3 research outputs found
Presentation1.PDF
<p>A new wheat viral disease was found in China. Bullet-shaped viral particles within the nucleus of the infected wheat leave cells, which possessed 180–210 nm length and 35–40 nm width, were observed under transmission electron microscopy. A putative wheat-infecting rhabdovirus vectored by the leafhopper Psammotettix alienus was identified and tentatively named wheat yellow striate virus (WYSV). The full-length nucleotide sequence of WYSV was determined using transcriptome sequencing and RACE analysis of both wheat samples and leafhoppers P. alienus. The negative-sense RNA genome of WYSV contains 14,486 nucleotides (nt) and seven open reading frames (ORFs) encode deduced proteins in the order N-P-P3-M-P6-G-L on the antisense strand. In addition, WYSV genome has a 76-nt 3′ leader RNA and a 258-nt 5′ trailer, and the ORFs are separated by conserved intergenic sequences. The entire genome sequence shares 58.1 and 57.7% nucleotide sequence identity with two strains of rice yellow stunt virus (RYSV-A and RYSV-B) genomes, respectively. The highest amino acid sequence identity was 63.8% between the L proteins of the WYSV and RYSV-B, but the lowest was 29.5% between the P6 proteins of these viruses. Phylogenetic analysis firmly established WYSV as a new member of the genus Nucleorhabdovirus. Collectively, this study provided evidence that WYSV is likely the first nucleorhabdovirus described infecting wheat via leafhopper P. alienus transmission.</p
Nitrogen-Doped Hollow Carbon Nanospheres for High-Performance Li-Ion Batteries
N-doped
carbon materials is of particular attraction for anodes of lithium-ion
batteries (LIBs) because of their high surface areas, superior electrical
conductivity, and excellent mechanical strength, which can store energy
by adsorption/desorption of Li<sup>+</sup> at the interfaces between
the electrolyte and electrode. By directly carbonization of zeolitic
imidazolate framework-8 nanospheres synthesized by an emulsion-based
interfacial reaction, we obtained N-doped hollow carbon nanospheres
with tunable shell thickness (20 nm to solid sphere) and different
N dopant concentrations (3.9 to 21.7 at %). The optimized anode material
possessed a shell thickness of 20 nm and contained 16.6 at % N dopants
that were predominately pyridinic and pyrrolic. The anode delivered
a specific capacity of 2053 mA h g<sup>–1</sup> at 100 mA g<sup>–1</sup> and 879 mA h g<sup>–1</sup> at 5 A g<sup>–1</sup> for 1000 cycles, implying a superior cycling stability. The improved
electrochemical performance can be ascribed to (1) the Li<sup>+</sup> adsorption dominated energy storage mechanism prevents the volume
change of the electrode materials, (2) the hollow nanostructure assembled
by the nanometer-sized primary particles prevents the agglomeration
of the nanoparticles and favors for Li<sup>+</sup> diffusion, (3)
the optimized N dopant concentration and configuration facilitate
the adsorption of Li<sup>+</sup>; and (4) the graphitic carbon nanostructure
ensures a good electrical conductivity
Atom-Thick Interlayer Made of CVD-Grown Graphene Film on Separator for Advanced Lithium–Sulfur Batteries
Lithium–sulfur
batteries are widely seen as a promising next-generation energy-storage
system owing to their ultrahigh energy density. Although extensive
research efforts have tackled poor cycling performance and self-discharge,
battery stability has been improved at the expense of energy density.
We have developed an interlayer consisting of two-layer chemical vapor
deposition (CVD)-grown graphene supported by a conventional polypropylene
(PP) separator. Unlike interlayers made of discrete nano-/microstructures
that increase the thickness and weight of the separator, the CVD-graphene
is an intact film with an area of 5 × 60 cm<sup>2</sup> and has
a thickness of ∼0.6 nm and areal density of ∼0.15 μg
cm<sup>–2</sup>, which are negligible to those of the PP separator.
The CVD-graphene on PP separator is the thinnest and lightest interlayer
to date and is able to suppress the shuttling of polysulfides and
enhance the utilization of sulfur, leading to concurrently improved
specific capacity, rate capability, and cycle stability and suppressed
self-discharge when assembled with cathodes consisting of different
sulfur/carbon composites and electrolytes either with or without LiNO<sub>3</sub> additive