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Chestnut internal rot is the main disease of chestnut during postharvest storage, which causes rot and mildew of chestnut kernel and brings huge economic losses to production. In order to clarify the pathogenic bacteria and its biological characteristics, the strain ZHZF21 was obtained by tissue isolation method. The strain was identified by morphological characteristics and ITS, TUB2 and CAL multi-gene sequence analysis. The pathogenicity of strain ZHZF21 was determined by mycelial inoculation method, and its biological characteristics were studied. The results showed that the colony of strain ZHZF21 was dark green ring concentric circles, with sexual and asexual reproduction stages. This strain was clustered with Colletotrichum fructicola numbered NDSTY31 in GenBank based on multi-gene sequences. Combined with colony morphological characteristics and molecular tree, strain ZHZF21 was preliminarily identified as Colletotrichum fructicola. The brown lesions after inoculation of strain ZHZF21 were consistent with the natural symptoms. The strain ZHZF21 could grow at 5~35 °C, the optimum temperature was 25 °C, the lethal temperature was 45~50 °C, and the optimum pH was 6. Under the condition of full darkness, strain ZHZF21 grew fastest, the utilization rates of arabinose and yeast were the highest, the utilization rate of lactose was the lowest, and urea could hardly be used. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) is a promising material for a wide range of applications, including mechanical nano‐resonators, quantum photonics, and non‐linear photonics. However, its chemical inertness poses challenges for etching in terms of resolution and smoothness. Herein, a novel approach known as helium ion‐bombardment‐enhanced etching (HIBEE) is presented to achieve high‐quality SiC etching. The HIBEE technique utilizes a focused helium ion beam with a typical ion energy of 30 keV to disrupt the crystal lattices of SiC, thus enabling wet etching using hydrofluoric acids and hydrogen peroxide. The etching mechanism is verified via simulations and characterization. The use of a sub‐nanometer beam spot of focused helium ions ensures fabrication resolution, and the resulting etched surface exhibits an extremely low roughness of ≈0.9 nm. One of the advantages of the HIBEE technique is that it does not require resist spin‐coating and development processes, thus enabling the production of nanostructures on irregular SiC surfaces, such as suspended structures and sidewalls. Additionally, the unique interaction volume of helium ions with substrates enables the one‐step fabrication of suspended nanobeam structures directly from bulk substrates. The HIBEE technique is expected to facilitate and accelerate the prototyping of high‐quality SiC devices. [ABSTRACT FROM AUTHOR]

This study proposes a method to fabricate sub-wavelength gratings based on the TM0 mode in a symmetric metal-cladding dielectric waveguide. The TM0 mode is excited by 325 nm laser in a symmetric metal-cladding dielectric structure comprising of a resist sandwiched between two metal film layers. Numerical results show that a sub-wavelength grating with a half-period of 46 nm (approximately λ / 7 ) can be obtained, and its period can be adjusted by changing the resist thickness. The lithography method of symmetric metal-cladding dielectric structure has various advantages over asymmetric ones, including smaller periods of sub-wavelength gratings, higher contrast, and larger exposure depth of resist. In addition, both positive and negative resists can be used to fabricate better sub-wavelength gratings in practical lithography applications. The proposed lithography method provides not only a theoretical reference for the fabrication of rich sub-wavelength gratings but also an approach for the development of near-field imaging and micro–nano lithography. [ABSTRACT FROM AUTHOR]

Manipulating the strain induced poly-domains and phase transition in a correlated oxide material is important for high performance device fabrication. Though the electronic transport in the strained oxide film at macroscopic scales can be directly measured, the anisotropic electronic state and the controllable phase separation cross the insulator-to-metal transition within nanoscale size are still elusive. Here, we selected a VO2 crystal film as prototypical oxide and achieved the manipulation of anisotropy electronic phase separation via injecting a He+ nanobeam into the VO2 film at room temperature. In addition, this nanoscale phase separation was directly visualized by infrared near-field imaging measurements, showing the pronounced and unique cR-axis dependent anisotropy on the VO2 surface. Our results offered insight toward understanding the anisotropic nanoscale phase separation in strained metal oxide films. [ABSTRACT FROM AUTHOR]