Monolayer antimonene is fabricated on PdTe by an epitaxial method. Monolayer antimonene is theoretically predicted to have a large bandgap for nanoelectronic devices. Air-exposure experiments indicate amazing chemical stability, which is great for device fabrication. A method to fabricate high-quality monolayer antimonene with several great properties for novel electronic and optoelectronic applications is provided.

Due to continuous spread of coronavirus disease 2019 (COVID-19) worldwide, long-term effective prevention and control measures should be adopted for public transport facilities, as they are increasing in popularity and serve as the principal modes for travel of many people. The human infection risk could be extremely high due to length of exposure time window, transmission routes and structural characteristics during travel or work. This can result in the rapid spread of the infection. Based on the transmission characteristics of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and the nature of public transport sites, we identified comprehensive countermeasures toward the prevention and control of COVID-19, including the strengthening of personnel management, personal protection, environmental cleaning and disinfection, and health education. Multi-pronged strategies can enhance safety of public transportation. The prevention and control of the disease during the use of public transportation will be particularly important when all countries in the world resume production. The aim of this study is to introduce experience of the prevention and control measures for public transportation in China to promote the global response to COVID-19.

The identification of the active sites in heterogeneous catalysis is important for a mechanistic understanding of the structure–reactivity relationship. Among others, the oxide/metal boundaries are expected to contain the active sites in various catalytic reactions. To reveal their nature and their chemical evolution under reaction conditions, the catalytic role of an oxide/metal system consisting of well-ordered ZnO nanoislands grown on Pt(111) in low-temperature CO oxidation was studied by near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) in operando conditions, and additionally by ultra-high vacuum scanning tunneling microscopy. To illustrate the special role played by the oxide/metal boundaries, a systematic comparative study of ZnO/Pt(111) with the pristine Pt(111) surface was undertaken. The regimes where mass transfer limitation starts to occur were identified using NAP-XPS and mass spectrometry measurements in combination, allowing a sound discussion on the relation between steady-state molar fractions of reactants/product and surface reactivity. Via the measurement of the steady-state CO2 molar fraction, we observed that the CO oxidation reaction rate over the ZnO/Pt(111) system is superior to that over Pt(111) in a temperature range extending to 410 K. The pivotal, albeit unexpected, role of ZnO-bound hydroxyls was clearly highlighted by the observation of the chemical signature of the CO + OH associative reaction at the ZnO/Pt boundaries. The carboxyl formed at low temperature (410 K) can be the intermediate species in the CO oxidation reaction, the OHs at the Pt/ZnO boundary being the cocatalyst, which explains the synergistic effect of ZnO and Pt. However, the species formed at higher temperature (from 445 K) are formates that would essentially be spectators.

Tailing off release in the sustained release of water-insoluble curcumin (Cur) is a significant challenge in the drug delivery system. As a novel solution, core–shell nanodrug containers have aroused many interests due to their potential improvement in drug-sustained release. In this work, a biodegradable polymer, poly­(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and hydrophilic polyvinylpyrrolidone (PVP) were exploited as drug delivery carriers by coaxial electrospinning, and the core–shell drug-loaded fibers exhibited improved sustained release of Cur. A cylindrical morphology and a clear core–shell structure were observed by scanning and transmission electron microscopies. The X-ray diffraction pattern and infrared spectroscopy revealed that Cur existed in amorphous form due to its good compatibility with PHBV and PVP. The in vitro drug release curves confirmed that the core–shell container manipulated Cur in a faster drug release process than that in the traditional PHBV monolithic container. The combination of the material and structure forms a novel nanodrug container with a better sustained release of water-insoluble Cur. This strategy is beneficial for exploiting more functional biomedical materials to improve the drug release behavior.

ZnO nanoporous belts with a smooth surface and high pore density have been successfully synthesized; the simple growth method is applicable to produce high-yield single-crystalline ZnO nanoporous belts with a relatively high purity and at a low cost. The morphology and microstructure and optical properties of ZnO nanoporous belts were analyzed by X-ray diffraction (XRD), Fourier transform infrared system (FTIR), scanning electron microscope (SEM), field-emission transmission electron microscope (FETEM), selective area electron diffraction (SAED), and photoluminescence (PL) spectroscopy. Results reveal that ZnO nanoporous belts possess good crystalline quality. The formation mechanism of the special ZnO microstructure is discussed, emphasizing the effect of polar orientation on the nucleation and growth of ZnO nanoporous belts.

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The ionization/dissociation mechanism of cyclopentanone has been experimentally investigated in molecular beam by irradiating with intense 394 and 788 nm laser fields with pulse duration of 90 fs. The range of laser intensities varied from 3 x 10(13) to 4 x 10(14) W/cm(2). For both wavelengths, the singly charged parent ion is observable while the doubly charged one cannot be found easily, although the fragmentation pattern supports its presence. Meanwhile, the extent of fragmentation at 788 nm is less than that in the 394 nm case. We quantitatively analyze the ionization processes of cyclopentanone in intense femtosecond laser by comparing the calculation results of ionization rate constants obtained from Ammosov-Delone-Krainov, Keldysh, and Keldysh-Faisal-Reiss (KFR) theories based on hydrogenlike atom model. We also compare the experimental and theoretical results; the generalized KFR theory is found to be useful in predicting the ionization yields of singly and doubly charged cyclopentanone ion. To interpret the dissociation patterns of the cyclopentanone ions, we have used the Rice-Ramsperger-Kassel-Marcus theory with the potential surfaces obtained from the ab initio quantum chemical calculations.

The various crop species are major agricultural products and play an indispensable role in sustaining human life. Over a long period, breeders strove to increase crop yield and improve quality through traditional breeding strategies. Today, many breeders have achieved remarkable results using modern molecular technologies. Recently, a new gene-editing system, named the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology, has also succeeded in improving crop quality. It has become the most popular tool for crop improvement due to its versatility. It has accelerated crop breeding progress by virtue of its precision in specific gene editing. This review summarizes the current application of CRISPR/Cas9 technology in crop quality improvement. It includes the modulation in appearance, palatability, nutritional components and other preferred traits of various crops. In addition, the challenge in its future application is also discussed.