利用纳米磁性材料表征地表溅蚀特征的初探

发布时间：2018-04-22 04:00

  本文选题：溅蚀 + 磁性示踪剂　； 参考：《土壤学报》2017年05期

【摘要】：磁性示踪研究坡面土壤侵蚀已取得一定成果,但目前的磁性示踪方法不能满足次降雨后的溅蚀特征研究。因此,在无磁性的石英砂上施用不同浓度(1.5%、2.5%、3.5%)和不同粒径(20 nm、200 nm)的纳米磁性材料,而后进行人工模拟溅蚀试验,利用磁化率仪和3D手持微地形扫描仪研究地表磁性变化与溅蚀后地表特征变化之间的关系,研究利用纳米磁性材料表征溅蚀特征的可行性。结果表明:20 nm磁性材料提高石英砂磁性背景值的幅度远高于200 nm磁性材料且不同浓度的磁性差异极显著,两种纳米磁性材料均呈现出布设浓度越大,示踪时间越长的特点;溅蚀后表层磁化率随溅蚀时间的延长而逐渐衰减,二者呈现出相关性较高的χ_1=aln(t)+b对数函数关系;20 nm磁性材料在3.5%浓度下可有效定量表征出石英砂溅蚀量的变化(p0.01),二者之间的相关关系可用χ_2=a Mb幂函数表示;20 nm磁性材料在溅蚀3 min内的磁化率变化与微地形高差变化呈极显著相关关系(p0.01),说明20 nm磁性材料可以在短时间内有效表征出溅蚀地表的侵蚀程度,可表征出的侵蚀厚度在-5~10 mm内。该研究证明20 nm磁性材料表征溅蚀地表特征的方法在一定程度上是可行的,可为磁性示踪法的深入研究提供新的思路和方法。
[Abstract]:Magnetic tracer has achieved some achievements in soil erosion on the slope, but the current magnetic tracing method can not meet the characteristics of splash erosion after secondary rainfall. Therefore, the magnetic materials of different concentrations (1.5%, 2.5%, 3.5%) and different particle sizes (20 nm, 200 nm) are applied on the non magnetic quartz sand, and then the artificial simulated splash corrosion test is carried out, and the magnetic field is used in the magnetic field. The relationship between the change of surface magnetism and the change of surface characteristics after splashing is studied by the rate meter and the 3D handheld microtopography scanner. The feasibility of using the nano magnetic material to characterize the splash corrosion is studied. The results show that the amplitude of the magnetic background value of 20 nm magnetic materials is much higher than that of the 200 nm magnetic materials and the magnetic difference poles of different concentrations are different. Obviously, the larger the two nano magnetic materials show the larger the concentration and the longer the tracing time, the surface magnetization decreases gradually with the prolongation of the splashing time, and the two has a higher correlation logarithmic function relationship with the X _1=aln (T) +b, and the 20 nm magnetic material can effectively characterize the splash erosion of quartz sand under the concentration of 3.5%. Change (P0.01), the correlation between the two can be expressed by the X _2=a Mb power function; the magnetic susceptibility change of 20 nm magnetic material in the splash corrosion 3 min has a very significant correlation with the change of the height difference of the microtopography (P0.01). It shows that the magnetic material can effectively characterize the erosion degree of the splashed surface in a short time, and the erosion thickness can be characterized in -5. ~10 mm. The study shows that the method of characterizing the surface characteristics of the splash erosion by 20 nm magnetic materials is feasible to some extent. It can provide new ideas and methods for the further study of magnetic tracer method.

【作者单位】： 福建农林大学资源与环境学院福建省土壤环境健康与调控重点实验室;
【基金】：国家科技支撑计划项目(2014BAD15B0303) 国家自然科学基金项目(41571272) 福建省自然科学基金项目(2015J01156)资助~~
【分类号】：S157
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本文编号：1785481