SummaryNematode communities in the soils of wheat (Triticum aestivum Linn.) rhizosphere grown alone and grown in jujube (Ziziphus jujuba Mill.) orchard were investigated for three years in Hetian arid area, Xingjiang Uygur Autonomous Region, northwest of China. The results showed that eu-dominant families were Rhabditidae, Cephalobidae and Aphelenchidae among 15 families and 19 genera. Nematode abundance in wheat rhizosphere soil was smaller in wheat/jujube intercropping system, mainly because of lower numbers of bacterial feeders and fungal feeders. Besides, the nematode numbers of cp-1 and cp-2 (cp, colonizer-persister) guilds were signifi cantly lower in wheat/jujube intercropping system than that in monoculture wheat system, due to the markedly lower numbers of Rhabditidae and Cephalobidae, although those of cp-3 and cp-4 guilds had no signifi cant differences between monoculture and intercropping systems. Shannon-Weaver index (H'), genus dominance index (Ig) and structural index (SI), represented soil food web diversity and structure, had no differences between monoculture and intercropping systems. Signifi cantly lower values of Wasilewska index (WI) and PPI/MI in monoculture wheat than in intercropping system. It was concluded that the soil status in monoculture wheat system exhibited better soil ecosystem in compared with wheat/ jujube intercropping system.

This paper investigates the mechanical behaviour of a bi-layered panel containing many particles in one layer and demonstrates the size effect of particles on the deflection. The inclusion-based boundary element method (iBEM) considers a fully bounded bi-material system. The fundamental solution for two-jointed half spaces has been used to acquire elastic fields resulting from source fields over inclusions and boundary-avoiding multi-domain integral along the interface. Eshelby’s equivalent inclusion method is used to simulate the material mismatch with a continuously distributed eigenstrain field over the equivalent inclusion. The eigenstrain is expanded at the centre of the inclusion, which provides tailorable accuracy based on the order of the polynomial of the eigenstrain. As a single-domain approach, the iBEM algorithm is particularly suitable for conducting virtual experiments of bi-layered composites with many defects or reinforcements for both local analysis and homogenization purposes. The maximum deflection of solar panel coupons is studied under uniform vertical loading merged with inhomogeneities of different material properties, dimensions and volume fractions. The size of defects or reinforcements plays a significant role in the deflection of the panel, even with the same volume fraction, as the substrate is relatively thin.