Selective Electro-oxidation of Phenol to 1,4-Hydroquinone Employing Carbonaceous Electrodes: Surface Modification is the Key

The oxidation of phenol leading to 1,4-hydroquinone with high conversion, remarkable selectivity and excellent yields (87% isolated) has been accomplished under electrolytic conditions in an aqueous medium employing carbon-based electrode....

The strategy developed for high conversion and the multiplicity problems of biochemical reaction in a real CSTR with Cholette’s model

In this paper we used the examples for four kinetic schemes under substrate and product inhibition of a biochemical reaction occurring in a real CSTR with Cholette’s model to demonstrate the strategy for high conversion and the multiplicity problem. In addition, it is found that the non-ideal mixing indeed influences the necessary and sufficient conditions for input multiplicity and output multiplicity. Meanwhile, for each of four kinetic schemes under substrate and product inhibition of a biochemical reaction, the input multiplicity regions are found inside the output multiplicity regions. This fact reveals that when deriving an operating strategy to obtain a high conversion and to avoid the control problem, only the output multiplicity is needed to consider even in the CSTR with the input and output multiplicity occurring simultaneously.

Terahertz broadband polarization converter based on the double-split ring resonator metasurface

A terahertz broadband polarization converter based on the metasurface of a double-split ring resonator is proposed. The structural parameters of this device have been optimized in numerical simulations. The results show that in the frequency range from 0.49 to 1.88 THz (bandwidth of 1.39 THz) the proposed device rotates incident linearly polarized waves through 90°. The polarization conversion rate is more than 80%. The coefficient of reflection for cross polarization is greater than 90% with a transmission loss of 1 dB. The surface current distribution of this structure was simulated and analyzed at three frequencies that give high conversion rates of the polarization. The mechanism underlying this high conversion rate is presented, and the dependence of the conversion rate on incident angle and polarization angle is stimulated and analyzed. The results show that the conversion performance of this device is good for incidence angles ranging from 0 to 30° and polarization angles ranging from − 10 to 10°. Compared with previous designs, the polarization converter has a simple structure and a broad operational bandwidth. It has potential applications in the field of terahertz polarization modulation.