宿迁市PM2.5积累机制及重污染天气过程分析

统计宿迁市2017—2021年秋冬季PM2.5数据以及同期常规气象观测资料,基于PM2.5日变化特征,根据15:00—23:00的浓度变化将其分为快速积累、慢速积累、消散三大过程,从积累速率的角度分析了宿迁市PM2.5的积累特征,并将其应用于重污染天气过程下的环流形势与积累速率相关性的探讨。结果表明,发生快速积累过程的平均积累速率为7.14μg·m-3·h-1 ;慢速积累过程平均积累速率为3.27μg·m-3·h-1 ;发生消散过程的PM2.5平均消散速率为5.42μg·m-3·h-1 。PM2.5慢速积累过程中气温高,风速大,湿度小,逆温强度弱,快速积累则与之相反。慢速积累过程的PM2.5潜在源区主要位于苏北地区及北部的山东、河北地区,快速积累过程的PM2.5主要潜在源区则位于西部的安徽、湖北地区。快速积累过程以高空槽后配地面高压前部型为主,慢速积累过程以纬向环流配合地面均压场为主。     

2007号台风“海高斯”快速加强的成因分析

利用欧洲中期天气预报中心(European Center for Medium-Range Weather Forecasts,ECMWF)ERA-Interim逐6h再分析数据(水平分辨率0.25°×0.25°)和国家气象中心提供的逐小时台风业务数据,分析了2020年第7号台风“海高斯”的路径和强度特征,并在此基础上...     

一种单频GPS快速静态定位技术

针对在短时间内GPS观测方程的法方程容易形成病态的实际,探讨用附加约束条件来消除其病态性的方法,然后用LAMBDA方法确定其整周模糊度。实际实验证明,对于单频GPS接收机,利用几个历元数据,使用该技术即可正确确定整周模糊度,从而实现cm级定位。     

双k型岭估计及其在GPS快速定位中的应用

针对GPS快速定位中设计阵病态性的特点,文中对现有的有偏估计进行了改进,提出了一种新的有偏估计———双k型岭估计。由广义岭估计和普通岭估计出发,讨论并给出了双k型岭估计中两个岭参数的选择方法。最后给出了实测GPS动态定位算例,验证了新估计的稳定性和有效性。     

2020年西北太平洋和南海台风活动概述

利用中央气象台台风实时业务定位资料和地面气象观测资料对2020年西北太平洋和南海的台风活动主要特征以及主要影响我国的台风路径、强度及风雨情况进行了统计分析。2020年西北太平洋和南海共有23个台风生成,较多年平均值（27.0个）偏少4.0个;有5个台风登陆我国,较多年平均值（7.0个）偏少2.0个。2020年台风活动的主要特征有：台风生成源地明显偏西;生成总数偏少,极值强度偏弱;7月“空台”,是1949年以来历史首次;8月台风活跃,出现多个近海快速增强的台风;8月下旬至9月上旬,3个台风连续北上影响我国东北地区,历史罕见;10月生成的台风个数较常年偏多,先后影响我国南海或中南半岛。     

Relationship of Rapid Intensification of Tropical Cyclones to Dynamical/Thermodynamical Parameters

Many avenues of research are currently being tried for understanding and predicting hurricane intensity forecasts. We have listed several such research avenues being pursued by the research community. This article addresses the use of high-resolution aircraft reconnaissance datasets used for daily data assimilation over three years of hurricane histories that cover rapid intensification cases. We show a number of dynamical and thermodynamical parameters, derived from these datasets, which seem to hold promise for future use in short range statistical forecasts on rapid intensification. These include the vertical differential of heating in the complete potential vorticity equation, the conversion of divergent kinetic energy to rotational kinetic energy, the transformation of shear vorticity to curvature vorticity, and the advection of the earth's and the relative angular momentum into the inner core of hurricanes. We find a rapid growth in the time history of each of these parameters as the rapid intensification occurs. These are demonstrated for a number of recent hurricanes.     

Seismic response evaluation of the linked column frame system

The linked column frame (LCF) system is proposed as a seismic load resisting system that uses conventional components to limit seismic damage to relatively easily replaced elements. The LCF features a primary lateral system, denoted the linked column, which is made up of dual columns connected with replaceable links, and a secondary flexible moment frame system with beams having fully restrained connections at one end and simple connections at the other. The linked columns are designed to limit seismic forces and provide energy dissipation via link yielding, while preventing damage to the moment frame under certain earthquake hazard levels. A design procedure is proposed that ensures plastic hinges develop in the links of the linked columns at a significantly lower story drift than when plastic hinges develop in the moment frame beams. The large drift difference helps enable design of this system for two distinct performance states: rapid return to occupancy, where only link damage occurs and relatively simple link replacement is possible, and collapse prevention, where both the links and the beams of the moment frame may be damaged. A series of 3‐story, 6‐story, and 9‐story prototype LCF buildings were designed using the proposed design approach. Nonlinear models were developed for the designs with the link models validated using recent experimental results. The seismic response of these systems was investigated for ground motions representing various seismic hazard levels. Results show that the LCF system not only provides collapse prevention, but also has the capability of limiting economic loss by reducing structural damage and allowing for rapid return to occupancy following earthquakes with shorter return periods. Copyright © 2012 John Wiley & Sons, Ltd.     

气象卫星大雾遥感自动识别技术研究

鉴于大雾对城市和沿海地区国民经济和人们生命财产带来的巨大灾害,迫切需要研制快速、有效、准确的雾遥感监测和识别方法。在对雾的辐射特性与卫星光谱特征试验分析基础上,找出不同时相可见光遥感图像下垫面反射率与云雾反射率之间的相对关系,并通过对图像反射率的相对变化率进行计算分析,自动生成准雾区动态判别阈值,并在准雾区范围初步确定基础上,采用基于图像游程编码的快速连通区域标记技术,结合纹理分形分析、形态分形分析、平滑度分析、模板特征分析等实用方法,对气象卫星遥感图像进行雾自动识别和云雾分离研究,取得了良好的应用效果。     

建立地震预警、地震报警和烈度速报综合系统的思考

如何减少地震灾害所引起的人员伤亡、次生灾害以及快速判断灾情以落实全面的防御观,是我国自汶川地震以来非常关注的问题.在建设我国地震烈度速报和预警系统的背景下,我们提出尽可能减少投资以改变传统模式、建设不需要专门观测房的监测系统,提高烈度速报和预警系统的监测点密度,实现地震预警、报警和烈度速报综合系统,为全社会提供更好的防...     

山西数字地震台网地震自动定位系统运行分析

选取2009年7月至2010年8月山西地震台网速报软件的自动定位结果与＂十五＂Jopens系统人机交互处理的定位结果进行对比分析,得出,速报软件自动定位地震参数与人机交互处理的编目结果基本吻合,可以作为地震速报的依据和参考。