In recent years, interfacial solar vapor generation has shown great potential in realizing desalination and wastewater treatment with high energy conversion efficiency. However, high evaporation rate cannot be maintained because of the seemingly unavoidable fouling or salt accumulation on the solar absorbers. The degradation accelerates as the solute concentration increases. Here, we demonstrate a water lily–inspired hierarchical structure that enables efficient evaporation (~80% solar-to-vapor efficiency) out of high-salinity brine [10 weight % (wt %)] and wastewater containing heavy metal ions (30 wt %). More notably, neither decrease in evaporation rate nor fouling on absorbers was observed during the entire evaporation process until water and solute were completely separated. With the capabilities of stable and high-rate evaporation out of high-salinity brine and the effective separation of solute from water, it is expected that this technology can have direct implications in various fields such as wastewater treatment, sea-salt production, and metal recycling.

Accumulation of human capital is indispensable to spur economic growth. If students fail to acquire needed skills, not only will they have a hard time finding high-wage employment in the future but the development of the economies in which they work may also stagnate owing to a shortage of human capital. The overall goal of this study is to try to understand if China is ready in terms of the education of its labour force to progress from middle-income to high-income country status. To achieve this goal, we seek to understand the share of the labour force that has attained at least some upper secondary schooling (upper secondary attainment) and to benchmark these educational attainment rates against the rates of the labour forces in other countries (e.g. high-income/OECD countries; a subset of G20 middle-income/BRICS countries). Using the sixth population census data, we are able to show that China's human capital is shockingly poor. In 2010, only 24 per cent of China's entire labour force (individuals aged 25–64) had ever attended upper secondary school. This rate is less than one-third of the average upper secondary attainment rate in OECD countries. China's overall upper secondary attainment rate and the attainment rate of its youngest workers (aged 25–34) is also the lowest of all the BRICS countries (with the exception of India for which data were not available). Our analysis also demonstrates that the statistics on upper secondary education reported by the Ministry of Education (MoE) are overestimated. In the paper, we document when MoE and census-based statistics diverge, and raise three possible policy-based reasons why officials may have begun to have an incentive to misreport in the mid-2000s.

Recovery of the end-of-use products has become a topic of considerable interest in the advanced manufacturing industry due in part to uncertainties in the quality and volume of product returns. The Internet of Things (IoT) that enables the tracing, detecting, storing, and analyzing the product life cycle data for each individual item can mitigate or eliminate these uncertainties. In this paper, an integrated three-stage model is presented based on IoT technology for the optimization of procurement, production and product recovery, pricing and strategy of return acquisition. The remaining value is used to measure the return condition. The model considers three recovery options related to refurbishing, component reuse and disposal, and the value deterioration for satisfying the product demand in each stage of product life cycle (PLC). A novel particle swarm optimization (PSO) algorithm based on two heuristic methods is proposed to solve the problem. A numerical example and sensitivity analysis are used to illustrate the performance of both algorithm and applicability of the model.