In the process of internationalization of construction contractors, international enterprises as main contractors (IMC) need to consider whether part of the contract should be subcontracted to local subcontractors (LSC) to gain a competitive advantage when competing with local main contractors (LMC). The involvement of local subcontractors can usually help reduce cost through the cost spillover effect. However, it should be noted that the share of local subcontractors with local main contractors with an inferior quality may lead to quality spillover. The Hotelling model is therefore adopted to investigate the subcontracting decisions of main contractors considering both cost and quality spillover effects. Many scenarios are simulated and the results show that LMCs with inferior quality can always choose the subcontracting strategy to obtain increased profit regardless of the strategy that IMCs adopt. On the other hand, IMCs need to balance the cost spillover of subcontracting and the quality spillover for improving the quality level of LSCs. The results are useful for contractors to make decisions that are relevant to the adoption of subcontracting strategies to obtain competitive advantages.@en

Removal of bromate (BrO3−) has gained increasing attention in drinking water treatment process. Photocatalysis technology is an effective strategy for bromate removal. During the photocatalytic reduction of bromate process, the photo-generated electrons are reductive species toward bromate reduction and photo-generated holes responsible for water oxidation. In this study, the monoclinic bismuth vanadate (BiVO4) single crystal was developed as a visible photocatalyst for the effective removal of bromate. The as-synthesized BiVO4 photocatalyst with optimized {010} and {110} facets ratio could achieve almost 100% removal efficiency of BrO3− driven by visible light with a first-order kinetic constant of 0.0368 min−1. As demonstrated by the electron scavenger experiment and density functional theory (DFT) calculations, the exposed facets of BiVO4 should account for the high photocatalytic reduction efficiency. Under visible light illumination, the photo-generated electron and holes were spatially transferred to {010} facets and {110} facets, respectively. The BiVO4 single crystal photocatalyst may serve as an attractive photocatalyst by virtue of its response to the visible light, spatially charge transfer and separation as well as high photocatalytic activity, which will make the removal of BrO3− in water much easier, more economical and more sustainable.@en