Ferroelectricity in Epitaxial Perovskite Oxide BiWO Films with One-Unit-Cell Thickness.

Retaining ferroelectricity in ultrathin films or nanostructures is crucial for miniaturizing ferroelectric devices, but it is a challenging task due to intrinsic depolarization and size effects. In this study, we have shown that it is possible to stably maintain in-plane polarization in an extremely thin, one-unit-cell thick epitaxial BiWO film. The use of a perfectly lattice-matched NdGaO (110) substrate for the BiWO film minimizes strain and enhances stability.

Emergence of ferroelectricity in a nonferroelectric monolayer.

Ferroelectricity in ultrathin two-dimensional (2D) materials has attracted broad interest due to potential applications in nonvolatile memory, nanoelectronics and optoelectronics. However, ferroelectricity is barely explored in materials with native centro or mirror symmetry, especially in the 2D limit. Here, we report the first experimental realization of room-temperature ferroelectricity in van der Waals layered GaSe down to monolayer with mirror symmetric structures, which exhibits strong intercorrelated out-of-plane and in-plane electric polarization.

Adaptiveness of RGB-image derived algorithms in the measurement of fractional vegetation coverage.

Background: Fractional vegetation coverage (FVC) is a crucial parameter in determining vegetation structure. Automatic measurement of FVC using digital images captured by mobile smart devices is a potential direction for future research on field survey methods in plant ecology, and this algorithm is crucial for accurate FVC measurement. However, there is a lack of insight into the influence of illumination on the accuracy of FVC measurements.

Local Kondo scattering in 4d-electron RuO nanoclusters on atomically-resolved ultrathin SrRuO films.

Perovskite SrRuO is a unique 4d transition metal oxide with coexisting spin-orbit coupling (SOC) and electron-electron correlation. However, the intrinsic, non-reconstructed surface structure of SrRuO has not been reported so far. Here we report an atomic imaging of the non-reconstructed, SrO-terminated SrRuO surface by scanning tunneling microscopy/spectroscopy.

Defect-Engineered Dzyaloshinskii-Moriya Interaction and Electric-Field-Switchable Topological Spin Texture in SrRuO.

In situ electrical control of the Dzyaloshinskii-Moriya interaction (DMI) is one of the central but challenging goals toward skyrmion-based device applications. An atomic design of defective interfaces in spin-orbit-coupled transition-metal oxides can be an appealing strategy to achieve this goal. In this work, by utilizing the distinct formation energies and diffusion barriers of oxygen vacancies at SrRuO /SrTiO (001), a sharp interface is constructed between oxygen-deficient and stoichiometric SrRuO .

A handheld device for measuring the diameter at breast height of individual trees using laser ranging and deep-learning based image recognition.

Background: Accurate and efficient measurement of the diameter at breast height (DBH) of individual trees is essential for forest inventories, ecological management, and carbon budget estimation. However, traditional diameter tapes are still the most widely used dendrometers in forest surveys, which makes DBH measurement time-consuming and labor-intensive. Automatic and easy-to-use devices for measuring DBH are highly anticipated in forest surveys.

Atomically Resolved Edge States on a Layered Ferroelectric Oxide.

The emerging surface/edge electronic phases driven by broken symmetry effects have attracted great attention in low-dimensional electronic systems. However, experimental proof on their existence in ferroelectric oxides at the atomic scale is still missing. In this work, metallic surface states are observed on layered BiWO by scanning tunneling microscopy/spectroscopy.

Real-Space Imaging of Orbital Selectivity on SrTiO(001) Surface.

Real-space access of the orbital degree of freedom in complex oxides is still challenging due to intricate electronic hybridization. Here, we report a direct observation of reproducible orbital-selective tunneling on a novel SrTiO(001) surface by scanning tunneling microscopy. The electronic structures reversibly switch between two different sets of symmetries depending on the sample bias, which is accompanied by a remarkable change in energy-dependent spectroscopy data.

Habitat differentiation and conservation gap of , , and in China.

The flower buds of , , and are the materials of Xinyi, a traditional Chinese medicine. The harvest of flower buds and habitat fragmentation caused by human disturbance heavily threatens the natural regeneration and survival of these three species. With the aim to support the conservation and improve the effectiveness of conservation, we performed an assessment on habitat suitability, influences of environmental variables on habitat suitability, and the conservation gap of these three species, based on the Maxent modeling method.