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71.
波吉卵囊藻的固定化培养及利用   总被引:3,自引:0,他引:3  
以褐藻酸钙为固定化载体,探讨了胶球直径、不同接种量、CaCl2溶液浓度、褐藻酸钠浓度等条件对波吉卵囊藻(Oocystisborgei)固定化培养及对养殖水体水质的影响。结果表明:波吉卵囊藻固定化培养的最好条件是微藻接种量为1×106 mL-1,CaCl2溶液的质量浓度为30g/L,褐藻酸钠溶液的质量浓度为20g/L。在此条件下制备的固定化藻珠,波吉卵囊藻的生物量从1 83×10-2 mg/粒增加到17. 46×10-2 mg/粒,增加了近10倍,生长率相对较高,证明了它的生理活性不会因固定化而受干扰。引入固定化的波吉卵囊藻不但可以降低养殖水体中氨氮、亚硝酸氮等有害因子的浓度,还能提高水中溶解氧含量,使水体环境长时间处于良好的动态平衡状态。  相似文献   
72.
MODIS-Aqua derived eight-day composite chlorophyll concentration data analyzed to study the impact of cyclones and depressions on the Bay of Bengal productivity. A total of 15 cyclonic storms and depressions picked up from the India Meteorological Department datasets. MODIS-Aqua data analyzed during October 2002 to December 2009. There was observation of depressions (D), deep depressions (DD), cyclonic storms (CS), severe cyclonic storms (SCS), and very severe cyclonic storms (VSCS) with categories of intensities (“T” numbers 1.5–6) and wind speeds (25–108 knots). The chlorophyll concentration observed to be high (1.0–5.0 mg/m3) with the impact in the coastal and offshore waters. Quickscat scatterometer data showed high wind speed (about 10 meters/second). Sea surface temperature (SST) observed to be decreased (roughly 2°C) with effect of cyclones. The cyclone numbers, intensity, and chlorophyll concentration has been observed to be increasing from 2002 to 2009, with observation of VSCS “Sidr” during 2007. The study would be interesting to link carbon flux/sequestration, marine food chain, and harnessing fishery resources in a postcyclone period.  相似文献   
73.
扎龙湿地是我国北方同纬度地区保留最完整、最原始、最开阔的湿地生态系统,地处中温带,属大陆性季风气候。为了探究其藻类植物群落的变化特征及其与水环境的关系,本文于2011年春、夏、秋季对扎龙湿地的藻类植物群落进行调查分析,共发现藻类植物349个分类单位(包括变种、变型),隶属于8门105属,藻类植物群落全年均以绿藻为主导,其组成呈绿藻-硅藻型。优势种中绿藻门主要以镰形纤维藻(Ankistrodesmus falcatus)和四尾栅藻(Scenedesmus quadricauda)为主,硅藻门以弯棒杆藻(Rhopalodia gibba)和隐头舟形藻(Navicula cryptocephala)为主,优势种组成具有明显的季节演替现象。藻类植物细胞密度呈现明显的单峰型,夏季最高,平均为10.74×10~4ind./L。湿地研究区域分为开阔型水域、小型封闭水域、湿地型水域和湖泊型水域四个生态类型,不同水域藻类植物群落结构特征明显不同。经聚类和多维尺度分析,将不同采样点的藻类植物群落分为四组,多样性指数表明湿地水体处于轻度污染或无污染状态。综合研究结果可以认为扎龙湿地的水体基本处于贫营养-中营养状态,只有极少数水域处于富营养状态。  相似文献   
74.
Coral mortality may result in macroalgal proliferation or a phase shift into an alga-dominated state. Subtidal, high-latitude western Indian Ocean coral communities at Sodwana Bay on the KwaZulu-Natal coast, South Africa, have experienced some mortality because of warm-water anomalies, storms and other causes, but the response of the macroalgae is unknown. We investigated the abundance and diversity of benthic algae on different hard natural substrata (dead digitate, brain and plate corals and beach rock) on Two-Mile Reef, Sodwana Bay. We also compared algal communities colonising ceramic, marble and pretreated ceramic tiles placed on the reef for six months. We identified 95 algae (14 Chlorophyta, 11 Phaeophyceae, 69 Rhodophyta and one cyanobacterium). Assemblages on natural and artificial substrata were dominated by the brown alga Lobophora variegata (Lamouroux) Womersley ex Oliveira and non-geniculate corallines (Rhodophyta, Corallinaceae). Cluster and ordination analyses revealed that the algae showed no affinity for particular substrata, whether natural or artificial. Algal cover was occasionally higher on rougher tiles and crustose corallines were significantly more abundant on marble than ceramic tiles. Two-Mile Reef had 23.1% dead and 48.4% live scleractinian coral cover, where dead corals were colonised indiscriminately by many small algal species, but there was no evidence of algal proliferation. The results provide a baseline for monitoring this high-latitude reef system.  相似文献   
75.
Heavy metal is a main pollutant in the marine ecosystem, so study on the effect of heavy metal on phytoplankton is important. Algae (Chaetoceros sp.,Dunaliella sp.,Dicrateria zhanjiangenis Hu. var. sp.) were laboratory cultured to observe the effect of heavy metals on their growth. The effect of different metal ion concentration, the detoxication effect of complexation agents and the growth of algae in different media and different nutrition levels were studied to evaluate the effect of metal speciation. It is proved that trace amount of heavy metals can stimulate the growth of algae cells but that high concentration is lethal. The sequence of toxicity is Cd2+>Zn2+>Pb2+. In ordinary nutrition conditions, the detoxication sequence of complexation agents toChaetoceros sp. is EDTA >sodium salicylate>sodium oxalate >sodium citrate>sulfanilic acid>O-phenanthroline. This is in good conformity with the stability constant sequence of these agents with copper and good evidence that toxicity of metal ion is related to its activity and not to its total concentration. Project supported by the Fund of Excellent Young Teachers of State Educational Commission of China.  相似文献   
76.
Polyc·lonal antibodies raised against LHC II isolated from SDS-solubilizedBryopsis corticulans thylakiod membranes by SDS-PAGE, were characterised by double immunodiffusion, Rocket immunoelectrophoresis and antigen-antibody crossed immunoelectro-phoresis assays showed the antibodies had strong cross-reaction with allB. corticulans LHC II components (even with those which were incubated in boiling water) and showed immunological cross-reactivity with LHC II polypeptides of spinach and the marine green algaCodium fragile. The results suggested that LHC II of different species had similar antigenic determinants and also conservation of amino acid sequences of the polypeptides during evolution, and that the antibodies could cross react with apoproteins of D2 proteins (which contain P680) fromB. corticulans, spinach andC. fragile, but not with apoproteins of P700 Chl-proteins. Our results indicated some similarities in primary structure between LHC II of different species, and between LHC II and D2 proteins of marine green algae and spinach. Our finding that D2 and P700 Chl-proteins are not immunologically related suggested that P700 Chl-proteins and D2 proteins pass through independent evolutionary pathways. Contribution No 1717 from the Institute of Oceanology, Academia Sinica, This subject was supported by the National Science Foundation of China.  相似文献   
77.
78.
马桥遗址经多次发掘,取得了很多成果。本次采集了2005年发掘的05MMT4探方样品,进行孢粉、藻类研究。根据孢粉、藻类成分特征,划分出了3个孢粉组合带,它们分别是:1带是以Quercus(evergreen)-Gramineae-Typha-Pi-nus-Polypodiaceae-Concentricystes为主孢粉带;2带是以Concentricystes-Quercus(evergreen)-Salvinia-Polypodiace-ae-Typha-Gramineae为主孢粉带;3带是以Pinus-Salix-Quercus(evergreen)-Chenopodiaceae-Pteridium-Polyp-odiaceae-Concentricystes为主孢粉带,并以此恢复了当时古植被和古地理环境。且对马桥先人的生活环境、农耕发展作了探讨,为上海地区文化发展及文明化进程提供了新资料。  相似文献   
79.
In situ primary production data collected during 1978–1981 period and 1997–2000 period were combined to improve understanding of seasonal and spatial distribution of primary production in the southeastern Bering Sea. Mean daily primary production rates showed an apparent seasonal cycle with high rates in May and low rates in summer over the entire shelf of the southeastern Bering Sea except for oceanic region due to lack of data. There was also an increasing trend of primary production rates in the fall over the inner shelf and the middle shelf. There was a decreasing trend of primary production rates between late April and mid-May over the inner shelf while there was an abrupt increase between late April and mid-May over the middle shelf and the outer shelf. In the shelf break region, there was an increasing pattern in late May. These suggest that there was a gradual progression of the development of the spring phytoplankton bloom from the inner shelf toward the shelf break region. There was also a latitudinal variability of primary production rate over the middle shelf, probably due to either spatial variations of the seasonal advance and retreat of sea ice or horizontal advection of saline water in the bottom layer. Annual rates of primary production across the southeastern Bering Sea shelf were 121, 150, 145, 110, and 84 g C m−2 yr−1 in the inner shelf, the middle shelf, the outer shelf, the shelf break, and oceanic region, respectively. High annual rates of primary production over the inner shelf can be attributed to continuous summer production based on regenerated nitrogen and/or a continuous supply of nitrogen at the inner front region, and to fall production. There were some possibilities of underestimation of annual primary production over the entire shelf due to lack of measurement in early spring and fall, which may be more apparent over the shelf break and oceanic region than the inner shelf, the middle, and the outer shelf. This study suggests that the response of primary production by climate change in the southeastern Bering Sea shelf can be misunderstood without proper temporal and seasonal measurement.  相似文献   
80.
Bituminous rocks in the Ozank(?)y(Ankara) field are different from those of the Paleocene- Eocene Mengen and Güineytepe(Bolu) regions in metal enrichment levels.Organic carbon(C_(org)) content of organic material-rich rocks in the Ozank(?)y(Ankara) field is 3.66-40.72% wt averaging 14.34%.The dominant organic materials are algae/amorphous accompanied by minor amount of herbaceous material(The dominant kerogen type is Type-Ⅰwith a limited amount of Type-Ⅱkerogen.). The bituminous rocks in the Ozank(?)y field are enriched in heavy metals such as Ni,Mn,As and Cr.In comparison with the average enrichment values of elements,Ni,Mn,As and Cr in bituminous shales of the Ozank(?)y field are as about 4.38,14.93,10.90 and 5.58 times as average values.The average concentrations of these heavy metals are also as high as 215×10~(-6),828×10~(-6),58.54×10~(-6),and 148×10~(-6) respectively.In addition,sorption properties of clay and organic materials are also important for metal enrichments in the bituminous shales.  相似文献   
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