PromotionLens: Inspecting Promotion Strategies of Online E-commerce via Visual Analytics.

Promotions are commonly used by e-commerce merchants to boost sales. The efficacy of different promotion strategies can help sellers adapt their offering to customer demand in order to survive and thrive. Current approaches to designing promotion strategies are either based on econometrics, which may not scale to large amounts of sales data, or are spontaneous and provide little explanation of sales volume. Moreover, accurately measuring the effects of promotion designs and making bootstrappable adjustments accordingly remains a challenge due to the incompleteness and complexity of the information describing promotion strategies and their market environments. We present PromotionLens, a visual analytics system for exploring, comparing, and modeling the impact of various promotion strategies. Our approach combines representative multivariant time-series forecasting models and well-designed visualizations to demonstrate and explain the impact of sales and promotional factors, and to support "what-if" analysis of promotions. Two case studies, expert feedback, and a qualitative user study demonstrate the efficacy of PromotionLens.

Enriching Atomic Cobalt in an Ultrathin Porous Carbon Shell for Enhanced Electrocatalysis.

Developing nonprecious electrocatalysts operating in acidic and alkaline media for an oxygen reduction reaction (ORR) is essential for sustainable energy technologies. Increasing the metal active site density is an effective strategy to enhance the activity, but it remains challenging because of metal sintering during pyrolysis. Here, we report a novel strategy of enriching atomically dispersed cobalt species in nitrogen-doped carbon for improving the electrocatalytic performance. A hollow carbon nanosphere with reduced shell thickness was obtained by taking advantage of the carbothermic reaction between carbon and ZnO template, and the resulting cobalt enrichment in the ultrathin carbon shell leads to an increase of the density of Co atoms. Together with advantageous microstructure features such as high surface area and multiscale porosity, the corresponding catalyst demonstrated promising oxygen reduction reaction performance in strong acidic and alkaline electrolytes and has two times higher kinetic current density than the nonenriched one. The present work provides an attractive and facile route to engineer active site in electrocatalysts.