全文获取类型
收费全文 | 96篇 |
免费 | 2篇 |
专业分类
公路运输 | 1篇 |
综合类 | 7篇 |
水路运输 | 89篇 |
综合运输 | 1篇 |
出版年
2023年 | 1篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 5篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 1篇 |
2010年 | 1篇 |
2009年 | 11篇 |
2008年 | 5篇 |
2007年 | 13篇 |
2006年 | 10篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2001年 | 6篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 8篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有98条查询结果,搜索用时 140 毫秒
41.
海洋平台钢结构壁厚50mm以上的中厚板焊缝,按照规范要求需要进行焊后热处理(PWHT)。这些构件通常为平台的主要构件或特殊构件,焊缝质量直接影响到平台的安全。当前随着海洋平台设计规模的日益增大,建造过程中需要进行焊后热处理(PWHT)的焊缝越来越多,暴露的问题也日益多样性。本文结合工程实际,详细总结海洋平台钢结构在焊后热处理(PWHT)过程中常出现的但不易被发现的一些隐患问题,以期通过介绍,达到相互交流和借鉴的目的。 相似文献
42.
李宪徐 《广州航海高等专科学校学报》2012,(4):43-46
中华文明博大精深、源远流长,海洋文明始终都是中华文明的有机组成部分.中华民族的复兴需要借力人类已经取得的海洋文明成果,进一步开拓人类海洋新文明也需要中国人的努力及贡献.海洋文明教育作为海洋文明建设的一种极为重要的方式,必须适应新时代的要求,扎根于海洋文明、在海洋文明辛勤耕耘,以弘扬海洋文明为己任. 相似文献
43.
Masahiko Ozaki Junichi Minamiura Yoshinori Kitajima Shuji Mizokami Kazuhisa Takeuchi Katsunori Hatakenaka 《Journal of Marine Science and Technology》2001,6(2):51-58
Ocean sequestration of the CO2 captured from fossil-fuel burning is a possible option to mitigate the increase in CO2 concentration in the atmosphere. It can isolate huge amounts of CO2 from the atmosphere for a long time at relatively low cost, if it is acceptable from the viewpoint of the environmental impact
on the ocean. The concept of CO2 dispersion in the ocean depths by ships is a promising method for efficient dilution. That is, liquefied CO2 is delivered to the site and injected into the ocean at depths of 1000–2500 m with a suspended pipe towed by a slowly moving
ship. In addition to the horizontal movement of the release point, the vertical journey of CO2 droplets until they disappear by dissolution is effective for the dilution of CO2 in seawater. In this paper, the possibility of the generation of relatively large-sized droplets from a moving nozzle is
investigated experimentally. In addition, the terminal velocity of CO2 droplets in deep-sea circumstances is measured in a large high-pressure tank to investigate the influence of the hydrate
film formed on the surface of the droplet. Finally, it is shown by simulation that an initial dilution ratio of one to some
ten thousandths is possible on a realistic engineering scale in the moving ship type of CO2 ocean sequestration.
Received: August 7, 2001 / Accepted: September 13, 2001 相似文献
44.
During the late austral summer of 1994, Antarctic waters were characterized by low phytoplankton biomass. Along the 62°E meridian transect, between 49°S and 67°S, chlorophyll (Chl.) a concentration in the upper 150 m was on average 0.2 mg m−3. However, in the Seasonal Ice Zone (SIZ) chlorophyll a concentrations were higher, with a characteristic deep chlorophyll maximum. The highest value (0.6 mg Chl. a m−3) was measured at the Antarctic Divergence, 64°S, corresponding to the depth of the temperature minimum (100 m). This deep biomass maximum decreased from South to North, disappeared in the Permanently Open Ocean Zone (POOZ) and reappeared with less vigour in the vicinity of the Polar Front Zone (PFZ). In the SIZ, the upper mixed layer was shallow, biomass was higher and the >10 μm fraction was predominant. In this zone the >10 μm, 2–10 μm and <2 μm size fractions represented on the average 46%, 25.1% and 28.9% of the total integrated Chl. a stock in the upper 100 m, respectively. The phytoplankton assemblage was diverse, mainly composed of large diatoms and dinoflagellate cells which contributed 42.7% and 33.1% of the autotrophic carbon biomass, respectively. Moving northwards, in parallel with the decrease in biomass, the biomass of autotrophic pico- and nanoflagellates (mainly Cryptophytes) increased steadily. In the POOZ, the picoplanktonic size fraction contributed 47.4% of the total integrated Chl. a stock. A phytoplankton community structure with low biomass and picoplankton-dominated assemblage in the POOZ contrasted with the relatively rich, diverse and diatom-dominated assemblage in the SIZ. These differences reflect the spatial and temporal variations prevailing in the Southern Ocean pelagic ecosystem. 相似文献
45.
应用当量温差计算法对欧—亚航线上船舶在不同航区的空调动态负荷和风机可调送风量进行了定量描述;阐述了变频技术应用于空调风机的途径;得出了空调风机变频调速,舒适性好,节能率高达58%以上,具有广阔发展前景的结论 相似文献
46.
47.
This article examines the acceptance of aquaculture development by residents and visitors of two islands, Cephallonia and Ithaki, in the Ionian Sea, in western Greece. Aquaculture farms have been established recently in both islands, and processing and packaging units in Cephallonia, generating jobs for the local communities and land rents for the villages in the coastal areas near the fish cages. However, the farms and processing and packaging units entail certain negative impacts on the environment. This study reveals that aquaculture farms have found better acceptance in Ithaki, where aqua culture is a form of development suited to this remote, small, predominantly rural island. The degree of acceptability is higher for locals than for tourists, but also for islanders who do not live in the areas where the processing units are situated. Respondents who consider the pollution of the marine environment by the farms to be high, mostly locals and residents of the villages in the vicinity of the aquaculture infrastructure or the main cities in the islands, are more likely to express a negative attitude toward aquaculture and its further development. 相似文献
48.
49.
朱江 《南通航运职业技术学院学报》2013,(3):36-39
文章介绍了阴极保护基本工作原理,并阐述了其在海洋工程中对控制船体外壳防锈方面的应用。实例证明,在海洋工程中采用外加电流阴极保护更有优势。 相似文献
50.
Ocean-biogeochemical models show typically significant errors in the representation of chlorophyll concentrations. The model state can be improved by the assimilation of satellite chlorophyll data with algorithms based on the Kalman filter. However, these algorithms do usually not account for the possibility that the model prediction contains systematic errors in the form of model bias. Accounting explicitly for model biases can improve the assimilation performance. To study the effect of bias estimation on the estimation of surface chlorophyll concentrations, chlorophyll data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) are assimilated on a daily basis into the NASA Ocean Biogeochemical Model (NOBM). The assimilation is performed by the ensemble-based SEIK filter combined with an online bias correction scheme. The SEIK filter is simplified here by the use of a static error covariance matrix. The performance of the filter algorithm is assessed by comparison with independent in situ data over the 7-year period 1998–2004. The bias correction results in significant improvements of the surface chlorophyll concentrations compared to the assimilation without bias estimation. With bias estimation, the daily surface chlorophyll estimates from the assimilation show about 3.3% lower error than SeaWiFS data. In contrast, the error in the global surface chlorophyll estimate without bias estimation is 10.9% larger than the error of SeaWiFS data. 相似文献