Shen Z.,Beijing Normal University |
Hou X.,Beijing Normal University |
Li W.,China Waterborne Transport Research Institute |
Aini G.,Beijing Normal University
Landscape and Urban Planning | Year: 2014
Landscape characteristics have a substantial effect on non-point source (NPS) pollution. The relationship between landscape characteristics and water quality provides important information for effectively addressing planning and NPS management problems. Multiple stepwise regression analysis and redundancy analysis were integrated to explore the quantitative association between landscape metrics, at both the landscape and class levels, and water quality in the highly urbanized Beiyun River Watershed. The relationship between water quality and the landscape pattern metrics was more significant during the rainy season than after the rainy season. The landscape composition was found to explain 46.9% of the variation in water quality. A total of 60.3% of the variation in water quality could be explained if the landscape configuration metrics were also included in the analysis. This result indicated the importance of the landscape configuration for the water quality of the watershed. Compared with the indices at the landscape level, the class metrics were more effective in predicting water quality. Three metrics, namely, the patch density of water, the largest patch index of forest and the proportion of unused land, could jointly effectively represent the influence of the landscape pattern on the water quality during the rainy season. It is probable that water quality can be improved by maintaining the connectivity of urban rivers, controlling the proportion of unused land and retaining a widespread distribution of unfragmented forest. Furthermore, avoiding the compact distribution of urban land use might reduce the overall emission of pollutants from all forms of transport. © 2013 Elsevier B.V.
Yang D.,China Waterborne Transport Research Institute |
Chin A.T.H.,National University of Singapore |
Chen S.,Shanghai Maritime University
Maritime Policy and Management | Year: 2014
The Chinese government has been exploring various paths to find a direction that better suits China's national conditions during the past 60 years. Meanwhile, a series of political and economic events and policy transformations have had different effects on the port industry. This article attempts to ascertain how these events and port policies have influenced Chinese port traffic through an empirical study on data covering 1952-2009. The findings suggest that foreign trade has been the prime driver of the throughput of Chinese ports. The increase in the ports' throughput has enabled an increase in domestic demand and the urgent need for further port investment. Chinese port throughput has been subject to multiple shocks. The Great Leap Forward1 is found to have had the largest, but only a short-term impact. China's accession to the World Trade Organization, however, led to a longer and exclusive effect on ports, with little observed effect on the other variables. The reform of port governance is shown to have had a more lasting positive effect on port throughput than physical investment. However, these latter effects are minor, the economic and political factors remain the primary driving factors of port throughput. © 2013 Taylor & Francis.
Li W.,China Waterborne Transport Research Institute
Zhongguo Kongjian Kexue Jishu/Chinese Space Science and Technology | Year: 2016
With more powerful space stirling cooler coming out, if the controller still uses traditional slow-startup and LC energy storage and filtering series circuits, an unstable and large overshoot start-up current will be caused, which leads to the controller overcurrent protection and potential surge damages to satellite power and other devices. Under the condition of not adding components, a slow-startup circuit connecting LC energy storage and filtering circuit cooperative way with start-up current feedback function was proposed. Firstly, the new and old cooperative circuits with low frequency equivalent model of nonlinear MOSFET were modeled. Secondly, the models both in the condition of small inductance and small capacitance and in the condition of large inductance and large capacitance were simplified and analyzed. In the condition of small inductance and small capacitance, both cooperative circuits can be simplified to non-overshot first-order system. In the condition of large inductance and large capacitance, the traditional cooperative circuits was simplified to second-order system with oscillation characteristics. However, the new cooperative circuits is still first-order system, which satisfies the requirements of non-overshoot start-up current in the condition of large inductance and large capacitance. Finally, the simulation contrastive analysis and experimental verification was used to proof the new cooperative circuits rationality and effectiveness. The test shows the start-up current stable and no overshoot and the peak of the start-up current is restrained up to about 50%. © 2016, Editorial Office of Journal of Chinese Space Science and Technology. All right reserved.
Lei L.,China Waterborne Transport Research Institute |
Yan Y.,China Waterborne Transport Research Institute
Advanced Engineering and Technology II - Proceedings of the 2nd Annual Congress on Advanced Engineering and Technology, CAET 2015 | Year: 2015
The simulation of gas-liquid-solid flow and gas-liquid mass transfer using computational fluid dynamics (CFD) was carried out in a bio-fluidized bed reactor. CFD was properly able to capture the characters of the three-phase flow in the reactor and found that presence of solid restricted the liquid turbulence intensity. It was also revealed that the decreasing gas-liquid mass transfer with the presence of solid was attributed to reduction of turbulence intensity. Furthermore, a model for describing the mass transfer in gas-liquid-solid flow was recommended. © 2015 Taylor & Francis Group, London.
Xu S.B.,China waterborne transport research institute
Applied Mechanics and Materials | Year: 2014
After 9/11, container transport security and efficiency gain more and more concern, the secure and smart container concept is put forth by the USA for national security firstly. Based on the questionnaire survey analysis, this paper puts forth the exact concept and function of the secure and smart container, analyzes related key technology and elaborates detail technical solution based on The Internet of things how to make the common container become the secure and smart container. © (2014) Trans Tech Publications, Switzerland.
Cai O.C.,China Waterborne Transport Research Institute
Advanced Materials Research | Year: 2014
As nanotechnologies become more widely used, titania nanoparticles are being released to the subsurface environment via wastewater sludge applications. Titania nanoparticles are not only toxic to organisms in the environment, but recent studies revealed that they may also serve as carriers of hydrophobic organic contaminants and affect their fate and distribution in the subsurface environment. The mobility of titania nanoparticles varies depending on nanoparticle morphology characteristics, pH and the ionic strength of solutions, flow velocity, nanoparticle concentration, and the presence of surfactant or natural organic matter. Analogous to findings for natural and engineered carbonaceous nanoparticles, titania nanoparticles may enhance the transport of hydrophobic organic contaminants in porous media. However, to prove this hypothesis, further research is necessary. Thus experiments examining the impacts of titania nanoparticle on the hydrophobic organic matter transport in porous media were designed, which consist of three different sets of column experiments. These experimental sets will investigate the effects of the presence of titania nanoparticles, the size of nanoparticles and the organic carbon content in soil, respectively. Due to the estimation of the potential for the titania nanoparticles to facilitate organic contaminant transport, the experiment results are expected as: (a) the presence of titania nanoparticles will enhance the organic contaminant transport in porous media; (b) smaller nanoparticles will adsorb more organic contaminants and enhance their transport as the result of the increasing specific surface area; (c) soil containing higher organic matter content will compete for the adsorption of organic contaminants and retard their facilitated transport by titania nanoparticles. © (2014) Trans Tech Publications, Switzerland.
Zhu J.,China Waterborne Transport Research Institute |
Wei M.,China Waterborne Transport Research Institute
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015
To provide effective analysis tools, an early warning system is proposed for China's foreign trade container shipping market. Firstly, by analyzing volatility mechanism of foreign trade container shipping market, a set of monitoring indicators is presented, including container throughput, freight index CCFI and PMI new export orders index et al. The monthly samples of the indicators from 2005 to 2014 are collected. Secondly, the warning threshold and interval of each indicator are determined by the combination method of statistical analysis and expert scoring. According to the design principle of early warning signal system and the indicator state division method, the early warning signal system of China's foreign trade container shipping market is proposed. To monitor the long-Term market wave trend, an early warning index model is further proposed by the method of synthetic index, in which the indicator weights are determined by the principal component analysis method. Finally, the comparison results between the system operating and the real market volatility further demonstrate the validity of the proposed system. © ASCE.
Zhao Y.,China Waterborne Transport Research Institute |
Liu M.,China Waterborne Transport Research Institute
Procedia Engineering | Year: 2014
In order to quickly identify the kinds of volatile organic compounds(VOCs) and quantified their concentrations, a method based on portable GC-MS was developed, which was especially suitable for the detection of aromatic compounds and chlorides. The mixed gases were directly collected by solid phase microextraction head for 120 seconds. After that, they were analyzed on the portable GC-MS, identified by retention time and MS peaks, quantified by external standard method. It only took 6.4 min from sampling to get the result. The linear correlation was larger than 0.98, and the minimum detectable concentration was lower than half of their occupational exposure limits, respectively. In the simulation test, the relative error was lower than 4.4%. This method can directly collect the air sample in the field, rarely depends on external conditions, and is very convenient to carry out. It takes very short time to complete the detection, at the same time it can identify and quantify multiple kinds of gases at a time. So this method is quite suitable for the emergency detection at the gas leak site. © 2014 The Authors. Published by Elsevier Ltd.
Wang S.,China Waterborne Transport Research Institute |
Yu X.,China Waterborne Transport Research Institute
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014
In this paper, we propose a vision-based target detection scheme based on video saliency to find the rescue targets automatically. A new definition of video saliency is first proposed to comprehend the target properties based on structure similarity among adjacent video frames. Then, a cascaded target detection is devised with the local image feature and regional video saliency. We treat the salient objects in aerial images as a basic feature and filter the false candidates based on the region-based video saliency. The propose method can improve the search and rescue of targets, and reduce the economical losses in marine accidents. © 2014 SPIE.
Sun G.-Q.,China Waterborne Transport Research Institute
ICTIS 2013: Improving Multimodal Transportation Systems - Information, Safety, and Integration - Proceedings of the 2nd International Conference on Transportation Information and Safety | Year: 2013
The growing volume of hazardous cargo shipments and the potential consequences of a materials release have raised public concern and scrutiny over the safe handling and transport of hazardous cargo. This has prompted intensive regulatory review and technical studies directed at identification and resolution of critical issues impacting the safe transport of hazardous cargo. This paper addresses these issues, both from the standpoint of what is currently known and for the development of an agenda for enhancing hazardous cargo transport safety in the future. Attention is focused principally on those areas where the needs are particularly acute, namely the regulatory environment, information systems, accident analysis, hazard mitigation, risk assessment, routing, community preparedness, and incident management. The basis for this review is the condition of dangerous goods safety transportation problems plague our countries, it is expected that many of the conclusions and recommendations reported herein will have application to the international community. © 2013 American Society of Civil Engineers.