An organizational model and border port hinterlands for the China-Europe Railway Express

Facilities connectivity is a priority area for implementing the Belt and Road Initiative (BRI). The “China-Europe Railway Express” (CER Express) mode of transport organization links China with Europe by fast-track cargo rail. A major instance of facilities connectivity related to this project is an important practical and symbolic instance of BRI transport cooperation. The strategic significance of the CER Express and a number of operational issues are outlined, as are the implications of limited market potential for costs and competitiveness. A “hub-and-spoke” organizational model that can generate scale economies and reduce costs is proposed. To examine the establishment of an organizational model of this kind, the economic hinterlands of Alashankou, Erenhot, and Manzhouli are identified under high-, mediumand low-cost scenarios using an analytical methodology that determines distance and economic costs, and a number of transport hubs (that include Harbin, Zhengzhou, and Lanzhou) are identified. The results found that the cost of the routes from 314 Chinese cities to Moscow is the lowest via Manzhouli in the high- and medium-cost scenarios, but the routes change via Erenhot in the low-cost scenario. A number of policy recommendations should follow up.     

Complete mitochondrial genomes of two deep-sea pandalid shrimps,Heterocarpus ensifer and Bitias brevis: insights into the phylogenetic position of Pandalidae (Decapoda: Caridea)

Journal of Oceanology and Limnology - The mitochondrial genome (mitogenome) analysis is a significant tool for investigating the evolutionary history of metazoan animals. The family Pandalidae is a...     

Distribution of aliphatic des-A-triterpenoids in the Dajiuhu peat deposit, southern China

Aliphatic des-A-triterpenoids have been tentatively assigned in samples taken from a 260 cm thick peat sequence from the Dajiuhu Basin of southern China using gas chromatography–mass spectrometry (GC–MS). The compounds, possessing the carbon skeletons of oleanane, ursane or lupane, are generally considered as the microbial degradation products of plant triterpenoids under anoxic conditions. Abundant aliphatic des-A-triterpenoids were observed only in peat samples during the transitional period from the last glaciation to the early Holocene (9.5–11.6 cal ¹⁴C ka BP). Among these, des-A-lupane is the only saturated ring A-degraded compound, whilst mono- and di-unsaturated des-A-triterpenes are dominated by oleanane and ursane derivatives. The mono- and di-unsaturated des-A-triterpenes show a strong correlation (R² 0.94) in abundance, indicating that they may be derived from the same source or process. Des-A-lupane shows no correlation in abundance with the mono- or di-unsaturated des-A-triterpenes (R² < 0.25) and may be derived from a different source or process in the catchment. The period with abundant aliphatic des-A-triterpenoids corresponds to the interval with relatively high sedimentation rate (> 0.3 mm per year). These data indicate that the abundance of aliphatic des-A-triterpenoids in the Dajiuhu peat deposit in the early Holocene may result from the prevailing reducing conditions in the water table or surficial sediment and/or rapid preservation of the early diagenetic products. Our study highlights the potential application of des-A-triterpenes in the reconstruction of palaeoenvironments based on peat sequences.     

气候变化对寒区水循环的影响研究进展

随着全球气候变暖,气候的变异性变得越来越极端,极端天气事件的频率和强度也在不断地上升.气候变化改变了水文循环,其变化趋势对世界水资源的管理提出了严峻的考验.气候变化对寒区水循环的影响包括对降水、蒸散发、径流、降雪与积雪面积、冰川和冻土等方面的影响: 近百年来,全球降水在波动中略有增加;在北半球水面蒸发量呈逐步减少的趋势,径流量及其时空分布发生了巨大变化;全球以积雪形式的降水越来越少,且积雪面积越来越小; 冰川出现加速退缩的现象.随着全球变暖,多年冻土融化,导致活动层厚度有明显增大趋势.所有现存的模型都表明了一个更暖的未来世界.为降低地球各圈层系统对气候变化的脆弱性,需要控制温室气体的排放,建立更精确的气候预测模型,提高水资源管理者的技术水平等手段来提高系统的适应能力,以解决人类的水资源需求问题.     

Mini SAR遥感系统测图

Mini SAR遥感系统,用微小型SAR做传感器,通过小型飞机或无人机为遥感平台获取地物信息,但载机平台在空中易受气流影响而偏离预设航线产生运动误差。文中首先分析载机平台运动特点,介绍系统中IMU/GPS组合导航数据预处理过程,论述载机平台转动误差、速度误差对SAR成像距离模型的影响。MiniSAR遥感系统获取的影像清晰,可用于制作正射影像图、基础地理信息库更新、灾害监测应急等领域,但不足之处在于影像中某些金属目标出现方位散焦现象。     

近55年淮河上中游流域气候要素多时间尺度演变特征及关联性分析

选取1960~2014年淮河上中游流域19个气象站点的月降水量、气温和日照时数等数据,采用气候倾向率、Mann-Kendall、Morlet小波和相关系数法,对流域年和四季降水、气温和日照时数的变化趋势、多时间尺度演变特征以及相关性进行了研究。结果表明：① 降水在年和四季线性变化趋势不显著;气温除夏季不显著外,年和春、秋、冬季变暖趋势显著;日照时数除春季不显著外,年和夏、秋、冬季节变短趋势显著;② 降水、气温、日照时数在年和四季分别表现出多个时间尺度的相对丰枯、冷暖和长短交替特征;第一主周期尺度及其相应的平均变化周期在年和四季有的较接近有的相差较大,第一主要平均周期介于2~10 a之间;③ 气温的复相关系数均小于降水和日照时数;除冬季气温复相关系数较小外,其他季节各要素均较大。降水-日照的偏相关系数绝对值在年和四季均最大。降水-日照时数、降水-气温大部分情况呈反相关系,冬季气温和日照时数在主周期尺度28 a下呈同相变化。     

海城地震地区地壳三维结构特征

用一种新的地震波速图象研究方法和计算程序，处理了辽宁省地震台网观测资料，反演得到海城地震地区及其周围地壳三维速度结构，再次证实海城震区东西两侧的地壳结构有明显差异，海城地震的震源位于一个北西走向的低速体上方     

中国外商直接投资的地域结构研究

改革开放以来,我国引进外资工作取得了较大进展。然而,外资地域分布的不平衡,成为导致区域经济发展水平差距拉大的一个重要原因。如何改善外资地域分布结构,成为各界关注的焦点之一。文中采用定量和定性相结合的方法,研究了中国外资地球分布的现状及特点,分析了外资地域分布的动态变化趋势,并在此基础上提出若干改善外资地域分布结构的举措。     

黔中茶店桥地下河流域不同水体硫酸盐浓度特征及来源识别

茶店桥地下河位于西南岩溶区,流域内"三水"转换迅速,地下水是当地的重要饮用水源。本文对流域内雨水、地表水、地下水中的SO_4~(2-)浓度进行了测试,利用氘(δD_(H_2O))、氧(δ~(18) O_(H_2O))同位素示踪地表水、地下水补给来源,用硫酸盐硫(δ~(34)S_(SO4))、氧(δ~(18) O_(SO4))同位素探讨了地表水、地下水中SO_4~(2-)的来源,并计算了地下河出口河水中不同SO_4~(2-)来源的贡献比例。结果表明:1不同水体中SO_4~(2-)浓度大小顺序为地表水地下水雨水,与邻近区域相比,茶店桥地下河流域雨水、地表水、地下水呈现富集SO_4~(2-)的特征。2地表水、地下水的主要补给来源为大气降水,硫酸不仅和HCO_3~-共同参与了流域内碳酸盐岩的溶解,也参与了雨水中含钙镁颗粒物的溶解。3地表水δ~(34)S_(SO4)、δ~(18) O_(SO4)值分别介于-12.98‰~-10.19‰和-0.54‰~+9.13‰之间,地下水δ~(34)S_(SO4)、δ~(18) O_(SO4)值分别介于-14.32‰~+16.58‰和+2.81‰~+14.35‰之间,SW02的SO_4~(2-)主要来源于大气降水,SW01、SW03、GW02、GW03、GW06主要来源于煤层,GW05主要来源于石膏,GW01、GW04为混合输入源。4地下河出口河水中大气降水带来的SO_4~(2-)贡献比例为13%,煤层硫化物氧化的贡献比例为40%,石膏溶解的贡献比例为47%。