贵州省西秀区耕地土壤硒元素地球化学特征及成因分析

针对多阅读器竞争共享介质和覆盖区域重叠造成射频信号干扰和碰撞的问题，依据阅读器在识别范围内受干扰的程度，将其设定为稀疏或稠密阅读器，给出双层规划阅读器避碰模型，并提出相应的双层规划混合智能优化算法。将鱼群算法的拥挤度和追尾行为引入免疫优化算法中，增强群体的局部勘探能力，获得免疫鱼群优化算法；进而，将此算法作为算子模块嵌入到遗传算法中，得到求解此避碰模型的混合智能优化算法。比较性的数值实验显示，该算法的搜索效果稳定且具有明显优势。

Analysis on Geochemical Characteristics and Genesis of Selenium Element in Cultivated Soil of Xixiu District, Guizhou Province

In order to promote the development of agriculture with local characteristics, based on the results of the survey of cultivated land quality in Xixiu District, the characteristics and distribution of soil selenium in Xixiu District were analyzed by using the method of ecological geochemistry, which was used to study the geochemistry of soil selenium, the source, accumulation and agricultural effects of selenium in soil were studied. The results showed that the average content of Se in cultivated soil was 0.56 mg / kg,and higher than the average value of A layer in China, the Selenium element is generally rich. The content of Se in soil is 0.43.0 mg / kg, which accounts for 89.40% of the total area of cultivated land. The soil Selenium content in the study area was obviously affected by soil type, land use pattern and organic matter content, and was negatively correlated with pH value in a certain range, and positively correlated with heavy metals, such as Mo, Cd, As, Zn, and so on.It is further explained that selenium has certain inheritance to the parent material of soil formation, and is also supplied by external sources. The correlation coefficients were all lower than 0.50. The Se-enriched Rice, tea and rape were produced in the Se-enriched cultivated land, and the Se-enriched rates were 62.5% , 62.5% and 100%, respectively, which showed the potential of Se-enriched industry.