[en] Nanoparticles supporting a distinct series of Mie resonances have enabled a new class of nanoantennas and provide efficient ways to manipulate light at the nanoscale. The ability to flexibly tune the optical resonances and scattering directionality are particularly essential for various applications ranging from biosensing to nanolasers. In this paper, we investigate the core-shell nanoparticles that support both electric and magnetic Mie resonances and for the first time systematically reveal the mode evolution from a pure high-index dielectric nanosphere to its plasmonic counterpart. Abrupt mode transition and hybridization of Mie resonances are found in Ag-dielectric core-shell spheres when core-shell ratio increases from 0.4 to 0.5. Furthermore, by engineering the electric and magnetic resonances, we demonstrate the unidirectional forward and backward scattering in such a system and reveal its tunability via geometric tuning. (paper)

[en] Femtosecond laser pulses used in micro-drilling, which allows precise and thermal-damage-free removal of material, has progressed remarkably in recent years to become an essential tool for microhole drilling. Helical drilling is the most common method for processing high-precision microholes. Compared to multi-pulse drilling or circular scanning drilling, it is more convenient to process the requested radius and needed depth hole. The mechanism of interaction between the ultra-fast laser and materials is very complex. Exploring the influence of processing parameters on the drilling process not only helps to guide the actual processing, but also helps our understanding of the mechanism. In this study, laser processing parameters for drilling microholes in three materials are investigated. The influence of processing parameters on hole drilling is analysed, and the relationship between the overlapping rate influence on drilling depth and ablation threshold is explored. (paper)

[en] Highlights: • Hierarchically porous boron-doped carbon material (B-HPC) were successfully constructed. • It exhibits high specific surface area and enhanced surface hydrophilicity/wettability. • B-HPC possesses high specific capacitance (379.9 F/g) and excellent cycling stability. • SSCs reach up to 1.8 V potential window and achieve excellent energy density in neutral electrolyte. -- Abstract: Heteroatoms doped nano-porous carbon materials possess well-designed porosity and also exhibit extremely advantages over high-performance electrodes for supercapacitors (SCs). Herein, we fabricate hierarchically porous boron-doped carbon material (B-HPC) with high specific surface area by a facile synthesis strategy using boric acid as B doping agent, NaCl as retrievable template and ZnCl₂ as activation agent. The B doping significantly enhance surface hydrophilicity/wettability and improve capacitance thereby via efficient electrolyte ion penetration and interactions with the surface of carbon electrode. As a result, B-HPC exhibits high specific capacitance (379.9 F/g at 1 A/g) and excellent cycling performance (96.3% capacitance retention over 10 000 cycles). Furthermore, the symmetric SC based on B-HPC can reach up to a high voltage window (1.8 V) and achieve excellent energy density of 25.9 Wh/kg at 447.2 W/kg using 1 M Na₂SO₄ as electrolyte. B-HPC electrode is demonstrated to possess excellent capacitive behaviors and supposed as a promising material for application in SCs and other energy storage systems.