Numerical Study on Instantaneous Discharge of Unsorted Particle Cloud in Cross Flow     

顾杰  李志伟杨红 詹咏 《中国海洋工程》2007,21(2):305-316

The mixing characteristics of particles such as dredged sediment of variable size discharged into cross flow are studied by a 3D numerical model, which is developed to model the particle-fluid two-phase flow. The Eulerian method with the modified k-ε parameterization of turbulence for the fluid phase is used to solve fluid phase, while a Lagrangian method for the solid phase (particles), both the processes are coupled through the momentum sources. In the model the wake turbulence induced by particles has been included as additional source term in the k-ε model; and the variable drift velocities of the particles are treated efficiently by the Lagrangian method in which the particles are tracked explicitly and the diffusion process is approximated by a random walk model. The hydrodynamic behavior of dumping a cloud of particles is governed by the total buoyancy of the cloud, the drag force on each particle and the velocity of cross-flow. The computed results show a roughly linear relationship between the displacement of the frontal position and the longitudinal width of the particle cloud. The particle size in the cloud and the velocity of cross flow dominate the flow behavior. The computed results are compared with the results of laboratory experiments and satisfactory agreement is obtained.  相似文献   

高纯河豚毒素对蛙坐骨神经动作电位的影响     

赵立强  许晨  叶本兰  张业  洪专 《台湾海峡》2007,26(3):410-414

用电生理学方法观察了4种不同浓度的高纯河豚毒素(tetrodotoxin,TTX)对蛙离体坐骨神经动作电位的影响.实验结果表明:1μmol/dm3TTX在给药后7 min能显著抑制动作电位的上相幅度(P<0.05),但在给药后10 min才显著抑制动作电位的下相幅度(P<0.01);20μmol/dm3TTX在给药后3 min内能完全抑制动作电位的形成.1μmol/dm3TTX在给药后1~5min对动作电位传导速度的影响没有统计学意义,5μmol/dm3TTX在5min时可显著抑制传导速度(P<0.05),而10μmol/dm3TTX在2min时便显著抑制传导速度(P<0.05).实验结果提示高纯河豚毒素对蛙离体坐骨神经动作电位的影响存在剂量效应关系.  相似文献   

海底沉积物分析测试方法标准的研究   总被引：3，自引：0，他引：3  

夏宁  宋苏顷  刘昌岭  张红  林学辉 《海洋科学》2002,26(11):53-56

依据海底沉积物分析测试方法标准研究的总体设计，完成了40个分析项目的21份验证报告，进行了实验室间精密度协作性检验工作，在海底沉积物CaCo3,H2Os^-，H2O^ 的分析方法研究中取得新进展，并建立了ICP－AES法测定海底沉积物中常量、微量、稀土元素分析方法。  相似文献   

Species composition and distribution of marine nematode community in the North Taiwan Strait   总被引：9，自引：4，他引：9  

Cai Lizhe  Hong Huasheng  Zou Chaozhong  Fang Shaohu  L&#; Xiaomei  Zhang Yueping 《海洋学报(英文版)》2001,20(2):221-229

I~IOW~ne nelnatode is a ban gIOup of benthic OrgAnsrns. Abbot 5 000 spotes Of free-livingnelnatedes have ben dedbo so far, and it has ho estimated that abbot 20 (XX) are as yetunknoWn. Chinese bothologist has Paid attention to marine nelnatodes in China seas in yare. The spatial distribution and shoes commotion of marine nelnatedes in the HUanghe EstUary, Qinhuangdao waters, QingdaO Bay and Xiamen ~ have ho reported (Zhang etal., 1990, 1991, 1993; ac and Li, 1998). ~ new shoes in the…  相似文献   

长江口中肋骨条藻赤潮发生过程环境要素分析──营养盐状况   总被引：34，自引：6，他引：34  

洪君超  黄秀清  蒋晓山  王桂兰 《海洋与湖沼》1994,25(2):179-184

从长江口１９９０年６月的一次中肋骨条藻赤潮发生过程中营养盐含量变化可见，由于潮汐的作用，观测水域各营养盐要素都在不同程度上存在周日波动特征，其中，ＮＯ３－Ｎ在一个潮周期内变化幅度可达１倍以上。赤潮发生时表层水体ＮＯ３－Ｎ，ＰＯ４－Ｐ和ＳｉＯ３－Ｓｉ值都呈下降趋势，降幅最大的ＰＯ４－Ｐ达３倍上；Ｎ／Ｐ值则急剧上升，峰值为４５０。随着赤潮肖亡，ＮＯ３－Ｎ，ＮＯ２－Ｎ和ＳｉＯ３－Ｓｉ浓度很快恢复正常，Ｎ  相似文献   

旅游中心城市在旅游业中的地位和功能研究   总被引：10，自引：0，他引：10  

董志文  盛红 《海岸工程》2002,21(1):57-62

从中国旅游业发展实际出发,深入分析了旅游中心城市在旅游业发展中的地位和作用.通过探讨旅游资源开发与旅游城市建设的关系,确立旅游中心城市的主导地位,阐述旅游中心城市的主要功能,分析区域旅游发展的时空演化规律,并对发展旅游中心城市提出3点建议.  相似文献   

Integration of a Multi-Stage Bulk Materials Acquisition System from the Viewpoint of Dock Operations     

Hong Tau Lee 《Marine Georesources & Geotechnology》2001,19(3):207-219

A multi-stage bulk materials acquisition system is examined from the viewpoint of dock operations. The whole process can be divided into four stages and treated as four subsystems: ships scheduling planning, material yard planning, dock arrangement, and material discharging. Since the structure and the complexity of each subsystem is different, the solution approaches applied are also different with respect to each. To increase operations efficiency and data consistency, an integration of the subsystems by coordinating the operations sequence and data communications for the four subsystems is discussed. The four subsystems are illustrated by using the material docks of China Steel Corporation, and the models developed in this research are also validated. The results indicate that the models developed are capable of deriving solutions better than the existing ones. Although the discussions are confined to China Steel Corporation, the models can be applied to other companies with similar operations.  相似文献   

渤海海域油气勘探进展与前景展望   总被引：3，自引：0，他引：3  

许红  蔡瑛 《海洋地质前沿》2007,23(5):26-29

通过回顾我国渤海海域近50年的勘探历程,分析了油气发现的特点,指出从下第三系到上第三系勘探思路的转变是导致发现系列亿吨级大油气田的关键。迄今为止的重大发现主要分布于环渤中凹陷油气富集圈和沿岸两大地区。认为在有据可查的历史上,渤海海域发生过7级以上大地震的周围地区均发现有大油气田,因此将是发现油气田的有利地区。根据全国3轮油气资源评价数据,我国在渤海海域的油气勘探尚大有可为,重要的是要求较高的科技研究水平和更大的投入力度,渤海深浅层次资源潜力将获得更进一步的发掘。认为在50余年的勘探历程中,我3大国有石油公司及全国相关科技工作者均做出过重大贡献。  相似文献   

南海高钙沉积物中18种常微量元素的ICP-AES测定方法研究     

王湘芹  陈志华  任红  孙琼 《海洋科学进展》2007,25(2):220-225

在利用ICP-AES分析南海高钙沉积物中的常微量元素时,钙、镁常常干扰其它元素测试。通过采用优化仪器工作参数、扣除背景值、谱线干扰校正和基体匹配的步骤,消除了元素干扰和钙、镁基体效应,提高了方法的灵敏度和准确度。通过对南海沉积物样品的大量实验和国家一级标准样验证,建立了适宜高钙海洋沉积物元素含量的ICP-AES测试方法。该方法检出限为1.55~271μg/L,相对标准偏差RSD<4.54%(n=6)。  相似文献   

罗非鱼、南美白对虾对重金属富集的研究   总被引：11，自引：0，他引：11  

李来好  杨贤庆  郝淑贤  刁石强  石红  吴燕燕  周婉君  李刘冬  陈培基 《热带海洋学报》2006,25(4):61-65

对广东省养殖的罗非鱼Oreochromis niloticus及南美白对虾Litopeneaus vannamei体内Pb、Cd、Hg、As 4种重金属富集及分布状况进行研究。比较了不同规格罗非鱼及南美白对虾体内重金属差异。分析重金属在罗非鱼及南美白对虾不同部位的分布状况。结果表明,罗非鱼及南美白对虾体内Pb、Cd、Hg、As均有不同程度的检出,但含量均低于国家限定标准(NY5125-2002);其中Pb的含量最高,罗非鱼和南美白对虾体内Pb含量最高值分别为限量的39.32%和42.18%;重金属含量因其规格大小及部位而异,趋势为大规格样品重金属含量相对较高,重金属含量在罗非鱼及南美白对虾体内的增长情况与其体重具有正相关性;罗非鱼内脏重金属含量明显高于肌肉组织,虾头为虾重金属富集的主要部位。  相似文献