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应用自回归积分移动平均法预测铁路货源货流发展趋势 被引量:10
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作者 袁振洲 《铁道学报》 EI CSCD 北大核心 1996年第A00期52-56,共5页
在分析铁路货源货流数据的内在规律及其时间序列特性的基础上,提出应用自回归积分移动平均(ARIMA(p,d,q))模型预测其发展趋势的理论依据,详细说明ARIMA方法的基本原理和建模步骤,并给出模型的实际应用效果。
关键词 预测 货源 铁路运输 物物运输 ARIMA法
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Mineral distributions in surface sediments of the western South Yellow Sea:implications for sediment provenance and transportation 被引量:11
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作者 卢健 李安春 +1 位作者 黄朋 李艳 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第2期510-524,共15页
The South Yellow Sea(SYS) is strongly influenced by the substantial sediment loads of the Huanghe(Yellow)(including the modern Huanghe and abandoned old Huanghe subaqueous delta) and Changjiang(Yangtze) Rivers. Howeve... The South Yellow Sea(SYS) is strongly influenced by the substantial sediment loads of the Huanghe(Yellow)(including the modern Huanghe and abandoned old Huanghe subaqueous delta) and Changjiang(Yangtze) Rivers. However,the dispersal patterns of these sediments,especially in the western SYS,have not been clearly illustrated. In this study,we have analyzed clay minerals,detrital minerals,and grain sizes for 245 surface sediment samples(0–5 cm) collected from the western SYS. The clay minerals,on average,consist of 67% illite,14% smectite,11% chlorite,and 8% kaolinite. Clay minerals,detrital minerals,and grain size analyses of surface sediments,combined with water mass hydrology analysis,reveal that sediments in the western SYS are mainly derived from the modern Huanghe River,the abandoned subaqueous delta of the old Huanghe River,some material from the Changjiang,and coastal erosion. The clay minerals(especially illite and smectite) and quartz/feldspar ratio distribution patterns,reveal that the influence of modern Huanghe sediments can reach 35°N in the northwestern part of the study area,an influence that can be enhanced especially in winter owing to northerly winds. Conversely,sediments along the Jiangsu coast are mixed,in summer,with material from the Changjiang arriving via northward flow of Changjiang Diluted Water. The Subei Coastal Current carries the refreshed sediments northward into the western SYS. Sediment distribution and transport in the western SYS are mainly controlled by the oceanic circulation system that is primarily related to the monsoon. 展开更多
关键词 South Yellow Sea clay mineral Subei Coastal Current PROVENANCE
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Innovation in Maritime Logistics Industry of Bangladesh for Doing Port Transport Business
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作者 Razon Chandra SAHA 《Journal of Shipping and Ocean Engineering》 2017年第2期78-92,共15页
Bangladesh has the lucrative maritime load centers or seaports to provide maritime logistics support as well as to do port transport business regionally with India, Nepal and Bhutan and internationally with China and ... Bangladesh has the lucrative maritime load centers or seaports to provide maritime logistics support as well as to do port transport business regionally with India, Nepal and Bhutan and internationally with China and Myanmar. Existing land ports as alternatives of dry ports are main strength of Bangladesh to connect with the seaports and offer port transport business for earning foreign exchange and able to play a vital role to develop the South Asia, SW part of China and Myanmar by serving the maritime logistics facilities timely and economically. In here, dry port concept is the main theme for developing port transport business where road, rail and waterways are the connectors or modes of transportation and seaports are the linking points with the sea world, Innovation is the key of success of a business idea and plan where maritime logistics business is the new opportunity of Bangladesh by using natural resources or seaport by mounting infrastructure facilities of nodes (seaport and dry port) and modes (road, rail and waterways) and adding speedy port transport for all. The intermodal freight transportation system is the new concept for creating the new era in the port transport business by using nodes, modes and technology innovatively. This research aims to find out the possible ways and innovations in maritime logistics for doing port transport business by using seaports and land ports by applying qualitative research methodology. The paper also describes the innovations of Rotterdam port as case study that facilitated the needs of a hinterland in Europe to explore the innovations for Bangladesh maritime logistics industry. 展开更多
关键词 INNOVATION MARITIME BUSINESS infrastructure intermodal ROTTERDAM hinterland.
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Origins of Terrestrial Organic Matter in Surface Sediments of the East China Sea Shelf 被引量:7
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作者 ZHANG Hailong XING Lei ZHAO Meixun 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第5期793-802,共10页
Terrestrial organic matter(TOM) is an important component of marine sedimentary OM, and revealing the origins and transport mechanisms of TOM to the East China Sea(ECS) is important for understanding regional carbon c... Terrestrial organic matter(TOM) is an important component of marine sedimentary OM, and revealing the origins and transport mechanisms of TOM to the East China Sea(ECS) is important for understanding regional carbon cycle. A novel approach combining molecular proxies and compound-specific carbon isotopes is used to quantitatively constrain the origins and transport mechanisms of TOM in surface sediments from the ECS shelf. The content of terrestrial biomarkers of(C_(27)+C_(29)+C_(31)) n-alkanes(52 to 580 ng g^(-1)) revealed a seaward decreasing trend, the δ^(13)CTOC values(-20.6‰ to-22.7‰) were more negative near the coast, and the TMBR(terrestrial and marine biomarker ratio) values(0.06 to 0.40) also revealed a seaward decreasing trend. These proxies all indicated more TOM(up to 48%) deposition in the coastal areas. The Alkane Index, the ratio of C_(29)/(C_(29)+C_(31)) n-alkanes indicated a higher proportion of grass vegetation in the coastal area; While the δ13C values of C_(29) n-alkane(-_(29).3‰ to-33.8‰) indicated that terrestrial plant in the sediments of the ECS shelf were mainly derived from C_3 plants. Cluster analysis afforded detailed estimates of different-sourced TOM contributions and transport mechanisms. TOM in the Zhejiang-Fujian coastal area was mostly delivered by the Changjiang River, and characterized by higher %TOM(up to 48%), higher %C_3 plant OM(68%-85%) and higher grass plant OM(56%-61%); TOM in the mid-shelf area was mostly transported by aerosols, and characterized by low %TOM(less than 17%), slightly lower C_3 plant OM(56%-72%) and lower grass plant OM(49%-55%). 展开更多
关键词 alkanes coastal terrestrial shelf sedimentary mostly aerosols vegetation quantitatively decreasing
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Relative pollen productivities of typical steppe species in northern China and their potential in past vegetation reconstruction 被引量:13
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作者 XU QingHai CAO XianYong +6 位作者 TIAN Fang ZHANG ShengRui LI YueCong LI ManYue LI Jie LIU YaoLiang LIANG Jian 《Science China Earth Sciences》 SCIE EI CAS 2014年第6期1254-1266,共13页
The Relative Pollen Productivities(RPPs)of common steppe species are estimated using Extended R-value(ERV)model based on pollen analysis and vegetation survey of 30 surface soil samples from typical steppe area of nor... The Relative Pollen Productivities(RPPs)of common steppe species are estimated using Extended R-value(ERV)model based on pollen analysis and vegetation survey of 30 surface soil samples from typical steppe area of northern China.Artemisia,Chenopodiaceae,Poaceae,Cyperaceae,and Asteraceae are the dominant pollen types in pollen assemblages,reflecting the typical steppe communities well.The five dominant pollen types and six common types(Thalictrum,Iridaceae,Potentilla,Ephedra,Brassicaceae,and Ulmus)have strong wind transport abilities;the estimated Relevant Source Area of Pollen(RSAP)is ca.1000 m when the sediment basin radius is set at 0.5 m.Ulmus,Artemisia,Brassicaceae,Chenopodiaceae,and Thalictrum have relative high RPPs;Poaceae,Cyperaceae,Potentilla,and Ephedra pollen have moderate RPPs;Asteraceae and Iridaceae have low RPPs.The reliability test of RPPs revealed that most of the RPPs are reliable in past vegetation reconstruction.However,the RPPs of Asteraceae and Iridaceae are obviously underestimated,and those of Poaceae,Chenopodiaceae,and Ephedra are either slightly underestimated or slightly overestimated,suggesting that those RPPs should be considered with caution.These RPPs were applied to estimating plant abundances for two fossil pollen spectra(from the Lake Bayanchagan and Lake Haoluku)covering the Holocene in typical steppe area,using the"Regional Estimates of Vegetation Abundance from Large Sites"(REVEALS)model.The RPPs-based vegetation reconstruction revealed that meadow-steppe dominated by Poaceae,Cyperaceae,and Artemisia plants flourished in this area before 6500–5600 cal yr BP,and then was replaced by present typical steppe. 展开更多
关键词 typical steppe modern surface pollen relative pollen productivity relevant pollen source area PALEOVEGETATION
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Towards the manipulation of topological states of matter: a perspective from electron transport 被引量:2
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作者 Cheng Zhang Hai-Zhou Lu +2 位作者 Shun-Qing Shen Yong P. Chen Faxian Xi 《Science Bulletin》 SCIE EI CSCD 2018年第9期580-594,共15页
The introduction of topological invariants, ranging from insulators to metals, has provided new insights into the traditional classification of electronic states in condensed matter physics. A sudden change in the top... The introduction of topological invariants, ranging from insulators to metals, has provided new insights into the traditional classification of electronic states in condensed matter physics. A sudden change in the topological invariant at the boundaw of a topological nontrivial system leads to the formation of exotic surface states that are dramatically different from its bulk. In recent years, significant advancements in the exploration of the physical properties of these topological systems and regarding device research related to spintronics and quantum computation have been made. Here, we review the progress of the characterization and manipulation of topological phases from the electron transport perspective and also the intriguing chiral/Majorana states that stem from them. We then discuss the future directions of research into these topological states and their potential applications. 展开更多
关键词 Topological insulator Dirac semimetal Weyl semimetal Quantum transport
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