首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   33篇
  国内免费   2篇
  完全免费   15篇
  海洋学   50篇
  2017年   2篇
  2016年   1篇
  2014年   2篇
  2013年   6篇
  2012年   2篇
  2011年   4篇
  2010年   1篇
  2009年   5篇
  2008年   3篇
  2007年   9篇
  2006年   1篇
  2005年   3篇
  2004年   1篇
  2002年   1篇
  2001年   4篇
  1999年   1篇
  1998年   2篇
  1988年   1篇
  1986年   1篇
排序方式: 共有50条查询结果,搜索用时 46 毫秒
1.
深海热液喷口生物群落的研究进展   总被引:10,自引:0,他引:10  
深海热液喷口生物群落并不依赖光合作用获取能量,它们是一类独特的生物类型,其食物链的基础是化学合成细菌,这些细菌依靠喷口热液中的还原无机物氧化.利用CO。合成有机碳,它们共生于大个体动物的软组织或绍中,向寄主提供生存必需的有机碳。地质时期古热液喷口生物群落的研究还表明,该类生物群落在古生代(可能更早)即已出现。此外,现代热液喷口与古热液喷口生物群落的比较研究,在探索该生物群落乃至早期生命的起源、演化方面也取得了可喜进展。  相似文献
2.
Kueishan Tao (24°51′N, 121°55′E) is located at a tectonic junction of the fault system extension of Taiwan and the southern rifting end of the Okinawa Trough. A cluster of over 30 vents, at a water depth of about 10-20 m off the eastern tip of the tao emits hy-drothermal fluids and volcanic gases such as H2S. A sulfur chimney or mound, formed by condensation of the sulfur contained in the hydrothermal fluid, can usually be seen around the  相似文献
3.
4.
TheSnake Pit Hydrothermal Site lies on the axis of the Mid-Atlantic Ridge at 23°22′ N latitude, about 30 km south of the Kane Transform Intersection. Active ‘black smoker’ vents and a surrounding field of hydrothermal sediment occur at the crest of a laterally extensive neovolcanic ridge. It is one of the first active hydrothermal vent fields to be found on a slow-spreading ridge axis and despite significant differences in its geologic setting from those of the East Pacific Rise, has many similarities to its fast-spreading counterparts. Although preliminary reports have documented many interesting aspects of these vents and their surroundings, new data collected from the manned submersible ALVIN and the deep-towed ANGUS camera system define the regional tectonic setting as well as the local geologic environment of this fascinating area. The Snake Pit vents are located on a local peak of a volcanic constructional ridge at a depth of 3450 m, 700–800 m deeper than vents known from the East Pacific Rise, Galapagos, or Juan de Fuca spreading centers. The vent field is at least 600 m long and up to 200 m wide and is covered by a thick blanket of greenish to yellow-orange hydrothermal sediment. Both active and extinct vents are perched along the crests of steep-sided sulfide mounds that reach heights of over 40 m. High-temperature (350° C) fluids are vented from black smoker chimneys and low-temperature (226° C) fluids seep from sulphide domes and subordinate anhydrite constructions. Water temperatures, flow rates, fluid chemistries, and mineralization are strikingly similar to vents of faster spreading ridge crests; however, a somewhat distinct fauna inhabit the area.  相似文献
5.
A new, automatic hydrothermal fluid sampler using a shape-memory alloy   总被引:2,自引:0,他引:2  
A new hydrothermal fluid sampler has been developed to provide more maneuverability in underwater operation. The sampler characteristically employs a shape-memory alloy, which senses high temperature and actuates the suction mechanism. A shape-memory alloy is also used to switch the intake valve of the sampler, the intention being to avoid missampling when the inlet is in low temperature water. Prototype samplers were designed to collect the fluids hotter than 80°C. Test sampling was performed at hydrothermal vents (1372–1374 m deep) in the submarine volcano, Suiyo Seamount, Izu-Bonin Arc, northwestern Pacific. Observed fluid temperature was between 138 and 298°C, while the ambient seawater temperature was 3.1°C. Each prototype collected about 100 ml fluid as designed. The magnesium concentration in the samples indicated a seawater content of 47.5–90.8%, which indicates the entrainment of ambient seawater. Microscopic observatinn revealed the occurrence of microorganisms in the sample fluids at a population density of 105 to 106 cells ml−1, which is 2–3 orders of magnitude higher than those in seawater at that depth. The use of the newly developed fluid sampler will greatly facilitate the collection of vent-associated microorganisms, which are of potential biological and biotechnological interest.  相似文献
6.
讨论了在冲绳海槽伊平屋海岭和南奄西海丘两处海底热液喷出口附近海水中的铀系子体放射性核素210pb和210po浓度的垂直分布剖面.在伊平屋海岭,甲烷及222Rn的数据表明海底热液活动不强,总210pb和210po放射性均低于它们各自母体的放射性,210pb和210po在海水中的平均停留时间分别为20和2~5 a,而在以"黑色烟雾"为特征的海底热液活动强烈的南奄西海丘,在"烟雾"中的总210pb含量(0.167×10-3~2.50×10-3 Bq/kg)相对其母体226Ra贫乏,而总210po含量(1.83×10-~2.83×10-3 Bq/kg)则相对其母体210pb过剩.该处海水中的210po的放射性高于东海陆架区及冲绳海槽其他海区,并且显示了210po过剩.210pb/226Ra以及210po/210pb放射性比值的范围分别为0.1~0.4和1.1~7.8.在热液扩散带中210pb被优先从海水中清除.控制南奄西海丘海水中210Pb浓度的可能机制涉及到210pb通过扩散作用的横向输送.在热液扩散带中高210po/210pb放射性比值表明210pb的耗尽及210po从海底热液喷出口的加入.  相似文献
7.
东太平洋海隆深海热液区沉积物古菌多样性分析   总被引:1,自引:0,他引:1  
采用PCR-RFLP方法对东太平洋海隆深海热液区3个站位沉积物中的古菌多样性进行了初步研究.结果显示,从古菌16S rRNA基因文库中随机挑取的296个阳性克隆分属奇古菌门(Thaumarchaeota,47.64%)、广古菌门(Euryarchaeota,44.93%)、泉古菌门(Crenarchaeota,6.77%)和未分类古菌(0.68%),其中优势菌群为奇古菌门的亚硝化侏儒菌属(Nitrosopumilus,35.47%)和广古菌门的热原体纲(Thermoplasmata,27.03%),DHVE3、DHVE5、DHVE6、MBGB和MBGE类群在沉积物样品中也均有发现.另外,3个站位沉积物中古菌类群组成存在差异,S5-TVG1站位样品文库的97个古菌克隆分属奇古菌门(49.48%)、广古菌门(49.48%)和泉古菌门(1.03%),S14-TVG10站位样品文库的103个古菌克隆由奇古菌门(84.47%)和广古菌门(15.53%)组成,S16-TVG12站位样品文库的96个古菌克隆包括广古菌门(71.88%)、泉古菌门(19.79%)、奇古菌门(6.25%)和未分类古菌(2.08%).研究结果表明,东太平洋海隆深海热液区沉积物中古菌多样性丰富,存在着许多新的古菌菌群;不同站位古菌菌群结构以及多样性存在差异,这与其所处环境的热液活动密切相关.  相似文献
8.
印度洋深海热液区可培养细菌的分子鉴定与系统发育分析   总被引:1,自引:0,他引:1  
采用MMJHS寡营养培养基从印度洋深海热液区沉积物和热液硫化物中分离获得16株细菌,通过16S rDNA序列比对和生理生化分析,对它们进行了鉴定并构建了系统发育树.结果表明,12株细菌属于γ-变型菌(γ-Gammaproteobacteria),其中6株属于盐单胞菌属(Halomonas),4株属于嗜冷杆菌属(Psychrobacter),2株属于食碱菌属(Alcanivorax);其余4株属于芽孢杆菌(Bacillus),其中1株为地衣芽孢杆菌(Bacillus licheniformis).分离获得的16株细菌中,4株为革兰氏阳性细菌,12株为革兰氏阴性细菌;H2S反应、吲哚测定反应、M.R和V-P均呈阴性.本研究为深入认识和开发利用深海热液区微生物资源奠定了基础.  相似文献
9.
The variability of the bioaccumulation of metals (Ag, Cd, Cu, Fe, Mn and Zn) was extensively studied in the mussel Bathymodiolus azoricus from five hydrothermal vent sites inside three main vent fields of increasing depth along the Mid-Atlantic Ridge: Menez Gwen, Lucky Strike and Rainbow. Metal bioaccumulation varied greatly between vent fields and even between sites inside a vent field with B. azoricus showing a great capacity to accumulate metals. The bioaccumulation of these metals also varied significantly among tissues. The main target was the gills where metals were mainly associated with soluble compounds whereas in the digestive gland they were mainly associated with insoluble compounds. Storage of metals under insoluble forms in B. azoricus seems to be a major pathway for the detoxification of both essential and non-essential metals. Mussels from the studied fields can be discriminated following their metallic load but the segregation relies partially on the composition of the metal-enriched fluids.  相似文献
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号