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1.
文中通过对黄砂船现状的调查,分析了目前黄砂船存在的一些问题及产生的原因,针对性地提出了如何解决问题的一些建议。  相似文献   

2.
实施ISM规则应注意的问题及对策   总被引:1,自引:0,他引:1  
阎羡功 《水运管理》2005,27(1):28-29
ISM规则已经实施多年,但国内一些航行国际航线的船公司对该规则仍处于初级熟悉的水平。分析了存在问题的原因,提出了一些相应对策。  相似文献   

3.
从压力仪表在使用中出现的主要问题入手,结合其发展现状,分析了压力仪表在潜艇上的应用,仔细讨论了仪表供货过程中存在的一些问题,并提出了改进措施。同时,对铅封问题也做了一些说明。  相似文献   

4.
蒋玮  潘斌  胡安康 《船舶》2002,(5):12-17
本文讨论MARPOL 13F和25A对巴拿马型油船总体方案的影响,对比分析了一些总体分舱方案的优缺点,提出了针对MARPOL新规则的一些有效的改善措施。  相似文献   

5.
对以图的顶点表示信息收发中心,边表示通信链的无产为基础,分析了无向图直径的一些特性,从而对通信网的可靠性加以研究。得到了一个通信网即无向图在去掉若干条边后,其直径的长度仍保持不变的一个必要充分条件,并对相应的必要条件和充分条件分别进行探讨,得到一些有益的结果,同时对如何求图的直径的算法进行设计和分析,丰富了通信网的可靠性方面的研究。  相似文献   

6.
船舶电站实验教学的发展方向及应对措施   总被引:2,自引:1,他引:1  
对船舶电站的发展及船舶电站实验教学过程中的一些问题进行了分析,并有针对性地提出了一些改善问题的基本思路及应对措施。  相似文献   

7.
对战略巡航导弹对抗方法的研究   总被引:1,自引:0,他引:1  
战略巡航导弹是美国远程空中打击力量的重要组成部分,对一些重大军事、经济目标构成严重威胁,因而对其实施有效对抗可以提高我军事、经济目标生存能力。针对其特点,进行分析,并提出了一些有效的对抗措施。  相似文献   

8.
对新造船主机和轴系安装调整的一点见解   总被引:1,自引:0,他引:1  
此文以中远5400TEU集装箱船主机和轴系的安装调整为例,浅述了主机和轴系的安装步骤和检查要点,分析了理论设计和实际安装中的一些差异;简单介绍MAN-B&W公司对主机安装的一些要求和造船厂的一些实际经验。  相似文献   

9.
在分析《规则》对遇局面条款的基础上,结合抗海实践,提出了针对对遇局面的一些观点。  相似文献   

10.
黄石 《珠江水运》2014,(4):82-83
本文通过对船舶空调系统的设计要点的分析,参考船舶空调系统的设计要求和规范,例举了一些小型船舶空调系统的常见问题,提出一些建议和解决方案,为新造船舶的空调设计建造提供参考。  相似文献   

11.
This paper provides an up-to-date review of the previous literature concerning the impact of passenger rail franchising on productivity and costs in Britain, and also presents important new evidence. In particular, the extension in time of previously-used datasets offers the first opportunity to study the impacts of re-franchising. The previous literature emphasised the failure of franchising to produce sustained productivity gains, with a sharp deterioration in productivity after 2000. The new evidence presented offers a somewhat more positive view of the British experience. It suggests that part of what was previously considered to be falling productivity may in fact be due to exogenous changes in diesel prices. Further, new data suggests that the recent increases in costs have resulted in higher quality of service. Finally, competitive re-franchising, and the associated unwinding of short-term management and re-negotiated contracts, seems to have led to improvements in productivity between 2006 and 2008. Nevertheless, it remains the case that passenger rail franchising in Britain has failed to reduce costs in the way experienced in many other industries and in rail in other European countries. The evidence is that somewhat larger franchises, avoiding overlapping and optimising train density and length, should reduce costs. We also speculate that the major increase in wages and conditions of staff might be moderated by longer franchises, although that remains to be proved. This re-appraisal of the British case is important in the context of the wider international interest in the use of franchising in passenger rail, and its relevance to the current review of ways of introducing competition into the domestic rail passenger market in Europe.  相似文献   

12.
航道护岸工程中基槽边坡稳定研究   总被引:1,自引:1,他引:0  
航道护岸工程中经常发生基槽边坡滑坡失稳事故,从而造成经济和安全问题。因此,就滑坡发生机理进行研究对保障航道护岸工程顺利建设有重大意义。从极限平衡原理出发,分别运用Fellenius法和Bishop法验算了苏北某航道护岸工程开挖边坡的设计稳定性,并分析比较两种方法的差异,得出了在多层土的计算中有时会出现Fellenius法比Bishop法的安全系数略大的结论。结合工程实际中可能出现的渗流和超载等因素,计算得到边坡安全系数的变化规律和极限平衡状态时的临界负荷,从而提出了相应的预防渗流、控制超载等措施,可以为航道护岸建设提供参考。  相似文献   

13.
近年来,随着与船舶自主航行相关的信息技术、人工智能技术水平的提高,无人船舶行业取得了长足的发展,其在海上安保、环境监测等领域应用也越来越成熟。为推动无人船在海事管理方面的应用研究,破解港口水域海事监管手段不足的瓶颈问题,文中在分析港口水域海事监管特点和无人船系统建设条件的基础上,定量研究了无人船在港口水域海事监管应用面临的性能指标确定、船型平台选择、载荷设备搭配、运行管理体系建设等方面的具体问题,提出了一种港口水域海事监管无人船系统的应用解决方案。  相似文献   

14.
通过分析近年来土工合成材料在长江口深水航道、洋山港、太仓港、吕四港、宁波港、曹妃甸等具有代表性的堤坝工程中的应用情况,系统总结了土工合成材料在堤坝工程中的应用经验,可对同类工程有所借鉴.  相似文献   

15.
郑清松 《港工技术》2011,48(2):28-30
由于后张预应力空心板的体积较小、预制安装简单方便,有利于规模化生产、运输和安装,已广泛应用于我国公路桥梁工程的上部结构中.结合福建地区港口工程中以后张预应力空心板作为上部结构的实例,介绍后张预应力空心板的设计、预制和安装的要点,并针对施工期空心板加载试验数据进行分析,总结在港口工程中采用后张预应力空心板的经验,供类似工...  相似文献   

16.
The growth of whale-watching internationally has been spectacular. It now occurs in almost 100 countries and is estimated to be worth in excess of U.S.$1 billion each year in revenue. Thus, whales have become valuable as a resource for tourism. The Vava'u island group in the northern part of the Kingdom of Tonga in the South Pacific is an area with a growing reputation as a whale-watching destination. However, the industry is relatively new there and the impacts of whale-based tourism in these islands is, as yet, unknown. In addition, there has been a recent consideration of a return to hunting whales in Tonga. As a result, concerns regarding the value of these animals for tourism and the potential impact of a return to hunting have arisen. Consequently, a study was designed to provide a preliminary assessment of the economic impacts of these animals for the island community. This study estimates that humpback whales may be worth in excess of U.S.$700,000 annually as a tourism attraction and that there is significant potential for future growth. Furthermore, the study shows that current visitors are opposed to any resumption of whaling practices in the islands and that such a move would likely displace large numbers of tourists from Tonga. Thus, it is concluded that a resumption of whaling in Tonga would likely have a significant opportunity cost in terms of lost tourism revenues.  相似文献   

17.
通常情况,实际海况的波浪更接近三维波,而在船舶运动预报时,目前主要考虑二维波(长峰波)中的响应,不能真正反映船舶在实际海浪中的运动.文中利用不同方法(频域方法、时域方法以及模型)研究了三维波的方向扩散性对船舶运动响应的影响.三种方法得到的三维波对船舶运动的影响是一致的.结果显示,在研究实际海况中的船舶运动时,考虑三维波的方向扩散性是非常重要的.  相似文献   

18.
半刚性基层沥青铺面结构在集装箱港区道路中的应用   总被引:1,自引:0,他引:1  
将半刚性基层沥青铺面结构应用于上海外高桥集装箱港区道路,在国内尚属首创。针对港区道路的特点,结合上海地区水文、地质和建材供应条件及港区生产使用功能要求,通过调查分析和总结集装箱港区已建类似工程道路铺面结构使用情况,分析论证相关施工技术方案,并进行必要的试验,对于半刚性基层沥青铺面结构在应用过程中遇到的各种技术问题,提出了较系统的处理办法。  相似文献   

19.
This paper presents a global ocean implementation of a multi-component model of marine pelagic biogeochemistry coupled on-line with an ocean general circulation model forced with climatological surface fields (PELAgic biogeochemistry for Global Ocean Simulations, PELAGOS). The final objective is the inclusion of this model as a component in an Earth System model for climate studies. The pelagic model is based on a functional stoichiometric representation of marine biogeochemical cycles and allows simulating the dynamics of C, N, P, Si, O and Fe taking into account the variation of their elemental ratios in the functional groups. The model also includes a parameterization of variable chlorophyll/carbon ratio in phytoplankton, carrying chl as a prognostic variable. The first part of the paper analyzes the contribution of non-local advective–diffusive terms and local vertical processes to the simulated chl distributions. The comparison of the three experiments shows that the mean chl distribution at higher latitudes is largely determined by mixing processes, while vertical advection controls the distribution in the equatorial upwelling regions. Horizontal advective and diffusive processes are necessary mechanisms for the shape of chl distribution in the sub-tropical Pacific. In the second part, the results have been compared with existing datasets of satellite-derived chlorophyll, surface nutrients, estimates of phytoplankton community composition and primary production data. The agreement is reasonable both in terms of the spatial distribution of annual means and of the seasonal variability in different dynamical oceanographic regions. Results indicate that some of the model biases in chl and surface nutrients distributions can be related to deficiencies in the simulation of physical processes such as advection and mixing. Other discrepancies are attributed to inadequate parameterizations of phytoplankton functional groups. The model has skill in reproducing the overall distribution of large and small phytoplankton but tends to underestimate diatoms in the northern higher latitudes and overestimate nanophytoplankton with respect to picoautotrophs in oligotrophic regions. The performance of the model is discussed in the context of its use in climate studies and an approach for improving the parameterization of functional groups in deterministic models is outlined.  相似文献   

20.
The influence of intrusions of eastern North Atlantic central water (ENACW) in the north and northwestern Iberian shelf on phytoplankton composition and abundance and on particle-size distributions of seston was analyzed using data collected on three extensive cruises during spring 1991 and 1992. Water with temperature and salinity values between 12.20 and 13.86 °C and between 35.66 and 35.98 psu, respectively, characteristics of the subtropical type of ENACW (ENACWt), was detected in the upper 100 m of the water-column in all cruises, but particularly in the western coast in 1992. The highest salinity values of this water were found near the surface (0–100-m depth) and in early spring 1992, while minimum salinity values, and also minimum geographical extension, were found in late spring in both years. Phytoplankton blooms concentrated in frontal areas between different water types, with maximum intensity and extension in early spring.Using temperature and salinity characteristics, samples were classified in four groups corresponding to the major water types found in the region: Bay of Biscay central water (BBCW), two segments of ENACW of different salinity and surface water influenced by continental runoff. This classification was significantly confirmed by three independent discriminant analyses using hydrographic and chemical (dissolved nutrients and chlorophyll) variables, phytoplankton species abundance variables and particle-size concentration of seston variables. Phytoplankton blooms related to the presence of saline waters were characterized by the dominance of either chain-forming diatoms or a mixture of diatoms and phytoflagellates and high concentrations of seston. The diatom species dominating in saline waters were typical of upwelling-induced blooms occurring generally during summer. Blooms occurring in waters influenced by runoff also contained diatoms but in lower numbers than those of saline waters. Nutrients were not exhausted in the region, suggesting that phytoplankton populations were still in active growth. These results are interpreted taking into account the known variability in water-mass formation and in the poleward current driving ENACWt along the shelf, and indicate that saline intrusions are a major feature affecting the distribution and composition of plankton in the spring in the southern Bay of Biscay, thus enlarging to a wider spatial scale their reported influence on the pelagic ecosystem.  相似文献   

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