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显影银丝定影溶解及其热力学基础
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作者 刘素文 胡逢凯 许可 《影像技术》 CAS 1998年第3期21-25,55,共6页
本文对银影像的密度在长时间的定影过程中变小的原因进行了分析和研究。采用复形、电镜观察等手段对显影银丝的微观形态进行探索,结果发展:银丝在长时间定影后会在空管中形成细细的芯,芯和显影银丝均为多晶结构的银丝,只是定影后所... 本文对银影像的密度在长时间的定影过程中变小的原因进行了分析和研究。采用复形、电镜观察等手段对显影银丝的微观形态进行探索,结果发展:银丝在长时间定影后会在空管中形成细细的芯,芯和显影银丝均为多晶结构的银丝,只是定影后所遗留下的芯比定影前的银丝细了许多。用电化学的知识对显影银丝的定影溶解反应进行了研究。 展开更多
关键词 电化学 显影 纳米银丝 银影像 定影溶解 热力学
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The Effect of Water Hyacinth (Eichhornia Crassipes) Infestation on Phytoplankton Productivity in Lake Naivasha and the Status of Control
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作者 J.M. Mironga J.M. Mathooko S.M. Onywere 《Journal of Environmental Science and Engineering》 2011年第10期1252-1260,共9页
The paper presents data collected in an assessment of the effects of water hyacinth (Eichhornia crassipes) infestation on phytoplankton productivity in Lake Naivasha. A summary of the status of control and strategie... The paper presents data collected in an assessment of the effects of water hyacinth (Eichhornia crassipes) infestation on phytoplankton productivity in Lake Naivasha. A summary of the status of control and strategies used is given. The ecological effects of water hyacinth on the lake have received little attention compared to the large body of work available on the weed's socioeconomic impact. This study was conducted to determine the effect of hyacinth infestation on the phytoplankton productivity. Several sampling stations were set up in the lake at sites containing floating mats of the weed and at sites where the weed was absent. Phytoplankton chlorophyll-a concentration and dissolved oxygen were measured at each station and used as proxies for phytoplankton productivity. The findings show that phytoplankton productivity in weed covered areas is reduced with significant change in species composition and biodiversity suggesting that water hyacinth can alter the ecology of the lake. Although water hyacinth has continued posing serious ecological consequences, the control strategies already adopted will continue to reduce deleterious impacts and allow sustained development in the Lake Naivasha Basin. There is need however to undertake research to quantify the level of ecological damage and the costs of control. There are other effects such as livelihood loss, diseases, and disruption of normal operations that also need to be quantified. 展开更多
关键词 Water hyacinth ecological effects phytoplankton.
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