排序方式: 共有56条查询结果,搜索用时 15 毫秒
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本文研究了强碱性条件下,以乙二胺为络合剂,用水合肼把二价镍离子还原为单质镍的方法。经过大量实验,镍粉的产率在99%以上,其纯度也在99%以上。通过这种方法,既回收了镍,又降低了对环境的污染,结果令人满意。 相似文献
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The data on plant growth conditions collected for 34 sites in the Barnsley and South Yorkshire Areas of the National Coal Board are analysed using methods of ordination and numerical classification in order to display the regional variations of plant growth characteristics. The potential value of such regional analyses and the manner in which such information could be used by reclamation agencies is discussed and a detailed example is presented for one site. The complete methodology and its limitations are reviewed and the implications for planning of reclamation projects discussed. 相似文献
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荒漠植物红砂研究进展 总被引:2,自引:0,他引:2
主要综述了荒漠植物红砂的分布区及其生境、解剖学特征、种子萌发及幼苗生长影响因素、组织培养、生理生态特征、繁殖及育苗、分子生物学特性等方面的研究。简要阐述了修复和重建红砂植被的必要性,并着重研究了红砂种子萌发的影响因素及育苗技术的发展现状,在此基础上指出红砂研究中的不足之处,并对今后的研究方向提出了建议。 相似文献
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Alexis Knight Satyendra P. Bhavsar Brian A. Branfireun Peter Drouin Ram Prasha Steve Petro Moustapha Oke 《环境科学学报(英文版)》2019,31(6):137-145
The use of biopsy plugs to sample fish muscle tissue for mercury analyses is a viable alternative to lethal sampling; however, the practice has yet to be widely implemented in routine monitoring due to concerns about variability of mercury concentrations in fish muscle tissues. Here we examine distribution of mercury in fillets of four fish species (Walleye, Northern Pike, Smallmouth Bass and Lake Trout), suitability of left/right side of fillet for biopsy sampling, and appropriateness of re-using a biopsy punch. The results showed that average mercury concentrations in left and right fillets of fish are similar. Mercury concentrations in biopsy plug samples, taken from the anterior dorsal area of the fish fillet, were statistically equivalent to the mercury concentrations in homogenized fillets. There was no discernible cross contamination between samples when a biopsy punch was reused after washing in hot soapy water, and as such, biopsy punches can be recycled during sampling to reduce the sampling cost. If a tissue mass collected from a specific site on the fillet is insufficient, then we suggest sampling corresponding locations on the other fillet rather than sampling two adjacent sites on one fillet to obtain more tissue. The results presented here can improve the accuracy of fillet biopsy plug sampling, minimize fish mortality for mercury monitoring, and reduce labor and material costs in monitoring programs. 相似文献