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The infrared (IR) remote sensing system comprised of a fluorescence-based thermal detector and image processing algorithm is proposed in this article. Instead of column readout architectures for integrated circuits for microbolometers, the fluorescent IR detector governed by IR-to-visible conversion can generate the thermal image directly, which can be easily processed by the back-end visible image sensor. Such architecture allows separate modulation of thermal conversion and signal processing. To improve the detectivity of the system, image processing algorithms are proposed to achieve robust quasi-real-time (QRT) human detection. Adjustable thresholds and edge enhance operators are combined to extract human candidate regions, which are compatible with commercial FPGA. The experimental results indicate that the noise intensity in the subtracted thermal image has been reduced by 98% compared to the nonlocal means method or bilateral method. A 5.8-fold improvement in terms of signal-to-noise ratio (SNR) is exhibited in long-wavelength human radiation. The detectivity of the proposed detector was improved from $5.06\times 10^{6}$ to $4.33\times 10^{8}$ cm $\cdot $ Hz $^{1/2}$ /W after being equipped with optimized image conditioning circuit. A QRT image processing verification platform was successfully established in Xilinx FPGA, providing a 16-bit $1360\times 1024$ resolution grayscale video stream output at 37 fps. Our work demonstrates the capability of the IR detection system in human activity detection, indicating its potential in human action recognition applications.

The contamination of chlorophenols in water has been considered as an urgent environmental issue. In this study, two polar photocatalysts with a similar structure, K3B6O10Br (KBB) and K3B6O10Cl (KBC) were synthesized through a high temperature solid phase method and applied for the effective mineralization and removal of the chlorophenols. More than 92.0% of 2-chlorophenols can be fully degraded within 16 min under UV light irradiation, which is six times faster than the commercial P25 TiO2catalyst. The out-of-center distortions capability of the XK6octahedrons is greatly influenced by X (X = Cl and Br) atoms. The magnitude of the out-of-center distortion of KBC and KBB were 0.137 and 0.027, respectively. A better photocatalytic activity performance was therefore observed for KBC due to its higher spontaneous polarization ability and facile charge separation process. Kelvin probe force microscopy (KPFM) experiments further proved KBC has a larger surface potential change before and after the light irradiation. Reactive species capture experiments confirmed the role of radicals in the order of O2−> e−> h+> OH.