High-speed fuel solenoid valves (HFSVs) are the key control elements of aero-engine vane regulators. A strong electromagnetic force generated from the HFSVs is essential to achieve precise control over timing and quantification for fuel supply. In this paper, the Taguchi method is adopted to improve the HFSV’s static electromagnetic characteristics. First, an electromagnetic model of the HFSV was established and experiments were conducted to modify and validate the model. Effects of key structural factors on the static electromagnetic characteristics of the HFSV are then investigated via the finite element method (FEM). Based on the optimization, an HFSV prototype is finally manufactured and tested. The experiment results are in good agreement with those of the simulations. It provides a significant guideline for the manufacturing process of such HFSVs.

This paper deals with the effects of manufacturing imperfections on the circulating current characteristics of an ironless brushless dc (BLDC) motor through a two-dimensional finite-element method (2-D FEM). The circulating current caused by the manufacturing imperfections of the windings’ spatial location and the permanent magnets’ magnetization is analyzed. It is found that the former has a larger impact on the circulating current, and the parallel magnetization is smaller than radial magnetization. Then, the effect of the circulating current generated from the impedance unbalance in the parallel branches on winding losses and disturbance torque is further studied. The results show that the circulating current leads to large winding losses and different torque characteristics. The torque ripple becomes small when the circulating current exists in all the phase windings and the outer radius of the parallel branches has the same spatial location. Finally, the ironless BLDC motor is manufactured and tested. The experimental results are in good agreement with the 2-D FEM. It gives a significant guideline to the manufacturing process of such ironless BLDC motors.

Poly(phenylene ethynylene)s (P1) with 4-vinylaniline pendant groups were successfully prepared by the Sonogashira coupling polymerization between 1,4-diethynyl-2,5-bis(pentyloxy)benzene and 4-[2-(2,5-dibromophenyl)vinyl]-aniline. In comparison with its analogue P2 without amino group, the emission of P1 is only enhanced by aggregation when adding n-hexane into its THF solution, exhibiting an aggregation-induced emission enhancement (AIEE) effect. When methanol or water instead of hexane was added into THF solution, P1, however, didn’t show AIEE. The results indicated that amino groups strengthen the inter-chain and intra-chain interactions in P1 and restrict the non-radiative energy transition. This strategy can provide a platform for developing highly sensitive and efficient bio- and chemosensors.