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Phytoremediation technology using aquatic plants is being used increasingly in constructed wetlands to purify wastewater. The physiological responses of water lettuce (Pistia stratiotes) and its effectiveness in removing fluoride (F -) from water are described in this article. The results indicate that Pistia stratiotes has the ability to accumulate F -. The removal efficiency ranged from 27.79% to 56.32% for the various initial F -concentrations tested, and was highest (56.32%) in the highest initial concentration group 60mg/L. The F - concentrations in control groups (without Pistia stratiotes) changed very little, from -1.135% to -0.007% of the initial concentrations. At the highest removal rate, the bioconcentration factor was 7.84. The rate of purification conformed to the Michaelis-Menten equation, and the correlation coefficients (R 2) were all greater than 0.97. The Specific Growth Rates (SGR) of the treatment groups were -8.03% to -1.22%, and the SGR of plants under F -stress decreased during the experimental period. The partial correlation analysis showed that concentrations of F - in water were strongly linearly correlated with peroxidase. 相似文献
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星载GPS相位观测值非差运动学定轨探讨 总被引:2,自引:0,他引:2
在几何法、动力学法和减缩动力学法定轨基础上,探讨了星载GPS相位观测值非差运动学定轨方法及其实现程序。该方法无需复杂的力学模型和地面资料,只需LEO(Low Earth Orbit)卫星上的GPS数据和IGS的GPS精密星历产品,它计算简单、方便,能快速、高精度地确定轨道,同时,还能确定一些动力学参数,但没有轨道预报功能;针对法方程系数矩阵比较庞大,提出了矩阵分块、上三角化的参数解算方法,并用CHAMP卫星资料分析了上述方法的定轨精度。 相似文献
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吊舱推进器与船体间相互影响研究进展 总被引:1,自引:0,他引:1
吊舱推进器是近年来发展起来的一种新型船舶推进装置.针对吊舱推进器与船体之间影响的成因、干扰形式和研究方法进行了阐述,总结了吊舱推进器与船体之间相互影响的理论研究和模型试验方面取得的成果.最后提出该领域的主要研究方向,作为进一步研究的参考. 相似文献
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CHAMP卫星的纯几何定轨及动力平滑中的动力模型补偿研究 总被引:3,自引:1,他引:3
探讨了利用CHAMP卫星星载GPS数据实现纯几何PPP定轨的方法 ,对该几何轨道的动力平滑过程进行了分析 ,提出了增加非参数项吸收动力模型误差的半参数动力平滑方法。 相似文献
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����GPS���ܶ����չ������ѧģ�� 总被引:1,自引:0,他引:1
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