Size fractionated biomass and productivity of phytoplankton and new production in the Prydz Bay and the adjacent Indian sector of the Southern Ocean during the austral summer 1998/1999

The paper deals with the studies on the cell abundance, the composition of dominant species, size fractionated biomass and productivity of phytoplankton, new production, the environmentally restricted mechanism in the Prydz Bay and the adjacent Indian sector of the Southern Ocean during the austral summer 1998/1999. The results showed that there was marked feature of spatial zonation in the sea areas investigated. In the Prydz Bay and its adjacent continental shelf, the biomass and productivity of phytoplankton were high; those of continental slope and open ocean area were obviously low. The nutrient concentration had opposite distribution trend, due to the consumption of phytoplankton. It mainly affected by the vertical stability of water column, grazing pressure of zooplankton, temperature and light etc. The results of size-fractionation showed that the average contribution of netplankton to total chlorophyll a in studied sea areas was 52.2 %, those of nano- and picoplankton were 29.4 % and 18.4 %, respectively. The average contribution of netplankton to total primary production was 52.4 %, those of nano- and picoplankton were 28.7 % and 18.9 %, separately. It is same as previous conclusion that the contribution of picoplankton to productivity is slightly larger than that to biomass of phytoplankton communities. The average new production and f-ratio were 230.6 mg/ (m(2.)d) and 0.43, respectively.

Distribution characteristics of size-fractionated chlorophyll a, primary production and new production in the Laizhou Bay, July 1997

The distributions of chlorophyll a concentration, primary production and new productionwere observed in the Laizhou Bay of the Bohai Sea in both spring and neap tides during July 1997. The results showed that there were marked features of spatial zonation in the surveyed area, due to the differences between the geographic environment and the hydrological conditions. Chlorophyll a, primary production and new production were all higher in spring tides than that in neap tides in the Laizhou Bay. The highest values of these parameters were encountered in the central regions of the bay. At most stations, chlorophyll a concentrations at the bottom were higher than that at the surface. The results of size-fractionated chlorophyll a and primary production showed that contributions of nanocombining pi-coplankton ( <20 μm) to total chlorophyll a and primary production were dominant in phytoplankton community biomass and production of the Laizhou Bay. The environmental factors, primary production and new production in the Laizhou Bay are compared with other sea areas.

珠江口初级生产力和新生产力研究

1996年 1 2月和 1 997年 8月在珠江河口湾及其毗邻海域对浮游植物生物量、初级生产力和新生产力及其环境制约机制的研究 .结果表明 ,调查海区的叶绿素a、初级生产力和新生产力均是夏季高于冬季 ,冬、夏两季的平均值分别为 ( 0 95± 0 4 1 )和 ( 1 0 8± 0 52 ) μg/dm3 ,( 6 9 2± 75 5)和 ( 1 98 7± 1 1 9 1 )mg/(m2 ·d) ,( 1 4 6±0 79)和 ( 3 0 5± 3 0 9)mg/(m3 ·h) .冬、夏两季平均 f -比分别为 0 4 5和 0 38.分级叶绿素a结果显示 ,冬、夏两季均以微型和微微型级分 ( <2 0 μm)占优势 ,其对海区叶绿素a的贡献分别为 79 6 %和 81 6 % ,对初级生产力的贡献分别为 70 7%和89 6 % .调查海区具显著的空间区域化特征 ,叶绿素a和潜在初级生产力的高值出现在冲淡水区的中部 ,向口门区和远岸区逐渐降低 .现场初级生产力的高值出现在远岸区 ,它与复合参数BeZpI0 (Be 为真光层平均叶绿素a ,Zp 为真光层深度 ,I0 为海面光辐射强度 -PAR)呈很好的正相关 ,说明光是研究海区初级生产力的主要限制因子 .新生产力冬。

南极普里兹湾浮游植物现存量与初级生产力粒级结构和新生产力研究

报道1998～1999年夏季在南极普里兹湾及其毗邻海域对细胞丰度、优势种类组成、生物量和初级生产力的粒级结构、新生产力及其环境制约机制的研究.结果表明,调查海区具有显著的空间区域化特征.普里兹湾及其毗邻陆架区浮游植物现存生物量和生产力均较高,大陆坡和深海区明显降低;营养盐浓度由于浮游植物的消耗则有相反的分布趋势.浮游植物生物量和生产力受水体的垂直稳定度、浮游动物摄食、水温和光照等环境条件的控制.粒度分级测定结果表明,对调查海区叶绿素a的贡献,小型浮游生物为52.2%,微型为29.4%,微微型为18.4%;对初级生产力的贡献,小型为52.4%,微型为28.7%,微微型为18.9%.研究海区的平均新生产力和f比分别为230.6mg/(m2·d)和0.43.

BKT-Ⅰ型浓缩磁选机的研制与工业试验研究

首钢矿业公司为了增加二段球磨机入磨浓度,提高磨矿效率,在二段球磨机前增加了浓缩磁选机,根据现场的安装条件和工艺要求,北京矿冶研究总院研制了BKT-I型浓缩型磁选机并进行了工业试验。结果表明,该类型浓缩磁选机运转稳定可靠、浓缩效果良好,二段球磨机的入矿浓度可以提高至70%以上,球磨机-74μm新生粒级相对提高了50%以上,循环负荷减少至400%。