ABSTRACT
Complex amplitude modulation metasurfaces (CAMM) that can independently control both amplitude and phase have fostered a broad research interest worldwide due to its more robust wave manipulation capability than metasurfaces that can only adjust phase. Although many CAMM structures have been reported, they still suffer from limitations such as low transmittance, complicated structure, polarization dependence, high cost, and difficulty in fabrication. This work proposes a high-transmission polarization-independent CAMM operating in an ultra-wide millimeter-wave frequency range from 30 to 50 GHz realized by cost-effective and easily implementable manners. Three CAMMs are designed to generate complicated millimeter-wave beams like holographic imaging beam, Airy beam, and vortex knot beam. The presented simulation and experimental results clearly demonstrate the effectiveness of the CAMMs. This work presents a new paradigm for CAMM that can be readily extended to other frequency bands. It may also advance further applications of millimeter-wave beams in communication, imaging and detection.
ABSTRACT
This paper presents a study of the synthesis of a polymer monolith column and its application to the analysis of PAHs in smoked meat products. A poly(butyl methacrylate-co-ethylene glycol dimethacrylate) monolith capillary has been successfully prepared with in situ polymerization method. The polymer monolith microextraction combined with HPLC determinations is employed for the analysis of naphthalene, biphenyl, phenanthrene, and anthracene. Various parameters affecting the extraction efficiency have been investigated and optimized. Under the optimum experimental conditions, the method provides an acceptable linearity (2-10,000 µg/L), low limits of detection (1.4-2.0 µg/L), and good precision (intraday relative standard deviations<4.1%, interday relative standard deviations<5.7%). When applied to the determination of the four PAHs in smoked meat samples, recoveries are obtained in the range of 86.6-101.5%.
