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Efficient and reversible absorption of SO 2 in six new deep eutectic solvents (DESs) composed of levulinic acid (LA) and quaternary ammonium salts (choline chloride, CC; choline acetyl chloride, CAC; tetraethylammonium chloride, TEAC; tetraethylammonium bromide, TEAB; tetrabutylammonium chloride, TBAC; tetrabutylammonium bromide, TBAB) was systematically investigated. The molar ratio of LA to quaternary ammonium salt was fixed at 3 : 1. The results showed that all DESs possessed satisfactory performance for SO 2 absorption, with the maximum absorption capacity of 0.625 g SO 2 per g DES of LA-TEAC at 293.15 K under ambient pressure. The absorbed SO 2 was easily released by bubbling N 2 at 323.15 K and the regenerated DES was recycled five times without obvious loss of absorption performance. The solubility of SO 2 in DES of LA-CC at T = 293. 15, 303.15, 313.15, and 323.15 K under subatmospheric pressures was also determined. The relative thermodynamic parameters, i.e., absorption enthalpy, absorption entropy, and absorption Gibbs free energy, were further calculated, giving results with small negative values. The influence of water content on the SO 2 absorption was also investigated. According to NMR and FTIR analyses, the absorption of SO 2 in DES was a physical process. Moreover, all the DESs exhibited high selectivity for SO 2 /CO 2 . The present DESs are promising absorbents for SO 2 because of their high absorption capacity and good reversibility.

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Reprocessable acrylate vitrimer needs to enhance its strength to expand the application in photo-three-dimensional (photo-3D) printing. However, the methods for improving mechanical properties by the addition of nanofillers or a multifunctional resin into acrylate vitrimers are inappropriate for photo-3D printing due to the low curing speed of photopolymerization induced by weakening light transmittance or reduction of dimensional accuracy caused by large shrinkage. At present, we demonstrate a new strategy for developing a kind of mechanically robust and reprocessable 3D printing thermosets by combining hydrogen bonds and exchangeable β-hydroxyl esters into acrylate vitrimers. To realize this purpose, diacrylate prepolymer containing β-hydroxyl esters was first synthesized from glycidyl methacrylate and suberic acid. Then, the resin formulations for 3D printing comprising the synthesized diacrylate prepolymer together with acrylamide generate exchanged β-hydroxyl ester and pendent amide in cross-linked networks. Here, hydrogen bonds resulting from the amide group as sacrificial bonds dissipate vast mechanical energy under an external load. With the inclusion of 20 wt % acrylamide, the average tensile strength and Young’s modulus are up to 40.1 and 871 MPa, which increased by about 4.4 and 3.85 times, respectively. The network rearrangement of cross-linked vitrimers can be achieved through the dynamic ester exchange reactions with gradual disappearance of hydrogen bonds at elevated temperatures, imparting reprocessability into the printed structures. Various photo-3D printing or UV irradiation shapes were successfully produced, and these dissolved in ethylene glycol could be remolded again.

A B S T R A C TInfluenza viruses with multiple subtypes have highly virulent in humans, of which influenza hemagglutinin (HA) is the major viral surface antigen. Simultaneous and automated detection of multiple influenza HA are of great importance for early-stage diagnosis and operator protection. Herein, a magnetism and size mediated microfluidic platform was developed for point-of-care detection of multiple influenza HA. With multiplex microvalves and computer program control, the detection process showed high automation which had a great potential for avoiding the high-risk virus exposure to the operator. Taking advantage of magnetism and size mediated multiple physical fields, multiple influenza HA could be simultaneous separation and detection depended on different-size magnetic beads. Using high-luminance quantum dots as reporter, this assay achieved high sensitivity with a detection limit of 3.4 ng/mL for H7N9 HA and 4.5 ng/mL for H9N2 HA, and showed excellent specificity, anti-interference ability and good reproducibility. These results indicate that this method may propose new avenues for early detection of multiple influenza subtypes.

This study presents a novel phase current reconstruction strategy for switched reluctance machines (SRMs) using two cross-winding current sensors. The phase currents are reconstructed by solving the linear equations associated with two adjacent phase currents in the different turn-on regions. The effect of current sensor offset and power transistor fault on the proposed reconstruction method is analysed. On the basis of the current difference at the rising edge of each drive signal, an offset sensor identification method is presented and two online compensation schemes are adopted. For power transistor short-circuit fault, the logic-judgment-based and freewheeling-time-based diagnostic methods are investigated and a virtual current sensor is introduced to ensure the effectiveness of the reconstruction process. The proposed phase current reconstruction strategy is free from power transistor open-circuit fault. In addition, the current reconstruction method is easily extended to SRMs with higher number of phases without additional current sensors. Simulations and experiments validate the effectiveness and flexibility of the proposed reconstruction strategy.

Solubilities of CO 2 in five biobased solvents (BBSs) were measured at temperatures ranging from 283.15 K to 323.15 K with 10 K intervals under a pressure of 0 kPa to 600.0 kPa using an isochoric saturation method. The BBSs include dibutyl succinate (DBS), gamma-valerolactone (GVL), furfuryl alcohol (FA), ethyl levulinate (EL), and butyl levulinate (BL). Henry's constant and thermodynamic properties (dissolution Gibbs free energy, dissolution enthalpy, and dissolution entropy) were derived from the solubility data. The obtained results demonstrated that the solubilities of CO 2 in BBSs followed the sequence of BL ≈ EL ≈ GVL ≈ DBS > FA. The enthalpies of solution were negative at all conditions. The solubilities of CO 2 in BBSs were further compared with those in ionic liquids (ILs) and ordinary absorbents, indicating that BBSs demonstrated similar absorption capacity with the commercial absorbent of polyethylene glycol dimethyl ether (NHD) except for FA.

Winding insulation degradation may lead to phase‐to‐phase fault in switched reluctance machines (SRMs). First, the fault modes are described considering the connected sequence of the coils and the fault behaviours are analysed in details. Second, the equivalent circuit of three‐phase windings is represented and the faulty SRM is modelled based on the derived electromechanical equations. Third, the locations of three current sensors are optimised to calculate the incoming line current and outgoing line current of each phase without utilisation of any extra hardware. The phase‐to‐phase fault can be detected and located by monitoring the residuals between the two line currents during motor operation. Forth, to improve the post‐fault operation performance of the motor, a triple closed‐loop control scheme aiming at suppressing the short‐circuit current is conducted by modifying the switching states of power transistors. Finally, simulations and comparative experiments on a three‐phase 12/8 structure SRM validate the effectiveness of the proposed methods.