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1.
根据仿生鱼类侧线细胞纤毛原理,设计、制造并测试了一种新型双纤毛压阻水听器,用于检测水下声信号.与传统的压电水听器相比,这种水听器具有体积小和矢量性的优点.利用聚氨酯仿生细胞壁作为透声帽,利用硅油模拟细胞液和压阻微梁模拟感觉纤毛三层拾振结构,从而提高纤毛式水听器的可靠性.封装以后的纤毛式水听器采用振动台和矢量水听器校准系...  相似文献   

2.
河口涨落潮槽水动力特征及河槽类型判定   总被引:4,自引:0,他引:4  
在前人对河口冲刷槽研究的基础上,选择长江口南支、新桥水道、南小泓和南港主槽作为典型涨、落潮槽研究对象,以2001年洪季和2003年枯季实测资料为根据,比较分析了长江口涨落潮槽的水流、泥沙、优势流和优势沙等动力特征,结果表明用单一因子分析河槽性质不够全面.提出了一个(无量纲因子)河槽类型系数(λ)来综合表述河槽的多种水文泥沙特征,可以较全面地用多个影响因子来合理地判断河槽类型.  相似文献   

3.
介绍了美国海军电子海图显示与信息系统(ECDIS-N)的发展动态,在分析美国海军向ECDIS-N转变的背景和历程、ECDIS-N标准及相应装备VMS发展的基础上,从总体协调规划、海图数据建设、装备研制、支持维护等方面,探讨了对我国加快向电子海图导航方式转变的启示。  相似文献   

4.
在海洋战略和清洁能源战略背景下,我国围绕海洋牧场和海上风电开展了规模化建设并取得了巨大成就。但工程成本高昂、海洋生境破碎化和用海冲突等问题日益显著,国内外由此开展了海上风电和海洋牧场融合发展的试点与探索。文章整理分析了国内外相关研究和试点工作,针对海上风牧融合发展的现状以及在经济和政策可行性、选址与规划、鱼种选择、配套设备开发、生态影响评估(噪声、电磁场、底座干扰和重金属迁移等)等方面的难题与挑战提出建议。  相似文献   

5.
黄河流域在我国经济社会发展和生态安全方面具有十分重要的地位,其下游的黄河三角洲分布有世界上暖温带保存最广阔、最完善、最年轻的滨海湿地生态系统,该区域特殊的地质地貌决定了其生态多样性,需要进行重点研究和保护。文章立足于我国现有湿地保护政策和湿地面积缩小的现状,提出黄河三角洲湿地保护可着重围绕其岸线变化、冲淤速率、地形地貌等开展研究,并采用减压分洪扩充法等治理修复方法扩大湿地面积,为推动黄河流域及黄河三角洲湿地的生态保护和高质量发展提供有效参考。  相似文献   

6.
高畦深沟种植水稻、有机蔬菜,沟中施投化粪池污水、生活废水、腐烂瓜果蔬菜、各类粪便、田间杂草、藤蔓秸秆等培养水蚯蚓、福寿螺、小球藻、水蚤等饵料生物,构成良性循环的人工生态系统,通过水生生物和农作物的作用使有机污染物在田间得到衰减和清除。这种立体生产、综合利用集约生产模式,有利于降低饵料生物生产成本,有助于解决自然耕种收获量较少、成本较高的问题,能使有机垃圾、污水处理工艺简单、费用少,并能变废为宝生产出大量的动物蛋白和植物蛋白。  相似文献   

7.
While neoliberalism is often framed as a withdrawal of the state, many scholars have noted that what is occurring is not so much a withdrawal, as a repositioning. Although many social services and regulatory functions once provided by government agencies have indeed been eroded, there has been a simultaneous channeling of new resources into other arenas, in an effort to create conditions in which private corporations can operate more profitably. This, however, often places the state in a contradictory position, simultaneously serving as regulator, investor, and development advocate for the private sector. This can become especially problematic in moments of ecological crisis when decisive and unbiased responses are needed. This paper explores these dynamics through an examination of the cycles of growth and crisis that have characterized the aquaculture industry on the south coast of Newfoundland since the late 1970s as well as the ongoing attempts by aquaculture advocates to characterize industrial-scale fish farming as a sustainable industry, despite evidence to the contrary.  相似文献   

8.
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   

9.
海藻研究开发的发展概述   总被引:16,自引:0,他引:16  
综述了海藻的资源、组成、性质和研究开发的进展概况,阐述了海藻今后的发展趋势。  相似文献   

10.
Variations are found in the shape and the steepness of wind-generated surface gravity waves between very young waves, such as seen in a laboratory tank, and larger waves of various wave ages encountered at sea as the result of wind stress over larger fetches. These differences in the characteristic shape of wind waves are presented as a function of the wave age. The wave steepness is also expressed as a function of wave age, the measurement of which is consistent with the 3/2-power law connecting wave height and characteristic period, normalized by the air friction velocity.  相似文献   

11.
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   

12.
综述了我国海域无脊椎动物的分类学和系统演化研究的历史和概况,以及我国分类系统学工作者在海洋无脊椎动物分类学、区系与动物地理学、系统发育与分子系统学领域的主要工作,重点介绍了中国科学院海洋研究所的海洋无脊椎动物分类学工作。涉及类群包括原生动物、海绵动物、刺胞动物、线虫、多毛类环节动物、星虫、螠虫、软体动物、节肢动物、苔藓动物、毛颚动物、棘皮动物、半索动物等主要的无脊椎动物门类。涉及海域以我国管辖海域,特别是中国近海为主,也涉及了西太平洋、西南印度洋等深海环境的无脊椎动物类群的分类学报道。本文总结过去,展望未来,对于在我国在海洋无脊椎动物分类与系统演化研究领域成就基础上,发现薄弱环节,研讨今后本学科的发展方向,填补研究空白,赶超本领域国际前沿,都有重要借鉴意义。  相似文献   

13.
将北斗通信技术、船舶自动识别系统技术、航标遥测遥控技术以及GPS差分技术进行有效结合,研制了海上导航信息远程传输监控系统,对我国中、远海海域装有AIS设备的船舶进行跟踪与监控、可疑船舶的辨认、船舶的岸基调度、航标遥测遥控、GPS差分信息远程播发等。相比单一技术的应用,海上导航信息远程传输监控系统不受天气条件限制,无需人员定期出海维护,具有设备集成度高、导航差错率低、功能全面、成本效益好等特点。  相似文献   

14.
褐藻多糖的药理作用与制备   总被引:3,自引:0,他引:3  
阐述了褐藻糖胶的化学组成和结构。从褐藻中提取分离得到的褐藻糖胶具有显著的抗癌、抗凝、降脂、免疫调节和抗衰老作用,既可作为保健食品,也可作为治疗药物。目前,我国制备褐藻糖胶,主要采用60%乙醇沉淀法和CPC沉淀法从海带水碱凝沉物中提取,或用稀酸直接从海带中提取,并用乙醇分级法和色谱法对褐藻糖胶进行纯化。  相似文献   

15.
The distribution of dissolved (soluble and total) and particulate (leachable and total) aluminum was examined in the Columbia River and estuary, in near-field and far-field river plumes, and in adjacent coastal waters of Washington and Oregon during the River Influence on Shelf Ecosystems (RISE) cruise of May/June 2006. Dissolved and particulate aluminum (Al) concentrations were significantly greater in the river than in the coastal waters that mixed to form the plume. Dissolved Al concentrations in the Columbia River (∼80 nM) were low relative to other major rivers. Leachable and total particulate Al concentrations within the river reached concentrations greater than 1000 nM and 18,000 nM, respectively. Dissolved Al within the Columbia River estuary showed a significant removal (∼60%) at salinities between 0 and 10 with salt-induced flocculation of colloidal Al complexes and enhanced particle scavenging being probable explanations for aluminum removal. Dissolved and particulate Al concentrations were significantly greater in near-field plumes relative to surrounding coastal waters. As the plume advected from near-field to far-field away from the river mouth, dilution of the plume with lower dissolved Al surface waters as well as particle scavenging along the flow path appeared to be controlling dissolved Al distributions. Particle settling as well as dilution with lower particle-load waters led to observed decreases in particulate Al as the plume moved from near-field to far-field. However, the percent-leachable particulate aluminum in both near-field and far-field plumes was remarkably constant at ∼7%. Dissolved and particulate Al in a far-field plume over 100 km southwest of the Columbia River mouth were over an order-of-magnitude greater than surrounding waters, illustrating the importance of the Columbia River plume as a mechanism for transporting Al offshore. Aluminum could be used to trace the input of biologically-required elements such as iron into waters off the shelf.  相似文献   

16.
The data on the species composition, trophic structure, and distribution of macrozoobenthos in Amur Bay obtained in 2001 are presented. Long-term changes in the benthos are analyzed. In 2001, the total benthos biomass significantly increased, although the parameters of the species richness declined as compared to 1986–1989. In 2001, as well as in the 1970s and 1980s, the benthos trophic structure was characterized by the prevalence of deposit feeders. The entire structure of the benthos is evaluated as an eutrophic one. Eutrophication of the bay is considered to be the most probable cause of the negative changes in the benthic communities of the bay in 2001, as well as 15 years ago.  相似文献   

17.
采用微生物富集培养分离法对南洋油田不同油样中的菲降解菌进行了分离鉴定。分离得到2株以菲作为唯一碳源和能源的细菌菌株S17和S28,经革兰氏染色及显微镜形态观察,发现两者都是具有极生单鞭毛的革兰氏阴性、无芽孢杆菌。根据生理生化特性分析,以及16S rDNA序列同源性分析,两者属于假单胞菌属的不同种。菌株S17与食树脂假单孢菌(Pseudomonas resinovorans)序列同源性为97%;菌株S28则为高温假单胞菌(Pseudomonas thermaerum),其序列同源性达到100%。在以菲为唯一底物的条件下,菌株S28的生长速度是S17的2倍多,第4天即达到最大生长量,但是对于菲的降解而言,两者都在第10天达到最大,降解率分别为88.86%和82.02%,但是二者在起始的两天内对菲的降解效率最高,分别达到70.21%和72.74%,因此可用于菲污染的快速治理领域。  相似文献   

18.
海洋三维温盐流数值模拟研究的有关进展和问题   总被引:1,自引:0,他引:1  
就海洋三维温盐流数值模拟使用的海洋模式和数据同化方法、在中尺度数值预报和再分析中的应用,以及所需支撑条件三方面,简述了国内外研究有关进展和问题。表述了开展大范围分辨中尺度乃至次中尺度涡的高分辨率海洋三维温盐流数值模拟正在研究的有关问题,扼要说明提供相匹配的高性能计算机模拟平台的必要性。初步探讨制约该研究快速发展的有关问题。  相似文献   

19.
20.
基于青岛崂山前海直立式防波堤兼码头工程的设计,通过规范计算值与断面物理模型试验数据的对比分析,合理确定断面尺度、堤顶高程和越浪量等重要设计参数。特别是通过多组试验的数据分析,对挡浪墙的外形尺度和护底宽度进行优化,采用通过增大护底块体重量的方式有效地减小护底长度,充分运用试验手段对于设计规范的护底相关规定做出了有益的探索和补充,为深水直立式防波堤的设计改进提供了借鉴。  相似文献   

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