Multiphase chemistry of NO2 and alkaline matter in aerosol water explains rapid sulfate formation and severe haze in China.

Agriculture faces great challenges to ensure global food security by increasing yields while reducing environmental costs. Here we address this challenge by conducting a total of 153 site-year field experiments covering the main agro-ecological areas for rice, wheat and maize production in China. A set of integrated soil-crop system management practices based on a modern understanding of crop ecophysiology and soil biogeochemistry increases average yields for rice, wheat and maize from 7.2 million grams per hectare (Mg ha(-1)), 7.2 Mg ha(-1) and 10.5 Mg ha(-1) to 8.5 Mg ha(-1), 8.9 Mg ha(-1) and 14.2 Mg ha(-1), respectively, without any increase in nitrogen fertilizer. Model simulation and life-cycle assessment show that reactive nitrogen losses and greenhouse gas emissions are reduced substantially by integrated soil-crop system management. If farmers in China could achieve average grain yields equivalent to 80% of this treatment by 2030, over the same planting area as in 2012, total production of rice, wheat and maize in China would be more than enough to meet the demand for direct human consumption and a substantially increased demand for animal feed, while decreasing the environmental costs of intensive agriculture.

Up-converting rare-earth nanophosphors (UCNPs) have great potential to revolutionize biological luminescent labels, but their use has been limited by difficulties in obtaining UCNPs that are biocompatible. To address this problem, we have developed a simple and versatile strategy for converting hydrophobic UCNPs into water-soluble and carboxylic acid-functionalized analogues by directly oxidizing oleic acid ligands with the Lemieux-von Rudloff reagent. This oxidation process has no obvious adverse effects on the morphologies, phases, compositions and luminescent capabilities of UCNPs. Furthermore, as revealed by Fourier transform infrared (FTIR) and NMR results, oleic acid ligands on the surface of UCNPs can be oxidized into azelaic acids (HOOC(CH2)7COOH), which results in the generation of free carboxylic acid groups on the surface. The presence of free carboxylic acid groups not only confers high solubility in water, but also allows further conjugation with biomolecules such as streptavidin. A highly sensitive DNA sensor based on such streptavidin-coupled UCNPs have been prepared, and the demonstrated results suggest that these biocompatible UCNPs have great superiority as luminescent labeling materials for biological applications.

Sustainably feeding a growing population is a grand challenge, and one that is particularly difficult in regions that are dominated by smallholder farming. Despite local successes, mobilizing vast smallholder communities with science- and evidence-based management practices to simultaneously address production and pollution problems has been infeasible. Here we report the outcome of concerted efforts in engaging millions of Chinese smallholder farmers to adopt enhanced management practices for greater yield and environmental performance. First, we conducted field trials across China's major agroecological zones to develop locally applicable recommendations using a comprehensive decision-support program. Engaging farmers to adopt those recommendations involved the collaboration of a core network of 1,152 researchers with numerous extension agents and agribusiness personnel. From 2005 to 2015, about 20.9 million farmers in 452 counties adopted enhanced management practices in fields with a total of 37.7 million cumulative hectares over the years. Average yields (maize, rice and wheat) increased by 10.8-11.5%, generating a net grain output of 33 million tonnes (Mt). At the same time, application of nitrogen decreased by 14.7-18.1%, saving 1.2 Mt of nitrogen fertilizers. The increased grain output and decreased nitrogen fertilizer use were equivalent to US$12.2 billion. Estimated reactive nitrogen losses averaged 4.5-4.7 kg nitrogen per Megagram (Mg) with the intervention compared to 6.0-6.4 kg nitrogen per Mg without. Greenhouse gas emissions were 328 kg, 812 kg and 434 kg CO equivalent per Mg of maize, rice and wheat produced, respectively, compared to 422 kg, 941 kg and 549 kg CO equivalent per Mg without the intervention. On the basis of a large-scale survey (8.6 million farmer participants) and scenario analyses, we further demonstrate the potential impacts of implementing the enhanced management practices on China's food security and sustainability outlook.

By employing a novel low-temperature synthetic pathway, highly ordered cubic mesoporous materials with hitherto the largest pores (up to 27 nm) and unit cells (up to 44 nm) have been successfully obtained.