Most existing experiments on radiative cooling are conducted in dry climates for better performance. However, many important applications require cooling in hot and humid climates. Here we theoretically analyze the temperature reduction and cooling flux at nighttime with the ambient temperature (Tambient) ranging from 0-40  C and the relative humidity (RH) from 0-100%. Our analysis reveals an interesting crossover: for lower (higher) RH, higher (lower) Tambient results in better cooling. Experimentally, we show that radiative cooling of 5  C below ambient can be achieved even at Tambient = 29  C with RH = 100%.

[Figure: see text].

Thin films of rare-earth (RE)-oxygen-hydrogen compounds prepared by reactive magnetron sputtering show a unique color-neutral photochromic effect at ambient conditions. While their optical properties have been studied extensively, the understanding of the relationship between photochromism, chemical composition, and structure is limited. Here we establish a ternary RE-O-H composition-phase diagram based on chemical composition analysis by a combination of Rutherford backscattering and elastic recoil detection. The photochromic films are identified as oxyhydrides with a wide composition range described by the formula REO H where 0.5 ≤ x ≤ 1.5. We propose an anion-disordered structure model based on the face-centered cubic unit cell where the O and H anions occupy tetrahedral and octahedral interstices. The optical band gap varies continuously with the anion ratio, demonstrating the potential of band gap tuning for reversible optical switching applications.

In this work, we demonstrate, theoretically and experimentally, a hybrid dielectric-plasmonic multifunctional structure able to provide full control of the emission properties of CsPbI3 perovskite nanocrystals (PNCs). The device consists of a hyperbolic metamaterial (HMM) composed of alternating thin metal (Ag) and dielectric (LiF) layers, covered by TiO2 spherical MIE nanoresonators (i.e., the nanoantenna). An optimum HMM leads to a certain Purcell effect, i.e., an increase in the exciton radiative rate, but the emission intensity is reduced due to the presence of metal in the HMM. The incorporation of TiO2 nanoresonators deposited on the top of the HMM is able to counteract such an undesirable intensity reduction by the coupling between the exciton and the MIE modes of the dielectric nanoantenna. More importantly, MIE nanoresonators result in a preferential light emission towards the normal direction to the HMM plane, increasing the collected signal by more than one order of magnitude together with a further increase in the Purcell factor. These results will be useful in quantum information applications involving single emitters based on PNCs together with a high exciton emission rate and intensity.

Atomic-scale control and manipulation of the microstructure of polycrystalline thin films during kinetically limited low-temperature deposition, crucial for a broad range of industrial applications, has been a leading goal of materials science during the past decades. Here, we review the present understanding of film growth processes—nucleation, coalescence, competitive grain growth, and recrystallization—and their role in microstructural evolution as a function of deposition variables including temperature, the presence of reactive species, and the use of low-energy ion irradiation during growth.

Heterogeneous catalytic hydrogenation reactions are of great importance to the petrochemical industry and fine chemical synthesis. Herein, we present the first example of gadolinium hydroxide (Gd(OH)) nanorods as a support for loading ultra-small Pd nanoparticles for hydrogenation reactions. Gd(OH) possesses a large number of hydroxyl groups on the surface, which act as an ideal support for good dispersion of Pd nanoparticles. Gd(OH) nanorods are prepared by hydrothermal treatment, and Pd/Gd(OH) catalyst with a low loading of 0.95 wt% Pd is obtained by photochemical deposition. The catalytic hydrogenation of p-nitrophenol (4-NP) to p-aminophenol (4-AP) and styrene to ethylbenzene is performed as a model reaction. The obtained Pd/Gd(OH) catalyst displays excellent activity as compared to other reported heterogeneous catalysts. The rate constant of 4-NP reduction is measured to be 0.047 s and the Pd/Gd(OH) nanocatalyst shows no marked loss of activity even after 10 consecutive cycles. Additionally, the hydrogenation of styrene to ethylbenzene over Pd/Gd(OH) nanorods exhibits a turnover frequency (TOF) as high as 6159 h with 100% selectivity. Moreover, the catalyst can be recovered by centrifugation and recycled for up to 5 consecutive cycles without obvious loss of activity. Our results indicate that Gd(OH) nanorods act as a promoter to enhance the catalytic activity by providing a synergistic effect from the strong metal support interaction and the large surface area for high dispersion of small sized Pd nanoparticles enriched with hydroxyl groups on the surface. The high performance of Pd/Gd(OH) in heterogeneous catalysis offers a new, efficient and facile strategy to explore other metal hydroxides or oxides as supports for organic transformations.

Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is caused by mutation of the DNAJC5 gene encoding cysteine string protein alpha (CSPα). The disease-causing mutations, which result in substitution of leucine-115 with an arginine (L115R) or deletion of the neighbouring leucine-116 (∆L116) in the cysteine-string domain cause CSPα to form high molecular weight SDS-resistant aggregates, which are also present in post-mortem brain tissue from patients. Formation and stability of these mutant aggregates is linked to palmitoylation of the cysteine-string domain, however the regions of the mutant proteins that drive aggregation have not been determined. The importance of specific residues in the cysteine-string domain was investigated, revealing that a central core of palmitoylated cysteines is essential for aggregation of ANCL CSPα mutants. Interestingly, palmitoylated monomers of ANCL CSPα mutants were shown to be short-lived compared with wild-type CSPα, suggesting that the mutants either have a faster rate of depalmitoylation or that they are consumed in a time-dependent manner into high molecular weight aggregates. These findings provide new insight into the features of CSPα that promote aggregation in the presence of L115R/∆L116 mutations and reveal a change in the lifetime of palmitoylated monomers of the mutant proteins.

Two-dimensional (2D) oxides have a wide variety of applications in electronics and other technologies. However, many oxides are not easy to synthesize as 2D materials through conventional methods. We used nontoxic eutectic gallium-based alloys as a reaction solvent and co-alloyed desired metals into the melt. On the basis of thermodynamic considerations, we predicted the composition of the self-limiting interfacial oxide. We isolated the surface oxide as a 2D layer, either on substrates or in suspension. This enabled us to produce extremely thin subnanometer layers of HfO, AlO, and GdO The liquid metal-based reaction route can be used to create 2D materials that were previously inaccessible with preexisting methods. The work introduces room-temperature liquid metals as a reaction environment for the synthesis of oxide nanomaterials with low dimensionality.Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.