Anisotropy of the horizontal velocity fluctuation field in the large wavenumber region

Mesoscale atmospheric wind, temperature, and density fluctuations are described in terms of their power spectra. In the early 1980s, VanZandt[1] showed that the observed spectrum of the atmospheric fluctuations can result, as in the ocean, from an interna…     

GPS伪距改正及精密动态单点定位精度分析

给出了GPS伪距定位在动态模式下的改正模型：对流层折射延迟、电离层延迟改正、地球自转改正、相对论效应改正、卫星天线和接收机天线改正、固体潮改正。并针对单频GPS接收机进行动态伪距定位的试验，分析了各项改正对GPS伪距定位的精度影响及综合改正后的精度分析。     

应用多种测量软件对地图后期处理

随着电子地图的出现和各种测量软件的开发，地形图实现了美观化和统一化。而各种测绘软件提供的开放性，也使我们可以在不同的测绘软件中对地形图加以编辑和修改，充分利用各个测绘软件的优势。本文结合实际工作经验，针对具体工作中遇到的一些问题，利用各种测绘软件的结合，使一些问题得到解决，并使图形更趋于美观化。     

高分辨率影像定位的一种新方法

提出了利用小比例尺地形图和多分辨率影像实现高分辨率遥感影像定位的方法。阐述了利用线状地物代替点状地物实现低分辨率影像相对于小比例尺地形图纠正定位的方法，并通过金字塔结构的多分辨率影像逐级匹配，使高分辨率影像上的细致目标得以绝对定位。     

一种基于Cross-Validation的盲图像恢复方法

图像盲复原所面临的主要问题是可利用的信息不足，目前已有的图像盲复原算法一般都是有先验知识，如非负和有限支持域的限制。但在实际中目标的支持域是未知的。文中介绍了CV(cross-validation)的基本原理，给出了一种基于CV原理的支持域确定方法的详细步骤；并针对计算大的问题提出了一定的改进。最后给出了实验结果，证明CV确定支持域的方法对于图像盲复原是有一定价值的。     

IMPACTS OF TRANSPORTATION CHANGES ON THE WOODWORKING INDUSTRY OF MEXICO'S PURÉPECHA REGION

ABSTRACT. The PurÉpecha region of Michoacán State, in west‐central Mexico, has a strong tradition of craft production, especially wooden items. Transportation improvements in the region since the mid‐twentieth century have led to a higher level of integration of the regional economy, yet access to the broader Mexican market remains limited. Towns throughout the region have experienced substantial changes in the types of crafts produced, the extent of their local and external markets, and the location of craft production. Transportation improvements have, in part, led to agglomeration economies and a resultant contraction in the number of different types and an increase in the volume of the crafts produced. Market changes have led to the proliferation of craft storefronts in towns with higher levels of accessibility. Conversely, remote towns still rely heavily on distributors and have not been able to expand their markets. As a result, the region has seen the development of a two‐tiered system whereby towns with increased accessibility have viable craft industries and towns with limited accessibility struggle with stagnant craft industries.     

基于紧支径向基函数的点插值无网格方法

紧支径向基函数能使支配方程中的刚度矩阵具有稀疏性,很适合应用于无网格方法中,其缺点是在插值计算时精度不高.点插值方法的插值函数具有Delta函数性质,可以很方便的施加本质边界条件,但在计算插值函数时矩阵易出现奇异.为了提高计算精度并避免点插值法的局限性,首先对紧支径向基函数进行完备性修正,然后用完备性修正的紧支径向基函数代替多项式来形成插值函数,建立了紧支径向基函数点插值方法.由于该方法中的形函数满足Delta函数性质,因此本质边界条件可以像传统的有限元方法一样很容易施加.然后将该方法用于二维弹性静力问题的求解,导出了其相应的离散方程.最后将该方法应用于一个悬臂梁的分析中,初步验证了该方法的有效性与合理性.     

流域水资源承载能力综合评价的多目标决策-理想区间模型

水资源承载能力评价，是一个由多目标组成的复杂巨系统，其难点是如何合理地建立评价该系统的数学模型。由于评价标准是区间概念而非点的概念，因而传统的多目标决策一理想点法把评价标准处理成理想点存在一定缺陷。为了克服这种缺陷，对多目标决策理想点法进行了改进，提出了一种新的评价模型——多目标决策一理想区间模型(MODMIIM)，介绍了MODMIIM的原理，给出了其构成方法，并用MODMIIM对淮河流域的水资源承载能力进行了综合评价，结论为淮河流域的水资源承载能力总体上较弱。MODMIIM可操作性强，计算结果稳定、合理。与多目标决策一理想点法相比，MODMIIM具有更大的适用性。MODMIIM可广泛应用于各种水资源综合评价问题中。     

突变理论在断层检测中的应用尝试

简述了突变理论中的尖点突变模型及其表达式，将地震信号转化为尖点突变的标准形式，在时间域内计算突跳势、突跳时间等突跳参数，发现突跳参数曲线上异常的位置与地下断层的位置有关。在这里尝试将突变理论应用于断层的检测，分析了突变理论在断层检测理论上的可行性，对实际地震剖面进行分析解释，取得了一定的效果。这说明利用突变参数进行断层的检测是可行的，突变理论将为地震资料解释提供一种新的途径。     

Paléoclimat des Petites Antilles depuis 4000 ans BP : l'enregistrement de la lagune de Grand-Case à Saint-Martin

A 2.5-m-thick sequence of lake sediments at the Étang de Grand-Case, Saint Martin (French West Indies) is studied here. Significant hydrological budget fluctuations allows distinction of three main climatic periods: (1) an overall dry period (4200 BP–2300 BP), characterised by carbonated mud, gypsum and storm sand layers; (2) a wet phase (2300 BP–1150 BP) dominated by organic mud; and (3) a more complex phase (1150 BP to present), with detrital inputs due to human activities. Comparison with other regional high-resolution records shows that similar climate modifications typify the whole Mesoamerican and Caribbean area. The climatic phenomena that are implicated in the variations of both precipitation and hurricane frequency over the Lesser Antilles are due to the latitudinal displacement of the inter-tropical convergence zone. These data give new support to the hypothesis of the existence of a correlation between peopling phases and climate variations in the Caribbean as previously proposed by some archaeologists. To cite this article: P. Bertran et al., C. R. Geoscience 336 (2004).