影响海陆交互相沉积物亮度的几个因素

对中国北方莱州湾南岸钻孔上部54m海陆交互相沉积物的亮度进行研究,探讨其作为海陆交互相沉积物的环境指标的可行性,同时通过对比不同样品处理方式所得的亮度值探讨影响亮度的几个因素。测量分2次进行,分别使用Minolta CM-2002分光光度计针对柱状原样及Minolta CR400/410色差计针对风干研磨后的散样进行。研究结果表明,海陆交互相沉积物的亮度,尤其是经过风干处理后样品的亮度值,与碳酸钙含量及粒度两个古气候代用指标均具有显著相关关系,可以将其作为碳酸钙含量的替代指标应用于海陆交互相沉积物的环境演化研究。而亮度值与碳酸钙含量不一致性,可归因于沉积物中非碳酸钙组分的性质及含量。粒度与亮度的相关性显示,钻孔砂质沉积中含有的大量深色的有机质使得钻孔中粒度0～31μm的部分比例越高,亮度会越大,而粒度>31μm的部分比例越高,亮度会越小。2次亮度值的对比表明,水分、氧化作用及研磨是沉积物2次测量所得亮度值存在差异的主要原因。     

基于车辆导航的路径分析与应用

在目前前的车辆自导航系统（VANS）中,普遍存在着路径分析功能不强的问题,本文围绕这个问题,从其相关技术方面进行了研究,并通过实例进行了验证。     

机载LiDAR正射影像镶嵌线智能优化研究

在机载LiDAR系统中,将点云数据进行滤波以去除高地物,确定出房屋树木等高出地面的地物的位置记为障碍区域。在配准后的正射影像上,利用改进A*算法自动避开障碍区域选择一条最优化镶嵌线。实验证明,该方法可以准确、智能地对镶嵌线进行优化,改善镶嵌后的影像质量。     

海南交通可达性的测度与空间分异格局分析

设定交通可达性指数及交通区位优势度、内部交通连通度和对外通达性3个分指数,全面测度海南各县级行政区的交通可达性,在此基础上,采用Global Moran’s I和Getis-Ord G_i^*指数分析与全局趋势分析方法,从多个维度系统研究海南交通可达性空间分异现状格局。结果显示,目前海南各县级行政区交通可达性差异很明显;海南岛交通可达性总体呈沿海内陆分异与北南方向类似U型分异格局,交通可达性的3个分指标均存在鲜明的空间分异特征,即交通区位优势度与交通可达性总体分异格局基本一致,内部交通连通度呈北部较高、中部内陆到西南沿海较低而东南沿海居中的分异格局,对外通达性呈沿海内陆分异及北南和东西方向双重类似U型分异格局;三沙市是海南一个特殊的沿海地级市,其交通可达性很差。地形地貌、经济发展水平、人口和政治因素对海南交通可达性空间分异产生了明显的影响。推进海南经济发展需要充分利用交通条件进行经济空间布局引导,并逐步增强交通布局的空间均衡性。     

A shortest path algorithm with novel heuristics for dynamic transportation networks

Finding an optimal route in dynamic real‐time transportation networks is a critical problem for vehicle navigation. Existing approaches are either too complex or incapable of managing complex circumstances where both the location of a mobile object and traffic conditions change over time. In this paper, we propose an incremental search approach with novel heuristics based on a variation of the A* algorithm–Lifelong Planning A*. In addition, we suggest using an ellipse to prune the unnecessary nodes to be scanned in order to speed up the dynamic search process. The proposed algorithm determines the shortest‐cost path between a moving object and its destination by continually adapting to the dynamic traffic conditions, while making use of the previous search results. Experimental results evince that the proposed algorithm performs significantly better than the well‐known A* algorithm.     

A non-LTE abundance analysis of the post-AGB star ROA 5701

An analysis of high-resolution Anglo-Australian Telescope (AAT)/University College London Échelle Spectrograph (UCLÉS) optical spectra for the ultraviolet (UV)-bright star ROA 5701 in the globular cluster ω Cen (NGC 5139) is performed, using non-local thermodynamic equilibrium (non-LTE) model atmospheres to estimate stellar atmospheric parameters and chemical composition. Abundances are derived for C, N, O, Mg, Si and S, and compared with those found previously by Moehler et al. We find a general metal underabundance relative to young B-type stars, consistent with the average metallicity of the cluster. Our results indicate that ROA 5701 has not undergone a gas–dust separation scenario as previously suggested. However, its abundance pattern does imply that ROA 5701 has evolved off the asymptotic giant branch (AGB) prior to the onset of the third dredge-up.     

Orbital solution for the MACHO*05:34:41.3–69:31:39 O3 If* +O6:V eclipsing binary system in the Large Magellanic Cloud

An orbital solution for the MACHO*05:34:41.3–69:31:39 eclipsing binary system is presented, based on the published light curve and spectral data obtained with the 2.15-m telescope at CASLEO. Based on these spectroscopic observations, the binary components of this system were classified as O3 If* and O6:V respectively. The radial velocity data along with the published light curve were analysed with the Wilson–Devinney code to derive the following masses and radii for the components of this system:             and     The solution shows that the system is in overcontact, as one would expect from the derived masses and the very short orbital period (∼1.4 d).     

5种不同颜色空间的均匀性研究

颜色的均匀性是评价颜色空间的优劣和影响其选择使用的重要指标之一,其色差计算值对于颜色再现评价的再现过程控制具有重要作用.在中国颜色体系的基础上,分别从明度、色相和彩度的角度对颜色空间CIE L*a*b*、CIE L*u*v*、NC-IIIC、L*a*b*-N和CIECAM02-UCS的均匀性进行了分析和比较.结果表明,这几种颜色空间明度的均匀性都比较理想,而色相和彩度的均匀性较差.就这5种颜色空间而言,NC-IIIC和L*a*b*-N颜色空间均匀性要优于其他颜色空间.     

A*搜索算法的正射影像镶嵌线自动提取

针对现有的正射影像镶嵌过程中镶嵌线的提取所存在的缺陷,该文提出一种基于A*搜索算法的镶嵌线自动提取方法,此方法首先提取重叠区域的Canny边缘图像,并把边缘图像中的边缘信息作为需要避开的范围;然后基于边缘图像的每一个像素及像素间的邻接关系构建带权有向图,将镶嵌线的自动提取转换为带权有向图中起点到终点的路径搜索问题,设计满足可接纳性准则的A*搜索算法提取满足一定条件的最短路径作为全局最优镶嵌线。利用实际影像数据进行实验,实验结果表明:该算法自动提取得到的镶嵌线可以快速、有效的避开边缘特征明显区域,对全自动正射影像制作具有应用价值。     

当前我国矿业改革与发展的资本市场问题

通过对我国大型矿山企业基本情况的分析提出了推进资产重组的必要性和建议 ,认为走股份制道路是其有效途径。并充分利用现有政策、措施和两个市场 ,两种资源 ,促进企业扭亏为盈 ,对资产重组中可能出现的几个问题提出了看法。