VENTILATION FLOW IN A BAROCLINIC VORTEX RELATED TO TROPICAL CYCLONE MOTION   总被引：1，自引：0，他引：1       下载免费PDF全文

田永祥 《Acta Meteorologica Sinica》1995,(3)

The tropical cyclone motion is numerically simulated with a quasi-geostrophic baroclinic model.The flow field of a tropical cyclone is decomposed into its axisymmetric and asymmetric components.The relation between the ventilation flow vector and the motion vector of the tropical cyclone is inves-tigated.The results of numerical experiments indicate:(1) There are both large-scale beta gyres andsmall-scale gyres in the asyrnmetric flow field.(2) The interaction between small-scale gyres andlarge-scale beta gyres leads to the oscillation of translation speed and translation direction for the tropi-cal cyclone.(3) There are the large deviations between the ventilation flow vector calculated bymeans of Fiorino and Elsberry's method and the motion vector of tropical cyclone.(4) The ventila-tion flow vector computed using the improved method closely correlates with the motion vector of thetropical cyclone.  相似文献   

用CAPPI和PPI资料测定区域降水量精度比较   总被引：5，自引：0，他引：5  

戴铁丕  詹煌  刘婉莉 《气象》1995,21(7):9-14

应用上海中心气象台７１４数字化天气雷达的体积扫描资料所得的不同高度上的ＣＡＰＰＩ资料和低仰角时ＰＰＩ资料。估算区域降水量并得到降水量分布形势。然后采用平均校准法进行了校准，最后又与用雨量计网测量的区域降水量及其分布形势作了比较，得到一些有意义的结果。  相似文献   

一种用于沉积相分析的新型模式识别方法   总被引：1，自引：0，他引：1       下载免费PDF全文

冉启全  李士伦 《沉积与特提斯地质》1995,(1):24-30

本文介绍一种用于沉识相分析的新型智能模式识别方法──神经网络模式识别方法。该方法利用关键井研究建立的测井相与地质相的对应关系作为识别模式，通过向识别模式学习获得模式识别智能知识，从而利用这些智能知识识别未知井、未知点的微相类型。本文方法成功地应用于中原油田文留地区沙四段沉积微相的识别与划分。  相似文献   

Deep crustal growth of quartz, kyanite and garnet into large-aperture, fluid-filled fractures, north-eastern Connecticut, USA   总被引：1，自引：1，他引：1  

J. J. AGUE 《Journal of Metamorphic Geology》1995,13(2):299-314

Abstract A petrographic and petrological analysis of exceptionally well-preserved hydrothermal veins from the Merrimack synclinorium, north-eastern Connecticut, has been carried out in order to place new field-based constraints on fracture aperture dimensions and porosity in the lower continental crust. The veins preserve substantial open space today in outcrop, and contain mineral assemblages including subhedral to euhedral crystals of quartz, kyanite and almandine-rich garnet. Textural evidence indicates unequivocally that the vein minerals grew into macroscopic (mm- to cm-scale) open space between the vein walls. The veins are interpreted to have been large-aperture fractures along which significant advective fluid infiltration and chemical reaction occurred. The porosity of the rock mass due to open space between fracture walls today is c . 0.3%, but it could have been as large as several percent when the flow system was active. Quantitative thermobarometry results from vein mineral assemblages indicate that the fractures formed at pressures and corresponding crustal depths of c. 0.8 GPa and c. 30km, and temperatures of 550–600° C. The depth of fracture formation corresponds to published estimates of the maximum burial depth of the Merrimack synclinorium during the Acadian orogeny. The formation of large-aperture fractures could increase significantly the transient permeability of the deep crust, and therefore influence metamorphic heat and mass transfer.  相似文献   

造山带的网结状构造样式   总被引：4，自引：0，他引：4  

索书田 《地质科技情报》1993,(2)

网结状构造样式是造山带地壳结构的一个重要特征,表现为线状强应变带与夹持其间的透镜状弱应变域规律组合格式。这种网结状型式在几何学上具有尺度不变性,并具三维特征,理论分析和实际观察指出,这种网结状构造样式,是在应变软化作用及变形分解作用控制下递进发育而成的,而造山带地壳结构的不均一性、组成造山带岩石的流变学特征以及变形物理环境,又是控制应变软化及变形分解作用的主要因素。  相似文献   

福建省西部大地热流值   总被引：2，自引：0，他引：2       下载免费PDF全文

熊亮萍  胡圣标 《地质科学》1993,28(1):96-101

根据福建省西部53个钻孔的实测地温数据和300多块岩石样品的实测热导率数据,计算了29个大地热流值,说明福建西部热流的平均值为74mW/m²,相当于中新生代活动区的热流值。  相似文献   

Multi-layer Tectonic Model for Intraplate Deformation and Plastic-Flow Network in the Asian Continental Lithosphere   总被引：5，自引：0，他引：5  

Wang Shengzu Institute of Geology  State Seismological Bureau  Beijing Liu Linqun 《《地质学报》英文版》1993,67(3)

In a large area of the east—central Asian continent there is a unified seismic network system composed of two families of large—seismic belts that intersect conjugately. Such a seismic network in the middle—upper crust is actually a response to the plastic flow network in the lower lithosphere including the lower crust and lithospheric mantle. The existence of the unified plastic flow system confirms that the driving force for intraplate tectonic deformation results mainly from the compression of the India plate, while the long-range transmission of the force is carried out chiefly by means of plastic flow. The plastic flow network has a control over the intraplate tectonic deformation.  相似文献   

青海湖人湖沙质物的计算与水下沙堤的形成     

赵鸿斌  何东宁  张登山  年奎  王彬 《湖泊科学》1993,(1)

青海湖流域沙漠以环湖分布为特点,又以ENE为集中。这一状态使多方向的风沙流入湖,而实际上入湖沙量是以W、N、E三个方向的流沙为主。根据入湖风沙公式计算,入湖风沙量为887.08×10~4t/a。并推算出河流泥沙入湖为35.77×10~4t/a,空中降尘为30.36×10~4t/a。入湖后的沙质物在湖流、波浪的作用下,由西向东运移,堆积成水下沙堤,逐渐增高加宽露出水面,分隔成子湖。同时在干燥的气候作用下,导致湖面收缩,生态环境恶化。  相似文献   

山西断陷带地热特征与地震活动性   总被引：2，自引：0，他引：2  

吴乾蕃  祖金华 《华北地震科学》1993,11(2):14-22

山西断陷带是我国著名的地震活动带之一,其地震活动频繁,强度大,震源浅,破坏性严重。山西断陷带地热场特征:各断陷盆地内部大地热流值或地温梯度值都比较高,吕梁山隆起区和太岳山丘陵区则比较低。提出清徐、临汾、蒲县、柳林四个地区的地壳、上地幔热结构,分别计算沉积岩层、花岗岩质层和玄武岩质层底部的温度和热流值。采用逐步逼近法计算浮山—临汾—蒲县剖面二维岩石圈地温结构。并用断陷盆地内的临汾、吕梁山隆起区的柳林、太岳山隆起区的沁源地区的大地热流值推导其岩石圈厚度和底部温度。地热异常影响着地震的孕育和发生,重点探讨了地球内热与地震孕育和发生的内在联系。  相似文献   

BED FORMS AND RESISTANCE PROPERTIES OF LIGHT-WEIGHT BED MATERIAL     

WANG Guixian  WANG Xingkui  GUO Jiachao Professor  Sediment Research Laboratory  Dept. of Hydraulic Engineering  Tsinghua University  Beijing  China. Associate Professor  Dept. of Hydraulic Engineering  Tsinghua University. Assistant  Dept. of Hydraulic Engineering  Tsinghua University. 《国际泥沙研究》1993,(3)

I. INTRODUCTIONResistance to flow in alluvial streams is one of the crucial problems in fluvial hydraulics. Despite that large amount of studies have been conducted for centuries, no perfectmethod describing and calculating the resistance to flow in alluvial streams is availablehll now. Investigation on bed forms and resistance properties of light--weight bed materials is even more scarce. USWES (1936) has conducted systematic experiments onlight--weight materials in a flume & m long an…  相似文献