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Chiral quantum optics has attracted considerable interest in the field of quantum information science. Exploiting the spin-polarization properties of quantum emitters and engineering rational photonic nanostructures has made it possible to transform information from spin to path encoding. Here, compact chiral photonic circuits with deterministic circularly polarized chiral routing and beamsplitting are demonstrated using two laterally adjacent waveguides coupled with quantum dots. Chiral routing arises from the electromagnetic field chirality in waveguide, and beamsplitting is obtained via the evanescent field coupling. The spin- and position-dependent directional spontaneous emission are achieved by spatially selective micro-photoluminescence measurements, with a chiral contrast of up to 0.84 in the chiral photonic circuits. This makes a significant advancement for broadening the application scenarios of chiral quantum optics and developing scalable quantum photonic networks., Comment: 19 pages, 5 figures

Permanent magnet vernier machines (PMVM) are drawing extensive attention due to its low-speed high-torque output. In this paper, four different PMVM topologies with different permanent magnet configuration are presented, while keeping the stator slot and winding configuration unchanged. The operating principle of the machine, magnet field modulation principle, is discussed by analytic method and their electromagnetic performance is calculated by finite element method (FEM). Comparison results are used to confirm and validate the advantages and disadvantages of the four topologies. Besides, the influence of several structure parameters on performance is analyzed.

Eleven coal samples of different metamorphism are studied with regard to their pore structures. Both low-pressure nitrogen gas adsorption (LP-N2GA) and scanning electron microscopy (SEM) were performed. The use of these techniques allows us to gain clearer insight into the nature of the pore structure including the pore volume, specific area, pore size distribution (PSD) and pore shape. The LP-N2GA isotherms demonstrate strong differences in gas adsorption capacity between the coal samples studied, consistent with variability in specific surface area (SSA) of the samples. Pore geometry of coals with different metamorphism varies a lot, indicative of heterogeneity on coal surface, which was verified with SEM observation. Adsorption analysis revealed that mesopore size distributions are multi-modal, whereas, the micropore structure of the samples tested appears to be unimodal, with a major peak between 1.6 and 2.0 nm. The influence of coal rank on pore structure was also analyzed. The U-shape relationship between mesopore SSA and Vdaf is observed, demonstrating that the number of mesopores within the lower rank coals (Vdaf > 15%) decreases with increasing coal rank and the coalification mainly affects the mesopore structure. For the higher rank coals with Vdaf < 15%, as the coalification effect increases, the mesopore size diminishes and the number of micropores ascends. Smaller mesopores and micropores gradually become the dominant roles. This phenomenon is due to the effect of intensive compaction within the coal bulk. The combination of LP-N2GA and SEM techniques gives a better understanding of pore characteristics in coal. The research results will provide guidance for the gas control in coal mines.

The bioreactor of immobilized cells was made with a strain of bacterium named D14 with high capability of denitrifying and phosphorus accumulation used as the main bacteria and activated carbon used as the adsorption carrier. After practical wastewater with 38.5mg/L total nitrogen, 5.99mg/L total phosphorus, 315.9mg/L CODCr and 112.7 mg/L BOD5 was treated for sixty minutes using the bioreactor, nitrogen removal rate was 60.80% , phosphorus removal rate was 85.97%, the removal rates of CODCr and BOD5 were 69.58% and 74.59% respectively. The various indexes of discharged water were up to the National Country Wastewater Treatment Factory Wastes Emission Standard II.