p-type ternary oxides can be extensively explored as alternative sensing channels to binary oxides with diverse structural and compositional versatilities. Seeking a novel approach to magnify their sensitivities toward gas molecules, e.g., volatile organic compounds (VOCs), will definitely expand their applications in the frontier area of healthcare and air-quality monitoring. In this work, delafossite CuCrO (CCO) nanoparticles with different grain sizes have been utilized as p-type ternary oxide sensors. It was found that singly ionized oxygen vacancies (V) defects, compared with the grain size of CCO nanoparticles, play an important role in enhancing the charge exchange at the VOCs molecules/CCO interface. In addition to suppressing the hole concentration of the sensor channel, the unpaired electron trapped in V provides an active site for chemisorptions of environmental oxygen and VOCs molecules. The synergetic effect is responsible for the observed increase of sensitivity. Furthermore, the sensitive (V defect-rich) CCO sensor exhibits good reproducibility and stability under a moderate operation temperature (<325 °C). Our work highlights that V defects, created via either in situ synthesis or postannealing treatment, could be explored to rationally boost the performance of p-type ternary oxide sensors.

Retinal organoids (ROs) derived from human induced pluripotent stem cells (hiPSCs) provide potential opportunities for studying human retinal development and disorders; however, to what extent ROs recapitulate the epigenetic features of human retinal development is unknown. In this study, we systematically profiled chromatin accessibility and transcriptional dynamics over long-term human retinal and RO development. Our results showed that ROs recapitulated the human retinogenesis to a great extent, but divergent chromatin features were also discovered. We further reconstructed the transcriptional regulatory network governing human and RO retinogenesis in vivo. Notably, NFIB and THRA were identified as regulators in human retinal development. The chromatin modifications between developing human and mouse retina were also cross-analyzed. Notably, we revealed an enriched bivalent modification of H3K4me3 and H3K27me3 in human but not in murine retinogenesis, suggesting a more dedicated epigenetic regulation on human genome.

Transparent conducting CuCrO2 thin films were prepared by pulsed laser deposition (PLD) from a nanocrystalline CuCrO2 target. The derived CuCrO2 films were highly c-axis oriented deposited at 800 K. The microstructural, electrical as well as optical properties were studied. It was found that the films were relatively smooth and behaved as semiconductors. The energy band of the CuCrO2 films is constructed based on the Mott–Davis model in order to investigate the conduction mechanism. The transmittances of the films in the visible region are about 60–80% with direct band gaps of about 3.2 eV. The results suggested that CuCrO2 films could be successfully prepared by the PLD method, which can broaden the applications of the transparent conducting oxide films.

It is a technological challenge to recognize landslides from remotely sensed (RS) images automatically and at high speeds, which is fundamentally important for preventing and controlling natural landslide hazards. Many methods have been developed but there remains room for improvement for stable, higher accuracy and high-speed landslide recognition for large areas with complex land cover. In this paper, a novel integrated approach combining a deep convolutional neural network (CNN) and change detection is proposed for landslide recognition from RS images. Logically, it comprises the following four parts. First, a CNN for landslide recognition is built based on training data sets from RS images with historical landslides. Second, the objectoriented change detection CNN (CDCNN) with a fully connected conditional random field (CRF) is implemented based on the trained CNN. Third, the preliminary CDCNN are optimized by the proposed postprocessing methods. Finally, the results are further enhanced by a set of information extraction methods, including trail extraction, source point extraction, and attribute extraction. Furthermore, in the implementation of the proposed approach, image block processing and parallel processing strategies are adopted. As a result, the speed has been improved significantly, which is extremely important for RS images covering large areas. The effectiveness of the proposed approach has been examined using two landslide-prone sites, Lantau Island and Sharp Peak, Hong Kong, with a total area of more than 70 km 2 . Besides its high speed, the proposed approach has an accuracy exceeding 80%, and the experiments demonstrate its high practicability.

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We conducted a series of triaxial creep experiments on shale specimens coming from Tournemire, France, using the stress‐stepping method up to failure, at a confining pressure of 80 MPa, on two orientations (parallel and perpendicular to bedding), and at temperatures of 26 and 75 °C. In these week‐long experiments, stress, strains, and P wave ultrasonic velocities were recorded (quasi‐) continuously. The strength at creep failure of Tournemire shale was ~70% higher than the peak strength measured during constant strain rate (~10−7/s) experiments, and failure was reached at larger strains. An overall transition from P wave velocity increase at moderate differential stress to P wave velocity decrease closer to brittle failure was also observed. At a smaller timescale, P wave velocities initially decreased and then increased gradually during each step of creep deformation. The magnitude of these variations showed important (i) stress, (ii) orientation, and (iii) temperature dependences: larger increase was observed for P wave propagating along the main compressive stress orientation, larger decrease for P wave propagating perpendicular to it, and a changing behavior enhanced at a higher temperature. Scanning electron microscopy performed postmortem revealed evidence of time‐dependent pressure solution, localized compaction, crack growth, and sealing/healing. Our data reveal that shale deformation is highly stress sensitive only in a narrow stress domain where stress corrosion cracking‐induced brittle dilatant creep deformation is dominant. At stresses below, pressure solution compaction creep dominates the deformation and shales compact, consolidate, and heal. This has important implications for the mechanics of shallow fault zones and accretionary prisms.

Recent advances in heterogeneous catalysts indicate that single atoms (SAs), anchored/stabilized on metal oxide nanostructures, exhibit not only high catalyst atom efficiency but also intriguing reactivity and selectivity. Herein, isolated Pt SA-anchored CuCrO2 (CCO) has been designed by a glycine–nitrate solution combustion synthesis (SCS) route. The density of isolated Pt SAs achieves the highest value of ∼100 μm–2 for the 1.39 wt % Pt-anchored CCO sample, which results in the drastically boosted H2S response characteristics, including a high response of 1250 (35 times higher than that of pure CCO) at 10 ppm H2S and a low operating temperature of 100 °C. Except for CH4S, the responses of a 1.39 wt % Pt-anchored CCO chemiresistor to diverse vapors with concentrations of 50–100 ppm are less than 2, exhibiting excellent selectivity. Various ex situ characterizations indicate that the spillover catalytic effect of Pt SA sites, other than the conventional sulfuration–desulfuration mechanism, plays a dominant role in the outstanding H2S response characteristics.

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