Surface methoxy species bound to an extra-framework Al (SMS-EFAL) was unambiguously identified by advanced C-{ Al} double-resonance solid-state NMR technique in the methanol-to-olefins reaction on H-ZSM-5 zeolite. The high reactivity of the SMS-EFAL leads to the formation of surface ethoxy species and ethanol as the key intermediates for ethene generation in the early reaction stage. A direct route for the initial C-C bond formation in ethene was proposed and corroborated by density functional theory calculations.

Trend detection in hydro-climatological time series is a prime task under the context of climate changes. Rainfall is a key component of the water cycle and its variability can profoundly influence agriculture, ecosystems and water resource management. In this paper, an innovative trend analysis (ITA) method with a significant test is used for rainfall trend detection at 14 stations in the Yangtze River Delta (YRD) during 1961 to 2016. The trends are separately evaluated for low (<10th percentile), medium (10th-90th percentile) and high (>90th percentile) rainfall at the annual and seasonal scales. The slope and significance of the rainfall trends derived from the ITA method are compared with those from the classical trend analysis methods Theil-Sen approach and Mann-Kendall test, respectively. The ITA shows significant increasing trends at the 99% confidence level in annual rainfall at all stations. While the same significant increasing trends are identified for summer and winter, decreasing trends dominate in spring and autumn. Contrasting trends are found for extreme rainfall with strong increasing trends in high rainfall in summer and winter and decreasing trends in low rainfall in spring and autumn. The results of the ITA confirmed by the classical trend analysis methods call for more attention to the risk management of flood in extreme seasons and drought in transitional seasons across the YRD region.

[1] We investigated the behavior of the Yellow River plume in the Bohai Sea through a year and its controlling mechanisms using a numerical model driven by monthly averaged wind stress, heat flux, and river discharge. The model produced a clear seasonal behavior of the Yellow River plume. In summer, the Yellow River plume extends northeastward into the central Bohai Sea; in autumn, it turns southward and flows into Laizhou Bay along the coast; in winter, most of the diluted water is found around southeastern corner of Laizhou Bay; and in spring, a low-salinity area appears in southwest Laizhou Bay. With the same model, several well-designed numerical experiments were performed to investigate the effect on the behavior of the Yellow River plume of tidal current, river discharge, wind stress, and thermal stratification. The tidal currents promote the offshore spread of diluted water, while the tide-induced residual currents prevent the plume from extending further downstream (in the direction of Kelvin wave propagation). Wind stresses lead to pronounced changes in the path and shape of the plume. In autumn and winter, northwesterly or northerly winds drive the buoyant water into Laizhou Bay along the coast. In summer, the combination of southeasterly winds and thermal stratification drives the plume extend northeastward into the central Bohai Sea. By changing only the magnitude of wind stress or river discharge in the experiments, we examined the sensitivity of summertime plume to the magnitude of wind stress and river discharge.

The lithium-ion battery (LIB) recycling market is becoming increasingly important because of the widespread use of LIBs in every aspect of our lives. Mobile devices and electric cars represent the largest application areas for LIBs. Vigorous innovation in these sectors is spurring continuous deployment of LIB powered devices, and consequently more and more LIBs will become waste as they approach end of life. Considering the significant economic and environmental impacts, recycling is not only necessary, but also urgent. The WPI group has successfully developed a closed-loop recycling process, and has previously demonstrated it on a relatively small scale 1 kg spent batteries per experiment. Here, we show that the closed-loop recycling process can be successfully scaled up to 30 kg of spent LIBs from electric vehicle recycling streams, and the recovered cathode powder shows similar (or better) performance to equivalent commercial powder when evaluated in both coin cells and single layer pouch cells. All of these results demonstrate the closed-loop recycling process has great adaptability and can be further developed into industrial scale.

The eco-physiological response and adaptation of Populus euphratica Oliv and Tamarix ramosissima Ldb during water release period were investigated. Nine typical areas and forty-five transects were selected along the lower reaches of Tarim River. The groundwater table as well as plant performance and the contents of proline, soluble sugars, and plant endogenous hormone (ABA, CTK) in leaves were monitored and analyzed. The groundwater table was raised in different areas and transects by water release program. The physiological stress to P. euphratica and T. ramosissima had been reduced after water release. Our results suggested that the groundwater table in the studied region remained at −3.15 to −4.12 m, the proline content from 9.28 to 11.06 (mmol/L), the soluble sugar content from 224.71 to 252.16 (mmol/L), the ABA content from 3.59 to 5.01 (ng/g FW), and the CK content from 4.01 to 4.56 (ng/g FW), for the optimum growth and restoration of P. euphratica indicated by the plant performance parameters and the efficiency of water application was the highest. The groundwater table in the studied region remained at −2.16 to −3.38 m, the proline content from 12.15 to 14.17 (mmol/L), the soluble sugar content from 154.71 to 183.16 (mmol/ L), the ABA content from 2.78 to 4.86 (ng/g FW), and the CK content from 3.78 to 4.22 (ng/g FW), for the optimum growth and restoration of T. ramosissima indicated by the plant performance parameters and the efficiency of water application was the highest. The rational groundwater table for the restoration of vegetation in the studied region was at −3.15 to −3.38 m.

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