北极通航下的集装箱运输模式选择优化     

杜刚  唐超乙 《世界地理研究》2014,(4):56-60

随着北极气候的变暖,北极冰川融化,开辟北极新航线成为可能。而作为北极航线东北航道两端的中国和欧洲则是世界上最大的发展中国家和发达国家集团,经济发展日益密切,因此,对中国至欧洲集装箱运输航线模式选择的研究迫在眉睫。如何在新旧两种航线通航的情况下选择一种经济、安全与合理性为一体的运输模式,对中欧的贸易发展有重要影响。首先分析和总结了中国至欧洲集装箱运输航线国内外研究现状,其次构建了中国至欧洲集装箱航线优化的数学模型,并进行了实证研究。本文的研究可为航线管理者提供一定的决策依据。  相似文献   

Sources and transport of organic carbon from the Dongjiang River to the Humen outlet ofthe Pearl River,southern China简   总被引：4，自引：0，他引：4  

FU Yingchun  TANG Congguo  LI Jun  ZHAO Yaolong  ZHONG Wei  ZENG Xiantie 《地理学报(英文版)》2014,24(1):143-158

Transport of organic carbon via rivers to estuary is a significant geochemical proc- ess in the global carbon cycle. This paper presents bulk total organic carbon （TOC） from the Dongjiang catchment to the adjacent Humen outlet, and discusses the applicability of 613C and ratio of carbon to nitrogen （C/N） as indicators for sources of organic matter in the surface sediments. Survey results showed that organic carbon concentration in summer were higher than in the winter. An elevated trend of TOC occurred along the river to the Humen outlet in both surveys, and the highest mean values of dissolved and particular organic carbon （DOC-279 μmol L-1 and POC-163μmol L-1） were observed in the urban deltaic region in summer flood flow. Winter samples had a wide range of b＇13C and C/N （5-3C -24.6%o to -30.0%o, C/N 4-13）, and summer ones varied slightly （8-3C -24.2%o to -27.6%0, C/N 6-18）. As results suggest that POC in the three zones of upstream-delta-outlet dominantly came from riverbank soil, phytoplankton and agricultural C3 plants in winter, whereas main sources were from the riverbank and mangrove soil in summer. Moreover, anthropogenic sewage inputs had 11% and 7% contribution to POC in the deltaic and outlet. Transport accompanied with seasonal freshwater variation, phytoplankton production and degradation, and removal be- havior caused variation of organic carbon concentration. The results also discovered that TOC export bulk in Dongjiang was approximately one quarter of Humen flux in the dry flow, and anthropogenic activity significantly impacted the river export contribution.  相似文献   

影响阿拉善盟现代物流业发展的因素分析     

胡小明 《西部资源》2014,(4):203-204

现代物流业是现代经济社会中不可缺少的中间链条,已经成为国民经济发展的基础性产业。本文通过对阿拉善盟物流业发展的现状、存在的问题和影响现代物流业发展的因素分析,提出了推动当地现代物流业发展的对策及建议。  相似文献   

Optimization of ice cuttings transportation by cable-suspended core auger drills     

HONG Jialin  Pavel Talalay  Mikhail Sysoev 《东北亚地学研究》2014,(1):48-54

Ice cores contain an abundance of information about the Earth＇s climate in the past, and recovered from shallow drilling down to 300-350 m give sufficient information for reconstructing of the last climatic changes and for monitoring of pollution from human being. Cable-suspended core auger drills use an armored cable with a winch to provide power to the down-hole motor system and to retrieve the down-hole unit. Because of their lightweight, convenient transportation and installation, high penetration rates and low power consumption, core auger drills are widely used for shallow drilling in ice. Nowadays at least 14 types of auger electromechani- cal drills were designed and tested in different foreign and national glaciological laboratories. However, auger options were usually determined by experience, and the main parameters （ helix angle of the fights and rotational speed） are varied in a wide range from drill to drill. If parameters of auger are not chosen properly, poorly en- gineered drills had troubles with low efficiency of cuttings transportation, jam of ice cuttings, repeated fragmen- tation, cutters icing and stop penetration, abnormal power consumption, high rotation torques, and so on. Thus, this paper presents the method of optimization of iee cuttings transportation of cable-suspended core auger drill on the base of the theory of rotary auger. As the result, the optimal helix angle was determined correspond- ing to the rotational speed from the transportation efficiency point of view.  相似文献   

隧道斜井无轨运输应急避险车道设计与施工     

赵鹏飞  赵维炜 《地下水》2014,(5)

东湖电站引水隧洞8#支洞投影长度1084.12m,坡度为21.76%属于斜井,支洞开挖成洞断面为5.5m×5.5m。支洞采用无轨运输,由于现场施工各种不确定因素影响,主支洞交叉口安全防护处于薄弱环节,为杜绝安全事故的发生,采用上坡自重减速原理设置应急避险车道,为类似工程提供了参考。  相似文献   

新闻资讯     

《中国勘察设计》2014,(7)

正国务院部署建设综合立体交通走廊打造长江经济带近日,国务院总理李克强主持召开国务院常务会议,部署建设综合立体交通走廊打造长江经济带。会议强调,建设长江经济带,要注重发挥水运运量大、成本低、节能节地的优势,抓好综合立体交通走廊建设。一是加快实施重大航道疏浚整治工程,消除通行瓶颈,扩大三峡枢纽通过能力和干线过江通行能力,提升长江黄金水道功能。二是建设快速大能力铁路通道、高等级广覆盖公路网和航空网络,加强各种运输方式与港区的衔接,完善油气运输通道和储备系统,大力关键词综合立体交通走廊长江经济带  相似文献   

基于BDS的海上运输监控系统设计          下载免费PDF全文

曹宇  刘昕  赵永旗  宋育泽  唐小波  张馨予 《全球定位系统》2022,47(5):81-87

海上运输往往受到高温、高盐及高湿环境的影响,尤其是贵重和精密货物,在运输过程中容易出现损坏风险,因此研发了一种海上运输货物通讯监控系统;这对于海运质量的提升是十分重要的.本文设计了一种基于北斗卫星导航系统(BDS)的海上运输监控系统,将物联网技术和BDS相结合,以实现对货物的实时监测、导航定位及通讯功能,并以多相流量计的运输为例详细阐述了系统的功能实现方式.该系统可以作为减少货损成本,提高运输管理效率的工程化辅助工具.  相似文献