Inhomogeneous substrate analysis using EM300 backscatter imagery   总被引：2，自引：0，他引：2  

Yves Le Gonidec  Geoffroy Lamarche  Ian C. Wright 《Marine Geophysical Researches》2003,24(3-4):311-327

Backscatter reflectivity from multibeam echo-sounders provides a powerful tool to efficiently characterize seafloor substrates. A comprehensive EM300 bathymetric and backscatter survey has been completed of Cook Strait, in central New Zealand. This paper presents a detailed analysis of the realtime corrections applied to the raw EM300 multibeam data and additional corrections required to compute angular variations of the backscatter strength. The corrections, including the local absorption coefficient, the influence of seafloor topography and sound refraction in the water column, are determined for different Cook Strait seafloor substrates. Modifying MB-System software code, we extracted the backscatter signal parameters in order to quantify the raw backscatter strength and apply additional processing. Profiles of backscatter strength versus incidence angle were computed for a variety of sites characterized by flat seafloor and homogeneous substrates, and for which ground-truth data were available. For each homogeneous site, different but characteristic backscatter profiles are observed that can be interpreted in terms of sediment facies. To analyze heterogeneous substrates, we present a statistical technique, based on a 3-dimensional distribution of (incidence angle, backscatter strength) couples that preserves geological information of the substrate components. This analysis, using backscatter data acquired on a submarine volcano, north of New Zealand, clearly differentiates soft sediments and lava flows within a heterogeneous substrate.  相似文献   

我国海洋软相底质底栖经济贝类的可持续利用探讨   总被引：1，自引：0，他引：1  

吴进锋  梁超愉  陈利雄  陈素文  李夏 《海洋湖沼通报》2005,(2):93-98

分析了海洋软相底质底栖贝类的资源特性和我国的资源利用现状及存在问题．并从规模化苗种生产、海区增殖、高效养殖模式开发及增养殖环境保障与产品无公害生产等方面对该资源的可持续利用进行了探讨。  相似文献   

Recruitment patterns of Serpula vermicularis L. (Polychaeta, Serpulidae) in Loch Creran, Scotland   总被引：1，自引：0，他引：1  

Nicola D. Chapman  Colin G. Moore  Dan B. Harries  Alastair R. Lyndon 《Estuarine, Coastal and Shelf Science》2007,73(3-4):598-606

This study aimed to contribute to conservation management of reefs of Serpula vermicularis by increasing understanding of the factors influencing larval settlement. The study was carried out in Loch Creran, which supports the most extensive known development of S. vermicularis reefs in the world. Settlement plates were deployed to examine the influence of season, depth, reef density, substrate type and orientation. Monthly deployment of plates revealed settlement of S. vermicularis to occur predominantly from mid-June to mid-October, peaking in late August to early September. Settlement of Pomatoceros spp. peaked much earlier, in late May to early June. Deployment of plates at different depths revealed a marked reduction in S. vermicularis settlement intensity between 6 and 12 m. As this corresponds with the deeper limit of the peripheral fringe of serpulid reefs in the loch, it is suggested that this limit is imposed by a depth-correlated settlement response, rather than reduction in available substrata. Comparisons of various substrata showed a preference by S. vermicularis larvae for a slate over a scallop substrate and no evidence of enhanced recruitment to occupied or unoccupied tubes of S. vermicularis, suggesting that gregarious attraction is unlikely to be a factor causing reef formation. Settlement onto the upper side of a horizontal scallop substrate was found to be insignificant in comparison with the underside or a vertically orientated scallop. Evidence for the role of light in controlling the depth and substrate-orientation preferences of S. vermicularis larvae is discussed. Based on the results of this study, recommendations are made regarding remediation of areas suffering reef damage.  相似文献   

单体褶牡蛎(Crassostrea sp.)的研究     

王昭萍  王如才  徐从先  仇宝志  姜福正  张祝绪 《中国海洋大学学报(自然科学版)》1992,(2)

采用肾上腺素(EPI)和去甲肾上腺素(NE)诱导、颗粒固着基和先固着后脱基三种方法,对褶牡蛎的眼点幼虫进行处理,产生单体蛎苗。EPI和NE诱导的最适浓度为10~(-4)M,最适处理时间为3h,幼虫的不固着变态率分别达47.7％和46.6％。处理时间延长,变态率增加不明显。EPI和NE的诱导效果差别不明显,其诱导作用对稚贝的生长无明显副作用。颗粒固着基以贝壳粉为佳,最适颗粒的规格为幼虫的壳长。幼虫先固着后脱基而形成单体蛎苗,以可弯曲的灰色塑料板效果最好,固着的小贝可通过来回弯曲塑料板而从上面脱落下来,小贝长至1～2cm大小时,脱基最容易。  相似文献   

海山铁锰结壳基岩岩石学特征及其生长关系   总被引：2，自引：0，他引：2  

张丽洁  姚德 《海洋地质与第四纪地质》2002,22(2):49-56

为了研究海山铁锰结壳基岩类型与结壳壳层生长的关系。对麦哲伦海山及中太平洋海山区取得的铁锰结壳及其基岩样品在电子显微镜下进行了观察和研究。结果表明，上述2个区域基岩岩石类型主要有玄武岩，火山熔岩，火山碎屑岩，硅质岩和碳酸盐岩，其中麦哲伦海山玄武岩为块状构造，中太平洋海山玄武岩则主要为气孔-杏仁状构造，多发生蚀变或完全蚀变，硅质岩颗粒物质主要是硅藻，碳酸盐岩则以晶质灰岩为主，结壳壳层厚度在各类基岩类型上都有变化，以在玄武岩和碳酸盐岩上变化最大。  相似文献   

菲降解菌的降解特性及酶促反应动力学研究     

席宏波  杨琦  尚海涛  郝春博 《地学前缘》2008,15(6)

通过对取自MBR膜生物反应器中的活性污泥加入菲进行富集培养、驯化,分离、纯化出一株能以菲为唯一碳源和能源的短杆状革兰氏阴性菌J-1,细菌长2～5μm,宽1～3μm;研究了初始底物浓度、温度、pH对菌株J-1降解菲的影响,探讨了菌株J-1胞内酶对菲降解的底物抑制动力学。试验表明:菌株J-1在48h内能将不同浓度菲的水溶液中的菲完全降解;菲浓度增加,达到完全降解的时间延长。温度对细菌的降解能力影响较大,菌株J-1对菲降解的最佳温度为28℃。1.15mg·L-1的菲,28℃时48h内能完全降解,而相同时间内10℃时的降解率仅为36.65%。菌株J-1对pH的波动具有一定的适应性,pH在一定范围内(6.0～8.4)变化对菲降解的影响不大,降解反应的最佳pH为7.2。菌株J-1对菲的降解符合一级动力学反应方程。较高的底物浓度对酶促降解反应具有抑制作用,酶促反应的最大速率常数vm=1.17mg·L-1·h-1,米氏常数Km=61.70mg·L-1;底物抑制常数kS=49.60mg·L-1;最佳底物浓度[S]opt=55.32mg·L-1。  相似文献   

附着基粗糙度等因素与海藻密度的相关性研究   总被引：1，自引：0，他引：1  

施超  梁振林  梅俊学 《海洋学报》2016,38(10):105-112

海藻附着基表面粗糙度与孢子附着密度有密切的相关性;已经由许多研究证实。但是海藻苗的密度是否仍然受到附着基粗糙度的影响;还缺乏明确的结论。本文以尼龙和亚克力两种材料作为海藻附着基;悬挂于自然海区中使海藻孢子附着并萌发生长;用以研究附着基表面粗糙度对4种海藻密度的影响。结果显示;多管藻、尾孢藻、点叶藻、硬毛藻这4种海藻;在不具沟槽的光滑面;密度显著低于任何有沟槽的粗糙面;但粗糙度不同的附着基之间比较;对海藻密度的影响并不显著。室内培育的海带苗;在尼龙上的密度与粗糙度成正相关;但是将海带苗移至海上培育后;不再与粗糙度有相关性;可能与其假根状固着器下海后的发育有关。本文还试验了海泥、灭活海泥和低栖硅藻3种沉积物与附着基粗糙度对海藻密度的影响;结果表明;沉积物和附着基粗糙度;以及它们的交互作用对海藻密度的影响;因附着基的材料和海藻种类而有差别。  相似文献   

Biomonitoring of coastal pollution status using protozoan communities with a modified PFU method   总被引：10，自引：0，他引：10  

Xu K  Choi JK  Yang EJ  Lee KC  Lei Y 《Marine pollution bulletin》2002,44(9):877-886

Structural and functional parameters of protozoan communities were assessed as indicators of water quality in Korean coastal waters in the summer of 2000. A modified polyurethane foam unit (PFU) method, named the bottled PFU (BPFU) system, was used in order to carry out the bioassessment. Both parameters suggested that biomonitoring using the BPFU system was more effective than the conventional PFU method in offshore areas. The species number collected by the BPFU system generally decreased as pollution intensity increased at three main stations and was greater than that collected using the PFU method (paired t-test, t = 4.83, p < 0.0001). The Margalef diversity index coincided well with the water conditions. The diversity index values calculated from the BPFU system were also significantly higher than those from the PFU method (paired t-test, t = 5.37, p < 0.0001). Furthermore, the functional parameters, i.e. S(eq),G and T90%, correlated with the pollution status and could thus clearly discriminate the different classes of water quality.  相似文献   

Degradation of Tetrachloroethene by Several Co-metabolism Substrates in Groundwater          下载免费PDF全文

SHI Jinghua LIU Fei CHEN Honghan LI Ye 《《地质学报》英文版》2007,81(5):827-832

Tetrachloroethene （PCE） is biodegraded by reductive dechlorination with co-metabolism substrates under anaerobic conditions. By inoculating sludge from an anaerobic pool, a biodegradation test of PCE is conducted in the anaerobic condition. In the test, several substrates including methanol, ethanol, formate, acetate, lactate and glucose, are conducive to the conversion from PCE to TCE and 1,1-DCE. The results show the microbe can be cultivated well under the anaerobic circumstances of mixture of sewage （sludge） and soil with the index of COD after eleven days. Degradation of PCE accords with one order reaction kinetics equation. The sequence of the reaction rate constant is Kacetate 〉Kglucose 〉 Klactate 〉 Kethanol 〉 Kformate 〉 Kmethanol, and acetate is an outstanding co-metabolism substratum whose reaction rate constant is 0.6632d^-1.  相似文献   

莫来石陶瓷在电学和光学中的应用研究          下载免费PDF全文

靳正国  吕楠 《地质找矿论丛》1998,13(4):85-89

莫来石在电子,光学和高温结构中的应用已广泛以受到关注。本文介绍了以电子基板材料和红外辐射材料为应用背景下,有关莫来石基陶瓷的组成与性能间的关联研究,显示了新型莫来石材料在这些应用领域的潜在优良和良好的应用前景。  相似文献