车贝雪夫多项式的约简算法

解释了文献「１」中关于化整后的车贝雪夫多项式约简处理的技术原理,给出了一种可快速实现多项式约简处理的求算方法。     

绥中一次暴雪伴雷电天气过程的成因分析

为了探讨绥中一次暴雪伴雷电天气过程的成因,利用常规观测资料、NCEP每6h间隔的1°×1°的再分析资料和营口多普勒雷达的资料,分析此过程的天气形势特点、高低空急流的作用、雷达回波的特征及反映动力、热力和水汽条件的相关物理量场的特征。结果发现:雷电发生在对流层中层的西南风急流和底层偏东风均处在最强的时刻,当对流云团发展到-20℃温度层时,温差起电产生雷电;雷电发生在低层850hPa附近存在的逆温层消失之后,同时配合低层水汽的辐合,产生了暴雪天气;雷电和强降雪发生在大气底层南风和北风转换的过程中,强降雪的时间与冷空气扩散加强的时间比较一致,当冷空气扩散到整个大气底层时强降雪结束;引起雷电和强降雪的对流不稳定层结主要处在对流层中层,并为上升运动的发生提供了动力和热力条件,促使雷电发生和强降雪的维持。     

东胜区污染状况分析

文章利用东胜区主要污染源排放情况以及2005年9月1日-2007年8月31日每日SO2、NO2、PM10浓度监测值和2005-2007年SO2、NO2、PM10平均值,分析了东胜区主要污染类型、污染物来源以及东胜区近3年SO2、NO2、PM10监测值日、月、季、年分布特征和变化规律;提出了消减大气污染物排放的对策。     

三种土层结构反应谱平台值的统计分析

本文以建筑抗震设计规范规定的反应谱为目标谱,通过调整加速度峰值和特征周期来人工合成数百条加速度时程曲线,并将其作为土层地震反应分析的地震动输入。在若干有工程意义的场地剖面中,选取和构造了部分软弱土层分别在底部、中部和顶部的三种土层剖面,利用土层地震反应分析的一维等效线性化波动方法,计算了不同土层剖面在不同地震动输入下的地表加速度反应谱的平台值。在统计分析的基础上,给出了不同场地三种土层结构的反应谱平台值的平均值。通过与正常剖面的反应谱平台值比较,给出了三种土层结构的反应谱平台值的影响系数。本文的研究获得了一些有意义的成果。     

地震行业地面骨干网与应急卫星通信网互联路由设计方案的探讨

本文介绍了地震行业地面骨干网与应急卫星通信网的运行现状及互联存在的路由问题,讨论了实现两网互联的路由设计目标和策略,根据OSPF协议与BGP协议的特点和适用范围,提出了统一互联的接入方法,以及联合使用OSPF和BGP协议解决两网互联路由问题的具体方案,经网络仿真平台测试证明,该方案切实可行,效果良好。     

不规则网土壤测量在水系沉积物异常查证中的应用

在大兴安岭森林沼泽景观区,植被茂盛、土壤表层腐殖质发育,且通视条件差,运用传统的规则网土壤测量方法进行1/5万水系沉积物异常查证,工作周期长、劳动强度大;采用不规则网土壤测量方法进行异常查证,取得了快速评价异常、追踪异常源,缩短找矿周期的效果。     

Vertical Observations and Analysis of PM2.5, O3, and NOx at Beijing and Tianjin from Towers during Summer and Autumn 2006

During the period between 18 August and 22 September 2006, an ultraviolet photometric O3 analyzer, a NO-NO2-NOx chemiluminescence analyzer, and a quartz micro-oscillating-scale particle concentration analyzer were simultaneously used for monitoring at three different heights each at Beijing (325-m tower) and Tianjin (255-m tower). These towers belong to the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences (CAS) and to the Tianjin Municipal Meteorological Bureau, respectively. These measurements were used to continuously measure the atmospheric O3 and NOx volume-by-volume concentrations and the PM2.5 mass concentration within a vertical gradient. When combined with meteorological data and information on the variation of vertical characteristics of the various atmospheric pollutants in the two cities, analysis shows that these two cities were seriously polluted by both PM2.5 and O3 during summer and autumn. The highest daily-average concentrations of PM2.5 near the ground in Beijing and Tianjin reached 183 μg m-3 and 165 μg m-3, respectively, while the O3 concentrations reached 52 ppb and 77 ppb, and NOx concentrations reached 48 ppb and 62 ppb for these two cities, respectively. The variations in the daily-average concentrations of PM2.5 between Beijing and Tianjin were demonstrated to be consistent over time. The concentrations of PM2.5 measured in Beijing were found to be higher than those in Tianjin. However, the overall O3 concentrations near the ground in Tianjin were higher than in Beijing. NOx concentrations in Tianjin were consistently lower than in Beijing. It was also found that PM2.5 pollution in Beijings atmosphere may also be affected by the pollutants originating in and delivered from Tianjin, and that Ti     

关中活断层和地裂缝的年代学研究

取该区活动断裂中的断层泥,并首次在几个断层面附近的劈理化黄土中取样测出热释光年龄。12个断层热释光年龄数据在20-240ka B P之间变化,证实中更新世晚期和晚更新世期间断层曾有一次活动,为本区断层的活动性提供了证据。本研究成果也为西安地裂缝的活断层与人工抽水双重成因提供了证据。      

基于地面运动强度及标准贯入试验的上海地区砂土地震液化评价

上海市地处长江三角洲前缘,黄浦江和苏州河交汇区域,特殊的地理环境与沉积环境导致浅部砂层广泛发育。随着城市建设的不断推进,上海城市区域范围的砂土地震液化风险评价成为亟待研究的课题。文章基于上海市工程钻孔数据,结合地震地面运动加速度分布与标准贯入试验,建立区域性地震液化危险性评价模型,对上海市进行了地震液化危险性评价。研究认为当发生50年超越概率10%的地震条件下,上海市陆域面积的66.0%将不会产生地震砂土液化灾害,21.8%的陆域面积仅发生轻微液化,只有崇明、横沙、长兴三岛,黄浦江及苏州河两岸地震液化等级达到中等甚至严重,占全市陆域面积12.3%;50年超越概率2%的地震条件下,随着峰值地面运动加速度整体升高,全市范围内轻微—严重液化区域明显增多,可能发生地震液化的总面积达到全市陆域面积46.25%。上海市存在砂土地震液化的危险性,但是发生概率较低。研究认为,目前的抗震设计规范中上海市的设防烈度偏高,可能导致不必要的建设成本。同时研究中的不同超越概率下的地震液化危险性评价结果为上海市工程建设相关标准的合理化改进的提供了建议和参考。     

Fracture mechanics analysis of multiple cracks in anisotropic media

This paper presents a single‐domain boundary element method (BEM) for linear elastic fracture mechanics analysis in the two‐dimensional anisotropic material. In this formulation, the displacement integral equation is collocated on the un‐cracked boundary only, and the traction integral equation is collocated on one side of the crack surface only. A special crack‐tip element was introduced to capture exactly the crack‐tip behavior. A computer program with the FORTRAN language has been developed to effectively calculate the stress intensity factors of an anisotropic material. This BEM program has been verified having a good accuracy with the previous researches. Furthermore, by analyzing the different anisotropic degree cracks in a finite plate, we found that the stress intensity factors of crack tips had apparent influence by the geometry forms of cracks and media with different anisotropic degrees. Copyright © 2010 John Wiley & Sons, Ltd.