中国沿海城市海洋经济密度时空变迁与趋同演化研究

在回顾海洋经济与经济密度相关文献的基础上,以沿海53个城市海洋经济密度面板数据为基础,运用Kernel密度估计、标准差椭圆等方法分析其时空分布格局和变迁轨迹,分别运用传统以及空间马尔科夫链方法,得到4种类型下一步转移、条件转移概率矩阵,探析考虑邻域类型与否对海洋经济密度趋同演化特征的影响。结果表明:地区密度差异呈"先增、后减"变化趋势,空间集聚点数目不断减少;密度重心整体由东北方朝着西南方变动,分布范围"先扩大、后缩小",变化方向"先减小、后增加";不考虑邻域类型时,本地密度类型维持原有状态稳定性较强,短期内不会跨越式跃迁;考虑邻域类型时,本地区状态类型的趋同演化程度和方向会因邻域类型的不同产生一定的差异。

生物传感器在海洋红酵母发酵生产中的应用

生物传感器与常规发酵控制系统整合,在发酵生产中实现了发酵液在线取样、稀释和检测。整合后的发酵罐控制系统,既能在线监测发酵液中的葡萄糖、乳酸、乙醇等生物量指标,还可以控制发酵温度、搅拌、pH值、溶氧等常规发酵参数。在海洋红酵母高密度发酵过程的应用结果表明:活细胞数达100亿/ml,生产周期缩短至40 h,显著提升了生产效率。

海温预报知识讲座 第一讲 海水温度预报概况

1 国外水温预报概况 海洋热学是海洋研究中的一个重要方面。因为海洋中密度的变化主要受制于温度的 变化,所以要了解海洋中的动力场,温度场是个先决条件。要了解海洋中密度的垂直分 布,以有效地使用潜艇和其他水下兵器,也必须首先知道海洋中温度的垂直分布。不仅 如此,渔场的分布、渔汛期的确定等,主要与海水中温度的分布和变化有关。所以海洋 环境要素中海水温度状况对海洋渔业资源开发。

Effects of Urechis unicinctus Juveniles on Chemical Characteristics of Organically Contaminated Coastal Sediment

Biological activities of marine benthos such as burrowing and feeding may change sediment characteristics.We conducted three experiments to examine the potential of using juveniles of a spoon worm Urechis unicinctus to improve the quality of organically contaminated coastal sediment.Sediment samples were collected from a site that was heavily contaminated with organic matter (Seonso) and two sites that were clean (Myo-do,Dolsan-do).Urechis juveniles,obtained by artificial fertilization and cultured in the laboratory,were introduced to the sediment (weight 3 kg,depth 10 cm) at a density of 500 individuals per aquarium (length 50 cm,width 35 cm,height 30 cm) (Experiment 1),or at densities ranging from 100 to 900 individuals per beaker (Experiment 2).To examine how sediment contamination can be modified by the effects of Urechis,500 individuals (per aquarium) were exposed to the Seonso contaminated sediment that had been mixed with 0-100% clean sand (Experiment 3).Each experiment lasted two months and sediment samples were collected every 15 d to determine the several indexes of sediment quality,which included acid volatile sulfide (AVS),chemical oxygen demand (COD) and total ignition loss (TIL).In Experiment 1,the existence of Urechis did not result in significant changes in quality indexes in the sediments collected from Myo-do,Dolsan-do.However,AVS,COD and TIL of the Seonso sediment all decreased significantly after co-incubation with Urechis juveniles for 30 to 45 d.Experiment 2 showed that a density of at least 300 juveniles per beaker was necessary to significantly reduce all three quality indexes,and the magnitude of reduction was positively correlated with juvenile density.Experiment 3 revealed that Urechis juveniles were effective in reducing the AVS,COD and TIL of the Seonso sediment that had been mixed with 60%,80%,and 80% of clean sand,respectively.The results of the present study therefore indicated that juveniles of this spoon worm have the potential to be used to improve the quality of organically contaminated sediment in coastal waters.

Determination of the Current System on Isopycnal Surface Between Mindanao and New Guinea from GDEM

In this study, we used the Navy’s Generalized Digital Environmental Model (GDEM) climatological temperature and salinity data on a 0.5°×0.5° grid to investigate the seasonal variabilities of the southwest Philippines Sea (0.5°–9°N, 123.5°–136.5°) thermohaline structure and circulation. The GDEM for the area was built up on historical (1930–1997) temperature and salinity profiles. A three-dimensional estimate of the absolute geostrophic velocity field on isopycnal surface was obtained from the GDEM temperature and salinity fields using the P-vector method. The seasonal variabilities of the thermohaline structure and currents (obtained from the inverse method) such as the Mindanao Current, Mindanao Undercurrent, North Equatorial Counter Current, New Guinea Coastal Undercurrent, and dual-eddies (cyclinic Mindanao Eddy and anticyclonic Halmahera Eddy) are identified.

The standards for skill assessment of operational marine forecast system

To support navigational and environmental applications in coastal waters, marine opera- tional forecast models must be developed and implemented. A forecast model must guarantee that it is scientifically sound and practically robust for performance and must meet or excel all target frequencies or durations before being released to the public. This paper discusses the standard policies and procedures for evaluation of operational marine forecast models. The primary variables to be evaluated are water lev- els, currents and water density (water temperature and salinity).

The Upper Mixed Layer during Coastal Upwelling Events on the Northern Portugal Shelf

The upper mixed layer (UML) depth obtained from temperature is very close to that from density:the maximum is about 15m. This indicates that temperature is a good indicator of mixed layer during measurements. When the surface heat flux is balanced by a cross-shore heat flux, the surface mixed layer depth obtained from the WM model (Weatherly and Martin, 1978),hPRT, is roughly the same as observed. The mixed layer depth calculated from the PWP model (Price, Weller and Pinkel, 1986) is close to the depth obtained from thermistor chain temperature data. The results show that both the WM model and PWP model can provide a good estimate of stratification in the study area during the cruise. The value of log( h/u3) is about 9.5 in the study area, which shows that the study area is strongly stratified in summer. Observations on the northern Portugal shelf reveal high variability in stability, giving rise to semi-diurnal, semi-monthly and diurnal oscillations, and long term variations. The fortnightly oscillations are highlighted by post-springs and post-neaps. The stirring of spring tide is reinforced by strong wind mixing which brings about complete vertical homogeneity everywhere. The semi-diurnal periodic stratification is very pronounced because the major axis of the tidal ellipse is orientated acrossshore, even though the tidal current is weak in this area, the maximum stratification is observed around the middle of ebb, and, the water at this time is much warmer. The diurnal oscillation results from the upper ocean response to heating and wind mixing when solar heating warms and stabilizes the upper ocean. There is a clear relationship between upper mixed layer depth and wind-stress magnitude at subtidal frequencies. Stronger winds result in a deeper surface mixed layer. Typically, the surface mixed layer depth lags the wind stress by 6 -12 h.

Production of dimethylsulfide and acrylic acid from dimethylsulfoniopropionate during growth of three marine microalgae

We measured the concentrations of dimethylsulfide(DMS),acrylic acid(AA),and dimethylsulfoniopropionate(DMSP) during growth of three microalgae:Prorocentrum micans,Gephyrocapsa oceanica,and Platymonas subcordiformis.The DMSP,AA,and DMS concentrations in culture media varied significantly among algal growth stages,with the highest concentrations in the late stationary growth stage or the senescent stage.In the stationary growth stage,the average DMSP concentration per cell in P.micans(0.066 5 pmol/cell) was 1.3 times that in G.oceanica(0.049 5 pmol/cell) and 20.2 times that in P.subcordiformis(0.003 29 pmol/cell).The average concentrations of AA were0.044 6,0.026 9,and 0.003 05 pmol/cell in P.micans,G.oceanica,and P.subcordiformis,respectively,higher than the concentrations of DMS(0.272,0.497,and 0.086 2 fmol/cell,respectively).There were significant positive correlations between cell density and AA,DMSP,and DMS concentrations.The ratios of DMS/AA and AA/(DMSP+AA) in the three algae differed significantly over the growth cycle.In all three microalgae,the DMS/AA ratios were less than 25%during the growth period,suggesting that the enzymatic cleavage pathway,which generates DMS,was not the main DMSP degradation pathway.The changes in the DMS/AA ratio indicated that there was a higher rate of enzymatic breakdown of DMSP in the early growth period and a lower rate during senescence.In all three microalgae,the AA/(DMSP+AA) ratio(degradation ratio of DMSP) decreased during the exponential growth phase,and then increased.The variations in these ratios can approximately indicate the cleavage mechanism of DMSP at different stages of algal growth.

Polar Motion Excited by Atmosphere and Ocean in Multi-frequency Bands

This research aims to study the influences of the atmospheric and oceanic excitations on polar motion.Power spectrum density analyses show that the efficiencies of the atmospheric and oceanic excitations differ not only at different frequencies but also in the retrograde and prograde components,but the sum of atmospheric and oceanic excitations shows the best agreement with the observed excitation.