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Near-infrared (NIR) phosphors play a key role in the preparation of NIR phosphor-converted light-emitting diodes (NIR pc-LEDs) for night vision, sensing and non-destructive detection, but how to search for broadband NIR phosphors still remains a big challenge. In this work, we obtained an abnormal broadband NIR emission in La2CaHfO6:Cr3+ with an ordered structure. It shows an emission maximum of 906 nm and a large full width at half-maximum (FWHM) of 276 nm. An empirical rule for discovering broadband NIR phosphors with double perovskite structures was suggested by considering their structural parameters, which helped to find La2CaSnO6:Cr3+ and LaCa2NbO6:Cr3+ with FWHM values of 280 and 290 nm. This work provides an interesting perspective for developing NIR phosphors with double perovskite structures. [ABSTRACT FROM AUTHOR]

The competition among world powers for the rights and interests regarding Antarctic science and technology frontiers, geopolitics, and resource exploitations tends to be fierce. Therefore, constructing and operating Antarctic aviation infrastructure becomes strategically important for China as it assists in enhancing China’s comprehensive influence in the Antarctica, expanding the scale of Antarctic scientific expedition, and rapidly delivering personnel and materials. This study comprehensively reviews the current status of Antarctic airport construction and investigates the technical challenges faced by China regarding the same issue. We also analyze the engineering technology systems of polar research powers for ice and snow runway construction and summarize the key technologies that China should master for Antarctic airport construction. For future construction of large airport runways in the Antarctica, the core engineering technology system for China should cover three major engineering steps (i.e., runway site selection, pavement material design, and manual treatment of ice and snow pavements) and one core technology (i.e., compacted snow layer construction). Considering the demand for aviation capacities by the innovative development of China’s Antarctic scientific expedition, we propose the following key research directions: natural environmental conditions of airport sites, snow compaction, construction equipment, and design of the airport operation monitoring system.

The presence of exceptionally old ice and relative ease of access make Antarctic blue-ice areas (BIAs) attractive paleoclimate archives. However, only a handful of BIAs, mostly situated in West Antarctica and along the Transantarctic Mountains, have been investigated for this purpose. Here, we present the age of surface ice from the Grove Mountains BIA in Princess Elizabeth Land, East Antarctica, determined by measuring 81 Kr in the trapped air. Two samples yield an average age of 143-29+33 kyr. Together with the reported terrestrial age of a chondrite, we conclude that the Grove Mountains BIA holds considerable potential for paleoclimate studies. [ABSTRACT FROM AUTHOR]

Ice-penetrating radar (IPR) imaging is a valuable tool for observing the internal structure and bottom of ice sheets. Subglacial water bodies, also known as subglacial lakes, generally appear as distinct, bright, flat, and continuous reflections in IPR images. In this study, we use available IPR images from the Gamburtsev Subglacial Mountains to extract one-dimensional reflector waveform features of the ice–bedrock interface. We apply a deep-learning method to reduce the dimension of the reflector features. An unsupervised clustering method is then used to separate different types of reflector features, including a reflector type corresponding to subglacial lakes. The derived clustering labels are then used to detect features of subglacial lakes in IPR images. Using this method, we compare the new detections with a known-lakes inventory. The results indicate that this new method identified additional subglacial lakes that were not previously detected, and some previously known lakes are found to correspond to other reflector clusters. This method can offer automatic detections of subglacial lakes and provide new insight for subglacial studies. [ABSTRACT FROM AUTHOR]

The presence of exceptionally old ice and the relative ease of access make Antarctic blue ice areas (BIAs) attractive paleoclimate archives. However, only a handful of BIAs, mostly situated in West Antarctica and along the Trans-Antarctic Mountains, have been investigated for this purpose. Here, we present the age of surface ice from the Grove Mountains BIA in Elizabeth Princess Land, East Antarctica, determined by measuring 81Kr in the trapped air. Two samples yield an average age of 143+33-29 kyr. Together with the reported terrestrial age of a chondrite, we conclude that Grove Mountains BIA holds considerable potentials for paleoclimate studies. [ABSTRACT FROM AUTHOR]

Radio-echo sounding (RES) is widely used for polar ice sheet detection due to its wide coverage and high efficiency. The multivariate variational mode decomposition (MVMD) algorithm for the processing of RES data is an improvement to the variational mode decomposition (VMD) algorithm. It processes data encompassing multiple channels. Determining the most effective component combination of the penalty parameter (α) and the number of intrinsic mode functions (IMFs) (K) is fundamental and affects the decomposition results. α and K in traditional MVMD are provided by subjective experience. We integrated the particle swarm optimization (PSO) algorithm to iteratively optimize these parameters—specifically, α and K—with high precision. This was then combined with the four quantitative parameters: energy entropy, signal-to-noise ratio (SNR), peak signal-to-noise ratio (PSNR), and root-mean-square error (RMSE). The RES signal decomposition results were judged, and the most effective component combination for noise suppression was selected. We processed the airborne RES data from the East Antarctic ice sheet using the combined PSO–MVMD method. The results confirmed the quality of the proposed method in attenuating the RES signal noise, enhancing the weak signal of the ice base, and improving the SNR. This combined PSO–MVMD method may help to enhance weak signals in deeper parts of ice sheets and may be an effective tool for RES data interpretation. [ABSTRACT FROM AUTHOR]

Pure red mixed halide CsPbBr3−xIx perovskite nanocrystals (NCs) exhibit a high photoluminescence quantum yield (PLQY) and narrow full width at half maximum (FWHM), but there are phase stability issues that hinder their application in displays. In this work, we propose pure red CsPbBr0.96I2.04/SiO2 core/shell NCs by using (3-aminopropyl)triethoxysilane as the surface ligand and silicon source via a hot-injection and in situ hydrolytic process. The CsPbBr0.96I2.04/SiO2 NCs not only show excellent optical properties with a near-unity PLQY but also exhibit high stability against moisture, blue light, and heat. Pure red CsPbBr0.96I2.04/SiO2 NC inks were prepared by dispersing CsPbBr0.96I2.04/SiO2 NCs into a mixed solvent of toluene and dodecane and used to inkjet print NC color conversion films (NC-CCFs) with excellent luminescence uniformity and high stability. Finally, white-emitting Mini-LEDs were fabricated by combining pure red CsPbBr0.96I2.04/SiO2 NC-CCFs with green CsPbBr3/SiO2 NC-CCFs and blue Mini-LED chips, showing a high external quantum efficiency (EQE) of 24.8% and an ultrawide color gamut of 132.58% NTSC and 99.2% Rec. 2020 standards. This demonstrates the potential of pure red CsPbBr0.96I2.04/SiO2 NCs for Mini-LED backlights. [ABSTRACT FROM AUTHOR]

Near‐infrared phosphor‐converted light‐emitting diodes (NIR‐pc‐LEDs) are superior to traditional NIR‐LEDs in spectral modulation, volume, and cost, and their optoelectronic properties are dominantly controlled by the NIR phosphors, which thus boosts the search for high efficiency and broadband NIR phosphors. In this work, we attempt to realize ultra‐broadband NIR phosphors by doping Cr3+ in self‐emitting SrHfO3 with a weak crystal field. Dual emission bands centered at 770 (host) and 1000 nm (Cr3+) are observed, leading to a wide spectral range of 700–1400 nm. The Cr3+ ions enter the HfO6 octahedron and thus produce an NIR emission with a full width at half maximum of 190 nm and an internal quantum efficiency of 24% under 460 nm excitation. A prototype NIR‐pc‐LED surface light is demonstrated for machine vision by using NIR‐pc‐LEDs that combine the blue LED with SrHfO3:Cr. The work paves an avenue for designing super‐broadband NIR phosphors by doping Cr3+ or other ions into hosts with self‐trapped exciton emission (e.g., halide perovskites). [ABSTRACT FROM AUTHOR]