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A double-stranded RNA virus termed Curvularia thermal tolerance virus was identified in fungus Curvularia protuberata, conferring thermal tolerance to the host fungus and tropical panic grass, while no other mycoviruses have characterized in this fungal genus. Here, a mitovirus, tentatively named Curvularia pseudobrachyspora mitovirus 1 (CpMV1), was detected by high-throughput sequencing (HTS) approach in Curvularia pseudobrachyspora isolated from a pear leaf, and its full genome was determined by Sanger sequencing of the RT-PCR amplification products of the assembled contigs and the terminal regions determined by rapid amplification of cDNA ends. CpMV1 is 2497 nucleotides (nt) in length excluding the poly (A) tail and contains an open reading frame (ORF), which encodes an RNA-dependent RNA polymerase (RdRp) with 724 amino acids when the fungal mitochondrial genetic code is used. A BLASTp search revealed that CpMV1 RdRp shares high amino acid sequence identities (33.84–75.94%) with those of other mitoviruses. Phylogenetic analysis based on RdRps indicated that CpMV1 is a new member under Unuamitovirus of the family Mitoviridae, with the closest relationship with Plasmopara viticola lesion associated mitovirus 6 and Alternaria brassicicola mitovirus. To our knowledge, this is the first report of a mitovirus infecting Curvularia fungi.

In this study, a novel positive-sense single-stranded RNA (+ssRNA) mycovirus, tentatively named Colletotrichum fructicola RNA virus 1 (CfRV1), was identified in the phytopathogenic fungus Colletotrichum fructicola. CfRV1 has seven genomic components, encoding seven proteins from open reading frames (ORFs) flanked by highly conserved untranslated regions (UTRs). Proteins encoded by ORFs 1, 2, 3, 5, and 6 are more similar to the putative RNA-dependent RNA polymerase (RdRp), hypothetical protein (P2), methyltransferase, and two hypothetical proteins of Hadaka virus 1 (HadV1), a capsidless 10- or 11-segmented +ssRNA virus, while proteins encoded by ORFs 4 and 7 showed no detectable similarity to any known proteins. Notably, proteins encoded by ORFs 1 to 3 also share considerably high similarity with the corresponding proteins of polymycoviruses. Phylogenetic analysis conducted based on the amino acid sequence of CfRV1 RdRp and related viruses placed CfRV1 and HadV1 together in the same clade, close to polymycoviruses and astroviruses. CfRV1-infected C. fructicola strains demonstrate a moderately attenuated growth rate and virulence compared to uninfected isolates. CfRV1 is capsidless and potentially encapsulated in vesicles inside fungal cells, as revealed by transmission electron microscopy. CfRV1 and HadV1 are +ssRNA mycoviruses closely related to polymycoviruses and astroviruses, represent a new linkage between +ssRNA viruses and the intermediate double-stranded RNA (dsRNA) polymycoviruses, and expand our understanding of virus diversity, taxonomy, evolution, and biological traits. IMPORTANCE A scenario proposing that dsRNA viruses evolved from +ssRNA viruses is still considered controversial due to intergroup knowledge gaps in virus diversity. Recently, polymycoviruses and hadakaviruses were found as intermediate dsRNA and +ssRNA stages, respectively, between +ssRNA and dsRNA viruses. Here, we identified a novel +ssRNA mycovirus, Colletotrichum fructicola RNA virus 1 (CfRV1), isolated from Colletotrichum fructicola in China. CfRV1 is phylogenetically related to the 10- or 11-segmented Hadaka virus 1 (HadV1) but consists of only seven genomic segments encoding two novel proteins. CfRV1 is naked and may be encapsulated in vesicles inside fungal cells, representing a potential novel lifestyle for multisegmented RNA viruses. CfRV1 and HadV1 are intermediate +ssRNA mycoviruses in the linkage between +ssRNA viruses and the intermediate dsRNA polymycoviruses and expand our understanding of virus diversity, taxonomy, and evolution.

Odor pollution caused by toxic chemicals with low human olfactory thresholds, such as hydrogen sulfide (H

Odor pollution caused by toxic chemicals with low human olfactory thresholds, such as hydrogen sulfide (H2S), has become a major cause of environmental grievance world-wide. Although the low-temperature (

Iron-based catalysts were developed to achieve the hydrodechlorination (HDC)/oxidation of polychlorinated biphenyls (PCBs) from thermal desorption off-gas, and Fe3O4/γ-Al2O3 showed higher dechlorination efficiency than Fe2O3/γ-Al2O3. The optimal Fe loading resulted in 95.5% degradation efficiency and 76.9% toxicity reduction of gaseous PCBs, and the optimal Fe3O4/γ-Al2O3 exhibited excellent stability during a 60-h test. The gas chromatography–mass spectrometry analysis of intermediate products indicated the presence of two competitive degradation pathways, namely, hydrodechlorination and oxidation with Fe3O4/γ-Al2O3 as catalyst. During the first stage (reductive dechlorination), the reductive activity of iron-based catalysts was effectively enhanced in the presence of water, which was confirmed by density functional theory (DFT) calculations. The removal of chlorine atoms was found in the order of meta > para > ortho. During the second stage (oxidation), hydroxyl and superoxide anion radicals were found to attack PCBs on the surface of Fe3O4/γ-Al2O3. This study provides an insight into the HDC and oxidation mechanism of gaseous PCBs over iron-based catalysts.

DFIG-based series-compensated can increase the capacity of wind power transmission, but it can also cause the sub-synchronous resonance (SSR) problem. There are some SSR analysis methods will be explained, including complex torque analysis method, eigenvalue analysis method and impedance analysis method. Impedance analysis is used to determine the stability of the system by establishing a small signal frequency domain impedance model of power electronic devices, utilizing the Nyquist criterion or generalized Nyquist criterion. Previous studies have not considered the effect of the grid-side converter (GSC) side current on the sub-synchronous resonance characteristics of the system. In this paper, the influence of GSC side current and GSC control parameters on the damping characteristics of the system sub-synchronous resonance is analyzed in detail. The results show that the GSC side current has a positive damping effect on the stator torque. Considering the GSC side current, the phase margin between the stator torque and the rotational speed is changed from 359° to 229°, and the effect on the SSR is changed from negative to positive damping. The positive damping effect will increase with larger controller gain or lower connection inductance.

In this work, heat assisted magnetic recording (HAMR) is simulated to assess the areal density advantages of various realistic thermal profiles. Specifically, finite element simulation and micromagnetic modeling are used to assess the areal density consequences of a straighter thermal profile with an associated wider track. This assessment is done by simulating the thermal profiles created by heads with gapped near field optical transducers (NFTs) and split magnetic poles. By varying the gap width of the NFT and the thickness of the medium interlayer, the above variation in transition straightness and associated written transition is achieved. At specific operating points, we find that a wider track with a straighter transition results in a slightly higher recording density (1.2Tb/in2 vs 0.9 Tb/in2). As expected, the former case finds its optimum at higher linear bit densities (1370 kFCI) and lower track densities (850 kTPI) than the latter case (870 kFCI and 1000 kTPI).In this work, heat assisted magnetic recording (HAMR) is simulated to assess the areal density advantages of various realistic thermal profiles. Specifically, finite element simulation and micromagnetic modeling are used to assess the areal density consequences of a straighter thermal profile with an associated wider track. This assessment is done by simulating the thermal profiles created by heads with gapped near field optical transducers (NFTs) and split magnetic poles. By varying the gap width of the NFT and the thickness of the medium interlayer, the above variation in transition straightness and associated written transition is achieved. At specific operating points, we find that a wider track with a straighter transition results in a slightly higher recording density (1.2Tb/in2 vs 0.9 Tb/in2). As expected, the former case finds its optimum at higher linear bit densities (1370 kFCI) and lower track densities (850 kTPI) than the latter case (870 kFCI and 1000 kTPI).