通过大田试验,在轻度镉-铅复合污染菜地向小白菜叶面喷施不同浓度的硅溶胶、铈溶胶及硅铈复合溶胶,研究其对产量、品质、抗氧化酶活性及Cd、Pb吸收的影响。结果表明,喷施硅铈溶胶均能促进小白菜生长,增加小白菜生物量和提高维生素C、可溶性糖的含量,降低亚硝酸盐的含量;显著增强抗氧化系统保护酶(SOD、POD)活性和降低小白菜地下部、地上部中镉、铅的含量及累积量。在不同浓度的施硅和施铈处理中,喷施0.50 g kg-1SiO2处理和0.20 g kg-1CeO2处理在增产、提升品质和缓解重金属对小白菜毒害上效果最佳,喷施硅铈复合溶胶虽效果显著,但与单独施硅、施铈相比无明显提高。 相似文献
Stress wavelet properties are inherently involved in the process of the drop-shatter method of assessment on soil structural characteristics. The analogies between wavelet analysis and the drop-shatter process are based on two factors: scale and resolution. By carefully following the requirements of wavelet analysis, a standard procedure of soil fragmentation and sieving is described. Following this procedure, a set of equations can be derived from which surface contacting energy between soil aggregates of a specific scale can be calculated. The resultant values in fact mirror the multi-resolutions of wavelets.
Natural soil clods as well as artificial structured soil cores were used for fragmentation. Though the experiment can do well on natural soil clods, and it is precise enough in predicting structural state of a sub-dimensional clods of 8 mm, its use on artificial soil cores produced a set of data that was quite chaotic. The unique behavior experienced in the process of fragmentation of artificial soil structure indicates that there is no distinct stage between mother soil clods (cores) and its constituent primary particles. Such a state should result from an excessively large impact energy (too low a resolution in the wavelet analysis) for each drop stroke impact.
With an ultimate goal for soil process simulation, the construction of the experiment for artificial structured soil core preparation brings the traditional methods of sample preparation a step forward further by creating an environment much nearer to the field conditions experienced in natural soils. Still, extensive refinements are needed, especially for the mode of water application, cycle and intensity of management. 相似文献
A new indirect competitive fluorescence-linked immunosorbent assay (cFLISA) method for the detection of sulfamethazine (SM2) in chicken muscle tissue was demonstrated using quantum dots (QDs) as the fluorescence label coupled with secondary antibody. The sensitivity of the cFLISA was compared with that of the HPLC method. The 50% inhibition value (IC50) and the limit of detection (LOD) of the cFLISA were 7.7 and 1.0 ng/mL, respectively. When SM2 was spiked at levels of 50, 100, and 200 ng/g, recoveries ranged from 80.6% to 117.4%, with a coefficient of variation of 6.9-9.6%. In the incurred sample analysis, the amounts of SM2 quantified by cFLISA were similar to the results obtained by the HPLC method. This study shows that cFLISA could be used as a screening method in practice. 相似文献