Research On Complex Network Of Chemical Elements In Urban Dust Of Jinhua City

Complex network theory is an effective method to study complex systems,and research methods are becoming more and more mature,and are widely used in the research of computer network,biological network,scientist cooperation network,power network and transportation network.In this paper,the complex network research method is introduced into the study of urban dust,with chemical elements as nodes,and the relationship between elements is connected.The chemical elements network of laterite and the network elements of urban dust are constructed.By comparing the topological characteristics of the two networks in order to reveal the overall behavior and characteristics of urban dust chemical composition system and the role and influence of individual elements in the system from the perspective of system theory,so as to better reveal the environmental significance of urban dust.After samplecollection,data analysis and discussion,the conclusions are as follows:1.Some of the elements in the dust sample have reached a level of mild enrichment or even extreme enrichment,especially heavy metal elements and calcium enrichment is more significant.The calculation of the cumulative index of the laterite sample shows that most of the elements are not enriched,and only individual elements are slightly enriched and are less affected by human activities and are not contaminated by human activities.In the case of Pb and SiO2,the correlation between elemental relationships is stronger than that in laterites,and the correlation between.them is much weaker than that in laterite.2.The clustering coefficient and the shortest path of the chemical element network of urban dust are 0.657 and 1.490 respectively,while the clustering coefficient and the shortest path of the chemical element network of laterite are 0.817 and 1.297 respectively,both of which are small worlds,that is,human factors are not Resulting in changes in the chemical element network type.This may explain to some extent that the chemical element network type is greatly influenced by the geochemical properties of the element.3.Although the types of chemical elements in urban dust and the types of chemical elements in laterite are similar,the characteristics of network topology are obvious.This is mainly manifested in the following aspects:(1)In the node degree of chemical element network,the node degree of urban dust chemical element network is generally tower than that of laterite chemical element network node,and its constant element node degree and laterite chemistry(2)In the clustering coefficient of the network,the clustering coefficient of the dust chemical element network is generally lower than that of the laterite network,and the nodal degree of the elemental network is not correlated with the node degree of the laterite network.(3)In the aspect of network interdependence,the relationshp between the clustering coefficient and the concentration of trace elements is related to the clustering coefficient of chemical elements in the laterite,but the correlation degree is weak and the constant elements are not related to each other.The number of trace elements is higher than that of the laterite chemical element network,and the constant elements are different.4.Compared with the network type,the network topology of urban dust is more sensitive to human impact,which can reveal the environmental significance of dust.The topology index reveals the origin of dust chemical elements and its symbiotic combination characteristics to a certain extent,the results show that the elements of lead,zinc and sulfur in dust can be used as indicator elements of human activities.In addition,the chermical composition of the dust in the dust,the community structure in the elemental network may reflect the symbiotic combination of elements.5.The difference of the network topology characteristics of the two types of networks is mainly on the constant elements,although there are some differences in the trace elements,but it is still quite similar.In general,the constant element is the main rock-forming element,and the difference in the topology of the constant element network may be the difference between the laterite and the urban dust source.Second,although the accumulation of trace elements in urban dust,especially heavy metal elements,resulting in a certain degree of pollutior,and cause widespread concern.It is worth noting that the changes in the topology of the dust chemical elements seem to be mainly reflected in the constant elements.Therefore,the topotogy of the constant element network changes,it may be pointed out that the elements and their relationship with the existence of elements of the study,is conducive to further clarify the source of dust material Thirdly,in the two types of networks,some of the elements of the network topotogy is significantly different from most of the elements of the topology changes,such as silicon,aluminum and so on In the previous study of urban dust,the focus is mainly on the heavy metal elements,the study of the above elements is inadequate,so the study of these elements may provide a direction for t e subsequent urban dust geochemical research.