A simulation study of polarization characteristics of ultrathin CsPbBr3 nanowires with different cross-section shapes and sizes

The polarization characteristics of ultrathin CsPbBr3nanowires are investigated. Especially, for the height of crosssection of nanowires between 2 nm and 25 nm, the normalized intensity and polarization ratio ρ of CsPbBr3nanowires with triangular, square and hexagonal cross-section shapes are compared. The results show that, along with the increase of the height of cross-section, the polarization ratios of these three nanowires decrease until T = 15 nm, and increase afterwards.Also, along with the increase of the cross-section area up to 100 nm~2, the polarization ratios of these three nanowires increase too. In general, for the same height or area, the polarization ratio ρ of these nanowires follows ρhexagon> ρsquare>ρtriangle. Therefore, the nanowire with the hexagonal cross-section should be chosen, where for a cross-section height of 2 nm and a length-height ratio of 20 : 1, the maximal polarization ratio is 0.951 at the longitudinal center of the NW. Further,for the hexagonal NW with a cross-section height of 10 nm, the hexagonal NW with a length-height ratio of 45 : 1 exhibits the maximal polarization ratio at the longitudinal center of the NW. These simulation results predict the feasible size and shape of CsPbBr3nanowire devices with high polarization ratios.

RNA ac^(4)C modification in cancer biology:from regulatory mechanisms to clinical applications

RNA modifications are increasingly recognized for their significance in diverse physiological and pathological processes,with over 170 types of chemical modifications having been discovered since the1960s.Among these modifications,N4-acetylcytidine(ac^(4)C)is the first acetylated modification identified on eukaryotic RNAs,previously reported in transfer RNA(t RNA)and ribosomal RNA(rRNA)。

High Sensitivity Plasmonic Metal-Dielectric-Metal Device With Two Side-Coupled Fano Cavities

In this paper, we propose a compact plasmonic sensor structure comprised of a metal-dielectric(MDM) waveguide, and a baffle plate in waveguide core and two side-coupled rectangular cavities. In this structure, two Fano resonances are achieved and can be tuned independently by changing the structural parameters of the cavities. Especially, when the resonant wavelengths of the two Fano resonances are the same, the sensing sensitivity can be enhanced by coupling between two Fano resonances. By investigating the transmission spectrum, the effect of structural parameters on Fano resonances and the refractive index sensitivity of the sensor structure are analyzed in detail. The numerical simulations demonstrate a sensitivity as high as 1295nm/RIU and a figure of merit of 1647.

Four-junction AlGaAs/GaAs laser power converter

Four-junction A1GaAs/GaAs laser power converters （LPCs） with n＋-GaAs/p＋-A10.37Ga0.63As hetero- structure tunnel junctions （TJs） have been designed and grown by metal-organic chemical vapor deposition （MOCVD） for converting the power of 808 nm lasers. A maximum conversion efficiency ηc of 56.9% ＋ 4% is obtained for cells with an aperture of 3.14 mm2 at an input laser power of 0.2 W, while dropping to 43.3% at 1.5 W. Measured current-voltage （I-V） characteristics indicate that the performance of the LPC can be further improved by increasing the tunneling current density of TJs and optimizing the thicknesses of sub-cells to achieve current matching in LPC.