Comments on “a Practical Method for Relating Scalar Concentrations to Source Distributions in Vegetation Canopies” by M. R. Raupach

This paper considers a modification to the localized near-field (LNF) theory for predicting scalar concentrations from source distributions in plant canopies. It is argued that the non-diffusive, near-field part of the transition probability P_n, and thus the near-field contribution of the scalar concentration C_n, in the original theory are simply errors. The (approximate) equality of the sum of C_n and the diffusive, far-field contribution C_f with the total scalar concentration C is not guaranteed in general by this theory. A revision is suggested.     

南昌市降水概率预报方法研究(二)

介绍了两种降水概率预报方法,一种是根据多因子场相似原理作降水概率预报,另一种是用武汉区域气象中心的MAPS降水资料作降水概率预报。     

大中型水库坝前年最高水位统计变化特性分析

根据全国１６０座大中型水库的实际观测资料,对坝前年最高水位的变化特性进行了较系统的分析研究。结果表明：年最高水位为独立随机变量,概率分布多为负偏,可由三参数对数正态表征。参数由概率权重矩法估计。     

一次二阶矩方法在斜坡稳定性概率评价中的应用

介绍一次二阶矩理论的基本原理及斜坡稳定性概率评价中的应用。论述了斜坡可靠指标、破坏概率和安全系数的关系,给出了应用实例。     

霍山地区十年尺度地震强度估计及减灾对策

】霍山地区是著名的地震活动区和“震情窗”,通过对该地区地震资料分析,对霍山地区十年尺度地震强度进行了概率估计——地震强度为５．９级,并根据估计结果,提出了综合减轻地震灾害对策。     

煤系岩石工程地质性质指标变异性研究

对山东金山矿区３煤覆岩及底板工程地质性质类型的物理力学性质指标的变异性进行了研究,用Ｋ－Ｓ法进行的概率分布类型拟合检验表明,各指标基本服从正态分布;另外,还对煤系岩石物理力学性质指标的关联性及各向异性特征进行了初步分析,为煤矿工程地质可靠度研究提供了依据。     

马尔柯夫链原理在海雾短期预报中的应用

本文应用了马尔柯夫链原理,采用转移概率矩阵的方法,建立了预报南海海雾的模式方程,且通过实际的业务试报反映出具有较好的预报能力。     

概率权重矩法计算P—Ⅲ分布参数公式及其应用

本文对文献〔1〕导出的PWM法计算P-Ⅲ型分布参数公式作了改进,使PWM法能够应用于实际。文中还提出了一种简化的PWM法,经统计试验及实际算例表明,此法比现有方法更简单,又能满足精度要求。     

Parametric Analysis and Experimental Study on Local Flexibility of TY-Type Tubular Joints

Loal flexibility of tubular joints has important effect on the static and dynamic behaviour of offshore platforms, therefore, the determination of it becomes an important research subject in the field of offshore engineering. In this paper, the local flexibility of TY-type tubular joints, which are widely used in offshore platforms, is calculated by using semi- analytical method. Based on the calculated results, parametric formulae for evaluating element in the local joint flexibility matrix of TY- type tubular joints are derived by regression. A test on PVC models of TY-type tubular joints to measure the local joint flexibility is also reported. A comparison of the results calculated from the parametric formulae presented in this paper with those measured from the model test shows that the parametric formulae are reliable. It is recommended that these formulae be used in the global structural analysis of offshore platforms.     

辽东湾JZ20—2海域海冰参数的概率分布

基于辽东湾JZ2 0 2海域 1996 2 0 0 0年 4个冬季的海冰定点观测资料和海冰数值模拟结果 ,对该海域的平整冰厚、冰速、冰向和压缩强度等海冰参数进行了概率分析 ,确定了各自的分布参数 ,并对冰速和冰向进行了联合概率分析。结果表明 :冰厚和冰速分别服从对数正态分布和瑞利分布 ,海冰压缩强度服从正态分布。计算结果可用于JZ2 0 2海域海洋结构可靠性设计和疲劳累积损伤分析的海冰参数 ,也可作为其邻近海域的参考资料