黔东南州近30年气温的时空变化特征

利用贵州省黔东南州16个地面气象站1971～2007年的气温资料,分析近30多年黔东南州气温的时空变化特征.结果表明:黔东南州1970年以来.整体呈升温趋势,且由北向南增温幅度逐渐加大;1990年开始异常偏暖,21世纪初达到最大;EOF分解的第一主分量表征了黔东南州全体一致的升温趋势;第二主分量发现在某些年份,以凯里～台江～榕江北部～黎平～锦屏为分界线,南北温度变化呈反相位趋势.     

数字地图图像的基本形态学变换和结构元素的分解

本文是作者关于“数学形态学与数字地图图像的分析和识别”研究成果的一部分。文章提出了地图图形的集合概念和地图图像形态分析的基元确定原则,证明了结构元素的基元最小分解定理;同时,介绍了基本的形态学变换,统一并扩展了带约束条件的数学形态学变换模型;从而,奠定了数字地图图像分析和识别的数学基础。     

动态变形数据的EMD卡尔曼滤波降噪模型

文章介绍了kalman滤波与经验模态分解的基本原理,定义了经验模态分解的多尺度分解与合成结构。结合kalman滤波与经验模态分解(EMD)理论提出一种新的动态变形数据降噪模型。文章首先对动态变形信号进行EMD分解,选择合适的高频分解模量进行kalman滤波降噪,然后进行经验模态重构获得降噪后的动态变形信号,达到降噪的效果;最后采用单历元解算的变形数据序列进行模型验证,并与小波降噪模型、直接EMD降噪模型对比,视觉评价与量化结果表明此方法最优。     

二维风暴潮模式并行计算研究

通过对串行程序的分析、探讨,提出了基于区域分解的二维风暴潮模式并行算法;通过生成派生数据类型的方式,解决了二维数组子块传送和不同类型数组对应并行化读写的问题;通过子程序全局通信的方式,解决了边界处理的复杂性,提高了模式的可扩展性.并在选取不同的网格规模、不同的进程数的条件下进行了测试,得到了较为理想的结果.     

Determination of trace and rare-earth elements in Chinese soil and clay reference materials by ICP-MS

Inductively coupled plasma mass spectrometry(ICP-MS) has become a powerful tool for providing reliable analytical results in many laboratories around the word. In this study, the mixture of HF and HNO3 acids in high-temperature and high-pressure closed-vessel digestion technique were used to decompose some Chinese reference materials, and thirty seven elements were determined by ICP-MS. Most of the results for Chinese soil reference materials were found to be in reasonable agreement with the reference values, except Cs, Ta, Li, Ge, Zn, Nd, Tb and Ta whose values need to be revised. Their precisions were typically lower than 5% RSD. However, the Precisions of Chinese clay reference materials, especially for GBW03102 and GBW03102a, were significantly different with reference values, probably reflecting the existence of a coarser-grained fraction(70 μm) in samples, and the formation of fluorides in Al-rich samples during sample decomposition by using the mixture of HF and HNO3 acids. Moreover, thirty-seven trace elements covering the mass range from Li to U in four Chinese clay reference materials were firstly provided with good precision and accuracy in this study.     

东江流域枯水期最长连续无降水日数的变化特征

利用1956-2008年东江流域各降雨站点逐日降雨资料,建立枯水期最长连续无降水日数时间序列（LCDD）,采用经验模态分解（EMD）方法分析该序列的多尺度振荡变化及趋势变化,应用Mann-Kendall法识别突变点,采用R／S分析方法探讨变化趋势的持续性特征,并初步分析LCDD变化的可能原因。结果表明：近53年来,最长...     

Textural and Geochemical Characteristics of Proglacial Sediments: A Case Study in the Foreland of the Nelson Ice Cap, Antarctica

This paper presents a detailed study on the textural and geochemical characteristics of the proglacial sediments near the edge of modern Nelson Ice Cap, Antarctica. The grain size distributions of the proglacial sediments are characteristic of glacigenic deposits, but very different from those of aeolian and lacustrine sediments. Moreover, the grain size distributions of the proglacial sediments are fractal with a dimension of about 2.9, and the fractal dimensions can be used as another summary statistical parameter for quantifying the relative amounts of coarse and fine materials. Correlations between the absolute element abundances of the proglacial sediments are very weak due to mineral partitioning and other effects of glacial processes, but correlations between the element/Rb ratios are statistically significant. This finding indicates that element/Rb ratios can be used to reduce or eliminate the effects of glacial processes, evaluate geochemical data and determine the sediment provenance in the for     

基于切割环分解的三维建筑物细节层次模型构造

提出一种基于切割环分解的建筑物LOD（细节层次）模型的自动生成方法,该方法首先通过二面角操作算子识别建筑模型中的切割环,然后通过切割环将建筑物模型迭代分割成建筑主体和一系列细部特征,并将分割的结果存储在一棵构造实体几何树（CSG tree）中,最后对特征部件按重要性进行等级划分,同时进行简化处理。试验结果表明该方法具有较高的计算效率,能有效减少模型表面的细节和较好保持模型的结构特征。     

长江口及邻近海域表层水体溶解氧饱和度的季节变化和特征

根据“908”ST04区块调查的夏、冬、春、秋季四个航次和“908”补充调查的8月航次资料对长江口及邻近海区表层水体溶解氧及其饱和度进行了探讨.研究表明东海北部表层水体在夏季和春季以浮游植物光合作用为主要控制过程,特别是7、8月份长江口外、杭州湾外及浙江近海存在大范围的强光合作用区;秋季以有机质氧化分解过程为主,表层溶...     

Hilbert-Huang变换在瞬变电磁去噪中的研究与应用

瞬变电磁法(TEM)是电法勘探的一个重要分支,具有受地形影响小、工作效率高、对低阻体分辨率高纯异常测量等优点.在野外数据采集过程中,瞬变电磁数据容易受到周边环境噪声的干扰.由于瞬变电磁的晚期信号能量弱,极易被噪声淹没,使得数据处理过程中出现假异常.为了更好地减弱噪声的影响,剔除假异常,得到真实的地下介质信息.本文把Hilbert-Huang变换(Hilbert-Huang Transform,简称HHT)方法应用到瞬变电磁数据处理中,通过对含有噪声的瞬变电磁仿真数据进行经验模态(Empirical Mode Decomposition,EMD)分解、重构,得到了真实的电磁信号,证明HHT方法在瞬变电磁去噪中可行.最后对TEM实测数据进行EMD分解、重构,结果表明该方法能够有效的压制噪声的干扰,突出TEM真实信号,较好的识别异常体的位置,提高TEM解译结果的准确性.