中国-丝路国家基础设施连通性评估方法与格局

基础设施互联互通是不同区域之间空间网络形成的支撑,对区际生产要素流动、市场融合和资源配置具有重要作用,也是“一带一路”建设的重点内容和前提条件。立足于综合基础设施网络,以“一带一路”沿线国家/地区为分析地域,设计数理模型,评价了中国与沿线国家的基础设施网络连通性,考察其基本特征与空间格局,然后分别从铁路、公路、航运、通讯、能源等各种基础设施方式的视角,分析了不同基础设施网络的互联互通水平,探讨了基础设施连通的类型分异及其主导因素,凝练基础设施连通的空间模式。主要结论如下：① 从海陆属性来看,岛屿型国家与中国设施连通性最高,其次为综合型国家,内陆型国家最低。对国际区域而言,俄蒙和东南亚地区与中国的设施连通性最高,中东欧地区连通性最低。从国家尺度来看,俄罗斯和越南是与中国设施连通水平最高的国家,巴勒斯坦、东帝汶等5个国家与中国尚未形成设施连通性。从连通方式的构成来看,航运网络的连通性最高,其次为航空和光缆。② 空间距离、连通方式和重大交通走廊共同主导了设施连通性的类型分异。③ “一带一路”沿线国家/地区与中国的设施连通形成了四种典型模式,包括海陆融合型外缘连通模式、陆路通道直接连通模式、陆心内生性低水平连通模式、远距离不均衡连通模式。     

The identification of global strategic shipping pivots and their spatial patterns

In concert with developments in global trade and energy resource transportation, there has been a marked increase in reliance on overseas shipping. Unimpeded marine transportation has therefore become a key issue which influences national maritime interests including the security of trade and energy resources. A strategic shipping pivot thus performs a vital controlling function for global shipping networks. In this study strategic shipping pivots are defined and subdivided into sea hubs, channels and areas. We then develop a model to identify strategic shipping pivots on a global scale. The results show that, depending on differences in location, function, and type, the concept of strategic shipping pivot permits the identification of both spatial and structural differentiation with respect to strategic hubs, corridors, and seas. Now 44 strategic hubs have formed across the globe. These hubs have become the control centers of local shipping network organization. At the same time, seven strategic corridors containing most shipping routes and transportation capacity connect important sea areas, and permit a high-degree of control over the transport of strategic materials. The strategic seas, the Caribbean, the Mediterranean, Southeast Asia, and the Pacific provide vital import and export pathways, so that the formation of strategic shipping pivots is mainly influenced by factors such as physical geographical conditions, the spatial distribution of socio-economic activities, business organization, technical progress, geopolitical patterns and geopolitical disputes. Physical geographical conditions provide the potential foundations for strategic shipping pivots, while the spatial distribution of socio-economic activities and communications determine the strategic value of these points. Finally, business organization, technical progress, and geopolitical disputes all function to strengthen the strategic mechanisms and the mutagenicity of strategic shipping pivots.     

长江流域港口煤炭运输的空间演化及其影响因素

长江流域是中国相对完整的经济区,依托长江的煤炭运输一直是支撑流域社会经济发展的重要力量,分析长江流域港口的煤炭运输职能对揭示长江港口在流域经济发展中的作用有重要意义。基于此,本文刻画了20世纪80年代以来长江流域港口的煤炭运输格局与演化过程,重点分析煤炭进出港空间格局演变,归纳主要特征,测度空间集散水平并总结演变规律。借助区位商和进出港系数,分析了长江流域煤炭运输职能空间分异的演变过程,并探讨了不同运输职能之间的空间关系。基于不同阶段下港口煤炭运输的空间特征,本文凝练了长江流域港口煤炭运输的空间模式,全面总结了煤炭运输格局演变的驱动因素。以此,为长江流域港口的建设与功能优化提供参考。     

On the variability of vertical eddy heat flux in the upper ocean

Ocean eddies produce strong vertical heat flux (VHF) in the upper ocean, exerting profound influences on the climate and ecosystem. Currently, mooring array provides a standard way to estimate the eddy-induced VHF (EVHF) based on the adiabatic potential density equation. Apart from the validity of adiabatic assumption, it remains unclear to what extent the estimated EVHF at a single location within a limited time period is representative of its climatological mean value. In this study, we analyzed the above issue by systematically evaluating the variability of EVHF simulated by a 1-km ocean model configured over the Kuroshio Extension. It is found that the EVHF at a single location exhibits pronounced variability. Even averaged over one year that is comparable to the current maintenance capacity of mooring array, the EVHF still deviates significantly from its climatological mean value. For more than 49% of locations in our computational domain (31°–40°N, 149°–166°E), the discrepancy between the one-year mean EVHF and its climatological mean value at the peaking depth is larger than the climatological mean itself. The mesoscale eddies play a dominant role in the variability of EVHF but contribute little to the climatological mean EVHF; the opposite is true for submesoscale eddies. Our findings indicate that nested mooring array allowing for isolating the effects of submesoscale eddies will be useful to obtain climatological mean EVHF.     

湘西北花垣县下寒武统清虚洞组浊积岩沉积特征及其地质意义

湘西北花垣县及邻区,在下寒武统清虚洞组下部发育一套地质特征典型、沉积序列明显的浊积岩。其底面侵蚀构造清楚,覆盖于底面上的各层段厚度变化较大,在各层段内由下往上碎屑粒度依次变细,并相继出现有变形纹层、平行纹层和波痕纹层理等沉积构造,是典型的浅海浊积岩。据各层段的发育情况可总结为5种剖面结构。因冰川消融而使海平面上升,故清水洞组浊积期海水深度增大。浊流活动受北东东向保靖—花垣断裂控制,其活动与新元古代发生并延续到早古生代的罗迪尼亚超大陆裂解事件有关。     

大庸地区早寒武世等深岩和风暴岩的发现及产出环境分析

根据发现大庸地区早寒武世等深岩、风暴岩的类型、岩性和剖面层序特征，以及它们的时空分布，分析了它们形成的沉积环境及其与构造活动的关系。     

浦市—辰溪浅层叠瓦状推覆构造特征及地质找矿意义

浦市－辰溪浅层叠瓦状推覆构造位于雪峰山弧形构造带的北西侧，主要由浦市、水井湾、辰溪三条推覆构造带组成，推覆体地层时代为石炭纪、二叠纪、三叠纪及侏罗纪。推覆滑动面呈缓波状弯曲，总体倾向南东，倾角５－４０度不等，推覆滑动面呈叠瓦式排列。原地岩层在推覆构造作用下发生不同程度的褶皱。     

利用样本生成方法进行机载多光谱LiDAR数据深度学习分类

机载多光谱LiDAR系统能够快速、准确地获取地物的空间几何和光谱信息,为地物覆盖分类和目标识别提供新的数据源。近年来,基于三维点云的深度学习算法取得了一系列突破性进展,然而直接将不规则的原始点云数据输入深度学习模型进行基于点的分类存在一定的困难。本文提出了一种基于FPS-KNN的样本生成方法,用于基于深度学习的机载多光谱LiDAR数据分类。该方法首先对输入数据进行归一化处理;然后利用最远点采样方法(FPS)和K近邻法(KNN)在输入数据中生成一系列规则大小的训练样本数据集。通过机载多光谱LiDAR数据的试验表明,该方法所生成的样本不仅符合卷积神经网络所要求的输入数据形式,而且能够确保对输入场景的完整覆盖。     

基于DMSP/OLS夜光遥感影像的城市扩张政策驱动因素分析

城市扩张的速度和方向已成为社会关注的焦点,利用夜光遥感进行城市扩张驱动力成因分析是近年来的研究热点。本文采用DMSP卫星所获取的年平均中国区域夜光影像数据,首先对1992—2012年共21年的时序夜光影像进行相对辐射定标;其次通过经验阈值法进行城市建成区面积提取,并通过Landsat影像进行精度验证;最后引入计量经济模型,以地级市主政官员政治周期为解释变量,对全国1992—2012年地级市扩张的政策驱动力因素进行了归因分析。通过本文的分析可知,地级市主政官员政治周期的更替对城市扩张方向存在显著影响。     

基于TECR的GPS三频数据周跳探测方法研究

基于三频伪距相位和无几何相位组合周跳探测与修复的基本原理,分析电离层活跃期电子含量变化率的特点,提出削弱电离层影响的三频组合周跳探测与修复方案。实验表明,本文方法能够有效探测和修复电离层活跃观测条件下观测数据中的所有周跳,且周跳探测阈值较小,不存在敏感周跳。