡岩型（水口山式、黄沙坪式）、岩浆热液型（桃林式、枞树板式）和沉积改造型（玛瑙山式）。以湖南四级大地构造单元为基础,结合铅锌矿产的分布特征,划分为20个Ⅳ级成矿带和16个Ⅴ级成矿区,提出19个重点勘查部署建议区。  相似文献   

河北任县地区热储地层划分对比及地热有利区     

陈庆龙  黄锐  蒲仁海 《江苏地质》2021,45(3):316-326

河北任县蕴藏着丰富的地热资源。为缓解城市供暖问题,确定任县地区热水层分布情况、构造断裂发育特征及地层展布,运用钻井、测井、大地电磁、二维地震资料,对该地区地下热水储层分布、砂体发育程度、地下构造特点、断裂发育情况进行研究。结果表明：任县地区存在古近系地层;研究区断裂发育呈雁列式展布,地堑地垒发育;明化镇组—馆陶组辫状河砂体厚度大、分布广、物性好,馆陶组孔隙度＞8%的砂岩质量分数为77%～97%;古近系—石盒子组曲流河、富泥低弯度河发育,砂体厚度较薄、物性较差,古近系砂体展布受北东向河道延伸控制,最大孔隙度为25%,平均孔隙度为10%～15%;石千峰组为泥质含量最高的致密隔水层;奥陶系灰岩水层地热温度较高,达95 ℃,DF2断层奥陶系顶面断距在400 m左右,沿断裂附近有较大流量的热水,可作为地热勘探开发甜点区。  相似文献   

矿物“微胶囊”在重金属污染土壤修复中的应用     

徐祖阳  夏同法  严维兵 《江苏地质》2021,45(3):306-310

矿物“微胶囊”技术用改性稳定矿物包裹重金属,使其长期无害存在于土壤中,原理是将一种土壤中的天然黏土矿物改性,赋予其巨大的比表面积和吸附能力,改性后的矿物混入重金属污染土壤后,将自行包裹土壤中的重金属并形成稳定的微胶囊。根据相关生态地球化学调查结果,结合快速调查,圈定了2个典型土壤As污染区块,运用矿物“微胶囊”技术开展土壤砷等重金属污染修复试验,在圈定地块按一定比例在耕种前均匀掺入修复试剂,并与空白土壤对比。试验结果表明：在As污染地块施加一定量的修复材料后,半年内可显著降低土壤中有效态As的含量,最大降幅达78%;土壤污染状况相同时,施加的修复材料最优添加量在1.20～1.50 kg/m2之间;施用该修复材料对土壤无二次污染,不影响农作物产量。试验结果可为治理农田As污染提供科学依据。  相似文献   

沿江丘陵平原工程地质分区研究——以安庆地区为例     

郭炳跃  王毅  戴俊成 《江苏地质》2021,45(3):327-334

长江中下游地区沿江丘陵平原地貌分布广泛且地质背景相似,开展单个地区的工程地质分区方法研究,对同类区域具有一定的借鉴意义。以安庆地区为例,提出一级分区以地貌类型,二级分区以岩土体类型、结构和重要工程地质层分布为划分原则的工程地质分区方法,将该区划分为5个工程地质区和14个工程地质亚区,并对各分区工程地质特性进行论述,旨在为同类区域水工环地质调查、城市地质调查研究提供参考。  相似文献