分析1999—2013年影响我国南部沿海的东风波,可分为3类:偏南东风波、西行东风波以及近海东风波。太平洋副热带高压是影响3类东风波特征的关键系统,其西伸与北进直接引导东风波路径及活动位置。东风波的分类合成结构特征显示:强涡度中心...分析1999—2013年影响我国南部沿海的东风波,可分为3类:偏南东风波、西行东风波以及近海东风波。太平洋副热带高压是影响3类东风波特征的关键系统,其西伸与北进直接引导东风波路径及活动位置。东风波的分类合成结构特征显示:强涡度中心指示东风波槽中心,强涡度中心通常位于850 h Pa及以下。东风波低层为强辐合场,槽后有整层的垂直上升区。偏南东风波波槽轴线随高度向西倾斜,西行东风波和近海东风波波槽轴线近乎垂直。合成诊断还显示,东风波的海上移动有向SST(Sea Surface Temperature,海表温度)大值趋暖的趋势。数值模拟证实,增强东风波槽前SST暖中心的强度,将引起槽区低层和槽后中层出现负变高中心,同时SST的增温将通过感热与潜热促使东风波槽强度加强,将进一步地增强东风波暴雨强度和雨带的北移。并增强中低层流场的气旋式气流成分,增强低层辐合场,维持深厚垂直上升运动层。典型西行东风波个例分析显示,螺旋度与东风波强度成正比,东风波纬向位温偏差显示东风波在热力场上具有"上暖下冷"的不稳定垂直结构。东风波涡度增强时,扰动动能向分层扰动位能转化。东风波强度减弱时,分层扰动位能向扰动动能转化。展开更多
The shapes of block within the rock mass have an important effect on the rock properties, so it＇s very important to evaluate the shapes of rock fragmentation and to determine the geometric characteristics distributio...The shapes of block within the rock mass have an important effect on the rock properties, so it＇s very important to evaluate the shapes of rock fragmentation and to determine the geometric characteristics distribution of the block. The previous methods to classify rock block shape are based on the assumption that a block shape is approximately orthogonal, which is acceptable in only a few rock masses. This paper proposes a new method for block shape classification using triangular diagram together with parameters of co-linearity e and volume coefficient K, which combines the shape categorization with block volume for statistical analysis. Rock block equivalent size calculation methods based on block shape is proposed and the block cumulative percentage of total volume statistical analysis is given. In order to verify this block shape classification method, three ideal rock masses with approximately orthogonal joint sets have been generated and simulated.展开更多
文摘分析1999—2013年影响我国南部沿海的东风波,可分为3类:偏南东风波、西行东风波以及近海东风波。太平洋副热带高压是影响3类东风波特征的关键系统,其西伸与北进直接引导东风波路径及活动位置。东风波的分类合成结构特征显示:强涡度中心指示东风波槽中心,强涡度中心通常位于850 h Pa及以下。东风波低层为强辐合场,槽后有整层的垂直上升区。偏南东风波波槽轴线随高度向西倾斜,西行东风波和近海东风波波槽轴线近乎垂直。合成诊断还显示,东风波的海上移动有向SST(Sea Surface Temperature,海表温度)大值趋暖的趋势。数值模拟证实,增强东风波槽前SST暖中心的强度,将引起槽区低层和槽后中层出现负变高中心,同时SST的增温将通过感热与潜热促使东风波槽强度加强,将进一步地增强东风波暴雨强度和雨带的北移。并增强中低层流场的气旋式气流成分,增强低层辐合场,维持深厚垂直上升运动层。典型西行东风波个例分析显示,螺旋度与东风波强度成正比,东风波纬向位温偏差显示东风波在热力场上具有"上暖下冷"的不稳定垂直结构。东风波涡度增强时,扰动动能向分层扰动位能转化。东风波强度减弱时,分层扰动位能向扰动动能转化。
基金supported by the Yunnan Provincial College and Institute Science and Technology Cooperation Projects (Grant No.2006YX26)the Technological Innovation and Technical Development Special Projects in Yunnan Province (Grant No.2007GA007)
文摘The shapes of block within the rock mass have an important effect on the rock properties, so it＇s very important to evaluate the shapes of rock fragmentation and to determine the geometric characteristics distribution of the block. The previous methods to classify rock block shape are based on the assumption that a block shape is approximately orthogonal, which is acceptable in only a few rock masses. This paper proposes a new method for block shape classification using triangular diagram together with parameters of co-linearity e and volume coefficient K, which combines the shape categorization with block volume for statistical analysis. Rock block equivalent size calculation methods based on block shape is proposed and the block cumulative percentage of total volume statistical analysis is given. In order to verify this block shape classification method, three ideal rock masses with approximately orthogonal joint sets have been generated and simulated.
