The role of Mo in the natural passivation behavior and pitting corrosion resistance of duplex stainless steels (DSSs) in alkaline medium was investigated by X-ray photoelectron spectroscopy and electrochemical analyse...
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The role of Mo in the natural passivation behavior and pitting corrosion resistance of duplex stainless steels (DSSs) in alkaline medium was investigated by X-ray photoelectron spectroscopy and electrochemical analyses as a function of immersion time. It is shown that the Mo participated directly in the formation process of natural passive film, which affected the chemical distribution and thickness of the film by modifying the contents of other species (e.g. Cr oxide). With the increasing of prepassivation time, the oxidized Cr species were gradually enriched in the passive film, and the corrosion resistance of DSSs in alkaline solution containing Cl- was enhanced. Mo greatly improved the pitting corrosion resistance and the tolerance to Cl- attack of the passive film formed on DSS surface by inhibiting the initiation and growth of pitting.
Developing efficient passivating sorption materials for the treatment of combined pollution by phthalate esters (PAEs) and Cd2+ has become a critical focus in environmental protection and soil remediation. In this stu...
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Understanding functions and co-occurrence patterns of microbial communities in various ecosystems enriches the knowledge on ecosystem characteristics and microbial ecology. However, such analyses have rarely been repo...
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UAV is increasingly popular in the field of military, civil and scientific research, since its low loss, strong adaptability and high mobility. This paper introduces the design and implement of the visual tracking sys...
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ISBN:
(纸本)9781510840232
UAV is increasingly popular in the field of military, civil and scientific research, since its low loss, strong adaptability and high mobility. This paper introduces the design and implement of the visual tracking system based on the rotor UAV, and gives the UAV a function of continuous and stable tracking of the ground target. Based on the standard Mean Shift algorithm, we introduce the improved object tracking algorithm with the spatial histogram and scale estimation. The robustness to scale adaptive and background related interference is improved with the enhanced tracking algorithm. It is finally implemented in our image processing board with TMS320 C6657 and ZYNQ 7020. The whole system is optimized and accelerated by both of the two core of DSP. We finally achieve the real-time tracking and monitoring of the ground target in the range of 100 m ~ 1 km.
Siphonophores (Cnidaria: Hydrozoa) are abundant predators found throughout the ocean and are important constituents of the global zooplankton community. They range in length from a few centimeters to tens of meters. T...
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Siphonophores (Cnidaria: Hydrozoa) are abundant predators found throughout the ocean and are important constituents of the global zooplankton community. They range in length from a few centimeters to tens of meters. They are gelatinous, fragile, and difficult to collect, so many aspects of the biology of these roughly 200 species remain poorly understood. To survey siphonophore genome diversity, we performed Illumina sequencing of 32 species sampled broadly across the phylogeny. Sequencing depth was sufficient to estimate nuclear genome size from k-mer spectra in six specimens, ranging from 0.7 to 2.3 Gb, with heterozygosity estimates between 0.69% and 2.32%. Incremental k-mer counting indicates k-mer peaks can be absent with nearly 20x read coverage, suggesting minimum genome sizes range from 1.4 to 5.6 Gb in the 25 samples without peaks in the k-mer spectra. This work confirms most siphonophore nuclear genomes are large relative to the genomes of other cnidarians, but also identifies several with reduced size that are tractable targets for future siphonophore nuclear genome assembly projects. We also assembled complete mitochondrial genomes for 33 specimens from these new data, indicating a conserved gene order shared among nonsiphonophore hydrozoans, Cystonectae, and some Physonectae, revealing the ancestral mitochondrial gene order of siphonophores. Our results also suggest extensive rearrangement of mitochondrial genomes within other Physonectae and in Calycophorae. Though siphonophores comprise a small fraction of cnidarian species, this survey greatly expands our understanding of cnidarian genome diversity. This study further illustrates both the importance of deep phylogenetic sampling and the utility of k-mer-based genome skimming in understanding the genomic diversity of a clade.
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