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自从对虾工厂化育苗成功之后,我国对虾养殖事业发展很快,但单位面积产量仍然偏低,有少数单位虽然达到500kg/亩以上,但很不稳定。近几年来不少国家进行对虾高密度养殖试验,有的亩产1500kg以上。为了探索中国对虾稳产、高产、高效益的高密度养殖技术,我们于1987年在山东省胶州市营海渔业公司对虾育苗场利用4个育苗池进行对虾高密度养殖试验,取得了较好的效果。当年10月25日通过专家们的技术验收,4个试验池,总面积为78.43m~2,平均产虾1.98kg╱m~2,折合亩产1322kg。其中较好的3号池,单产2.80kg/m~2,折合亩产1868.3kg,对虾平均体长11.77cm,体重19.03g。专家们认为,该实验在国内属首次试验成功,创国内单位面积养虾最高记录,为我国的对虾养殖开辟了一条新的途径。 相似文献
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The average concentration of total Sn in surface layer is 2.90 μg/1 and that of total Bi 0.50 μg/1. The free ion, bound and particulate forms of Sn in Changjiang (Yangtze River) Estuary account for 20%, 30% and 50% of the total Sn respectively, and those of Bi 25%, 35% and 40% respectively. In the surface water of the Pacific, the total Sn is 2.06 μg/1, and the percentages of the three forms of Sn are 50, 30 and 20% respectively. The total Bi are 0.38 μg/1, and the percentages of the three forms of Bi are 55, 25 and 20% respectively. The concentrations of free ions of Sn and Bi in 0-1400 m and 0-1900 m in 18 and 19 stations are in vertical homogeneous distribution. The slight similarity in distribution between Bi ion and salinity may be due to the influence of organisms and biochemistry. 相似文献
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