Linking Tarim Basin sea retreat (west China) and Asian aridification in the late Eocene

The Tarim Basin in western China formed the easternmost margin of a shallow epicontinental sea that extended across Eurasia and was well connected to the western Tethys during the Paleogene. Climate modelling studies suggest that the westward retreat of this sea from Central Asia may have been as important as the Tibetan Plateau uplift in forcing aridification and monsoon intensification in the Asian continental interior due to the redistribution of the land‐sea thermal contrast. However, testing of this hypothesis is hindered by poor constraints on the timing and precise palaeogeographic dynamics of the retreat. Here, we present an improved integrated bio‐ and magnetostratigraphic chronological framework of the previously studied marine to continental transition in the southwest Tarim Basin along the Pamir and West Kunlun Shan, allowing us to better constrain its timing, cause and palaeoenvironmental impact. The sea retreat is assigned a latest Lutetian–earliest Bartonian age (ca. 41 Ma; correlation of the last marine sediments to calcareous nannofossil Zone CP14 and correlation of the first continental red beds to the base of magnetochron C18r). Higher up in the continental deposits, a major hiatus includes the Eocene–Oligocene transition (ca. 34 Ma). This suggests the Tarim Basin was hydrologically connected to the Tethyan marine Realm until at least the earliest Oligocene and had not yet been closed by uplift of the Pamir–Kunlun orogenic system. The westward sea retreat at ca. 41 Ma and the disconformity at the Eocene–Oligocene transition are both time‐equivalent with reported Asian aridification steps, suggesting that, consistent with climate modelling results, the sea acted as an important moisture source for the Asian continental interior.     

Geometric-based approach for integrating VGI POIs and road networks

Integrating heterogeneous spatial data is a crucial problem for geographical information systems (GIS) applications. Previous studies mainly focus on the matching of heterogeneous road networks or heterogeneous polygonal data sets. Few literatures attempt to approach the problem of integrating the point of interest (POI) from volunteered geographic information (VGI) and professional road networks from official mapping agencies. Hence, the article proposes an approach for integrating VGI POIs and professional road networks. The proposed method first generates a POI connectivity graph by mining the linear cluster patterns from POIs. Secondly, the matching nodes between the POI connectivity graph and the associated road network are fulfilled by probabilistic relaxation and refined by a vector median filtering (VMF). Finally, POIs are aligned to the road network by an affine transformation according to the matching nodes. Experiments demonstrate that the proposed method integrates both the POIs from VGI and the POIs from official mapping agencies with the associated road networks effectively and validly, providing a promising solution for enriching professional road networks by integrating VGI POIs.     

中国交通CO2排放时空格局演变及其影响因素——基于2000~2012年30个省（市）面板数据的分析

通过构建交通CO₂排放模型对2000~2012年中国30个省（市）的交通CO₂排放时空演变特征进行了分析。并采取“由大到小”逐步回归的建模方式,在传统的固定效应模型（面板数据模型）基础上引入时间固定效应,构建了双向固定效应模型对中国交通CO₂排放的社会经济、城市形态、交通发展等方面的影响因素进行研究。结果表明：2000~2012年期间,中国交通CO₂排放总量和人均交通CO₂排放量分别以9.29%和8.69%的年均增速增长,前者的区域差异呈先增后减趋势,后者的区域差异则首先呈周期性波动,而后一直保持减少趋势。人均GDP和城镇居民家庭人均可支配收入对人均交通CO₂排放具有显著的正向效应,表明社会经济发展和居民收入水平提高是交通CO₂排放增长的主要驱动因素。城市人口密度对交通CO₂排放亦具有显著的正向效应,这意味着未来中国应加强对城市人口密度的规划控制,以避免因人口过度集聚而额外增加产生交通CO₂排放。公共交通发展水平对交通CO₂排放增长具有显著的负向效应,但小汽车拥有率对交通CO₂排放的影响并不显著。     

Porphyry Molybdenum Prospectivity in the Zhongdian Arc,SW China: Use of Singularity and Factor Analyses for Resource Assessment

Natural Resources Research - The Zhongdian arc is an important mineral province in southwest China that hosts significant Cu- and Mo-rich ore deposits. These are mainly present as Late Triassic...     

Possible influence of Arctic oscillation on precipitation along the East Asian rain belt during boreal spring

Theoretical and Applied Climatology - The sandy land in the southern region of the Tengger Desert is adjacent to cities and towns, and land desertification poses a threat to the livelihood and...     

德阳市砂梨气候适应性区划

梨的总产量居德阳水果类第一。本文介绍了德阳砂梨种植现状、分析了气候条件对其品质的影响,利用“3S”技术将德阳划分为砂梨适宜区、次适宜区和不适宜区三大类型,并提出有针对性的对策建议,对德阳砂梨的产业化布局和发展将起到科学的指导作用。     

克氏原鳌虾气象因子影响研究现状与展望

克氏原螯虾主要养殖在长江中下游地区,目前最主要的养殖模式为虾稻共作模式。大量研究结果表明,克氏原螯虾的生长发育与气象要素密切相关。水温在25-30℃时,克氏原螯虾生长较快;16-25℃水温范围内,温度越高,越有利于雌虾卵巢发育;20-30℃水温范围内,水温越高,受精卵孵化时间越短。光明和黑暗时间之比为16 h∶8 h时,最有利于雌虾性腺发育。与克氏原螯虾养殖有关的气象灾害主要有暴雨洪涝、高温热害、低温冷害。鉴于目前的养殖和气象因子影响研究及服务现状,建议气象部门开展虾-稻种养基地气象观测站网建设,开展气温与水温相关性和水温预报研究,以及气象要素对克氏原螯虾影响的定量化研究。     

砒砂岩区地貌形态三维分形特征量化及空间变异

针对现有地貌形态三维分形模型结构存在的不足,构建一个新的地貌形态三维分形维数测算模型。基于该模型对砒砂岩区274个小流域的地貌形态三维分形维数进行计算并分析其空间变异规律。研究表明：① 基于该模型计算的分形维数能更准确地反映地貌形态复杂度信息;② 砒砂岩区小流域地貌形态三维分形维数介于1.683 6~1.948 6之间;③ 地貌形态三维分形维数整体上覆土砒砂岩区（均值为1.765 9）<裸露砒砂岩强度侵蚀区（均值为1.785 4）和剧烈侵蚀区（均值为1.774 8）<覆沙砒砂岩区（均值为1.796 6）。由于地表覆盖物、砒砂岩裸露程度和土壤侵蚀机理的差异而形成的不同地貌特征是该区地貌形态分形特征空间变异的主要原因。