南极冰退与深圳湾北岸海平面变化的地质记录     

郑洪汉  黄宝林 《热带海洋学报》1996,(4)

南极冰层的冰量为２４．５×１０６ｋｍ３，占地球总冰量的９０％以上，南极冰川进退控制着全球海平面变化和气候波动。酉部南极乔治王岛第四纪冰碛与湖积剖面记录了近１２０００ａ来南极曾于距今１１０００ａ，９０００ａ和６１００ａ出现过３次快速的冰消过程，近６０００ａ来是一小幅度冷暖交替的气候波动过程。深圳湾北岸潮间带堆积是在近６０００ａ以来发育的，堆积物的环境记录表明，海平面呈周期性升降变化，波动周期平均为６７０ａ，低海面时期发生于距今５５００—４９００ａ，３９００—３６００ａ，２４００—２２００ａ和１３００—１２００ａ。相邻低海面间则是海面上升时期，每一升降周期的海平面变化幅度为８０ｃｍ左右，近１００ａ的现代增温，海平面处于上升阶段，上升速率为２—３ｍｍ·ａ（－１）。  相似文献   

Wave Decay and Its Characteristics in Surf Zone     

Gu Jialong Shen Xianrong Professor  Hohai University  Nanjing Engineer  The Investigation  Design Institute  Bureau of Communications of Zhejiang Province  Hangzhou 《中国海洋工程》1991,(2)

In accordance with the similarity between breaking waves and hydraulic jumps, the expressions for estimating wave decay and wave energy dissipation in the surf zone are derived based on the fundamental equations of fluid mechanics. Using the numerical solution of cnoidal wave theory, the various kinematic properties of waves in the surf zone, including the relative wave crest height, wave energy, and radiation stress are discussed. The values calculated with the method proposed in this paper are in good agreement with the experimental data gained by other researchers. The present expressions can be used in the studies of sediment transport on gently sloping beaches, especially on muddy beaches.  相似文献   

舟山潮间带生态学研究：Ⅱ.数量及其分布   总被引：3，自引：0，他引：3  

蔡如星  郑锋 《海洋学研究》1991,9(3):58-72

舟山潮间带生物种类数量的平面分布与盐度和海岸开敞性有关,垂直分布与潮汐有关;群落数量的水平分布与底质和海岸开敞性有关,垂直分布与潮汐有关。舟山潮间带生物有明显的分带现象,隐蔽的岩岸区分为:滨螺带和藤壶-牡蛎带两个带;开敞性岩岸区分为:滨螺带,藤壶-(虫戚)-藻类带及藻类带3个带。沙滩区分为:沙蟹带和浅蛤-斧蛤带两个带;泥沙滩区分为:盐碱植物-滨螺带和招潮蟹-大眼蟹带;泥滩区分为:蟹守螺-囊螺带和蟹守螺-织纹螺带。  相似文献   

Studies on the distribution and antibacterial properties of Streptomyces in the intertidal zone of Southern Fujian     

Zhou Meiying  Zheng Zhicheng  Yao Bingxin 《海洋学报(英文版)》1991,10(1):155-160

The oceans have rich resources of microbes. In recent years, searching for antibiotic of new structure and special biological activity from marine microbes has received great attention. This paper reports the results of the studies on the distribution and the antibacterial properties of Streptomyces in the intertidal zone of Southern Fujian. These studies have important significance to further investigate  相似文献   

HY1200声速剖面仪计算测深仪声速改正数方法     

关致和  赵先龙  邵海涛  王莉娜  阮锐  于政 《海洋测绘》2006,26(1):66-67,74

介绍了HY1200声速剖面仪平均声速的定义及应用,以及用平均声速进行测深仪声速改正数的方法和公式。  相似文献   

A New Pursuit Mode of Nonlinear Wave Surface     

孙大鹏李玉成  郭海滨 《中国海洋工程》2004,18(2):257-266

The numerical mode of nonlinear wave transformation based on both the Laplace equation for water field and the Bemoulli equation for water surface is a kind of time-domain boundary problem with initial conditions. And the basis for establishing the numerical mode of nonlinear wave in time domain is to trace the position of wave free surface and to calculale the instantaneous surface height and surface potential function. This paper firstly utilizes the ‘0-1‘ combined BEM to separate the boundary by means of discretization of Green‘ s integral equation based on the Laplace equation, then separates the free surface of wave with FEM and derives the FEM equation of wave surface that satisfies the nonlinear boundary conditions. By jointly solving the above BEM and FEM equations, the wave potential and surface height could be obtained with iteration in time domain. Thus a new kind of nonlinear numerical mode is established for calculating wave transformation. The wave test in the numerical wave tank shows that the numerical simulation with this mode is of high accuracy.  相似文献   

Characteristics of Scour and Deposition in Front of Breakwaters Under Irregular Broken Clapotis   总被引：1，自引：0，他引：1  

高学平张亚  李昌良 《中国海洋工程》2004,18(3):493-500

First the scour and deposition patterns of the sandy seabed in front of a vertical breakwater under the action of irregular broken clapotis are investigated experimentally and classified into five types: scour type Ⅰ , scour type Ⅱ, scour type Ⅲ, deposition type Ⅰ, and deposition type Ⅱ . Secondly, the processes of formation of scour and deposition patterns are probed in comparison with those induced by regular broken clapotis and standing waves. Thirdly, the criteria for distinguishing scour and deposition patterns under irregular broken clapotis are presented.  相似文献   

Modeling of Multi-Freedom Ship Motions in Irregular Waves with Fuzzy Neural Networks     

余建星  陆培毅  高喜峰  夏锦祝 《中国海洋工程》2003,17(2)

1 .IntroductionAshiptravelingatseaundergoesundesirablewave inducedmotions ,namely ,surge ,sway ,heav ing ,rolling ,pitchingandyaw .Thesemotionsoftencauseproblemstothecrew ,theonboardequip mentand ,intheworstcase ,thesafetyofthevessel.Tominimizethewave inducedshipmotions ,controlsystemsmaybeapplied .Theaccuratemodelingofshipmotionsisthereforeveryimportantforshipdesignanddesignofmotioncontrolsystems .Manyresearchershavedevelopedshipmotionpredictionmethodsbasedonthepotentialflowtheo ries (Dong ,…  相似文献   

Modal Wave Number Tomography for South China Sea Front   总被引：10，自引：0，他引：10  

彭临慧  王宁  邱晓芳  田纪伟 《中国海洋工程》2003,17(2)

1 .IntroductionTheSouthChinaSealiestothesoutheastpartoftheChinesecontinent.TheKuroshioflowsbytheeastsideoftheLuzonStraitfromsouthtonorthinwinter ,spring ,andautumn .TheKuroshioaf fectsnearcurrentfieldsandtemperaturefields,changingtheoceanenvironmentparametersandsoundpropagation .Thus ,theoceanacoustictomographytechniqueisofpotentialtolong term ,largescalemonitoringoftheocean .Themodalwavenumbertomographymethod (Rajanetal.,1 987;Frisketal.,1 989)isusedtoobtainthesoundspeedprofileinwatercol…  相似文献   

A New Probability of Detection Model for Updating Crack Distribution of Offshore Structures     

李典庆  张圣坤  唐文勇 《中国海洋工程》2003,17(3)

1 .IntroductionNondestructiveinspection (NDI)isveryimportantforensuringthereliabilityofoffshorestructuresintheirservicelives (Lauraetal.,1 996 ) .Itiswellknownthatdetectionofflawsinvolvesconsider ablestatisticaluncertainties.Asaresult,theprobabilityofdetection (POD)forallflawsofagivensizehasbeenusedintheliteraturetodefinethecapabilityofaparticularNDItechniqueinagivenen vironment.SincethedataofPODusuallyscatterlargely ,itisdifficulttodeterminewhichmodelfitstheavailabledatabest.Thismodelun…  相似文献