国外内河集装箱运输发展现状及趋势分析

通过对国外内河集装箱运输发展较好的主要国家和地区有关内河集装箱运输发展历程、航道及主要港口码头、船型及组织方式等基本情况的介绍,深入分析了国外内河集装箱运输发展的基本特点和主要趋势,总结了值得中国借鉴的国外内河集装箱运输发展经验。     

Inter-comparing five forecast operational systems in the North Atlantic and Mediterranean basins: The MERSEA-strand1 methodology

The methodology to achieve a real time inter-comparison of five state-of-the-art operational forecast systems for the North Atlantic and Mediterranean basins is presented. All systems provide analysis and near real-time prediction of the three-dimensional ocean through Opendap servers. A standard set of diagnostics called metrics, is described. Definition and examples of metrics are given. An inter-comparison of the five systems is conducted over a 1 year period using those metrics. It is shown that the methodology developed allows a successful inter-comparison. It has been adopted by the GODAE community. It is also shown that the systems are consistent with the current knowledge of the ocean circulation and climatologies. Systems are deficient in the representation of specific water masses characteristics as Mode waters. Data assimilation of vertical profiles of temperature and salinity solve such deficiencies. Metrics also allow a monitoring of the system's North Atlantic overturning stream function and will allow detecting any changes in the coming year system's thermohaline circulation.     

美国Magplane磁悬浮列车方案

美国Magplane磁悬浮列车方案有两种,一种是速度在500km/h的超导方案,另一种是速度约250 km/h的永磁方案.与其他高速磁悬浮列车相比,美国高速磁悬浮列车方案使用了永磁悬浮,使悬浮气隙达5～15 cm,这样可以大大降低轨道土建工程施工的精度要求,并且该系统使用电磁道岔,改变了多数磁悬浮列车系统使用机械道岔,占地面积大,操作不方便的缺点,从而该方案具有造价低、原理简单、悬浮间隙大、起浮速度低的优点.文章从原理、创新、存在问题等方面对美国Magplane磁悬浮列车永磁方案进行了较详细的介绍.     

Impact of forcing errors in the CAMCAT oil spill forecasting system. A sensitivity study

The CAMCAT oil spill forecasting system is presented in this paper, and an evaluation of the impact of errors in the forcing fields over its forecasts is carried out. The system is formed by several independent modules which provide forecasts of winds, currents and waves to an oil spill module which predicts the evolution of the spill.The typical twin-experiments experience is used paying special attention to a realistic characterization of the errors when perturbing the forcing fields. The results suggest that errors in the wind and current fields are the main limiting factor for the quality of the oil spill forecasts. The pollutant identification is also crucial to determine the final vertical position and characteristics of the product.     

Validation of the 3D biogeochemical model MIRO&CO with field nutrient and phytoplankton data and MERIS-derived surface chlorophyll a images

This paper presents results obtained with MIRO&CO-3D, a biogeochemical model dedicated to the study of eutrophication and applied to the Channel and Southern Bight of the North Sea (48.5°N–52.5°N). The model results from coupling of the COHERENS-3D hydrodynamic model and the biogeochemical model MIRO, which was previously calibrated in a multi-box implementation. MIRO&CO-3D is run to simulate the annual cycle of inorganic and organic carbon and nutrients (nitrogen, phosphorus and silica), phytoplankton (diatoms, nanoflagellates and Phaeocystis), bacteria and zooplankton (microzooplankton and copepods) with realistic forcing (meteorological conditions and river loads) for the period 1991–2003. Model validation is first shown by comparing time series of model concentrations of nutrients, chlorophyll a, diatom and Phaeocystis with in situ data from station 330 (51°26.00′N, 2°48.50′E) located in the centre of the Belgian coastal zone. This comparison shows the model's ability to represent the seasonal dynamics of nutrients and phytoplankton in Belgian waters. However the model fails to simulate correctly the dissolved silica cycle, especially during the beginning of spring, due to the late onset (in the model) of the early spring diatom bloom. As a general trend the chlorophyll a spring maximum is underestimated in simulations. A comparison between the seasonal average of surface winter nutrients and spring chlorophyll a concentrations simulated with in situ data for different stations is used to assess the accuracy of the simulated spatial distribution. At a seasonal scale, the spatial distribution of surface winter nutrients is in general well reproduced by the model with nevertheless a small overestimation for a few stations close to the Rhine/Meuse mouth and a tendency to underestimation in the coastal zone from Belgium to France. PO₄ was simulated best; silica was simulated with less success. Spring chlorophyll a concentration is in general underestimated by the model. The accuracy of the simulated phytoplankton spatial distribution is further evaluated by comparing simulated surface chlorophyll a with that derived from the satellite sensor MERIS for the year 2003. Reasonable agreement is found between simulated and satellite-derived regions of high chlorophyll a with nevertheless discrepancies close to the boundaries.     

浅谈北天山越岭隧道水文地质工作中的体会

研究目的:本文根据作者在北天山越岭隧道的工作经历,对北天山越岭隧道调绘和勘察全过程进行了总结,并阐述了自己的亲身体会,对工作中出现的一些问题提出了自己的一些看法。研究方法:在越岭隧道的勘察过程中,广泛采用了先进有效的技术手段,以遥感技术指导地面的调绘工作,通过综合物探,配合适量的钻探验证,以查明隧道通过区的地质及水文地质条件,通过钻孔内的地应力测试及综合水文测井,并取得相应的地质及水文地质参数;通过对泉水流量的测定,为隧道涌水量的预测提供了依据,并通过取样进行化学分析及氚分析,查明了地下水的补、径、排关系;通过水文地质计算,预测隧道的涌水量。研究结果:经过综合勘察,查明了隧道通过区的地层岩性、地质构造及地层的富水情况,取得了相应的水文地质参数,为隧道的设计及施工提供了依据。研究结论:通过对北天山越岭隧道的勘察,进一步认识了多种技术手段相结合的必要性,也充分意识到了水文地质工作在深埋长大隧道勘察中的重要性。但同时在工作中也发现了一些问题,通过经验总结提高了认识。     

Modelling Pseudocalanus elongatus stage-structured population dynamics embedded in a water column ecosystem model for the northern North Sea

This paper outlines an approach to couple a structured zooplankton population model with state variables for eggs, nauplii, two copepodites stages and adults adapted to Pseudocalanus elongatus into the complex marine ecosystem model ECOHAM2 with 13 state variables resolving the carbon and nitrogen cycle. Different temperature and food scenarios derived from laboratory culture studies were examined to improve the process parameterisation for copepod stage dependent development processes. To study annual cycles under realistic weather and hydrographic conditions, the coupled ecosystem–zooplankton model is applied to a water column in the northern North Sea. The main ecosystem state variables were validated against observed monthly mean values. Then vertical profiles of selected state variables were compared to the physical forcing to study differences between zooplankton as one biomass state variable or partitioned into five population state variables. Simulated generation times are more affected by temperature than food conditions except during the spring phytoplankton bloom. Up to six generations within the annual cycle can be discerned in the simulation.     

Ballast Water Risk Indication for the North Sea

The ballast water from ships carries marine organisms that have invasive potential. The International Maritime Organization Ballast Water Management Convention (2004) requires ballast water exchange or ballast water management (BWM) systems either onboard or ashore. Ships can be exempted on the basis of risk assessment, when exclusively sailing between specific ports or in an enclosed area. In reply to our questionnaire, the shipping sector argues that the North Sea is ecologically homogeneous and exemptions could therefore be granted. This paper proposes that the North Sea area is, in fact, not homogeneous in terms of hydrographical and biological conditions; therefore, ballast water is a relevant transport mechanism for organisms. Within the North Sea, the short shipping routes indicate a high risk for survival. We examined actual simulation models for ballast water risk assessment in the North Sea, and we have identified the major parameters that need to be included in such models. These models provided a basis; they further need to be combined and adapted for the purpose of evaluating the rationale for an exemption. We concluded that exemptions from BWM are not recommended for the North Sea area. Anticipating the Ballast Water Management Convention, ship owners might do well to study possibilities for installing BWM systems onboard.     

The Gulf Stream, rings and North Atlantic eddy structures from remote sensing (Altimeter and SeaWiFS)

Seasonal SeaWiFS chlorophyll a concentrations cycles and annual changes of altimeter Sea Level Anomaly are derived for the subtropical North Atlantic near  35°N and along a Gulf Stream axis. Spatial structure of SeaWiFS, is defined in terms of deviations from a local seasonal cycle and examined in relation to altimeter eddy structure. In the subtropical region near 35°N, SeaWiFS structure is evident during the spring bloom period with a scale of  430 km, or about twice the eddy scale. A Gulf Stream axis has been selected as a region where the Sea Level Anomaly variance is a maximum. Eddy propagation speeds and scales are examined. Cold-core (cyclonic) rings correspond to areas of high SeaWiFS chlorophyll a. Warm-core (anticyclonic) rings relate to areas of low chlorophyll concentration. Both SeaWiFS structure and eddy structure have a spatial scale of  450 km or twice the ring scale along the Gulf Stream axis. SeaWiFS chlorophyll anomalies and Altimeter Sea Level Anomaly structure have an overall negative correlation coefficient of r = − 0.34. Swirl currents between eddies redistribute surface chlorophyll concentrations and can spatially bias maximum and minimum concentration levels off eddy centre.     

Comparisons of urban transport sustainability: Lessons from West and North Africa

The diagnosis for urban transport sustainability depends on the context of different regions worldwide. We focus in this paper on West and North Africa which reveal similarities but also structural differences which are explored further. The importance of paratransit in its various forms is strongly observed in sub-Saharan Africa and to a lesser extent in North Africa. The attempts to regulate and organise this sector have been difficult; one interesting experience in Dakar occurred during a programme of fleet renewal. In parallel it is observed that there are positive but insufficient experiences of public transport authorities in some cities (Dakar, Abidjan) and similar projects postponed in other cities because of the institutional problems. One also observes the constant difficulties of designing sustainable schemes for bus companies. An answer to this crisis has been found in North Africa, through investment in new mass transport systems. However, mass transport projects in West Africa are very weak in comparison. The gap between public transport costs and income levels there remains a major obstacle to sustainable mobility exacerbated by the poverty of a significant part of the urban population in West Africa. Two other critical factors are also identified affecting sustainable mobility requirements, namely, the urban sprawl and increasing energy costs. Finally the conclusion recommends the use of research and expertise networks in order to help the design and the implementation of suited solutions.