Tunable System for Electrochemical Reduction of Ketones and Phthalimides

Herein,we report an efficient,tunable system for electrochemical reduction of ketones and phthalimides at room temperature without the need for stoichiometric external reductants.By utilizing NaN_(3) as the electrolyte and graphite felt as both the cathode and the anode,we were able to selectively reduce the carbonyl groups of the substrates to alcohols,pinacols,or methylene groups by judiciously choosing the solvent and an acidic additive.The reaction conditions were compatible with a diverse array of functional groups,and phthalimides could undergo one-pot reductive cyclization to afford products with indolizidine scaffolds.Mechanistic studies showed that the reactions involved electron,proton,and hydrogen atom transfers.Importantly,an N_(3)/HN_(3) cycle operated as a hydrogen atom shuttle,which was critical for reduction of the carbonyl groups to methylene groups.

Performance and safety of transport vehicles fueled with alternative fuels in plateau environment:A review

Alternative fuels including natural gas,alcohols and biodiesel for transport vehicles have been applied worldwidely.However,the performance and safety of alternative fuel vehicles have changed when the application environment varies from plain condition to the plateau,resulting from the variation of air density and atmospheric pressure.Natural gasfueled vehicles exhibited lower output and greater fuel consumption than gasoline-fueled vehicles in plateau environment.The oxygenated additives including alcohols and biodiesel can supply extra oxygen into the cylinder,which may benefit the engine performances compared with traditional petroleum in plateau environments.However,compared with plain environment,vehicles fueled with oxygenated fuels worsen the engine thermal efficiency,the power performance and the fuel economy in the plateau.With the increase of altitude,HC and CO emissions increase;whereas NO_(x)emissions show no evident change at various altitudes.Intake boosting,spark or injection timing optimization,and intake manifold optimization can effectively improve the combustion and performance of vehicles in the plateau.Safety is another significant factor for application of alternative fuels.Compared with plain environment,safeties of vehicles fueled with natural gas or biodiesel in the plateau have not been reduced,whereas safety of methanol and ethanol vehicles decrease,because they are easier to form air fuel mixture,have lower flash points,and have higher possibilities of gas resistance.The study proves that the performance and safety and alternative fuel vehicles deteriorate when the application locale varies from the plain region to the plateau region.

Cost-Based Research on Energy Management Strategy of Electric Vehicles Using Hybird Energy Storage System

This paper uses the minimization and weighted sum of battery capacity loss and energy consumption under driving cycles as objective functions to improve the economy of Electric Vehicles(EVs)with an hybrid energy storage system composed of power batteries and ultracapacitors.Furthermore,Dynamic Programming(DP)is employed to determine the objective function values under different weight coefficients,the comprehensive cost consisting of battery aging and power consumption costs,and the relationship between the hybrid power distribution.We also evaluate the real-time fuzzy Energy Management Strategy(EMS),fuzzy control strategies,and a strategy based on DP using the World Light vehicle Test Procedure(WLTP)driving cycle and a synthesis driving cycle derived from New European Driving Cycle(NEDC),WLTP,and Urban Dynamometer Driving Schedule(UDDS)as examples.Then,the proposed strategy is compared with the fuzzy control strategy and the strategy based on DP.Compared with fuzzy energy management strategy(namely FZY-EMS),the proposed EMS reduces the battery capacity loss and system energy consumption.The results demonstrate the effectiveness of the proposed EMS in improving EV economy.