海水甲壳类人工育苗过程中的水质控制     

朱明  茅云翔  张学成  阎斌伦  藤亚娟 《海洋湖沼通报》2002,(4):72-75

水质控制是海水甲壳类人工育苗中的关键技术之一，但是囿于设备条件的限制而难以有效进行，本文总结出两种简便的水质检测指标；pH值和水质指示生物，并对水质控制的一般原理方法进行了初步的探讨。  相似文献   

赤道暖池区漂流浮标运动轨迹分析     

侍茂崇  刘士军  周冰  温之平 《中国海洋大学学报(自然科学版)》1993,(Z2)

TOGA—COARE强化观测期间,对赤道暖池区海流作了多种方法、多层次的观测;根据美国释放的漂流浮标不同时刻位置的资料,分别对赤道及其南、北海域的表层漂流状况作了计算分析,指出:从1°N向北存在单一的北向流;从1°N～1°S这个近赤道区域内为东向流;1°N～2°S区域为过渡区,以东向流为主,个别浮标出现涡旋状运动。2°S以南为一反时针运动的大涡旋。  相似文献   

Progress in Scatterometer Application   总被引：10，自引：0，他引：10  

W. Timothy Liu 《Journal of Oceanography》2002,58(1):121-136

Progress in the scientific application of space-based scatterometer data over the past two decades is reviewed. There has been continuous improvement in coverage, resolution, and accuracy. Besides the traditional applications in weather and ocean-atmosphere interaction, which are based on ocean surface wind vectors, emerging applications over land and ice are also described. Future missions and new technology are introduced. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

好望角附近海域春季大风的几种主要形势分析   总被引：1，自引：1，他引：1  

马卫民  陈信雄 《海洋预报》2001,18(2):62-66

通过普查和分析，概括出了春季好望角附近海域三种主要大风出现时的模型图，并以一个月中逐日4次船舶测风报告为例，分析了好望角大风的某些主要特征。  相似文献   

Eddy Diffusion Coefficients of Suspended Particulate Matter: Effects of Wind Energy Transfer and Stratification     

Lars Chresten Lund-Hansen  Morten Pejrup  Jens Valeur  Anders Jensen 《Estuarine, Coastal and Shelf Science》1994,38(6)

Gross sedimentation rates (GSR) have been measured using sediment traps placed at nine different levels above the bed (0·3, 0·5, 0·8, 1·0, 2·0, 4·0, 6·0, 8·0 and 10·0 m). The sediment traps were deployed for 1·25 years and recovered 28 times during the study period. Low average GSR values of 5·5 g m^-2 day^-1 were obtained at 10·0 m, and high average GSR values of 114·8 g m^-2 day^-1 were obtained at 0·3 m. An expression for the eddy diffusion coefficient of suspended particulate matter (K_s), based on the measured GSR is given. The expression has been used for modelling of K_s at the different trap levels above the bed. High values (≈42 cm² s^-1) of K_s were obtained at the upper traps, whereas low values (≈2 cm² s^-1) were obtained near the bed. Comparison between level of turbulent energy in terms of shear stress at the boundaries of the water column, i.e. from the wind and the bed flow, showed that wind energy exceeded that of the bed flow by a factor 16. At 5·0 m K_s was positively correlated (r=0·66) to the eddy diffusion coefficient of momentum (K_m) derived from the wind energy transfer to the water, giving an average β of 0·5 for K_s =βK_m. The density difference between surface and bottom waters has been designated a parameter of stratification, and is discussed in relation to variations of K_s and K_m .  相似文献   

Adaptive optimal control of an autonomous underwater vehicle in the dive plane using dorsal fins   总被引：1，自引：0，他引：1  

Mukund Narasimhan  Sahjendra N. Singh   《Ocean Engineering》2006,33(3-4):404-416

In this paper, adaptive control of low speed bio-robotic autonomous underwater vehicles (BAUVs) in the dive plane using dorsal fins is considered. It is assumed that the model parameters are completely unknown and only the depth of the vehicle is measured for feedback. Two dorsal fins are mounted in the horizontal plane on either side of the BAUV. The normal force produced by the fins, when cambered, is used for the maneuvering. The BAUV model considered here is non-minimum phase. An indirect adaptive control system is designed for the depth control using the dorsal fins. The control system consists of a gradient based identifier for online parameter estimation, an observer for state estimation, and an optimal controller. Simulation results are presented which show that the adaptive control system accomplishes precise depth control of the BAUV using dorsal fins in spite of large uncertainties in the system parameters.  相似文献   

The Effect of Internal Fluid on the Response of Vortex-Induced Vibration of Marine Risers   总被引：5，自引：1，他引：5  

郭海燕  王元斌傅强 《中国海洋工程》2004,18(1):11-20

Based on Iwan‘s wake oseillator model developed with the classical van der Pol equalion, the differential equation for the response of the vortex-induced vihration (VIV) of the riser considering the effect of the internal flowing fluid and the external marine environmental condition is derived. The effect of the intermal flowing fluid on the response of VIV of the riser is studied by means of the Finite Element Method. The results show that the effect of the internal fluid velocity on the VIV of the riser is strong when the natural frequency of the riser is close to the vortex shedding frequency. In addition, the increase of the top tension can decrease the sensitivity of the riser to the internal fluid velocity.  相似文献   

受扰线性系统的前馈-反馈最优控制     

唐功友  张颖璐 《中国海洋大学学报(自然科学版)》2005,35(1):121-124,48

针对具有外部持续扰动的线性系统，研究前馈-反馈最优控制律的设计问题。给出了最优控制律的存在唯一性条件。并提出了最优控制律的设计算法。利用滤波器解决了前馈控制的物理不可实现问题。仿真结果表明，此算法易于实现，与传统的反馈最优控制相比对抑制外部扰动具有较强的鲁棒性。  相似文献   

ARGO剖面浮标数据质量控制过程剖析   总被引：12，自引：4，他引：12  

童明荣  刘增宏  孙朝辉  朱伯康  许建平 《海洋技术学报》2003,22(4):79-84

ARGO计划的观测目标是能取得精度分别为0．5℃和0．01PSU的海水温度和盐度资料。然而，由于目前海水盐度是采用海水电导率间接导出的，而测量海水电导率的传感器很容易产生偏差。因此，必须对获得的ARGO数据进行质量控制。文章详细介绍了ARGO剖面浮标资料实时质量控制模式和延时质量控制模式及其采用的质量控制方法等。  相似文献   

东、黄海典型海区分粒级浮游植物叶绿素a的周日波动及影响因子   总被引：3，自引：0，他引：3  

林丽贞  陈纪新  刘媛  曹振锐  黄邦钦 《台湾海峡》2007,26(3):342-350

本文分析了东、黄海典型海区3个测站在2000~2003年间4个航次的叶绿素a周日变动特征,结果表明由于地理环境、水文特征以及季节差异,各海区叶绿素a表现出各自不同的变动特点.在东海陆架区,日变化上表层各粒级主要以半日周期为主,受黑潮入侵程度不同而略有变化;长江口由于受到潮汐的影响,各粒级的日变化同潮汐的涨落相对应,主要为半日周期;黄海中部海区叶绿素a尤其是NANO级浮游植物在周日变化上以全日周期为主,受黄海冷水团强弱不同而不同.本文进一步应用渐近回归初步分析了多种环境因子对叶绿素a周日变化的影响.  相似文献