大沙沟山字型构造

大沙沟石炭纪无烟煤勘探区位于甘肃省武威县西。区内出露地层主要为石炭系、二迭系和侏罗系,白垩系仅出露于小红沟以东。加里东晚期花岗岩在上述沉积盖层周围广泛分布。勘探区构造位置处于祁吕贺兰山字型西翼褶带与河西系武威—临洮构造带交接部位。成煤后的构造变动使该区屡经破坏和改造。形态各异,性质不同,规模悬殊的褶皱、断裂广泛发育,纵横交错,组成一幅复杂的应变图象(图1)。     

陇南煤田地质特征与找煤

陇南在70年代沿近东西向区域断裂带找煤收效甚微,原因是对侏罗纪煤系的沉积特征和古构造缺乏研究。而今认识到构造对含煤沉积的控制作用是通过其对古河流展布和古气候的控制而体现的。因此,陇南找煤应沿古武都河的西北—东南延伸方向寻找龙家沟组煤系。     

基于“黑格比”和“灿都”台风期间湍流数据的曳力系数和动力粗糙度长度参数化研究*

海面的曳力系数和空气动力学粗糙度长度是计算海气动量、感热和水汽通量交换必需的参数。基于在“黑格比”和“灿都”台风期间收集的涡动相关系统观测数据, 文章研究了10m风速和摩擦速度之间、10m风速和曳力系数之间、以及10m风速和动力粗糙度长度之间的参数化关系。结果表明: 曳力系数和摩擦速度及10m风速之间存在抛物线关系, 动力粗糙度长度与摩擦速度及10m风速之间存在自然指数关系; 临界摩擦速度为0.83m·s^-1, 临界10m级风速为23.69m·s^-1。     

王家山矿区层面断层的工程地质特征

距甘肃省靖远县城北约60公里的王家山矿区处于雷公山—六盘山褶带中段,为一轴向北65—80°西的向斜构造,走向长8.5公里,倾斜宽0.5—2.3公里,面积约19公里。地层自上而下有第四系、上第三系、白垩系、侏罗系、上三迭统和下志留统。中侏罗统窑街组含主要可采煤两层,2号煤层平均厚15.4米;4号煤层平均厚24米。      

TESTING DRAG COEFFICIENT APPROACHES BY USING THE BUOY DATA COLLECTED IN MODERATE TO HIGH WIND UNDER FOLLOWING, CROSSING AND OPPOSING SWELL CONDITIONS

Hurricane intensity and track are strongly affected by air-sea interactions. Classified as following swells, crossing swells, and opposing swells, the observed wave height was parameterized by using the 10-m wind speed collected on 5 buoys by the National Buoy Data Center during 13 hurricane events. The path information of these 13 hurricanes was obtained from the National Hurricane Center Best Track (NHC-BT). Results show that the wave height increases exponentially with the 10-m wind speed, and the wave height reaches the maximum value, 11.2 m (8.1 m), when 10-m wind speed is 40 m s-1 under the following and crossing (opposing) swell conditions. We find that the wave steepness (the ratio of wave height to wave length) is proportional to the -2/3 power of the wave age (the ratio of wave phase velocity to 10-m wind speed). The parameterizations of friction velocity and drag coefficient are tested using the buoy data collected in moderate to high wind under following, crossing and opposing swell conditions. A wave age dependent equation for drag coefficient is found more accurate and suggested for future usage in numerical models. Further, these algorithms also suggest that wind-swell orientation needs to be considered to retrieve accurate surface drag under high winds and strong swells.     

陇南煤田含煤沉积地质特征研究

通过对陇南煤田已知煤矿点有关资料的分析,研究了该区侏罗纪煤系的沉积特征和古构造展布特征。结果表明,陇南煤田的古构造对含煤沉积的控制作用,主要是通过对古河流展布和古气候的控制而体现的。不同层位的煤层,其下面普遍有河流相沉积,说明煤层是在古河流基础上发展起来的;适于成煤的气候自早侏罗世至晚侏罗世,具有由西向东迁移的特点,因此,陇南煤田的找煤勘探应沿古武都河的西北—东南延伸方向开展。      

甘肃北山地区中侏罗世含煤岩系沉积和构造特征

甘肃西部北山地区位于阴山-天山东西复杂构造带西段,是中生代以来在东西复杂构造带中发展起来的一个相对坳陷带,由北坳陷和南坳陷及其间的隆起组成,区域地层及构造线均呈近东西向。