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Trace doping of multiple elements enables stable battery cycling of LiCoO2 at 4.6 V
LiCoO2 is a dominant cathode material for lithium-ion (Li-ion) batteries due to its high volumetric energy density, which could potentially be further improved by charging to high voltages. However, practical adoption of high-voltage charging is hindered by LiCoO2’s structural instability at the deeply delithiated state and the associated safety concerns. Here, we achieve stable cycling of LiCoO2 at 4.6 V (versus Li/Li+) through trace Ti–Mg–Al co-doping. Using state-of-the-art synchrotron X-ray imaging and spectroscopic techniques, we report the incorporation of Mg and Al into the LiCoO2 lattice, which inhibits the undesired phase transition at voltages above 4.5 V. We also show that, even in trace amounts, Ti segregates significantly at grain boundaries and on the surface, modifying the microstructure of the particles while stabilizing the surface oxygen at high voltages. These dopants contribute through different mechanisms and synergistically promote the cycle stability of LiCoO2 at 4.6 V
Quantifying NDI Capability for Damage Tolerance Analyses
The damage tolerance approach to structural safety is centered on a philosophy of insuring safe operation in the presence of flaws. Accordingly, flaws are assumed to be present at all critical locations and it is demonstrated that these flaws will not grow to a critical size in the usage environment during the next period of operation. This process requires bounds on the sizes of the flaws that may be in the structure and the bounds must be quantified in terms amenable to analysis, i.e., in terms of an equivalent crack length, aNDI. Manufacturing quality control and field inspections are intended to eliminate all flaws but the capability of current inspection systems can only be expressed in probabilistic terms at the small crack sizes of interest. Since no guarantee can be given that all flaws greater than aNDI will be detected and eliminated, there is a failure risk associated with the damage tolerance process
Inference of Allelopathy about Spartina Alterniflora to Scirpus Mariqueter by Effects of Activated Carbon on Soil
AbstractSpartina alterniflora Loisel is an invasive species in Jiuduansha Islands and threatens the survival of native species Scirpus mariqueter. In this study, activated carbon (AC) was applied to study the allelochemicals remained in the soil. Seed germination and seedling growth bioassays were used to test the allelopathic effect, and GC-MS was used to identify the allelochemicals. Our results showed: due to the invasion of S. alterniflora, germination of S. mariqueter seeds and the growth of seedlings were significantly inhibited. When AC was added into S. mariqueter soil, the germination had not been affected while the seedling growth was promoted significantly. When AC was added into the soil of S. alterniflora, both the germination and the seedling growth had an obvious improvement. All indicated that S. alterniflora soil contained allelochemicals which would be absorbed by AC. The identified allelochemicals were hexadecanoic acid, octadecanoic acid, dibutyl phthalate, (adipic acid, isohexyl methyl ester) and (adipic acid, di (oct-4-yl ester))
Neuropilin 1 sequestration by neuropathogenic mutant glycyl-tRNA synthetase is permissive to vascular homeostasis
The mechanism by which dominantly inherited mutations in the housekeeping gene GARS, which
encodes glycyl-tRNA synthetase (GlyRS), mediate selective peripheral nerve toxicity resulting in
Charcot-Marie-Tooth disease type 2D (CMT2D) is still largely unresolved. The transmembrane receptor
protein neuropilin 1 (Nrp1) was recently identifed as an aberrant extracellular binding partner of
mutant GlyRS. Formation of the Nrp1/mutant GlyRS complex antagonises Nrp1 interaction with
one of its main natural ligands, vascular endothelial growth factor-A (VEGF-A), contributing to
neurodegeneration. However, reduced extracellular binding of VEGF-A to Nrp1 is known to disrupt
post-natal blood vessel development and growth. We therefore analysed the vascular system at early
and late symptomatic time points in CMT2D mouse muscles, retina, and sciatic nerve, as well as in
embryonic hindbrain. Mutant tissues show no diference in blood vessel diameter, density/growth, and
branching from embryonic development to three months, spanning the duration over which numerous
sensory and neuromuscular phenotypes manifest. Our fndings indicate that mutant GlyRS-mediated
disruption of Nrp1/VEGF-A signalling is permissive to maturation and maintenance of the vasculature in
CMT2D mice
Sparse Randomized Kaczmarz for Support Recovery of Jointly Sparse Corrupted Multiple Measurement Vectors
While single measurement vector (SMV) models have been widely studied in
signal processing, there is a surging interest in addressing the multiple
measurement vectors (MMV) problem. In the MMV setting, more than one
measurement vector is available and the multiple signals to be recovered share
some commonalities such as a common support. Applications in which MMV is a
naturally occurring phenomenon include online streaming, medical imaging, and
video recovery. This work presents a stochastic iterative algorithm for the
support recovery of jointly sparse corrupted MMV. We present a variant of the
Sparse Randomized Kaczmarz algorithm for corrupted MMV and compare our proposed
method with an existing Kaczmarz type algorithm for MMV problems. We also
showcase the usefulness of our approach in the online (streaming) setting and
provide empirical evidence that suggests the robustness of the proposed method
to the distribution of the corruption and the number of corruptions occurring.Comment: 13 pages, 6 figure
Laser Generation and Detection of Surface Acoustic Waves Using Gas-Coupled Laser Acoustic Detection
Laser generation and detection of ultrasound has the advantage of requiring no mechanical contact with the materials under investigation. We previously reported [1] laser-based measurements on Lamb waves in graphite/polymer composite laminates using a confocal Fabry-Perot interferometer for detection. Related work by other groups includes air-coupled detection of Lamb waves in similar composites using capacitive transducers [2,3] and interferometric detection of Lamb waves in paper [4]. Our earlier work has been extended using Gas-Coupled Laser Acoustic Detection (GCLAD), an economical alternative laser-based method which has the additional advantage that the detection laser beam is not reflected from the sample surface. GCLAD is thus particularly useful for materials with surfaces of poor optical quality. We demonstrate below that the combination of laser generation and GCLAD can be used to obtain well-resolved surface-acoustic waves (SAWs) in a variety of materials, including metals, paper, thin films, and composite pre-preg tape. We also show some preliminary SAW scans obtained with laser generation and GCLAD using metallic samples. Each pixel in the scans represents the strength of a SAW passing through a portion of the sample with an area of about 1 cm2. Scans of this type offer the possibility of economical testing of large sample areas, potentially on-line in a manufacturing environment
End-to-End Joint Antenna Selection Strategy and Distributed Compress and Forward Strategy for Relay Channels
Multi-hop relay channels use multiple relay stages, each with multiple relay
nodes, to facilitate communication between a source and destination.
Previously, distributed space-time codes were proposed to maximize the
achievable diversity-multiplexing tradeoff, however, they fail to achieve all
the points of the optimal diversity-multiplexing tradeoff. In the presence of a
low-rate feedback link from the destination to each relay stage and the source,
this paper proposes an end-to-end antenna selection (EEAS) strategy as an
alternative to distributed space-time codes. The EEAS strategy uses a subset of
antennas of each relay stage for transmission of the source signal to the
destination with amplify and forwarding at each relay stage. The subsets are
chosen such that they maximize the end-to-end mutual information at the
destination. The EEAS strategy achieves the corner points of the optimal
diversity-multiplexing tradeoff (corresponding to maximum diversity gain and
maximum multiplexing gain) and achieves better diversity gain at intermediate
values of multiplexing gain, versus the best known distributed space-time
coding strategies. A distributed compress and forward (CF) strategy is also
proposed to achieve all points of the optimal diversity-multiplexing tradeoff
for a two-hop relay channel with multiple relay nodes.Comment: Accepted for publication in the special issue on cooperative
communication in the Eurasip Journal on Wireless Communication and Networkin
Materials science: Carbon sheet solutions
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62936/1/442254a.pd
Low energy electron irradiation induced deep level defects in 6H-SiC: The implication for the microstructure of the deep levels E1/E 2
The deep level defects in 6H-SiC induced by low energy electron irradiation was investigated. Electron energies of 0.2, 0.3, 0.5 and 1.7 MeV were used to produce the deep level defects in the n-type 6H-SiC materials. The deep level transient spectroscopy (DLTS) technique, combined with isochronal thermal annealing experiments, was used for the study of the defects. It was observed that deep levels ED1, E1/E2 and Ei were created with irradiation energies of 0.3 MeV or greater than that. The deep levels were found to be associated with primary atom displacement on the C atom of SiC sublattice and had microstructure containing the carbon vacancy.published_or_final_versio
Histamine increases neuronal excitability and sensitivity of the lateral vestibular nucleus and promotes motor behaviors via HCN channel coupled to H2 receptor
published_or_final_versio
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