RESUMO
White-light scanning interferometry is a mature non-contact three-dimensional shape detection method. However, the batwing effect is an inherent problem that causes systematic error. In this paper, we proposed an algorithm for detecting and eliminating the batwing effect based on the Haar wavelet transforms without any prior knowledge of the sample surface. It is verified by simulation and experiment that the proposed algorithm can effectively eliminate the batwing effect and does not increase the time complexity significantly.
RESUMO
Recently, phase retrieval techniques have garnered significant attention with their exceptional flexibility. However, their application is limited in optical systems with high numerical aperture due to the disregarded polarization properties of the beam. In this paper, a fast wavefront sensing method for tightly focused systems is proposed. Firstly, a vector diffraction model based on the chirp-Z transform is established to analytically describe the focal spot using the modal coefficients of polynomials and diffraction basis vectors, which accommodating any pixel size and resolution, thereby enabling to break through sampling constraints and remove lateral errors. Additionally, a modified Newton-gradient second-order algorithm is introduced to simultaneously optimize wavefront in multiple polarization directions, without the need for diffraction operators during iterations. Both numerical simulations and error analysis confirm the efficacy and precision of the proposed wavefront sensing method.
RESUMO
The panoramic annular lens (PAL) system can capture plentiful scene information in real time. The locally described freeform surface can provide more degrees of freedom for the optical system design than the globally described one. In this paper, we propose a locally described annular Gaussian radial basis function freeform surface that enables a high-performance yet compact PAL system. The designed PAL system achieves an ultra-wide field of view (FOV) of (30∘â¼125∘)×360∘. The F-theta distortion of the system is less than 3%, and the modulation transfer function across the whole FOV is greater than 0.5 at 100 lp/mm. The proposed system can be implemented for various applications such as video conferencing or robotic navigation.
RESUMO
Stony corals (Scleractinia) are invertebrates that form symbiotic relationships with eukaryotic algal endosymbionts and the prokaryotic microbiome. The microbiome has the potential to produce bioactive natural products providing defense and resilience to the coral host against pathogenic microorganisms, but this potential has not been extensively explored. Bacterial pathogens can pose a significant threat to corals, with some species implicated in primary and opportunistic infections of various corals. In response, probiotics have been proposed as a potential strategy to protect corals in the face of increased incidence of disease outbreaks. In this study, we screened bacterial isolates from healthy and diseased corals for antibacterial activity. The bioactive extracts were analyzed using untargeted metabolomics. Herein, an UpSet plot and hierarchical clustering analyses were performed to identify isolates with the largest number of unique metabolites. These isolates also displayed different antibacterial activities. Through application of in silico and experimental approaches coupled with genome analysis, we dereplicated natural products from these coral-derived bacteria from Florida's coral reef environments. The metabolomics approach highlighted in this study serves as a useful resource to select probiotic candidates and enables insights into natural product-mediated chemical ecology in holobiont symbiosis.