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Two kinds of novel plasmonic high sensitivity of refractive index (RI) sensors based on analyte-filled photonic crystal fiber (AF-PCF) are proposed in this paper. The metallic gold and silver is used as the surface plasmon resonance activity metal. A full-vector finite-element method is applied to analyze and investigate the sensing and coupling characteristics of this designed AF-PCF with the gold or silver layer. Phase matching between the second surface plasmon polariton and fundamental modes can be met at different wavelengths as the analyte of the RI is increased from 1.40 to 1.42. The phase-matching wavelength of the designed AF-PCF with the gold layer is shifted to the longer wavelength direction compared with that with the silver layer, and the resonance strength is much stronger. The average sensitivities of 7040 and 7017 nm/RIU in the sensing are arranged from 1.40 to 1.42 with high linearity are achieved for the designed sensors with the gold and silver layers, respectively, which are almost the same. However, the figure of merit with the silver layer is much better than that with the gold layer.

Mobility is a significant robotic task. It is the most important function when robotics is applied to domains such as autonomous cars, home service robots, and autonomous underwater vehicles. Despite extensive research on this topic, robots still suffer from difficulties when moving in complex environments, especially in practical applications. Therefore, the ability to have enough intelligence while moving is a key issue for the success of robots. Researchers have proposed a variety of methods and algorithms, including navigation and tracking. To help readers swiftly understand the recent advances in methodology and algorithms for robot movement, we present this survey, which provides a detailed review of the existing methods of navigation and tracking. In particular, this survey features a relation-based architecture that enables readers to easily grasp the key points of mobile intelligence. We first outline the key problems in robot systems and point out the relationship among robotics, navigation, and tracking. We then illustrate navigation using different sensors and the fusion methods and detail the state estimation and tracking models for target maneuvering. Finally, we address several issues of deep learning as well as the mobile intelligence of robots as suggested future research topics. The contributions of this survey are threefold. First, we review the literature of navigation according to the applied sensors and fusion method. Second, we detail the models for target maneuvering and the existing tracking based on estimation, such as the Kalman filter and its series developed form, according to their model-construction mechanisms: linear, nonlinear, and non-Gaussian white noise. Third, we illustrate the artificial intelligence approach—especially deep learning methods—and discuss its combination with the estimation method.

White light-emitting diodes (WLEDs) are used in various lighting scenes because of their merits such as low energy consumption, high brightness, long lifetime, portable size, etc. In a recent development, full-spectra WLEDs with uniform spectra and a high color rendering index (CRI) have attracted more attention. The discovery and design of phosphor materials suitable for full-spectra WLEDs is a more recent research hotspot. In this review, the evolution of artificial lighting and the requirements for full-spectra WLED fabrication are outlined. First, the research progress of Ce3+/Eu2+ doped phosphors that can be excited by violet light, including structural models and spectral regulation, is summarized. Second, high-performance multi-color phosphors with high quantum efficiency and luminescence thermal stability are screened for full-spectra WLEDs. Finally, the development prospects and challenges of Ce3+/Eu2+ doped phosphors for full-spectra lighting are demonstrated. This review will not only promote the research of Ce3+/Eu2+ doped phosphors for full-spectra WLEDs but also contribute to a thorough comprehension of full-spectra lighting. It also helps to develop more Ce3+/Eu2+ doped phosphors with better luminescence properties meeting the requirements for full-spectra WLED encapsulation. [ABSTRACT FROM AUTHOR]

This paper investigated the lateral resistant behavior of grid-reinforced steel corrugated shear walls (GR-SCSWs), which are applied to shear walls with large width-to-height ratio. By revealing the resistant mechanism, the stiffness requirement of the subgrid, the wall–frame interaction, and the overall lateral resistance were studied. First, compared with ordinary steel corrugated shear walls, the lateral resistant behavior of GR-SCSWs and the bending moment of the boundary column were analyzed. Second, the threshold stiffness ratio was defined for the subgrid, and design suggestions were proposed to ensure that the infill panel has high and stable in-plane lateral resistance. Finally, the yielding development and shear force distribution in GR-SCSWs were explored, and an improved plate–frame interaction (PFI) model and formulas predicting the lateral resistance curve of GR-SCSWs were established by numerical analysis and theoretical derivations. It was found that, due to the full out-of-plane restraining effect of the subgrid, the GR-SCSW with optimized subpanels can achieve an in-plane shear yielding mechanism. GR-SCSWs can resist lateral loading with an appropriate yield sequence from the infill panel to the subgrid and then to the boundary frame. The modified PFI model proposed fully considered the interaction between the infill grid-reinforced panel and the boundary frame, while the theoretical formulas agreed with the FEA results and can be used to predict the lateral resistant curve and shear force distribution of GR-SCSWs. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) phosphors are enablers for NIR phosphor‐converted light‐emitting diodes (pc‐LEDs). However, fewer NIR‐emitting phosphors with both high internal/external quantum efficiency (IQE/EQE) and thermal stability are discovered, which obstructs the promotion of NIR pc‐LEDs. Herein, by partially replacing Al3+ in K‐β‐Al2O3:2Cr3+ with Ga3+, the photoluminescence (PL) intensity of the solid solution K1+δ(Al0.4Ga0.6)11O17:2Cr3+, (KA0.4G0.6O:Cr) phosphor is increased 2.75 and 1.25 times that of end‐members K1+δAl11O17:2Cr3+ (KAO:Cr) and K1+δGa11O17:2Cr3+ (KGO:Cr). The IQE/EQE of optimal KA0.4G0.6O:Cr reaches 88.9%/50.8% with high thermal stability (77.4%@150 °C). The PL intensity enhancement is due to the Al/Ga‐6O octahedral volume and distortion variation caused by the substitution of Ga3+ for Al3+ in K1+δ(Al1‐y,Gay)11O17:2Cr3+ (KA1‐yGyO:Cr), which leads to the forbidden d–d transition being broken and crystal field strength varied. Finally, a NIR pc‐LED device fabricated based on KA0.4G0.6O:Cr NIR‐emitting phosphor and blue chip reaches an electro‐optical efficiency of 16.3% under a drive current of 100 mA. Meanwhile, non‐destructive detection and plant germination applications of the NIR pc‐LED are demonstrated. These results prove that KA0.4G0.6O:Cr is a promising NIR phosphor for diverse applications. [ABSTRACT FROM AUTHOR]