Cu(OAc)_(2)-Mediated Synthesis of Fullerodihydropyridine-3-ones via the Reaction of[60]Fullerene with β-Substituted Ethylamines in the Absence or Presence of Arylacetaldehydes

A series of unreported fullerodihydropyridine-3-ones were synthesized as a new family of fullerene derivatives in moderate to good yields by a simple one-step reaction of[60]fullerene with cheap and readily available β-substituted ethylamines in the absence or presence of arylacetaldehydes under the assistance of Cu(OAc)_(2).The in situ generation of arylacetaldehydes by the C—N bond cleavage of arylethylamines avoided their complex synthesis in advance and realized the preparation of fullerodihydropyridine-3-ones with structural and functional diversities,which may have promising applications in perovskite solar cells to improve the performance of photovoltaic devices due to the existence of a largeπ-conjugated system on the dihydropyridine-3-one ring.

Stabilization mechanisms of lifted flames in a supersonic stepped-wall jet combustor

Flame stabilization is the key to extending scramjets to hypersonic speeds;accordingly,this topic has attracted much attention in theoretical research and engineering design.This study performed large eddy simulations(LESs)of lifted hydrogen jet combustion in a stepped-wall combustor,focusing on the flame stabilization mechanisms,especially for the autoignition effect.An assumed probability density function(PDF)approach was used to close the subgrid chemical reaction source.The reliability of the solver was confirmed by comparing the LES results with experimental data and published simulated results.The hydrogen jet and the incoming stream were first mixed by entraining large-scale vortices in the shear layer,and stable combustion in the near-wall region was achieved downstream of the flame induction region.The autoignition cascade is a transition of fuel-rich flame to stoichiometric ratio flame that plays a role in forming the flame base,which subsequently causes downstream flame stabilization.Three cases with different jet total temperatures are compared,and the results show that the increase in the total temperature reduces the lift-off distance of the flame.In the highest total temperature case,an excessively large scalar dissipation rate inhibits the autoignition cascade,resulting in a fuel-rich low-temperature flame.

Growth Promotion Effects of Bacillus subtilis on Bletilla striata Seedlings

Objective:The objective of the study is to study the growth promotion effects of Bacillus subtilis inoculants on the growth of Bletilla striata seedlings.Methods:Various concentrations(1/10×,1/50×,1/100×,and 1/500×dilutions)of B.subtilis inoculants were applied on the B.striata seedlings.Plant height,base diameter,leaf length,leaf width,relative chlorophyll content,tuber diameter,average fibrous root length,number of fibrous roots,and fresh weight were measured after incubation for 50 days.Results:Treatments with different concentrations of B.subtilis significantly increased the number of fibrous roots of the B.striata seedlings and promoted root elongation,and a higher concentration(1/10×dilution)is associated with more significant promotion effects.B.striata seedlings treated with different concentrations of B.subtilis all showed an increase of relative chlorophyll contents in leaves with the increasing inoculant concentration.Only B.subtilis inoculant at a high concentration(1/10×dilution)significantly promoted the plant height and base diameter of B.striata seedlings.The application of B.subtilis did not significantly promote the tuber diameter and fresh weight of B.striata seedlings.Principal component analysis confirmed the maximum growth promotion by B.subtilis inoculant in 1/10×dilution than the other treatments.Conclusions:The application of B.subtilis can increase the relative chlorophyll content,promote growth and development of roots,and increase plant height and base diameter of B.striata seedlings.Therefore,B.subtilis has significant growth promotion effects on B.striata seedlings.These findings provide theoretical basis for the ecological cultivation of B.striata.