一种新的波浪变形三维数值模式──0-1混合型边界元   总被引：4，自引：0，他引：4  

孙大鹏  李玉成 《海洋学报》2000,22(3):44-48

为提高边界元法模拟三维波场波浪变形的数值计算精度,借鉴常数元和线性元剖分方式、波势函数及波势函数法向导数对单元节点设定的各自适应性,提出了一种新的单元剖分模式──0-1混合型边界元,以控制和减缓由于计算误差累计而造成的波浪数值计算上的“横向振动”,借此结合边界元法的分区模式可实现较大范围的波场线性波浪变形计算,并为时域内的波浪非线性变形计算提供时间步长的数值保证.  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   

The DNA de-methylating agent 5-azacytidine does not restore CYP1A induction in PCB resistant Newark Bay killifish (Fundulus heteroclitus)     

Xabier Arzuaga  Wanda Calcao  Adria Elskus 《Marine environmental research》2004,58(2-5):517

Newark Bay (NB) killifish (Fundulus heteroclitus) have been chronically exposed to environmental contaminants that activate the aryl hydrocarbon receptor (AHR) and are tolerant to toxic effects and CYP1A induction provoked by AHR ligands. Resistance to CYP1A induction could be due to an epigenetic mechanism such as DNA methylation. We measured in-ovo CYP1A catalytic activity (ethoxyresorufin-O-deethylase, EROD) in NB and reference site killifish embryos aqueously exposed to various concentrations of the de-methylating agent 5-azacytidine, 5-AC (5, 50 and 500 μ(micro)M) with or without 0.2 μ(micro)g/l of the CYP1A inducer 3,3^′,4,4^′,5 pentachlorobiphenyl (IUPAC PCB126). Neither PCB126 alone, nor PCB126 plus 5-AC, induced EROD above levels in vehicle treated Newark Bay fish. In reference site fish, the same PCB126 dose provoked a 7.4-fold EROD induction relative to controls. We conclude that Newark Bay killifish are resistant to CYP1A induction by co-planar PCBs during early embryological development and our data suggests that DNA methylation does not play a critical role in resistance to CYP1A induction in this model.  相似文献   

无机碳与雨生红球藻(Haematococcus pluvialis)细胞调节物质   总被引：4，自引：0，他引：4  

刘建国  孙艳妮  殷明焱  刘伟  张展 《海洋与湖沼》2004,35(5):459-466

以单细胞雨生红球藻为材料，采用酸碱滴定和CO2加富通气培养微藻的方法，对旧液中HCO3^-和CO3^2-浓度变化以及对红球藻细胞生长的影响进行了研究。结果表明，旧液具有限制红球藻细胞生长和诱导细胞转化的作用。同时，旧液中无机碳离子浓度明显高于新液。培养液中富含CO3^2-时，各细胞数量与CO3^2-浓度呈正相关，相关系数为0．88。溶液中仅有HCO3^-时，各细胞数与HCO3^-浓度也呈正相关性。因此，排除了CO3^2-和HCO3^-作为旧液中的调节物质，限制红球藻细胞生长和诱导细胞转化的可能性。旧液乙酸乙酯提取物生物检测实验表明，在粗提取物中有降低细胞增长和诱导细胞转化的活性，表明调节物质能溶于有机相，也反过来证实无机碳离子不是旧液中的调节物质。DNA含量和倍性分析结果表明，红球藻游动细胞DNA复制可以加倍后不经过原生质分裂就可以再次进行，因此推测旧液中的调节物质对原生质分裂过程产生抑制作用，而不对DNA复制过程产生抑制作用。  相似文献   

威海地区高压岩石组合及其成因演化     

韩宗珠  王来明  张希道  毛振业 《中国海洋大学学报(自然科学版)》1993,(3)

利用矿物地质温压计估算变质高峰期温压条件、退变质作用温压条件。研究表明,本区为鲁苏构造带的北延部分,代表本区晚元古代华南陆块与华北陆块的碰撞及三叠纪华北陆块向华南陆块推覆事件的发生和演化。  相似文献   

SSA1—1型声学水位在长江口潮位站的应用     

万里明 《台湾海峡》1996,15(2):210-214

本文介绍了长江口区水文泥沙概况，举例说明了ＳＳＡ１－１型声水位计在崇头潮位站比测试验和投产应用情况，结果表明该水位计是收集长江口区潮位资料较理想的仪器。  相似文献   

LAPP对中国对虾(Penaeus chinensis)生长、缺氧耐受力及免疫抵抗力的影响   总被引：11，自引：0，他引：11  

王伟庆  李爱杰 《海洋湖沼通报》1996,(1)

实验研究维生素C多聚磷酸酯（LAPP）添加在对虾饲料中，对中国对虾的生长、缺氧耐受力及免疫抵抗力的影响；实验进一步证明了中国对虾饲料中LAPP的最适添加量为400mg／100g饲料;本文还提出饲料中的LAPP能够提高中国对虾的缺氧耐受力，在溶氧超过3．1mg／kg海水的情况下，效果显著，在降低到2．3mg／kg海水时，作用减弱；用副溶血弧菌（Vibroparahaemolyticus）注射入虾体内，12小时内记录发现，饲料中不含LAPP的一组中国对虾，死亡率高于其它组，并且，LAPP含量最高的一组，死亡率明显低，死亡时间也出现较晚，这证明LAPP能够提高中国对虾的免疫抵抗力；本实验用注射金黄色葡萄球菌后细胞的吞噬百分率作指标，研究对虾细胞的吞噬作用，发现饲料中不含LAPP的对虾的吞噬百分率较低，随着饲料中LAPP浓度的提高，对虾血细胞的吞噬百分率逐渐升高，说明中国对虾细胞的吞噬作用逐步增强。  相似文献   

长江口三维潮流数值计算及动力分析   总被引：10，自引：1，他引：10  

于凤香  宋志尧  李瑞杰 《海洋湖沼通报》2003,(3):14-23

采用三维动力学数学模型对长江口潮流场进行了计算，对长江口潮流流态在一个潮周期内逐时进行了分析，并对长江口南支盐水倒灌从动力学角度进行了初步探讨。计算结果表明：文中模型较好地重演长江口潮流场，可以用于大型复杂河口工程实际中的潮流场的计算和分析。  相似文献   

Reducing the short-term mortality of juvenile school prawns (Metapenaeus macleayi) discarded during trawling     

Macbeth  William G.; Broadhurst  Matt K.; Paterson  Brian D.; Wooden  Michael E.L. 《ICES Journal of Marine Science》2006,63(5):831-839

  相似文献   

Study on the connectivity of heavy oil reservoirs by ultraviolet spectrum technique in the western part of the QHD32-6 oilfield     

Yaohui Xu  Dan Chen 《中国地球化学学报》2008,27(3):306-309

As a new method, the ultraviolet spectrum technique is applied to studying the connectivity of biode-gradable heavy oil reservoirs. The similarity of crude oils can be judged according to the extinction coefficient （E） because aromatic hydrocarbons and non-hydrocarbons have conjugated bonds and obvious absorption in the ultraviolet range, and different materials have different characteristics and additives. The relationship diagram is made in terms of the extinction coefficients （E） of the samples by taking E as the Y-axis and wavelength as the X-axis. The connectivity of oil reservoirs is estimated according to the curve positions and characteristic fingerprints of the sampies. The connectivity of part of the reservoirs in the western part of the QHD32-6 oilfield was studied with this method. The results showed that the connectivity of samples from wells F7 and F8 in the Nm-2 oil reservoir zone is good, that of samples from wells F17 and F20 in the Nm-1 oil reservoir zone also is good, and that of samples from wells F17, F19, and F20 is poor.  相似文献