In a practical multichannel magnetocardiography (MCG) system based on superconducting quantum interference device (SQUID) magnetometers, the Tesla/Volt coefficient must be precisely calibrated for accurate analysis of heart diseases. In this article, we utilize the biplanar coil to calibrate the SQUID magnetometers in an MCG system for the first time. The coil design theory is discussed in detail, including the target-field theory and the Tikhonov regularization method. Also, the coil winding patterns can be obtained after discretization of the stream function, which is related to the current density. By defining the parameter of calibration uncertainty, the performance of the biplanar coil is analyzed and compared with a rectangular Helmholtz coil based on the COMSOL simulation method and experimental measurement. The measurement results are well in coincidence with the simulation ones, indicating that the biplanar coil has remarkable advantages over the Helmholtz coil. Also, Tesla/Volt coefficient calibrations of four SQUID magnetometers in an MCG system are conducted inside a magnetically shielded room (MSR) depending on these two coils. The final results show the superiority of the biplanar coil method in MCG system calibration.

In this article, a modified design method is proposed for a kind of highly uniform magnetic field (UMF) coil, whose target region is off-center defined. Combining the traditional target field method (TFM) with the slime mold algorithm (SMA), a new intelligent algorithm with excellent searching ability, optimal parameters can be obtained to determine the structure of the designed coil. To further improve the uniformity performance in the target region, a distance factor is introduced to optimize the distribution of target points. According to the simulation results from the finite element analysis (FEA), the absolute maximum uniformity error can be optimized from 0.098% to 0.060% if the SMA is utilized, and after the optimization of target points, the volume proportion of absolute uniformity error less than $10^{-4}$ can be increased to 64.60%. An upscaled coil of 10 times is fabricated via the flexible printed circuit technology, and test results of the magnetic field generated by this coil show a good agreement with the simulation ones. It indicates that the actual uniformity error in the range of ±0.35 R reaches to 0.11%, which is acceptable when taking manufacture and measurement errors into consideration.

Considering the requirements of the actual production scheduling process, the utilization of the genetic programming hyper-heuristic (GPHH) approach to automatically design dispatching rules (DRs) has recently emerged as a popular optimization approach. However, the decision objects and decision environments for routing and sequencing decisions are different in the dynamic flexible job shop scheduling problem (DFJSSP), leading to different required feature information. Traditional algorithms that allow these two types of scheduling decisions to share one common feature set are not conducive to the further optimization of the evolved DRs, but instead introduce redundant and unnecessary search attempts for algorithm optimization. To address this, some related studies have focused on customizing the feature sets for both routing and sequencing decisions through feature selection when solving single-objective problems. While being effective in reducing the search space, the selected feature sets also diminish the diversity of the obtained DRs, ultimately impacting the optimization performance. Consequently, this paper proposes an improved GPHH with dual feature weight sets for the multi-objective energy-efficient DFJSSP, which includes two novel feature weight measures and one novel hybrid population adjustment strategy. Instead of selecting suitable features, the proposed algorithm assigns appropriate weights to the features based on their multi-objective contribution, which could provide directional guidance to the GPHH while ensuring the search space. Experimental results demonstrate that, compared to existing studies, the proposed algorithm can significantly enhance the optimization performance and interpretability of energy-efficient DRs.

Magnetically shielded cylinder (MSC) is an efficient way to construct a proper working environment for spin-exchange relaxation-free (SERF) magnetometers. In this paper, we propose a modified hybrid method combining analytical solutions with finite element analysis (FEA) to improve the design efficiency and validity of an MSC. Focusing on the radial and axial shielding factors, the number of Permalloy-shell can be fast determined as 4 via analytical solutions. Then based on a carefully built FEA model in COMSOL, shielding factors together with uniformity factors extracted from magnetic distribution maps, are employed to optimize the distance of air gaps and the size and shape of access holes. The shielding performance is well tested after the realization of MSC with optimal structural parameters. It shows that the static residual field can reach as low as 0.50 nT and 1.39 nT in radial and axial directions, and the field uniformity are superior to 5% in most of the target region. The measurement results are well in coincidence with the simulation ones, indicating the validity of this hybrid design method.

Dielectric-metal nanostructures have lately emerged as one of the most promising approaches to modulating light at the optical frequency. Their remarkable electric and magnetic resonances give them a one-of-a-kind ability to augment local field enhancements with negligible absorption losses. Here, we propose a hybrid metal-dielectric-metal (MDM) nanoantenna that contains a dimer of three-layers of shell nanoparticles. In addition, we only theoretically and numerically show the optical properties of the hybrid dimer nanoantenna. We found that the nanoantenna sustained unidirectional forward scattering with narrow beamwidth (30.9 deg) and strong scattering intensity (up to 5 times larger than the single MDM particle). Furthermore, when the hybrid asymmetric dimer was excited by the plane wave with different electric polarization directions, our findings revealed that the hybrid nanoantenna boosted the gap’s electric near-field while also supporting unidirectional forward scattering. Finally, we analyzed the hybrid dimer with substrates of different materials. It supported strong electric high-order moments along the z-axis and x-axis in gaps between MDM nanoparticles and between MDM nanoparticles and the Ge substrate, owing to the intense displacement currents inside of the dielectric layer. We found that the local electric field of this MDM hybrid dimer nanoantenna with Ge substrate was well improved and attained 3325 v/m.