Efficient and durable oxygen evolution reaction (OER) catalysts are highly required for the cost-effective generation of clean energy from water splitting. For the first time, an integrated OER electrode based on one-step direct growth of metallic iron-nickel sulfide nanosheets on FeNi alloy foils (denoted as FeNi S /FeNi) is reported, and the origin of the enhanced OER activity is uncovered in combination with theoretical and experimental studies. The obtained FeNi S /FeNi electrode exhibits highly catalytic activity and long-term stability toward OER in strong alkaline solution, with a low overpotential of 282 mV at 10 mA cm and a small Tafel slope of 54 mV dec . The excellent activity and satisfactory stability suggest that the as-made electrode provides an attractive alternative to noble metal-based catalysts. Combined with density functional theory calculations, exceptional OER performance of FeNi S /FeNi results from a combination of efficient electron transfer properties, more active sites, the suitable O evolution kinetics and energetics benefited from Fe doping. This work not only simply constructs an excellent electrode for water oxidation, but also provides a deep understanding of the underlying nature of the enhanced OER performance, which may serve as a guide to develop highly effective and integrated OER electrodes for water splitting.

The accurate and automated determination of earthquake locations is still a challenging endeavor. However, such information is critical for monitoring seismic activity and assessing potential hazards in real time. Recently, a convolutional neural network was applied to detect earthquakes from single-station waveforms and approximately map events across several large surface areas. In this study, we locate 194 earthquakes induced during oil and gas operations in Oklahoma, USA, within an error range of approximately 4.9 km on average to the epicenter and 1.0 km to the depth in catalogs with data from 30 network stations by applying the fully convolutional network. The network is trained by 1,013 historic events, and the output is a 3D volume of the event location probability in the Earth. The trained system requires approximately one hundredth of a second to locate an event without the need for any velocity model or human interference.

Purpose Water management affects the bioavailability of cadmium (Cd) and arsenic (As) in the soil and hence their accumulation in rice grains and grain yields. However, Cd and As show opposite responses to soil water content, but information, particularly on irrigation, is missing on a field scale. The purpose of the present study was therefore to find a water management regime that can lower accumulation of both Cd and As in grain without yield loss. Materials and methods Two rice (Oryza sativa L.) cultivars, A16 and A159, with different grain Cd accumulation capacities were employed in field plot experiments with four water management regimes comprising aerobic, intermittent, conventional practice and flooded. The dynamics of Cd and As bioavailability in the soil and Cd and As concentrations in roots, straw and grains were determined at the early tillering, full tillering, panicle initiation, filling and maturity stages of crop growth. Results and discussion The lower water content regimes (aerobic and intermittent) mostly led to higher soil HClextractable Cd than the higher soil water content regimes (conventional and flooded). HCl-extractable As in contrast was favoured by the higher soil water content treatments. Conventional and flooded irrigation accordingly gave higher plant As concentrations but lower Cd compared to aerobic and intermittent irrigation. Cd concentrations in roots and straw of both varieties increased with growth stage, especially in aerobic and intermittent regimes, while As concentrations in plants showed little change or a slight decrease. As the water irrigation volume increased from aerobic to flooded, brown rice Cd decreased from 1.15 to 0.02 mgkg −1 in cultivar A16 and from 1.60 to 0.05 mgkgin cultivar A159, whereas brown rice As increased. Aerobic and flooded treatments produced approximately 10-20 % lower grain yields than intermittent and conventional treatments. Cultivars with low Cd accumulation capacity show higher brown rice grain As than those with high Cd uptake capacity.Conclusions Of the four water management regimes, the conventional irrigation method (flooding maintained until full tillering followed by intermittent irrigation) ensured high yield with low Cd and As in the brown rice and so remains the recommended irrigation regime.