An efficient, safe and one-pot convenient catalytic system has been developed for the reduction of alkenes using NaBH 4 -NiCl 2 $6H 2 O in EtOH/PEG-400 under mild conditions. In this catalytic system, a variety of alkenes (including trisubstituted alkene a-pinene) were well reduced and the Ni catalyst could be recycled.Scheme 1 Reduction of alkenes using NaBH 4 -NiCl 2 $6H 2 O in EtOH/ PEG-400 system.

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Grain loss rate is an important indicator to evaluate the performance of combine harvesters. It is indicted that signal voltage amplitude and signal frequency are the key factors for designing a grain loss sensor. In this work, the high-speed photography and signal high-speed acquisition technique were utilized to capture grain collision attitude and the corresponding collision signal characteristics and the effect of grain moisture content and collision angle on signal voltage amplitude and signal frequency was studied in detail, which lays a good foundation for optimizing grain loss signal processing circuit parameters. Then, monitoring resolution of the grain loss sensor was improved by adding constrained damping layer to the sensitive plate under the instruction of experimental modal analysis. At last, a field experiment was carried out; the field experiment results indicate that the monitoring performance improved.

A ruthenium nanocatalyst is utilized for the first time for the highly efficient and selective hydrogenation of 1,5-cyclooctadiene under atmospheric hydrogen pressure. Under the optimized reaction conditions, the conversion of 1,5-cyclooctadiene and the selectivity for cyclooctene are >99% and 95%, respectively. The turnover frequency is 451 h−1, which is higher than that ever reported for Ru complex catalysts.