Mechanical regulation to interfacial thermal transport in GaN/diamond heterostructures for thermal switch.

Gallium nitride offers an ideal material platform for next-generation high-power electronics devices, which enable a spectrum of applications. The thermal management of the ever-growing power density has become a major bottleneck in the performance, reliability, and lifetime of the devices. GaN/diamond heterostructures are usually adopted to facilitate heat dissipation, given the extraordinary thermal conduction properties of diamonds.

Thermal expansion, lattice vibration, and isotope effect on hydrogen diffusion in BCC Fe, Cr, and W from first-principles calculations.

Fe, Cr, and W are important elements in the alloys of in-reactor materials and operate in high-temperature environments with thermal expansion. Their tritium-impeding abilities are crucial to the radiation safety of various nuclear reactors. In this study, first-principles density functional theory is combined with quasi-harmonic approximation to evaluate factors that can affect the interstitial formation energy and diffusion coefficient of hydrogen isotopes in body-centered cubic (BCC) Fe, Cr, and W, including thermal expansion, metal host lattice vibrations, phonon density-of-states (pDOS) coupling diffusing atoms, and isotope effects.

Reorientation of Hydrogen Bonds Renders Unusual Enhancement in Thermal Transport of Water in Nanoconfined Environments.

Liquid confined in a nanochannel or nanotube has exhibited a superfast transport phenomenon, providing an ideal heat and mass transfer platform to meet the increasingly stringent challenge of thermal management in developing high-power-density nanoelectronics and nanochips. However, understanding the thermal transport of confined liquid is currently lacking and is speculated to be fundamentally different from that of bulk counterparts due to the unprecedented thermodynamics of liquid in nanoconfined environments. Here, we report that the thermal conductivity of water confined in a silica nanotube is nearly 2-fold as that of bulk status.

Self-aligned patterning of tantalum oxide on Cu/SiO through redox-coupled inherently selective atomic layer deposition.

Atomic-scale precision alignment is a bottleneck in the fabrication of next-generation nanoelectronics. In this study, a redox-coupled inherently selective atomic layer deposition (ALD) is introduced to tackle this challenge. The 'reduction-adsorption-oxidation' ALD cycles are designed by adding an in-situ reduction step, effectively inhibiting nucleation on copper.

Aramid Nanofiber/XNBR Nanocomposite with High Mechanical, Thermal, and Electrical Performance.

Aramid nanofibers (ANFs) were successfully produced by deprotonation of Kevlar fiber followed by grafting epichlorohydrin in dimethyl sulfoxide solution. The ANFs were then incorporated into carboxylated acrylonitrile butadiene rubber (XNBR) by means of latex blending, followed by vulcanization. The interaction between ANFs and XNBR, and the effects of ANFs on the mechanical strength, dielectric properties, and thermal stability of ANF/XNBR nanocomposites were investigated.

Origin of Ammonia Selective Oxidation Activity of SmMnO Mullite: A First-Principles-Based Microkinetic Study.

Based on first-principles calculations and microkinetic analysis, the reaction routes and origin of the activity of SmMnO mullite for the selective catalytic oxidation of ammonia (NH-SCO) are systematically investigated on three low-index surfaces under experimentally operating conditions. Key influencing factors and contributions of different iconic intermediate species (NH*, NH*, and HNO*) to the overall reaction process have been identified. In detail, Mn serves as the primary active site for NH adsorption, while lattice oxygen participates in the dehydrogenation of NH on (010) and (001) surfaces.

Fabrication of ZnO dual electron transport layer via atomic layer deposition for highly stable and efficient CsPbBrperovskite nanocrystals light-emitting diodes.

Electron transport layers (ETLs) are important components of high-performance all-inorganic perovskite nanocrystals light-emitting diodes (PNCs-LED). Herein, atomic layer deposition (ALD) of inorganic ZnO layer is combined to the organic 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) to form dual ETLs to enhance both the efficiency and stability of PNCs-LED simultaneously. Optimization of ZnO thickness suggested that 10 cycles ALD yields the best performance of the devices.

Promotional Effect of H Pretreatment on the CO PROX Performance of Pt/CoO: A First-Principles-Based Microkinetic Analysis.

Atomic Pt studded on cobalt oxide is a promising catalyst for CO preferential oxidation (PROX) dependent on its surface treatment. In this work, the CO PROX reaction mechanism on CoO supported single Pt atom is investigated by a comprehensive first-principles based microkinetic analysis. It is found that as synthesized Pt/CoO interface is poisoned by CO in a wide low temperature window, leading to its low reactivity.

Inherently Area-Selective Atomic Layer Deposition of Manganese Oxide through Electronegativity-Induced Adsorption.

Manganese oxide (MnO) shows great potential in the areas of nano-electronics, magnetic devices and so on. Since the characteristics of precise thickness control at the atomic level and self-align lateral patterning, area-selective deposition (ASD) of the MnO films can be used in some key steps of nanomanufacturing. In this work, MnO films are deposited on Pt, Cu and SiO substrates using Mn(EtCp) and HO over a temperature range of 80-215 °C.

Synergetic effect dependence on activated oxygen in the interface of NiO-modified Pt nanoparticles for the CO oxidation from first-principles.

CO oxidation on NiO-modified Pt nanoparticles (NPs) was investigated by first-principles calculations and microkinetic methods. The binding energies of O and CO on NiO/Pt suggest that CO adsorption is dominant and the CO oxidation mainly follows the Mars-van Krevelen (M-vK) mechanism. It was found that the interfacial O of NiO/Pt played a key role in the combination of adsorbed CO to O, as well as the O dissociation.

[Analysis of reduction effect of the evoked nystagmus in the non-affect side during Dix-Hallpike or Roll-test in unilateral posterior semicircular canal benign paroxysmal positional vertigo].

Comparative analysis of the reduction effect of the evoked nystagmus in the non-affect side during Dix-Hallpike（D-H） or Roll-test in unilateral posterior semicircular canal benign paroxysmal positional vertigo（PC-BPPV） and PC-BPPV without above evoked nystagmus. Retrospective analysis of 210 patients diagnosed with unilateral PC-BPPV by G-Force BPPV CRP system was made. Among them, 18 patients exhibited positive nystagmus only when the non-affected side was stimulated by D-H test（Group A）, 30 was evoked only when stimulated by Roll-test（Group B）, 26 was evoked when stimulated by both Roll-test and the non-affected side D-H test（Group C）, 136 without nystagmus in the above positions（Group D）.

Author Correction: Activation of subnanometric Pt on Cu-modified CeO via redox-coupled atomic layer deposition for CO oxidation.

A Correction to this paper has been published: https://doi.org/10.1038/s41467-020-19663-3 .

Activation of subnanometric Pt on Cu-modified CeO via redox-coupled atomic layer deposition for CO oxidation.

Improving the low-temperature activity (below 100 °C) and noble-metal efficiency of automotive exhaust catalysts has been a continuous effort to eliminate cold-start emissions, yet great challenges remain. Here we report a strategy to activate the low-temperature performance of Pt catalysts on Cu-modified CeO supports based on redox-coupled atomic layer deposition. The interfacial reducibility and structure of composite catalysts have been precisely tuned by oxide doping and accurate control of Pt size.

The influence of adjacent Al atoms on the hydrothermal stability of H-SSZ-13: a first-principles study.

The Al concentration and distribution have a great influence on the hydrothermal stability of the H-SSZ-13 zeolites in experiments. In this work, first-principles calculations are performed to clarify the decomposition mechanism of an H-SSZ-13 framework with adjacent Al atom pair distribution under hydrothermal conditions. It is found that the adjacent Al atoms have a tendency to occupy the para-sites of the 4-membered rings (4MRs) in the framework.

Highly Stretchable, Ultrasensitive, and Wearable Strain Sensors Based on Facilely Prepared Reduced Graphene Oxide Woven Fabrics in an Ethanol Flame.

The recent booming development of wearable electronics urgently calls for high-performance flexible strain sensors. To date, it is still a challenge to manufacture flexible strain sensors with superb sensitivity and a large workable strain range simultaneously. Herein, a facile, quick, cost-effective, and scalable strategy is adopted to fabricate novel strain sensors based on reduced graphene oxide woven fabrics (GWF).

Ultrathin CoO-modified hematite with low onset potential for solar water oxidation.

Photoelectrochemical water splitting holds great potential for solar energy conversion and storage with zero greenhouse gas emission. Integration of a suitable co-catalyst with an absorber material enables the realization of highly efficient photocleavage of water. Herein, nanostructured hematite film was coated with an ultrathin and conformal CoO overlayer through atomic layer deposition (ALD).

Titanium Trisulfide Monolayer as a Potential Thermoelectric Material: A First-Principles-Based Boltzmann Transport Study.

Good electronic transport capacity and low lattice thermal conductivity are beneficial for thermoelectric applications. In this study, the potential use as a thermoelectric material for the recently synthesized two-dimensional TiS monolayer is explored by applying first-principles method combined with Boltzmann transport theory. Our work demonstrates that carrier transport in the TiS sheet is orientation-dependent, caused by the difference in charge density distribution at band edges.

A first-principles study of sodium adsorption and diffusion on phosphorene.

The structural, electronic, electrochemical as well as diffusion properties of Na doped phosphorene have been investigated based on first-principles calculations. The strong binding energy between Na and phosphorene indicates that Na could be stabilized on the surface of phosphorene without clustering. By comparing the adsorption of Na atoms on one side and on both sides of phosphorene, it has been found that Na-Na exhibits strong repulsion at the Na-Na distance of less than 4.

Na(+) intercalation pseudocapacitance in graphene-coupled titanium oxide enabling ultra-fast sodium storage and long-term cycling.

Sodium-ion batteries are emerging as a highly promising technology for large-scale energy storage applications. However, it remains a significant challenge to develop an anode with superior long-term cycling stability and high-rate capability. Here we demonstrate that the Na(+) intercalation pseudocapacitance in TiO2/graphene nanocomposites enables high-rate capability and long cycle life in a sodium-ion battery.

Self-assembled 3D hierarchical sheaf-like Nb3O7(OH) nanostructures with enhanced photocatalytic activity.

Novel three-dimensional (3D) hierarchical Nb3O7(OH) nanostructures with a sheaf-like nanoarchitecture were fabricated for the first time by a hydrothermal process. Interestingly, the nanosheafs are composed of nanorods with an average diameter of about 25 nm. The as-prepared 3D hierarchical nanostructures possess a high surface area of 77 m(2) g(-1) with pore diameters of ca.

Co3O4-modified TiO2 nanotube arrays via atomic layer deposition for improved visible-light photoelectrochemical performance.

Composite Co3O4/TiO2 nanotube arrays (NTs) were fabricated via atomic layer deposition (ALD) of Co3O4 thin film onto well-aligned anodized TiO2 NTs. The microscopic morphology, composition, and interfacial plane of the composite structure were characterized by scanning electron microscopy, energy dispersion mapping, X-ray photoelectron spectra, and high-resolution transmission electron microscopy. It was shown that the ultrathin Co3O4 film uniformly coat onto the inner wall of the high aspect ratio (>100:1) TiO2 NTs with film thickness precisely controlled by the number of ALD deposition cycles.

Study of structural, electronic and optical properties of tungsten doped bismuth oxychloride by DFT calculations.

First-principle calculations have been carried out to investigate structural stabilities, electronic structures and optical properties of tungsten doped bismuth oxychloride (BiOCl). The structures of substitutional and interstitial tungsten, and in the form of WO6-ligand-doped BiOCl are examined. The substitutional and interstitial tungsten doping leads to discrete midgap states within the forbidden band gap, which has an adverse effect on the photocatalytic properties.

NO oxidation catalysis on copper doped hexagonal phase LaCoO3: a combined experimental and theoretical study.

Cobalt-based perovskite catalysts showed excellent performance towards NO-NO2 oxidation. We systematically investigated the influence of different levels of Cu-doping on the catalytic performance of hexagonal phase LaCoO3 (LaCo1-xCuxO3 (x = 0.1, 0.

Electrospun sillenite Bi12MO20 (M = Ti, Ge, Si) nanofibers: general synthesis, band structure, and photocatalytic activity.

Sillenite Bi12MO20 (M = Ti, Ge, Si) nanofibers have been fabricated through a facile electrospinning route for photocatalytic applications. Uniform Bi12MO20 (M = Ti, Ge, Si) nanofibers with diameters of 100-200 nm and lengths of up to several millimeters can be readily obtained by thermally treating the electrospun precursors. The photocatalytic activities of these nanofibers for degradation of rhodamine B (RhB) were explored under UV-visible light.