Estimation of plasma parameters in the process of micro-scale powder plastic and characteristics of its products

The temperature and density of plasma jets were estimated with a Boltzmann plot and Stark broadening of Ar I(696.54 nm) lines by optical emission spectroscopy(OES) in the process of plasma plastic, and the morphology and microstructure of tungsten(W) powders were investigated by scanning electron microscope(SEM) and x-ray Diffraction(XRD), respectively.The results show that the assumption of local thermodynamic equilibrium(LTE) was invalid at the end of the plasma jets, and earlier than this after the injection of tungsten powder. The temperature and electron density of the plasma jets were up to about T?=?6797 K with Qc?=?50 slpm and ne?=?1.05?×?1016 cm-3 with Qs?=?115 slpm at Z?=?60 mm, respectively, and both dropped rapidly with the injected tungsten powders of 20 μm. After the plasma plastic process,the spherical tungsten powders were prepared and there were some satellite particles on the surface of the spherical products. The tungsten powders were both composed of a single equilibrium α-W phase with a body centered cubic(bbc) crystal structure before and after plasma treatment.

Antibacterial Effects of Essential Oils from Pomegranate on Two Kinds of Postharvest Pathogenic Fungi

[Objectives]To explore the antibacterial effects of essential oils from pomegranate on two kinds of postharvest pathogenic fungi,and to provide reference for the exploration of new plant-derived preservatives for pomegranate.[Methods]The inhibitory effects of 15 kinds of plant essential oils on 2 kinds of pomegranate postharvest pathogenic fungi were studied.[Results]Tea tree oil and eucalyptus oil have good inhibitory effects on the mycelium growth of Coniella granati and Botrytis cinerea,and the fumigation treatment of pomegranate can inhibit the rot of fruit during storage to a certain extent.[Conclusions]Tea tree oil and eucalyptus oil can effectively inhibit the mycelium growth of two kinds of pathogenic fungi,and can better control the rot of pomegranate during storage.It is necessary to further study the fresh-keeping effect and antibacterial mechanism of plant essential oils on pomegranate.

The Global Landscape of SARS-CoV-2 Genomes, Variants, and Haplotypes in 2019nCoVR

On January 22,2020,China National Center for Bioinformation(CNCB)released the 2019 Novel Coronavirus Resource(2019nCoVR),an open-access information resource for the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).2019nCoVR features a comprehensive integration of sequence and clinical information for all publicly available SARS-CoV-2 isolates,which are manually curated with value-added annotations and quality evaluated by an automated in-house pipeline.Of particular note,2019nCoVR offers systematic analyses to generate a dynamic landscape of SARS-CoV-2 genomic variations at a global scale.It provides all identified variants and their detailed statistics for each virus isolate,and congregates the quality score,functional annotation,and population frequency for each variant.Spatiotemporal change for each variant can be visualized and historical viral haplotype network maps for the course of the outbreak are also generated based on all complete and high-quality genomes available.Moreover,2019nCoVR provides a full collection of SARS-CoV-2 relevant literature on the coronavirus disease 2019(COVID-19),including published papers from PubMed as well as preprints from services such as bioRxiv and medRxiv through Europe PMC.Furthermore,by linking with relevant databases in CNCB,2019nCoVR offers data submission services for raw sequence reads and assembled genomes,and data sharing with NCBI.Collectively,SARS-CoV-2 is updated daily to collect the latest information on genome sequences,variants,haplotypes,and literature for a timely reflection,making 2019nCoVR a valuable resource for the global research community.2019nCoVR is accessible at https://bigd.big.ac.cn/ncov/.