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71.
This study evaluated the potential impact of global fish trade on local food prices by analyzing a 16-year locally collected time series of disaggregated coral reef fish products and prices that differed in their market chain linkages—ranging from local to international markets. We were primarily interested in evaluating how local and global markets interacted with the local prices of beef, fish, and maize. There was no cointegration between the prices of exported octopus and that of maize and beef over this study period. Further, the three types of fish and associated markets responded in different ways to various price changes. For internationally traded octopus, we found a positive association between price and catch rates but no evidence that the global trade in octopus markets created local inflation, particularly the prices of the fish eaten by the poor. In general, there was no evidence for price transmission from export to nonexport fish products even though fishers appeared to focus on octopus when prices were high. Consequently, fishers' behaviors and trade policies that promote adjusting fishing effort to internationally traded fish did not appear to promote poverty or food insecurity in this fishery. 相似文献
72.
文章分析了西江下游长洲枢纽船闸附近江面大量船舶滞航的根本原因,结合国内外船闸管理机构的先进经验,提出了解决长洲枢纽船闸滞航问题的方案以及优化船闸管理与维护的方法。 相似文献
73.
甄远 《南通航运职业技术学院学报》2014,(2):81-86
长江口海运历史绵远,优势独具,这才成为下西洋船队的航海出发地。夏原吉治水,制淞通娄,娄江口水势骤增,造就了刘家港,而郑和下西洋远航从这里始发也取得了丰厚的收获。 相似文献
74.
从海洋工程基础打桩工艺、打桩船类型和关键技术等方面着手,阐述了打桩船的技术现状及发展趋势.研究发现,随着向海经济日趋繁荣,为满足超大桩径、桩深、集桩/补桩等打桩作业的需求,稳定性高、定位精度高以及环境友好型的超大专用打桩船将得到快速发展. 相似文献
75.
76.
杨俊生(1890~1982年),是我国造船工业著名的实业家,大中华造船厂的创始人,并长期担任该厂厂长。他忠诚爱国,一生为创建和发展我国的造船事业呕心沥血。他设计建造了大批内河及沿海船舶,教书育人培养了许多造船人才,为我国发展造船作出了杰出贡献。他当选为第一、二、三届全国人大代表。1978年被选为全国政协委员。本文简要回顾了杨俊生的崇高理想和主要业绩。 相似文献
77.
在CRM理论为基础的条件下,结合目前市场的航运市场的特点,分析了航运企业客户价值的评价,其中包括针对航运企业自身特点所建立的客户价值指标体系以及对这些指标的赋值计算,仅供参考。 相似文献
78.
During a repeat grid survey and drogue study carried out in austral summer 1994/95, the abundance and feeding activity of salps were estimated in the Lazarev Sea region from net tows and in situ measurements of gut fluorescence. Throughout the survey area, Salpa thompsoni accounted for >95% of the total salp stock while Ihlea racovitzai was consistently represented in very low abundances. Maximum densities of S. thompsoni, with ≈4000 ind. 1000 m−3, were recorded in the Marginal Ice Zone (MIZ) in December when chlorophyll-a concentrations were well below 1 mg m−3. A dramatic decrease in salp stock was observed at the beginning of January, when S. thompsoni virtually disappeared from the most productive area of the MIZ where chlorophyll-a concentrations had by then reached bloom levels of 1.5–3 mg (Chl-a) m−3. In situ grazing measurements showed that throughout the cruise S. thompsoni exhibited the highest ingestion rates per individual of any of the most abundant components of the grazing pelagic community, with maxima of ≈160 μg (pigm) ind. −1 d−1. These feeding rates are 3 to 5 times higher than those previously obtained using in vitro incubations. The total daily consumption of the population of S. thompsoni varied from 0.3 to 108% of daily primary production. We suggest that competitive removal of food by S. thompsoni, rather than direct predation, is responsible for the low krill abundances generally associated with salp swarms. 相似文献
79.
Angus Atkinson 《Journal of Marine Systems》1998,15(1-4)
Twelve epipelagic copepod species were reviewed to compare their adaptations to the short primary production season and low temperatures which characterise the Southern Ocean. The species show a spectrum of adaptations, but three broad life cycle strategies were defined: (1) herbivorous in summer, a short reproductive period and winter diapause at depth (Calanoides acutus and possibly Ctenocalanus citer); (2) predominantly omnivorous/detritivorous diet, an extended period of feeding, growth and reproduction and less reliance on diapause at depth (Metridia gerlachei, Calanus propinquus, Calanus simillimus, Oithona similis, Microcalanus pygmaeus, and possibly Oncaea curvata and Oithona frigida); (3) overwintering and feeding within sea ice as early nauplii or copepodids (Stephos longipes and Paralabidocera antarctica). The large species Rhincalanus gigas appears to be intermediate between strategies (1) and (2). Contrasting species from groups (1) and (2), namely C. acutus and O. similis, were selected for more detailed comparison. For C. acutus, maximum (probably food saturated) feeding and egg production rates are well below equivalent values for Calanus spp. at lower latitudes. Likewise, summer growth and moulting rates are slower, and the growth season of this herbivore is only 2–4 months. Therefore, both the low summer temperatures and short primary production season seem to dictate a long (1 year) life cycle for C. acutus. A collation of data on O. similis revealed that its abundance increases about tenfold from the Antarctic shelf northwards to the Polar Frontal Zone, where abundances are similar to those in temperate and tropical shelf seas. In contrast to C. acutus, O. similis appears to remain in the epipelagic and reproduce there year-round, although the food sources which sustain this are still uncertain. 相似文献
80.
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