Study of hydrodynamics and its impact on mariculture carrying capacity of Sanggou Bay:observation and modeling

主要介绍了从动力学研究桑沟湾养殖容量的主要思路、方法及结果。研究以精细过程观测为基础,以数值模型为手段,从物理海洋学角度考察养殖海区水动力特征,研究水动力对物质循环的影响、对颗粒态/溶解态营养物质的补充和对养殖生物量的影响,探寻不同养殖模式效果的技术路线;介绍了两个航次设计方案与目的。通过观测发现养殖对水动力垂直结构有很大影响,底层流速最大并滞后表层,发现弱动力条件下海底颗粒物和营养盐无法进入水体上层的事实。据此提出双边界层动力模型,建立一维数值模型进行机制探讨,将养殖阻力三维化建立水动力数值模型,定量给出养殖对水动力和水交换的阻碍;以此驱动三维养殖生态模型,充分考虑养殖对水动力的影响、水动力对生源要素的输运。建立了一个真正的物理-生物过程耦合模型。利用该模型进行的数值模拟和实验表明,贝藻兼养多元养殖是健康、高效养殖的有利措施;桑沟湾在现有养殖模式下,目前已基本达到了它的养殖容量,养殖品种分布不变,减少养殖密度至目前的0.9倍会略微提高产量,降低成本;减少湾口海带养殖密度,会大幅度提高贝藻兼养区的营养盐总量和养殖生物产量,从海带与贝类经济价值对比会有更高的效益。人为提高水动力混合或许是解决湾内营养盐缺乏的途径。The background and themes of dynamic study on mariculture carrying capacity of Sanggou Bay were described.The method used for this study was based on the fine processes observation,using physical oceanography theory and numerical model to examine the interaction between mariculture and hydrodynamics in Sanggou Bay.Design proposal and purposes for two cruises were introduced.Based on the observation we found that the kelp and the raft influenced the current vertical structure greatly,and the maximum velocity was at the lower layer with strong phase delay.It was also found that the damped current was too weak to mix the sediment detritus and nutrients into the upper layer.Based on these discoveries a double drag-boundary hydrodynamic model was proposed by adding the aquaculture drag at surface.The mechanism of kelp influence on the current profile was studied numerically by a one-dimension model.Considering the kelp drag in the water column besides the boundary drag,a three-dimension hydrodynamic model was adopted to quantify the influence of the aquaculture on hydrodynamics and water exchange of Sanggou Bay.A physical-biological coupled aquaculture ecosystem model was established using DIN,POM concentration and phytoplankton with kelp biomass as variable.The simulation and numerical experiments showed that polyculture was a useful method for healthy and high-efficiency aquaculture.Sanggou Bay has nearly reached its capacity under present aquaculture mode.By cutting down aquaculture density to 0.9 fold of the present density,the total production of kelp will slightly increase and the cost will be reduced.Cutting down the kelp density at the mouth of the bay could greatly enhance the amount of nutrients and biomass in the kelp-bivalve-culture area in the inner side.Artificial mixing might bring more nutrients from seabed in the bay.国家基础研究规划重点项目(2006CB400602);国家重点基金项目(40830854)共同资

用电导法研究红细胞聚集-沉降现象

本文建立了一种测量红细胞聚集-沉降现象的电导法。并对所得的结果进行了理论分析,给出了描写红细胞聚集-沉降理象的I—t函数半经验公式,首次引入了描写红细胞聚集-沉降现象的聚集指数f_a(t)、沉降因子H(t)以及它们与时间的函数关系

悬浮介质对红细胞变形指数—渗透压曲线的影响

用激光衍射法测得的红细胞变形指数—渗透压曲线表征红细胞可变性与缓冲液渗透压之间的关系,它与红细胞的寿命有密切关系。本文用PBS和PVP两种介质作缓冲液,系统地观测了悬浮介质物化性能不同对于红细胞变形指数—渗透压曲线的影响。结果表明: 1.在不同悬浮介质中测得的变形指数—渗透压曲线有显著差别,在高渗区尤其

用PBS作为悬浮介质代替PVP用于红细胞变形性测量的可能性评估

用激光衍射仪测量RBC的变形性一般要求所用缓冲液的粘度高于18CP,以其获得稳定的,具有可比性的数据,常用的是不同浓度的右旋糖酐溶液。这在实用中带来两个问题;(1)粘度太高,故实验时红细胞所受剪切应力远高于生理水平;(2)价格昂贵,不利于临床推广。因此,我们试图寻求一种可以代替右旋糖酐溶液的新的缓冲液。本文中用了两种缓冲液,即PBS和15％PVP和四种不同的红细胞组成的悬浮液,

悬浮介质粘度对红细胞变形性测量的影响

用具有不同粘度的液体作为悬浮介质,观测了悬浮介质粘度对红细胞变形性测量的影响。所用仪器是北京医科大学物理教研室与北京地质仪器厂共同研制的激光衍射仪,试样为兔耳静脉血,肝素抗凝,红细胞用缓冲液冲洗3次后,加不同的缓冲液配制成浓度为2×10~3个/ml的悬浮液进行测量。悬浮液pH等于7.4,渗透压为295mOsm/kg,实验温度为27±1度。所有实验在取血后5小时内完成。缓冲液粘度变化范围为0.89cP-94.64cP

不同悬浮介质对激光衍射法测得的变形指数—渗透压曲线的影响

本文用PBS和PVP两种介质作为激光衍射仪的悬浮介质,系统地观测了悬浮介质物化性能不同对红细胞变形指数(DI)—渗透压曲线的影响,发现:1.在不同悬浮介质中的变形指数—渗透压曲线有显著差别,在高渗区这种差别更明显.2.同一红细胞试样,在相同高渗压下,在不同的悬浮介质中进行交叉实验表明、PBS悬浮介质能使得红细胞变形性得到恢复,而PVP悬浮介质却使得红细胞变形性显著降低.3.在高渗情况下,首次观察到红细胞变形性随时间变化,一开始DI增大,约3小时后趋于稳定,无论PBS还是PVP其趋势皆相似