Poisson-Gumbel Mixed Compound Distribution and its application

With the development of offshore engineering, the joint probability study for extreme sea environments has been a subject of increasing interest for both mathematicians and engineers. However, the conventional multivariate probability distribution models do not describe the distribution of the occurrences of extreme sea states induced by typhoon, hurricane or winter storm, and thus fail to reflect the probability characteristics of sea environments in all the aspects. Extreme sea environments are typically to be found in storms like typhoon, and the occurrences of such storms in certain sea areas, varying from year to year, may be fitted to a discrete distribution. By compounding the discrete distribution with a bivariate continuous distribution of two extreme sea environments, a new kind of distribution--Bivariate Compound Extreme Value Distribution (BCEVD) is obtained in this note. This study proposes Poisson-Gum- bel Mixed Compound Distribution, one of the particular forms of BCEVD, and gives an example of its application by using it to compute the joint distribution of wind velocities and wave heights and to estimate the 100-year return level, based on the 20-year wind and wave data in the East China Sea. The results show the advantage of PGMCD model in its stable results and simple use.     

Southern Hemisphere mean zonal wind in upper troposphere and East Asian summer monsoon circulation

1 Introduction Variability of the East Asian summer monsoon (EASM) has been detected by considering roles of El Nino and Southern Oscillation (ENSO) cycle, snow cover over Eurasia and Tibetan Plateau, and signals from the soil (namely, the soil temperatur…     

双(多)基地天气雷达技术及其应用

近年来 ,利用双 (多 )基地天气雷达系统进行天气探测受到重视 ,我国用双 (多 )基地天气雷达系统进行天气探测基本上还处于起步阶段。简述了双 (多 )基地天气雷达系统的构成及性能特点 ,分析了它的探测原理 ,给出了它与单基天气雷达网探测结果比较。通过讨论说明了用双 (多 )基地天气雷达系统进行天气探测是有效的和实用的 ,有广泛的应用前景 ,特别对我国在经费有限的情况下尽快获取真实三维风场等天气信息有重大意义     

筒式风能采集系统及其试验研究

为了克服现有技术中风能采集装置对风速或风向适应能力不足、风能利用率不高的问题,提出了一种适合城市高空风能利用的新型筒式垂直轴风力发电系统,其不仅具有很强的风向适应能力,而且能够在较低风速时,充分利用导风板将风力集中到筒式风能采集系统内,提高了风轮利用风能的效率。这种风力发电系统将与城市高层建筑构成一体化,充分利用高空风能优势进行发电,噪音小,不会给城市的生活和工作带来影响。介绍了该筒式风能采集系统的主要组成部分,以及实验结果,初步证实了该设计的可行性。     

测压传压管路系统动态特性的试验分析

目的为得到脉动风压测压管路的动态特性。方法采用周期激励方法的试验方法，并用多项式回归方法对试验结果进行回归处理，给出了传压管路的频率响应函数。结果用简单的6阶多项式的形式便可以较好地拟合不同长度测压管路的频率响应函数。结论由回归得到的管路频率响应函数用于对实际管路脉动风压测试结果进行修正，结果较为满意，证明本文方法的有效性。     

Single-fluid 2D magnetohydrodynamic simulation of solar wind structure in comparison to ulysses observations

Two dimensional Magnetohydrodynamic (MHD) equations with and without the momentum addition respectively have been used to simulate the solar wind structure on the meridian plane. The results show that far away from the sun it isn't solar magnetic field that induces the cncave solar wind speed. Instead, there may be the fast speed streamer driven by the momentum addition and an interface between high and low speed streamers. The interaction between high and low speed streamers causes the sharp division. Foundation item: Supported by the National Natural Science Foundation of China (4999045) Biography: Deng Ling-yun (1976-), female, Master candidate, research direction: solar-terrestrial physics.     

风力发电机控制系统的剖析与总体设计

参考国外进口中型风力发电机，论述和剖析了定桨距中型风力发电机的机械、电气线路结构。并在此基础上分析了控制系统的输入输出关系、基本任务、状态转换，从而确定控制系统的硬件结构及软件流程的设计，以便为控制器的详细设计和开发提供依据。     

土壤渗透系数的理论分析

应用土壤的随机管子网络结构模型,从理论上对土壤的渗透系数进行了分析.     

危险风速理论对厂址选择的指导作用

运用数学推导，探讨容易被人忽略的“危险风速”问题，得出了风速、危险风速和地面污染物浓度的关系曲线图．然后，用所得的理论结果，结合实例，指出现行的教科书在厂址选择理论方面的缺陷，提出相应改进。     

抗风浪船型组合式网箱系统的研制及其应用

抗风浪网箱技术是发展浅海网箱养殖业迫切需要解决的问题，研制的经济、实用的抗风浪船型组合式网箱系统采用组合型结构，柔性、防碰连接和导流装置等抗浪、耐流技术，并对选材、结构、强度进行优化设计，在水深7～20m，潮差6.5m的乐清湾浅海能抗10～11级风，1.56m/s潮流，鱼类实养效果和经济效益良好。