温度、光强和盐度对鹧鸽菜幼体生长发育的影响     

王永川  潘国瑛  黄丕汕 《热带海洋学报》1994,(3)

从野外采集鹤鸪菜Ｃａｌｏｇｌｏｓｓａｌｅｐｒｉｅｕｒｉｉ（Ｍｏｎｔ．）Ｊ．Ａｇ．幼体，在室内控制条件下，以温、盐、光等不同条件进行模拟培养试验。所获得的数据经生物统计检验表明：鹧鸪菜幼体生长最适水温为２３℃；光照强度为４０００ｌｘ；海水盐度为１８。此结果与我们多年来在汕头港内观察鹧鸪菜的生长及其季节变化相似。  相似文献   

海洋天然气水合物调查地震采集技术——调查初始阶段研究   总被引：1，自引：0，他引：1  

伍忠良  曾宪军  王立明 《海洋技术学报》2006,25(4):79-87

地震调查方法在水合物中的应用分为两个主要阶段:调查初始阶段和调查深入阶段。调查初始阶段以“突出天然气水合物的四大主要识别标志(似海底反射、振幅空白带、穿层特征、振幅和速度结构异常)”为主要目的,为资料的处理、解释提供丰富的地震信息。从而圈定天然气水合物富集程度高、成藏条件好的“目标”靶区,开展深入调查,更好地展现“天然气水合物矿体立体上的形态特征”,了解“水合物矿体的厚度、顶底界面及富集程度”。文中从震源技术研究、高分辨率地震调查技术的调谐组合参数研究和野外施工方法等方面的内容出发,根据大量野外技术试验资料和有关科研成果,总结了在天然气水合物调查初始阶段的特点及相应的地震调查技术。  相似文献   

Crustal Structures of the Northernmost South China Sea: Seismic Reflection and Gravity Modeling   总被引：2，自引：0，他引：2  

Yi-Ching Yeh  Shu-Kun Hsu 《Marine Geophysical Researches》2004,25(1-2):45-61

The South China Sea (SCS) is a marginal sea off shore Southeast Asia. Based on magnetic study, oceanic crust has been suggested in the northernmost SCS. However, the crustal structure of the northernmost SCS was poorly known. To elaborate the crustal structures in the northernmost SCS and off southwest Taiwan, we have analyzed 20 multi-channel seismic profiles of the region. We have also performed gravity modeling to understand the Moho depth variation. The volcanic basement deepens southeastwards while the Moho depth shoals southeastwards. Except for the continental margin, the northernmost SCS can be divided into three tectonic regions: the disturbed and undisturbed oceanic crust (8–12 km thick) in the southwest, a trapped oceanic crust (8 km thick) between the Luzon-Ryukyu Transform Plate Boundary (LRTPB) and Formosa Canyon, and the area to the north of the Formosa Canyon which has the thickest sediments. Instead of faulting, the sediments across the LRTPB have only displayed differential subsidence offset of about 0.5–1 s in the northeast side, indicating that the LRTPB is no longer active. The gravity modeling has shown a relatively thin crust beneath the LRTPB, demonstrating the sheared zone character along the LRTPB. However, probably because of post-spreading volcanism, only the transtension-shearing phenomenon of volcanic basement in the northwest and southeast ends of the LRTPB can be observed. These two basement-fractured sites coincide with low gravity anomalies. Intensive erosion has prevailed over the whole channel of the Formosa Canyon.  相似文献   

海洋发光弧菌生长和发光条件的研究     

方宏达  董燕红  袁茵  李秀芹  易斌 《海洋通报》2007,26(4):66-70

海洋生物发光研究对渔业、环境监测等有着举足轻重的意义。根据从湛江东海岛海域沉积物样品中分离出的一株海洋发光弧菌(Vibrio sp.,编号为D2),对这株菌的生长和发光条件进行了初步研究。实验结果表明,海洋发光弧菌D2在pH7.0、温度35℃、NaCl浓度为2.0%时,生长状态最好;在pH5~6、温度20℃、NaCl浓度为3.0%、细菌密度OD600达0.08时,发光强度最高。  相似文献   

透射射线的非线性效应     

夏冬明  王修田  蒋卫焱 《中国海洋大学学报(自然科学版)》2006,36(5):705-708

根据Snell定律提出了透射射线的非线性效应的概念,从理论上证明了当地震射线的轨迹在1个界面上为1条直线时在另1个界面上可为1条曲线;并进一步通过射线追踪实验证明:当地下介质为非水平层状介质时,即使对应于地面同一条直线段上的接收点,来自地下同一个界面上的反射点的轨迹仍可为一条曲线。  相似文献   

An Application of Direct Ritz Method for Random Seismic Responses of Jacket Platforms     

韩晓双马骏  赵德有周波 《中国海洋工程》2006,20(4):673-679

1 .IntroductionNowadays tremendous efforts have been devotedtothe analysis of randomseismic responses .Forexample ,American PetroleumInstitute (API) has declared that the analysis of randomseismic re-sponsesis a useful tool for safety inspection. Owing to the complexity of platformand randomness ofload,it is difficult to carry out the randomresponse analysis of a jacket platform. The conventionalrandomvibration methods ,such as square root of the sumof squares (SRSS) and complete quadratic…  相似文献   

不同环境下镉对小球藻吸收磷速率的影响   总被引：1，自引：0，他引：1  

李定坚  徐明芳  许忠能  严国安  曹焕生 《海洋科学》2006,30(4):25-30

在人工配制的污水中进行静态模拟实验,研究了不同光照强度及不同pH值下,镉对小球藻(Chlorella vulgaris)在悬浮和固定状态下对污水中正磷酸盐的吸收速率的影响。结果表明,镉存在的情况下,在实验所设的各光照强度内,悬浮态小球藻对磷的吸收速率为4~10μg/(h.个),固定化小球藻为12~16μg/(h.个);而相同的镉浓度下,在不同的pH范围中,悬浮态小球藻对磷的吸收速率为1.9~9.4μg/(h.个),固定化小球藻为5.7~12μg/(h.个)。在不同光照强度下,镉总体上降低了小球藻对磷的吸收速率,其中使悬浮藻普遍下降40%~60%,而固定处理使藻受镉的影响较少,至多下降10%~20%,但在个别光照强度下镉反而促进了小球藻对磷的吸收速率。不同pH值时,无论悬浮态还是固定态,镉在大多pH下使小球藻的磷吸收速率下降20%~30%,固定处理并没有减少镉的影响,同样在个别pH下镉促进了对磷的吸收。  相似文献   

A new approach for predicting the extreme response of structures     

Ulla Botelho Machado 《Applied Ocean Research》2002,24(6):321-330

In this article a method to estimate the mean upcrossing intensity, μ(u), of a stochastic process is proposed. It is assumed that the stochastic process is a sum of a Gaussian process and a second-order correction term. The method is based on the two-dimensional Saddlepoint approximation. The accuracy of the method is tested on processes having analytical solutions for μ(u). Numerical examples are given where the stochastic process represents (i) the horizontal response of a floating offshore structure in a Gaussian sea, and (ii) the response of a structure subjected to a Gaussian wind velocity process. In addition, the estimates are compared to empirical upcrossing intensities of simulated responses. For case (ii), the obtained μ(u) estimates are compared to estimates obtained by numerical integration.  相似文献   

Hydrocarbon Potential of Pre-cenozoic Strata in the North Yellow Sea Basin     

蔡峰戴春山  陈建文李刚 孙萍 《海洋通报(英文版)》2005,7(1):21-36

The North Yellow Sea Basin ( NYSB ), which was developed on the basement of North China (Huabei) continental block, is a typical continental Mesozoic Cenozoic sedimentary basin in the sea area. Its Mesozoic basin is a residual basin, below which there is probably a larger Paleozoic sedimentary basin. The North Yellow Sea Basin comprises four sags and three uplifts. Of them, the eastern sag is a Mesozoic Cenozoic sedimentary sag in NYSB and has the biggest sediment thickness; the current Korean drilling wells are concentrated in the eastern sag. This sag is comparatively rich in oil and gas resources and thus has a relatively good petroleum prospect in the sea. The central sag has also accommodated thick Mesozoic-Cenozoic sediments. The latest research results show that there are three series of hydrocarbon source rocks in the North Yellow Sea Basin, namely, black shales of the Paleogene, Jurassic and Cretaceous. The principal hydrocarbon source rocks in NYSB are the Mesozoic black shale. According to the drilling data of Korea, the black shales of the Paleogene, Jurassic and Cretaceous have all come up to the standards of good and mature source rocks. The NYSB owns an intact system of oil generation, reservoir and capping rocks that can help hydrocarbon to form in the basin and thus it has the great potential of oil and gas. The vertical distribution of the hydrocarbon resources is mainly considered to be in the Cretaceous and then in the Jurassic.  相似文献   

Influence of seismic shooting on the lesser sandeel (Ammodytes marinus)     

Hassel  Arne; Knutsen  Tor; Dalen  John; Skaar  Kristian; Lokkeborg  Svein; Misund  Ole Arve; Ostensen  Oivind; Fonn  Merete; Haugland  Eli Kyrkjebo 《ICES Journal of Marine Science》2004,61(7):1165-1173

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