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1.
In china today,containers acconut for only 10% of all rail traffic volume in order to push forward china's container multimodal transport,the ministry of railways(MOR)is working hard to get domestic shippers/forwarders to containerise their conventional general cargo shipments,and for intemational ocean carriers,to get them to move a larger proprotion of the boxex inland by rail.  相似文献   

2.
China's Accession to the WTO ushered in a new chapter in the history of China's reform and opening-up. This move is generally held as the most significant event since China adopted the policy of opening and reform in the late 1970s. After clearly defining a socialist market economy as its reform goal in 1992, the country has speed up its efficiency-oriented economic reform in an all-out way. China's entry into the  相似文献   

3.
L.Y 《集装箱化》1998,(8):31-31
For all that there has been a great improvement in china's highway transport in the ninties,the present condition still lags far behind the actual demand set forth by the country's economic development,  相似文献   

4.
Shipping News     
BOX traffic boom in Changjiang region The container transport along the Changjiang River is developing rapidly. According to Shanghai port statistics,container lines initiated from the Changjiang ports to Shanghai has amounted to 11 with 21,000 TEU monthly volume, one times that of the last same period. The rapid development has attracted quite a lot of cornpanies to engage in cornpetition. Up to now,80%of total 150 domestic international lines set up cargo agencies at the Changjiang ports. Moreover, the container boom gives an impetus to the construction, rebudding and expansion for the transport facilities of the Changjiang ports. Additionally, the transhiprnent statiorls in the hinterland of the ports and along the major highways are being established along with the boom.  相似文献   

5.
In this study, a series of numerical calculations are carried out in ANSYS Workbench based on the unidirectional fluid–solid coupling theory. Using the DTMB 4119 propeller as the research object, a numerical simulation is set up to analyze the open water performance of the propeller, and the equivalent stress distribution of the propeller acting in the flow field and the axial strain of the blade are analyzed. The results show that FLUENT calculations can provide accurate and reliable calculations of the hydrodynamic load for the propeller structure. The maximum equivalent stress was observed in the blade near the hub, and the tip position of the blade had the largest stress. With the increase in speed, the stress and deformation showed a decreasing trend.  相似文献   

6.
YuLaibao 《集装箱化》1998,(12):30-31
Featuring modemization and high efficiency,multimodalism constitutes the most advanced stage of container transport in its development.With its salient superiorities and along with the process of global econcmic integration and technological progress,container multimodal transport has been popularized in many developed countries,and in some developing countries as well.  相似文献   

7.
The application of multi-hull ship or trimaran vessel as a mode of transports in both river and sea environments have grown rapidly in recent years.Trimaran vessels are currently of interest for many new high speed ship projects due to the high levels of hydrodynamic efficiency that can be achieved,compared to the mono-hull and catamaran hull forms.The purpose of this study is to identify the possible effects of using an unsymmetrical trimaran ship model with configuration(S/L) 0.1-0.3 and R/L=0.1-0.2.Unsymmetrical trimaran ship model with main dimensions: L=2000mm,B=200 mm and T=45 mm.Experimental methods(towing tank) were performed in the study using speed variations at Froude number 0.1-0.6.The ship model was pulled by an electric motor whose speed could be varied and adjusted.The ship model resistance was measured precisely by using a load cell transducer.The comparison of ship resistance for each configuration with mono-hull was shown on the graph as a function of the total resistance coefficient and Froude number.The test results found that the effective drag reduction could be achieved up to 17% at Fr=0.35 with configuration S/L=0.1.  相似文献   

8.
After 55 years' development, CCS actively takes her part in the international competition due to its fast development in the tide of China's opening up and reform process. With the rise of shipping and shipbuilding industries in China, CCS has bravely taken up the mission brought up by history in the volatile situation.  相似文献   

9.
WANG Xiao-hua 《水道港口》2010,31(5):320-320
In the high-energy environment of coastal seas and estuaries,strong sediment resuspension/ deposition events are driven by surface waves,tides,winds and buoyancy driven currents.In recent years,A POM based three-dimensional,wave-current coupled,sediment transport model has been developed by the University of New South Wales.This paper presents several examples of the model applications to study sediment dynamics in the environments where forcings such as waves,tides,and winds are equally important to affect sediment fluxes and distributions.Firstly,the sediment transport model coupled to the Yellow Sea general circulation model and a third generation wave model SWAN was implemented in the Yellow Sea to study the dynamics of the sediment transport and resuspension in the northern Jiangsu shoal-wate(rNJSW).The sediment distributions and fluxes and their inter-annual variability were studied by realistic numerical simulations.The study found that the surface waves played a dominant role over the tides to form the turbidity maxima along the muddy coast of NJSW. Secondly,the sediment transport model was used to explore the effect of suspended sediment-induced stratification in the bottom boundary laye(rBBL).The model uses a re-parameterized bottom drag coefficient Cd that incorporates a linear stability function of flux Richardson number Rf.The study has shown that the sediment induced stratification in the BBL reduces the vertical eddy viscosity and bottom shear stress in comparison with the model prediction in a neutrally stratified BBL.In response to these apparent reductions,the tidal current shear is increased and sediments are abnormally concentrated within a thin wall layer that is overlain by a thicker layer with much smaller concentration.The formation of this fluid-mud layer near the seabed has led to a significant reduction in the total sediment transport.This study contributes to the understanding of formations of tidal flats along the coasts of turbid seas and estuaries.  相似文献   

10.
Since 1960s the seatrade markets and the international ocean transport industry have undergone substantial changes. Freight origins and destinations shifted much more rapidly than in the past, and the types of cargo and their forms of packaging kept changing. These trends became more and more pronounced since the beginning of the 1980s. This article descrihes the conditions of seatrade market and ocean transport industry, and analysts the reasons and effectiveness of the chaneges, well as the trend of seatrade market. 1 Development in the international seatrade markets In 1960 the annual volume of international seatrade had reached a level of one billion tons, with equal shares of dry cargo and liquid cargo.  相似文献   

11.
Ship resistance issues are related to fuel economy, speed, and cost efficiency. Air lubrication is a promising technique for lowering hull frictional resistance as it is supposed to modify the energy in the turbulent boundary layer and thereby reduce hull friction. In this paper, the objective is to identify the optimum type of air lubrication using microbubble drag reduction(MBDR)and air layer drag reduction(ALDR) techniques to reduce the resistance of a 56-m Indonesian self-propelled barge(SPB). A model with the following dimensions was constructed: length L = 2000 mm, breadth B = 521.60 mm, and draft T = 52.50 mm.The ship model was towed using standard towing tank experimental parameters. The speed was varied over the Froude number range 0.11–0.31. The air layer flow rate was varied at 80, 85, and 90 standard liters per minute(SLPM) and the microbubble injection coefficient over the range 0.20–0.60. The results show that the ship model using the air layer had the highest drag reduction up to a maximum of 90%. Based on the characteristics of the SPB, which operates at low speed, the optimum air lubrication type to reduce resistance in this instance is ALDR.  相似文献   

12.
Presents the fin-propeller test set-up to solve the problem of roll stabilization with ships in full speed range, withwhich, tests were run in water rank for acquisition of data, and concludes from data acquired that the fin-propeller test set-up produces more lift than simple fin, and provides lateral thrust as well, and it is therefore an effective roll stabilization devicefor ships in full speed range.  相似文献   

13.
This paper presents a study on the numerical simulation of planing crafts sailing in regular waves. This allows an accurate estimate of the seas keeping performance of the high speed craft. The simulation set in six-degree of freedom motions is based on the Reynolds averaged Navier Stokes equations volume of fluid (RANSE VOF) solver. The trimming mesh technique and integral dynamic mesh method are used to guarantee the good accuracy of the hydrodynamic force and high efficiency of the numerical simulation. Incident head waves, oblique waves and beam waves are generated in the simulation with three different velocities (Fn =1.0, 1.5, 2.0). The motions and sea keeping performance of the planing craft with waves coming from different directions are indicated in the flow solver. The ship designer placed an emphasis on the effects of waves on sailing amplitude and pressure distribution of planing craft in the configuration of building high speed crafts.  相似文献   

14.
The frequency stability of a marine power system is determined by the dynamic characteristic of the diesel engine speed regulation system in a marine power station. In order to reduce the effect of load disturbances and improve the dynamic precision of a diesel engine speed governor, a controller was designed for a diesel engine speed regulation system using H2 control theory. This transforms the specifications of the system into a standard H2 control problem. Firstly, the mathematical model of a diesel engine speed regulation system using an H2 speed governor is presented. To counter external disturbances and model uncertainty, the design of an H2 speed governor rests on the problem of mixed sensitivity. Computer simulation verified that the H2 speed governor improves the dynamic precision of a system and the ability to adapt to load disturbances, thus enhancing the frequency stability of marine power systems.  相似文献   

15.
The Improvement of Port Management Stimulated by the Development of Container Traffic Container transport started to flourish in the 70s and grew rapidly. Comparing the traffic volume of 1990 with that of 1975, the Japanese ports handled 7. 82 million TEUs in 1990 and 1.87 million TEUs in 1975 while the "Four Small Dragonsnhandied 18. 10 million TEUs in 1990 and 1.68 million TEUs in 1975,4.2 times and 10.75 times increase respectively.  相似文献   

16.
In this paper, a 3D source distribution technique is used to calculate the coupled motions between two ships which advance in the wave with the same speed. The numerical results of coupled motions for a frigate and a supply ship have a good agreement with the experimental results. Based on the 3D coupled motions of two ships, a spectral analysis is employed to clearly observe the effect of speed, clearance and wave heading on the significant relative motion amplitude (SRMA) of two ships.The method presented in this paper will be helpful to select suitable clearance, speed and wave heading for underway replenishment at sea(RAS).  相似文献   

17.
一种基于PSO优化HWFCM的快速水下图像分割算法   总被引:3,自引:0,他引:3  
The S/N of an underwater image is low and has a fuzzy edge.If using traditional methods to process it directly,the result is not satisfying.Though the traditional fuzzy C-means algorithm can sometimes divide the image into object and background,its time-consuming computation is often an obstacle.The mission of the vision system of an autonomous underwater vehicle (AUV) is to rapidly and exactly deal with the information about the object in a complex environment for the AUV to use the obtained result to execute the next task.So,by using the statistical characteristics of the gray image histogram,a fast and effective fuzzy C-means underwater image segmentation algorithm was presented.With the weighted histogram modifying the fuzzy membership,the above algorithm can not only cut down on a large amount of data processing and storage during the computation process compared with the traditional algorithm,so as to speed up the efficiency of the segmentation,but also improve the quality of underwater image segmentation.Finally,particle swarm optimization (PSO) described by the sine function was introduced to the algorithm mentioned above.It made up for the shortcomings that the FCM algorithm can not get the global optimal solution.Thus,on the one hand,it considers the global impact and achieves the local optimal solution,and on the other hand,further greatly increases the computing speed.Experimental results indicate that the novel algorithm can reach a better segmentation quality and the processing time of each image is reduced.They enhance efficiency and satisfy the requirements of a highly effective,real-time AUV.  相似文献   

18.
The 2007 work meeting of national waterborne transport was convened in Beijing on July 5, a date to be for ever remembered by the Chinese rivers, lakes and seas, for on this date waterborne transport was re-positioned and the clarion of marching toward a strong shipping country was blown. The sound swept across the rivers and lakes and surged over the col-orful shipping lines on the seas.  相似文献   

19.
The creation of geometric model of a ship to determine the characteristics of hydrostatic and hydrodynamic, and also for structural design and equipments arrangement are so important in the ship design process. Planning tunnel high speed craft is one of the crafts in which, achievement to their top speed is more important. These crafts with the use of tunnel have the aero-hydrodynamics properties to diminish the resistance, good sea-keeping behavior, reduce slamming and avoid porpoising. Because of the existence of the tunnel, the hull form generation of these crafts is more complex and difficult. In this paper, it has attempted to provide a method based on geometry creation guidelines and with an entry of the least control and hull form adjustment parameters, to generate automatically the hull form of planning tunnel craft. At first, the equations of mathematical model are described and subsequent, three different models generated based on present method are compared and analyzed. Obviously, the generated model has more application in the early stages of design.  相似文献   

20.
As an independent industry, the emergence of the classification society was perhaps the demand of beneficial interests between shipowners, cargo owners and insurers at the earliest time. Today, as an indispensable link of the international maritime industry, class role has changed fundamentally. Start off from the demand of the insurersSeaborne trade, transport and insurance industries began to emerge successively in the 17th century. The massive risk and benefit brought by seaborne transport provided a difficult problem to insurers.  相似文献   

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