首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
海索面Nemalion helminthoides(Valley)Batt.Var.Vermicular(Sur.)Tseng属于红藻门(Rhodophyta)红藻纲(Florideophyceae)海索面目(Nemalionales)海索面科(Nemalionaceae)海索面属“(Ne-  相似文献   

2.
本文介绍了海索面的采集和对海索面腊叶标本的制作过程及其注意事项。  相似文献   

3.
西南太平洋弧后盆地(北斐济海盆和劳海盆)深海热液的生物群落DanielDesbruyeres等自1976年以来,沿洋中脊所作的调查航次都查明了火山口生物群落很多见,并且不受洋中脊扩张速度影响。这些生物群落在东太平洋海隆、加拉帕戈斯扩张中心、戈尔达海脊...  相似文献   

4.
本文根据对漂流藻属(Planktoniella)细胞形态观察,发现我国海域有两种漂流藻:太阳漂流藻(P.solSchutt)和美丽漂流藻(P.formosaQianetWang).后者是根据详细观察研究后对Valdiviellaformosa(SchimperexKarsten)Karsten重订的。  相似文献   

5.
黄、渤海几种海产无脊椎动物蛋白质与氨基酸含量分析   总被引:13,自引:1,他引:13  
三疣梭子蟹(Portunus trituberculatus)、虾蛄(Squillaoratoria)、刺参(Stichopus japonicus)、海地瓜(Acaudinamolpadioides)、脉红螺(Rapana venosa)、长竹蛏(Solengouldii)、泥蚶(Tegillarcagranosa)、菲律宾蛤仔(Ruditapesphilippinarum)、紫贻贝(Mytilus edulis)、长蛸(Octopusvariabilis)、马粪海胆(Hemicentrotu…  相似文献   

6.
西太平洋活动带的油气远景构造(关于鄂霍次克海和大洋洲)RaisaRodnikova等对西太平洋活动带构造格架的调查为确定那些与沉积盆地相关的特定的裂谷群奠定了基础.对这些盆地的勘探将会增强该地区的能源潜力。对石油勘探来说,目前这些盆地大部分仍不成熟....  相似文献   

7.
产于烟台的5种海产经济动物对Cr的富集存在明显差异。底栖的滤食性贝类(紫贻贝M.edulis、栉孔扇贝Chlamysfarreri、菲律宾蛤仔Ruditapesphilippinensis)的富集量远远超过自游泳的种类(中华马鲛Scomberomorussinensis,长额七腕虾Heptacarpuspandaloides)。紫贻贝为理想的海洋重金属Cr污染的指示动物.烟台海域各海区紫贻贝体内Cr含量最高,向边远海区逐渐降低。5种海产动物体内Cr的含量均在食品允许范围之内。  相似文献   

8.
实验比较新型虾保鲜剂(PPR—1)及其它类型的虾保鲜剂如亚硫酸氢钠(SBS)、植酸(PA)及日本虾保鲜剂(JPR)对中国对虾PenaeusChinensis的保鲜作用。实验指出:(1)在冷藏(4℃)与冷冻(-18℃)保藏条件下,PPR—1及JPR对中国对虾的保鲜效果均优于PA和SBS;(2)在冷藏(4℃)或冷冻(-18℃)条件下,去头保鲜效果均优于带头保鲜效果。  相似文献   

9.
全球电信系统(GTS)上的海洋观测数据格式*孔杰1引言全球电信系统(GTS,GlobalTelecommunicationsSystem)是世界气象组织(WMO,WorldMeteorologicalOrganization)为了迅速、准确地在全世界...  相似文献   

10.
根据珠江(广州河段)沉积物中As(T),As(Ⅲ),As(Ⅴ),MMA,DMA含量与Fe,Al,K,Ca,Mg及有机碳含量,研究了南亚热带近河口区沉积物中As形态的存在特征,并计算AS形态间及与其它元素间的相关性,从而说明AS形态在河口区的存在及迁移特征。  相似文献   

11.
采用生氧量生物测验法对影响水库初级生产力的微量元素进行了测定。结果表明,当氮、磷充足时,锰的限制作用较普遍,而锌、铜的抑制作用也常出现,铁、硒等其他元素在某些条件下也会起限制作用。围隔试验的结果也表明,在施氮、磷的基础上,加施锰剂后,浮游植物生物量(以活性叶绿素a表示)增高1.7倍以上,较之单纯施氮、磷肥,生物量亦增高了35%以上,高峰持续时间约10d,浮游动物生物量亦有所增加。这些结果都表明锰在提高水库鱼产力中有重要作用,同时也说明在大水域施肥养鱼中添加微量元素是可行的。  相似文献   

12.
Sediments are the particulate matter that are transported by the flow of water and eventually get deposited at the bottom of water bodies, such as oceans, rivers, lagoons, and so forth. The deposition of these materials due to continued intervention of natural as well as anthropogenic activities is a serious concern as the storage capacity (or health) of the system is reduced or otherwise affected. Keeping in view the emerging challenges associated with proper disposal and subsequent utilization of sediments, as a manmade resource, their extraction from such locations becomes necessary. Hence, it is essential to characterize the sediments in order to devise strategies to exploit them as a manmade resource in the best possible manner. With this in view, this article highlights the importance of different attributes and aspects of the sediments (viz., physical, chemical, morphological, geotechnical, toxicological, and microbial characteristics) deposited in the water bodies that will help in assessing their potential as a substitute material to natural resources.  相似文献   

13.
Geoindicators provide a management tool for rapid assessment of natural hazard risk potential, either as a supplement to long-term environmental auditing and monitoring, or for initial coastal assessment as in developing countries. Using examples of barrier island and bluffed coasts, indicators of process/response are examined regionally, locally, and site-specifically; the latter being the primary indicators of property-threatening hazards. Tabled evaluation parameters range from general (elevation and vegetation) to specific characteristics such as shoreline stability and configuration, inlet proximity, and barrier-island interior geomorphology. Geoindicators also provide guidance for local mitigation of hazard impacts. A case study of Bogue Banks, North Carolina, shows that the geoindicators approach is applicable to communities with extant management plans. Bogue Banks’ five communities must reevaluate mitigation strategies after every storm and because of changes induced through development. By applying the geoindicators approach, shoreline reaches as well as interior areas may be reassigned as to the level of risk, and appropriate mitigation actions taken.  相似文献   

14.
以硫酸铵水溶液为反应介质,以丙烯酰胺(AM)为主要单体,以甲基丙烯酰氧乙基三甲基氯化铵(DMC)和丙烯酸(AA)为离子单体,以DMC均聚物(PDMC)为稳定剂,以2,2′-偶氮二[2-(2-咪唑啉-2-代)丙烷]二氢氯化物(V-50)为引发剂,采用水分散聚合技术,合成了流动性好、具有良好稳定性的两性聚丙烯酰胺分散体系。NMR1H谱表明,聚合物中DMC单元的含量与原料中所占的比例相近。所制备的两性聚电解质具有明显的反聚电解质效应。硫酸铵浓度、稳定剂浓度、引发剂浓度和pH值对分散体系的粒子形貌和聚合物的特性黏数都有较大的影响。最佳合成条件为:硫酸铵浓度31%~33%、分散剂用量为0.46 g·g-1、引发剂用量400 mg·kg-1和pH值为5~6。  相似文献   

15.
Behaviors of organically-bound iron in an estuary having normal primary production and in a red tide outbreak estuary were investigated. In the former, the iron complex decreases with increasing salinity because of its flocculation. In the latter, the iron complex as well as nutrients except silicate are completely assimilated by phytoplankton. Among nutrients silicate diffuses by only water mixing because the main species of phytoplankton were green colored algae at the river mouth. High nitrite concentration was found at about 15‰ salinity. This means that the decomposition of phytoplankton as well as photosynthesis is also carried out. The iron complex assimilated would be released to seawater with the decomposition of phytoplankton and then red tide outbreaks at the estuary would be continued for a long period.  相似文献   

16.
Simulation of vortex-induced vibrations of a cylinder using ANSYS CFX   总被引:1,自引:0,他引:1  
In this paper, vortex-induced vibrations of a cylinder are simulated by use of ANSYS CFX simulation code. The cylinder is treated as a rigid body and transverse displacements are obtained by use of a one degree of freedom spring damper system. 2-D as well as 3-D analysis is performed using air as the fluid. Reynolds number is varied from 40 to 16000 approx., covering the laminar and turbulent regimes of flow. The experimental results of (Khalak and Williamson, 1997) and other researchers are used for validation purposes. The results obtained are comparable.  相似文献   

17.
总结浮式风力机类型及其对应的特征动力学问题,针对浮式风力机气动荷载、水动荷载的计算方法以及结构动力学、控制动力学典型问题进行论述。讨论了气动—水动—结构—伺服耦合分析的难点,重点分析了二阶波浪力、畸形波等非线性波浪荷载、流荷载及涡激运动对浮式风力机特征动力响应的影响。阐述了浮式风力机动力学研究的试验方法、数值仿真方法、样机测试方法,并对模型试验技术的相似理论、气动模型的实现和难点以及数值仿真的频域方法、时域方法和分析工具进行了归纳对比。研究表明:浮式风力机多场、多体耦合动力分析机理及相关技术仍不成熟,气动荷载、高阶非线性波浪荷载耦合模型的建立是动力学问题研究的重点,数值仿真及模型试验是浮式风力机动力响应研究的主要方法,样机测试技术的积累将促进设计标准的完善及浮式风电的产业化发展。  相似文献   

18.
An interpretation of the geoid in and around Scandinavia in terms of crustal depth structure has been made. Correlations as high as 0.92 were found between current models of crustal depth and the geoid for marine areas of Scandinavia. The Fennoscandian land uplift together with its corresponding resultant change of geoid were also found to be highly correlated with crustal depth structure. Results of these correlations compare favorably with theoretical models based upon large scale isostatic behavior of the lithosphere. These models indicate that the crustal thickness variations of Scandinavia are compensated generally at depths greater than 100 km. The results indicate that previous attempts to correlate the geoid with the causes of present land uplift have overestimated the remaining isostatic geoid anomaly in Fennoscandia. The application of these results would reduce the isostatic geoid anomaly by as much as 80% for marine areas of Fennoscandia. This may be interpreted as placing the estimated upper mantle viscosities for Fennoscandia closer to 1021 Pa s.  相似文献   

19.
A force action caused by the generation of internal waves in the vicinity of a density jump layer in a marine medium and exerted on underwater obstacles streamlined by a two-layer flow has been studied as part of a theoretical model. A horizontal element of an engineering structure, for example, a transport pipeline, which is modeled by a point dipole, is selected as an underwater obstacle. The integral representations for the wave resistance and the lift force are obtained. The characteristic features of variation in the hydrodynamic reactions to the streamlined obstacle, as well as the conditions of their significant intensification are revealed.  相似文献   

20.
A. Baz  H. Helal 《Ocean Engineering》1984,11(1):111-128
This study presents the flow-resistance characteristics of conventional exhalation valves used in underwater diving regulators. Evaluation of such characteristics is essential to quantifying the effect of the main design parameters of these valves on the diver's exhalation effort.Plain, tapered as well as tapered supported valves of different materials have been considered in this study.Valves seats of different geometrical configurations which varied from the simple multi-circular hole seats to the more imaginative Posiden-like seats have been studied. Triangular, multi-quadrant as well as full diaphragm exhalation valves have also been tested in details.New designs of exhalation valves have also been developed and tested in an attempt to define the optimum configuration as well as the best combination of the valve and its seat that would reduce the exhalation effort to a minimum. Among the considered new designs are the vortex and nozzle-assisted exhaust valves.The obtained results show that full diaphragm exhalation valves offer the least breathing resistance followed by the 13-hole Posiden-like exhalation valve, the nozzle-assisted valves and the vortex-assisted valves. Nonetheless, the 2.9-cm diameter plain, unsupported and untapered valve on the six-triangle seat exhibits flow characteristics that are not too far from the most fancy designs.The obtained results presents design guides, for improving the breathing characteristics of the exhalation valves, which can be extremely important to the designers and manufacturers of diving regulators.  相似文献   

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