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991.
Container ports serve as important conduits to facilitate the efficient flow of containerized cargo. As part of value-driven chain systems that intersect between hinterlands, efficiency gains that are generated within the container port will have a direct impact on the competitive advantage of its users and affect the economic potential of both the origin and destination hinterlands. As such, the paper proposes the usage of indifference analysis propounded in microeconomic theory as a useful means to examine inter-container port competition and complementarity. The framework presented can also be combined with Porter's 'Diamond' model in order for inter-container port demand relationships to be quantified, measured and analysed in an holistic manner. Apart from analysing inter-port relationships from the standpoint of container ports, the framework can also be used to analyse inter-port relationships from the perspective of other key players in the value-driven chain system and modified accordingly to incorporate various indicators that are deemed to be relevant to these parties. 相似文献
992.
M. Ziyaeifar 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2005,43(11):771-794
The investigation of problems related to the interaction of train, bridge and track systems has been accelerated by the emergence of high-speed trains. Such studies are required, not only for the endurance issues regarding bridge and tracks, but to assure trains' functionality and performance. The suspension mechanism of train systems is of prime importance in defining the functionality of high-speed trains, and accurate mathematical models of the mechanism are imperative. This paper introduces a numerical technique for an interaction study of train-bridge-track systems based on Maxwell (three-element type) modeling of the suspension mechanisms of vehicles. Track irregularity in sinusoidal form is also integrated into the mathematical model. Although the proposed technique is simple in formulation, it offers phenomenal accuracy in representing the interaction of train, track and bridge systems. In a numerical example, the dynamic behavior of a train-bridge system has been studied. Results of this analysis provide a valuable insight into the contributing roles of different parameters in this subject. 相似文献
993.
T.Mooney 《中国远洋航务公告》2004,(10):i001-i001
过去几个月中,中国消费品市场发生了巨大的变化,新出台的规定承诺将大力改变消费品的交易环境。自今年六月起,外国公司可以在中国建立全面运营的外商独资企业,从事商品的采购和转售。 相似文献
994.
异步电动机矢量控制(FOC)和直接转矩控制(DTC)方案的比较 总被引:2,自引:0,他引:2
磁场定向控制和直接转矩控制技术正在成为异步电动机转矩控制的工业标准.文章给出这两种控制方案的详细比较,重点是它们的优、缺点.从转矩和电流脉动、跟踪转矩命令阶跃变化的转矩瞬态响应等方面评估了两种控制方案的性能.根据数值仿真结果进行了分析,但未涉及系统硬件带来的二次影响. 相似文献
995.
市场经济是契约经济。合同是企业从事经济活动并且取得经济效益的桥梁和纽带。作为市场主体之一的建筑企业 ,从工程投标到建设工程合同的签订 ,从合同的覆行到工程索赔 ,从工程款的结算到合同纠纷的处理 ,无一不受合同的约束和合同法的规范。掌握了合同的本质 ,才能做到对合同法的灵活运用。本文通过对合同的概述 ,合同本质特征的论述 ,提出了合同的具体运作及合同法在实践中应当注意的问题。对今后建筑企业在复杂的经济活动中正确处理合同问题有较强的指导意义。 相似文献
996.
It's well knownthat redlead and zinc chromateare extensively used as anticorrosive pigment in thefor mulation of protective paints due totheir anticor-rosive efficiency.However,their applications havebeen gradually discouraged since1990because theyare hazardous and high toxic.Among several non-toxic anticorrosive pigments developed so far,zincphosphate is a desired alternative to the toxic pig-ments for its superior perfor mance.Unfortunately,zinc phosphate still cannot completelyreplacelead o… 相似文献
997.
Ships of opportunity have been used to investigate ocean–atmosphere CO2 fluxes in the English Channel and Southern Bight of the North Sea. Continuous underway measurements of the fugacity of seawater carbon dioxide (fCO2sw), chlorophyll, temperature and salinity have been performed along 26 transects during the spring and autumn periods. The spatial fCO2sw distribution along the Channel and Southern Bight is modulated by the photosynthetic activity, temperature changes and water mixing between inputs from the North Atlantic Ocean and riverine discharges. The seasonal variability of fCO2sw is assessed and discussed in terms of the biology and temperature effects, these having similar impacts. The variation of fCO2sw shows similar interannual patterns, with lower values in spring. The annual average of air–sea CO2 fluxes places the English Channel as neutral area of CO2 uptake. The spring and autumn data allow differentiating between distal and proximal continental areas. The Southern Bight shows a tendency towards net CO2 uptake on the distal continental shelf, whereas the Scheldt and Thames Plumes show a CO2 source behaviour on the proximal continental shelves. 相似文献
998.
J.F. Shriver H.E. Hurlburt O.M. Smedstad A.J. Wallcraft R.C. Rhodes 《Journal of Marine Systems》2007,65(1-4):3
A 1/32° global ocean nowcast/forecast system has been developed by the Naval Research Laboratory at the Stennis Space Center. It started running at the Naval Oceanographic Office in near real-time on 1 Nov. 2003 and has been running daily in real-time since 1 Mar. 2005. It became an operational system on 6 March 2006, replacing the existing 1/16° system which ceased operation on 12 March 2006. Both systems use the NRL Layered Ocean Model (NLOM) with assimilation of sea surface height from satellite altimeters and sea surface temperature from multi-channel satellite infrared radiometers. Real-time and archived results are available online at http://www.ocean.nrlssc.navy.mil/global_nlom. The 1/32° system has improvements over the earlier system that can be grouped into two categories: (1) better resolution and representation of dynamical processes and (2) design modifications. The design modifications are the result of accrued knowledge since the development of the earlier 1/16° system. The improved horizontal resolution of the 1/32° system has significant dynamical benefits which increase the ability of the model to accurately nowcast and skillfully forecast. At the finer resolution, current pathways and their transports become more accurate, the sea surface height (SSH) variability increases and becomes more realistic and even the global ocean circulation experiences some changes (including inter-basin exchange). These improvements make the 1/32° system a better dynamical interpolator of assimilated satellite altimeter track data, using a one-day model forecast as the first guess. The result is quantitatively more accurate nowcasts, as is illustrated by several model-data comparisons. Based on comparisons with ocean color imagery in the northwestern Arabian Sea and the Gulf of Oman, the 1/32° system has even demonstrated the ability to map small eddies, 25–75 km in diameter, with 70% reliability and a median eddy center location error of 22.5 km, a surprising and unanticipated result from assimilation of altimeter track data. For all of the eddies (50% small eddies), the reliability was 80% and the median eddy center location error was 29 km. The 1/32° system also exhibits improved forecast skill in relation to the 1/16° system. This is due to (a) a more accurate initial condition for the forecast and (b) better resolution and representation of critical dynamical processes (such as upper ocean – topographic coupling via mesoscale flow instabilities) which allow the model to more accurately evolve these features in time while running in forecast mode (forecast atmospheric forcing for the first 5 days, then gradually reverting toward climatology for the remainder of the 30-day forecast period). At 1/32° resolution, forecast SSH generally compares better with unassimilated observations and the anomaly correlation of the forecast SSH exceeds that from persistence by a larger amount than found in the 1/16° system. 相似文献
999.
使用表明:Д49型柴油机用组合结构活塞与其它类型柴油机及国外柴油机上所采用的整体活塞相比有着许多较严重的缺点.
1995年"十月"铁路局的特诺机务段在发给全俄铁路运输研究院的报告中说:Д49型柴油机活塞的头部有一很大的蓄热区.机务段发给该院13只这种活塞头,图4说明了活塞上蓄热区分布情况.从图4上看得很清楚:热量是沿活塞头边缘向活塞头中心位置大量地积蓄的,且同时几乎完全与由活塞头中心向活塞头边缘分布的油管孔重叠在一起(活塞头上有直径为5 mm的油孔12个). 相似文献
1000.
对某汽配厂接触噪声工人90项症状自评量表的调查研究 总被引:1,自引:0,他引:1
运用90项症状自评量表(SCL-90)对汽配厂接触高强度噪声[95dB(A)~100dB(A)]的工人进行调查发现,接触组工人的人际关系、抑郁、焦虑、敌对、恐怖、偏执、精神病性等因子均与对照有显著性差异,同时也高于正常成人组,提示90项症状自评量表可以应用于噪声接触工人的心理学研究和早期检测指标的职业流行病学的调查。 相似文献