Calculation Of The Height Of The Stable Boundary Layer In Practical Applications     

Sergej Zilitinkevich  Alexander Baklanov 《Boundary-Layer Meteorology》2002,105(3):389-409

Currently used and newly proposed calculation techniques for the heightof the stable boundary layer (SBL), including the bulk-Richardson-numbermethod, diagnostic equations for the equilibrium SBL height, and a relaxation-typeprognostic equation, are discussed from the point of view of their physical basis andrelevance to experimental data. Among diagnostic equations, the best fit to data exhibits an advanced Ekman-layer height model derived recently with due regard to the role of the free-flow stability. Its extension to non-steady regimes provides a prognostic equation recommended for use in practical applications.  相似文献   

关于ENSO及其统计预测方法评估     

丁裕国  程正泉 《山东气象》2002,22(3):6-9

结合近年来“九五”国家重中之重项目有关ENSO业务预报系统研究工作的体会和见解 ,简要综述了近年来ENSO的预报问题 ,尤其是ENSO统计预测方法的研究成果 ,并对各种预报方法的效果进行评价。  相似文献   

原油在储层介质中的加水裂解生气模拟实验   总被引：5，自引：2，他引：5  

冯子辉  侯读杰等 《沉积学报》2002,20(3):505-509

采用高温高压热模拟实验方法,开展了原油在砂岩和火成岩储层介质中的加水裂解生气模拟实验研究.结果表明,原油开始大量裂解的温度是400℃,随模拟温度增加,甲烷相对含量增大,乙烷以上重烃气尤其是丙烷相对含量减小.其中砂岩的油水混合物裂解生气主要发生在450～500℃之间,生气窗范围小,对应的烃气产率高,火成岩的油水混合物裂解生气主要发生在450～600℃之间,生气窗范围大,对应的烃气产率小.模拟烃气的组分碳同位素分馏显著,随模拟温度增加呈变重趋势.在裂解生气过程中,水解加氢和催化作用对烃气的组成、产率和碳同位素分布有重要影响。  相似文献   

Temporal patterns of suspended sediment yield following moderate to extreme hydrological events recorded in varved lacustrine sediments     

Scott Lamoureux 《地球表面变化过程与地形》2002,27(10):1107-1124

A 487‐year annually laminated (varved) sediment record from Nicolay Lake, Cornwall Island, in the Canadian High Arctic was evaluated to determine the impact that years with high sediment yields had on sediment yields in subsequent years. All of the 40 largest years showed evidence for increased sediment yield in the subsequent 10–30 years. The positive anomalies in lagging years were approximately scaled according to the size of the initiating year, although many intermediate years (25‐ to 100‐year recurrence) showed weak or variable responses. The smallest events considered (10‐ to 25‐year recurrence) showed a consistent, but low‐amplitude response. Additionally the 10‐year events revealed frequent negative sediment yield anomalies in the preceding decade. This behaviour was interpreted as a frequent sediment activation cycle initiated by the modest year, and leading to sediment yield hysteresis lasting 15–25 years. The largest years (greater than 50‐year recurrence) showed consistently above‐average sediment yields in the preceding decade, in part due to the frequent occurrence of moderate (Q₁₀) years. It is hypothesized that temporary storage of sediment and previous initiation of erosion sites resulted in extraordinary sediment yields during intense summer rainfall events. This study demonstrates the potential use of varved lake sediment records to improve our understanding of long‐term sediment dynamics. These records present an opportunity to further develop and test sediment dynamic and routing models to gain insight into the interaction of time and space in fluvial and sediment delivery processes. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Damaging properties of ground motions and prediction of maximum response of structures based on momentary energy response     

Norio Hori  Norio Inoue 《地震工程与结构动力学》2002,31(9):1657-1679

Dynamic damaging potential of ground motions must be evaluated by the response behaviour of structures, and it is necessary to indicate what properties of ground motions are most appropriate for evaluation. For that purpose, the behaviour of energy input process and hysteretic energy dissipation are investigated in this study. It is found that the momentary input energy that is an index for the intensity of input energy is related to the characteristics of earthquakes such as cyclic or impulsive, and to the response displacement of structures immediately. On the basis of these results, a procedure is proposed to predict inelastic response displacement of structures by corresponding earthquake input energy to structural dissipated damping and hysteretic energy. In this procedure the earthquake response of structures is recognized as an input and dissipation process of energy, and therefore structural properties and damaging properties of ground motions can be taken into account more generally. Lastly, the studies of the pseudodynamic loading test of reinforced concrete structure specimens subjected to ground motions with different time duration are shown. The purpose of this test is to estimate the damaging properties of ground motions and the accuracy of the proposed prediction procedure. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

神头泉流量变化规律研究--灰色系统理论的具体应用   总被引：2，自引：0，他引：2  

郭清海  王焰新  武全胜  邓安利 《地质科技情报》2002,21(1):27-31

在分析神头泉流量衰减特征的前提下，利用灰色系统理论建立了描述神头泉流量变化规律的数学模型。以1985年为界，神头泉的流量变化过程可分为两个阶段，GM（1，1）模型与灰色预测校正模型则分别用于对这两个阶段的流量变化特征进行刻画。神头泉2000－2004年的流量预测值表明，在神头泉域保证90年代中期的高降水量和朔州市各地下水用户对泉域内的地下水不进行超采的基础上，神头泉的流量在未来的一段时间内会维持1993年以来的增长趋势。  相似文献   

非常规综合物化探油气预测研究     

徐翔军  刘玉梅  郭少斌 《吉林大学学报(地球科学版)》2002,32(4):349-352

非常规综合物化探方法油气预测研究中存在的主要问题为：缺乏系统与综合的基础性理论研究，异常形成的机理还不十分清楚，在参数的优化组合及异常的求取上尚有诸多不足。针对后一种情况，选择松辽盆地东岭构造作为实验区进行了有益的探索。选取低能吸附烃、放射性测氡及土壤热释光三类参数进行了优化组合，分别计算了综合指标MAE与MAC及组合熵，然后对各值采用泛克里格法求取异常，取得了良好的效果。下一步研究应从异常形成的机理入手，建立三维非常规综合物化探油气预测模式，以提高油气预测成功率。  相似文献   

成矿系统与矿化网络研究   总被引：15，自引：2，他引：15  

翟裕生  王建平  邓军  彭润民 《矿床地质》2002,21(2):106-112

成矿系统研究体现了系统观和历史观的结合，是现代矿床学的一个发展趋势，本文简要总结了成矿系统及演化论的几个要点，即（1）按构造动力体制划分成矿系统大类；（2）我因耦合，临界转换的成矿作用机理；（3）矿床系列和异常系列构成的矿化网络；（4）矿床形成-变化-保存的演变过程，在此基础上，作者提出矿化网络是在一个成矿系统中形成的诸类矿床和相关异常的时空分布和结构，它是成矿系统的具体内容的表达。对成矿系统的深入研究应从矿化网络入手，着重在以下几个方面；（1）各类矿床的发育程度；（3）各类矿床的空间关系；（3）各类矿床的时间关系；（4）各类矿床的成因联系；（5）各类矿床被改造的情况。这些都是矿床学和找矿预测研究的基础内容。  相似文献   

断层周围的弹塑性区及其地质意义   总被引：9，自引：1，他引：9  

武红岭  张利容 《地球学报》2002,23(1):11-16

采用弹塑性有限单元方法 ,通过模拟符合实际状况的逐步加载过程所引起应力场和塑性形变区的研究 ,得出如下结果 :①在塑性或韧性剪切形变情况下 ,断裂或形变带的共轭剪切角往往大于 4 5° ;②在双向挤压应力条件下 ,先存断裂的前缘部位没有拉伸应力存在 ,但可能有伸展形变发生 ;③与最大主压应力夹角为 3 0°～ 90°的断层前缘是偏应力的优势方位 ,容易发生塑性剪切形变 ,特别是夹角为 60°左右的断层是最易发生新的构造活动的断层 ;④多数断层两侧一定范围内以及断层内部是相对的低应力区。这些应力的低值区 ,非常有利于矿液和油气的运移、聚集和成藏。  相似文献   

深井水氡主要干扰因素及映震效能分析          下载免费PDF全文

王志高 《地震工程学报》2002,24(3):251-256,261

对甘肃省玉门青6井和平凉泾川泾3井两口深水井的水氡及辅助项目观测资料采用多元逐步回归、相关距平、一阶差分等方法进行处理，分析并排除了主要干扰因素，显示出两井在肃南5.4级、托莱6.0级和礼县5.1级地震前有明显异常，对两井的映震效能和地震预报前景进行了评价。  相似文献