THE EARLY SUMMER FLOOD PERIODS OF SOUTHERN CHINA AND THE SUMMER MONSOON CIRCULATION OF EAST ASIA

Based on the thermodynamic characteristics of the summer monsoon and foe change of the lower layer wind fields, the relation between the early summer flood periods of southern China, Including the first flood period of South China and the plum rains period of the middle-lower reaches of the Yangtze River and the activities of the summer monsoon is analysed.The establishment processes of the summer monsoon circulation of East Asia are investigated.It is shown that the beginning and ending of the flood periods are exactly in accordance with the arrival and departure of the fore boundary of the summer monsoon.The establishment process of the circulation from the very beginning of the arrival of the monsoon to the time of great prosperity of development are not the same for each year.They can be classified into four categories.Each category may have four or three stages.Besides, the structure of the summer monsoon regime of East Asia is not unitary.There exist four types of structure model of the monsoon regime of East Asia.     

1996年震情屈曲图像预测分析

从地震活动性图像的屈曲成因观．分析了当前我国地震活动的势态．指出了在９５°Ｅ以东的我国东部地区存着以１０°±１°为内外半经的圆环形地震活动带．用１９９４—１９９５年的地震实况作了验证与解释。对１９９６年起的１—３年的地震趋势作了预测分析。     

孕镶金刚石钻头工作温升的理论分析

在研究钻进规程参数对钻头温升的影响过程中，以能量守恒定律为基础，建立了钻头与岩石系统的能量守恒数学模型。研究表明：在一定范围内，钻头的温升与钻压与转速的乘积呈线性关系，钻压与转速对钻头温升的影响是等效的；通过谐振子模型研究摩擦热能的产生和分配，得出以下结论：摩擦热能在钻头与岩石之间的分配，与其各自弹性模量(硬度)有关，热能的分配与其弹性模量成反比，即Q1：Q2=E2：E1。     

全球应力场与构造分析

介绍了近年来全球构造应力研究方面的一些新进展并以“世界应力图”提供的资料为背景 ,结合一些最新的研究成果 ,阐述了全球构造应力场的分布特征及其与板块构造运动之间的联系。研究结果表明 :(1)全球存在大尺度的统一性构造应力场 ;(2 )全球大多数板块内部地区为挤压应力作用 ,其应力结构多为逆断型、走滑型或逆走滑型 ;(3)大陆板块内部的扩张区大多位于高海拔异常地区 ,其应力结构为正断型或正走滑型 ,如青藏高原、东非裂谷和贝加尔裂谷等 ;(4)全球大部分地区的地壳上部构造应力作用方向较为均一 ,存在区域统一应力场 ;(5 )全球大部分地区的最大水平主应力方向与板块绝对运动 (角速度 )迹线保持较好的一致性 ,反映出构造应力与板块运动的关系密切 ;(6 )板块汇聚、洋脊扩张可能是产生岩石圈上部构造应力的主要力源。     

The abnormal pressure regime of the Pennsylvanian No. 8 coalbed methane reservoir in Liulin–Wupu District, Eastern Ordos Basin, China

Coalbed methane reservoir pressure is an important parameter used to assess the producibility of coalbed methane wells. Practices indicate that high production of coalbed methane well is partly related closely to abnormally high pressure. Permo-Carboniferous coalbed methane resources are very abundant in the Liulin–Wupu District, Eastern Ordos Basin, which has been the highlight of coalbed methane exploration in China in recent years. In this district, the abnormally high pressure is present locally in the Pennsylvanian No. 8 coalbed methane reservoir (the Taiyuan Formation). Based on the distribution of the abnormally high pressure, burial history, hydrocarbon generation, hydrodynamics, and sealing regimes, the authors suggest that the abnormal coalbed methane reservoir pressure is related closely to local hydrodynamic trapping. The gas generated during the qualification is preserved, owing to the confinement of lower permeable roof and floor rock layers, and water trapping in the updip direction (like the “fairway” in San Juan Basin). As a result of pressure reconstruction event, the abnormally high pressure is formed during the uplifting stage. The current coalbed methane wells with high production are always located in abnormally high pressure areas. Therefore, the areas with abnormally high pressure in Liulin–Wupu District can be the preferred areas for commercial coalbed methane development.     

黄河下游河型的特性及成因探讨

黄河下游具有辫状河流、弯曲河流和微弯顺直河流3种河型，从横断面上可见，辫状河段的河道变化最频繁且最不稳定，微弯顺直河段最稳定；而弯曲河段明显向上游延伸，随着输沙量在各河段的阶段性变化，冲淤 状况在各河段也表现出阶段性，但加积升高是各河段发展的总趋势，从河相关系可见，弯曲河段和微弯顺直河段基本相似，但和辫状河段有着本质的区别。辫状河段的演变主要受到中上游来水来沙等自然因素的综合影响，但其更大范围的摆动仍然受到人为作用的影响；弯曲河段是河流自动调整的必然结果，两岸河堤对它的形成及向上游的延伸具有促进作用，但对它侧向迁移的特性具有较大的限制作用；而微弯顺直河段是人力强迫下河流局部调整的产物。     

Occurrence of springs in massifs of crystalline rocks,northern Portugal

An inventory of artesian springs emerging from fractures (fracture springs) was conducted in the Pinh?o River Basin and Morais Massif, northern Portugal, comprising an area of approximately 650 km². Over 1,500 springs were identified and associated with geological domains and fracture sets. Using cross-tabulation analysis, spring distributions by fracture sets were compared among geological environments, and the deviations related to differences in rock structure and, presumably, to differences in deformational histories. The relation between spring frequencies and rock structures was further investigated by spectral determination, the model introduced in this study. Input data are the spring frequencies and fracture lengths in each geological domain, in addition to the angles between fracture strikes and present-day stress-field orientation (θ). The model's output includes the so-called intrinsic densities, a parameter indexing spring occurrence to factors such as fracture type and associated deformational regime and age. The highest densities (12.2 springs/km of lineament) were associated with young shear fractures produced by brittle deformation, and the lowest (0.1) with old tensional and ductile fractures. Spectral determination also relates each orientation class to a dominant structural parameter: where spring occurrence is controlled by θ, the class is parallel to the present-day stress-field orientation; where the control is attributed to the length of fractures, the spring occurrence follows the strike of large-scale normal faults crossing the region. Electronic Publication     

Néotectonique affectant les dépôts marins tyrrhéniens du littoral sud-est tunisien : implications pour les variations du niveau marin

Pleistocene marine deposits of so-called Tyrrhenian age in southeastern Tunisia include two lithostratigraphic units of Last Interglacial (marine isotopic substage 5e). The lower unit culminates at about +3 m above the sea level; the upper unit with Strombus bubonius culminates at +5 m. Brittle deformations affected the upper unit. The analysis of fault-slip data sets reveals a post-Tyrrhenian N020°E trending compression, consistent with joint patterns. This event induced limited vertical movements, showing that at the northeastern edge of the Saharan Platform, the coastal area of the southern Tunisia remained relatively stable since at least the Last Interglacial.     

30-year response to damming of a Mediterranean river in California,USA

Dry Creek is a major tributary of the Russian River in Northern California (USA) that has experienced hydrologic and morphologic alterations after the closure of Warm Springs Dam in 1983. Our objective is to present a detailed diagnosis of the modification of the creek’s flow and sediment regimes, and interpret the alterations regarding the ecomorphologic evolution previously observed in the creek. Statistical analysis of the river’s flow and sediment series indicates that dam operation has had significant impacts on the magnitude and frequency of occurrence of the highest floods, and the magnitude, variability, and duration of low and very low flows. Similarly, sediment concentration and discharge have also experienced major alterations. Loss of habitat complexity for native flora and fauna (especially endangered salmonids), channel incision, and vegetation encroachment are some of the negative trends found for the creek over the last 30 years, since river regulation began. We discuss the present dynamics of the river and propose, on that basis, the improvement of its hydromorphic functioning as part of future large-scale restoration initiatives.     

青海共和盆地风况及风沙地貌

利用共和盆地茶卡、共和、贵南站2012-2015年的风资料,分析盆地风向、风速和输沙势的变化特征,并结合Google Earth高清影像,对盆地风能环境与风沙地貌进行探讨。结果表明：（1）盆地年平均风速1.6～2.7 m·s^-1,西北部、中部和东南部年起沙风出现的频率分别为7.7%、3.5%、0.9%,起沙风主要发生在冬、春季,风向以WNW和W为主。（2）盆地属于低风能环境,风沙活动自西北部向东南部减弱,方向变率指数0.7～0.96,风况为窄单峰或宽单峰风况,西北部和中部风向变率属于低变率,东南部属于中等变率,合成输沙方向较一致,为281.0°～286.7°。（3）盆地沙丘类型有新月形沙丘（链）、格状沙丘、复合型链状沙丘、沙山、沙垄、抛物线沙丘等,沙丘类型和风况较吻合。