To tackle the problems of questioning authenticity products faced in e-commerce live streaming and low data integrity process product transactions, concept traceability a authentication scheme that integrates blockchain technology are proposed. The proposed deploys strategy on Ethereum form smart contract calls method body by executing to realize quality. A combination on-chain off-chain is use...

For what kind of intermediate input/service do firms often go outsourcing? This paper develops a model of two-stage production in which economies of scope are central to the production of both the intermediate and final good. The model is able to explain the patterns of outsourcing from the degree of product differentiation, economies of scope, and economies of scale in production of the interm...

The impact of R&D on growth through spillovers has been a major topic of economic research over the last thirty years. A central problem in the literature is that firm performance is affected by two countervailing “spillovers”: a positive effect from technological knowledge spillovers and negative business stealing effects from product market rivals. We develop a general framework incorporating...

background: creation of artificial gametes may provide a universal solution for these patients of lacking gametes. stem cell technology may provide a way to obtain fully functional gametes. retinoic acid (ra) can initiate meiosis. several studies have demonstrated that ra can promote sperm cells differentiation from mouse embryonic stem cells (mescs) and other cells from human embryonic stem ce...