Functional electrodes for batteries share a common design rule by which high electronic and ionic conductivity pathways must exist throughout the electrode in its pristine state. Notable amounts of ...conductive carbon additive in the composite electrode are usually included to form an electronically conductive matrix. However, excellent high rate cycling performance has been achieved in electrodes composed of the insulating Li4Ti5O12 without any conductive additives. This behavior opens the possibility of a new paradigm for designing functional electrodes by which high electronic conductivity in the pristine electrode is not required. The mechanism of operation that enables such unexpected electrochemical behavior is evaluated and discussed. Electronically conductive pathways due to the reduction of Ti4+ to Ti3+ form and percolate throughout the Li4Ti5O12 electrode in the early stage of Li insertion, eliminating the need for conductive additives. This work highlights the importance of the mass and charge transport properties of the intermediate states during cycling and of good interparticle ohmic contact in the electrode. This physical behavior can lead to novel system designs with improved battery utilization and energy density.
Li‐ion battery electrodes based on Li4Ti5O12, an electronic insulator, can be successfully cycled without any conducting additives, even at high rates. The mechanisms of phase propagation and origin of such good performance are investigated. The importance of interparticle contact and the transport properties of the intermediate states during cycling are highlighted.
Interfacial side-reactions at a LiNi0.5Mn1.5O4 spinel electrode in LiPF6/organic carbonate-based electrolyte were investigated using FTIR and fluorescence spectroscopy. In situ measurements at a ...carbon- and binder-free LiNi0.5Mn1.5O4 electrode showed formation of fluorescent species that coincides with the oxidation of NiII+ in LiNi0.5Mn1.5O4. The majority of these electrolyte oxidation products diffuse away into the electrolyte but fluorescence images of cycled LiNi0.5Mn1.5O4 composite electrodes also show fluorescent residues at the surface of the electrode. FTIR and Raman spectra of the surface layer indicate formation of metal-ion doped organic and inorganic compounds upon electrolyte oxidation at potentials above 4.2V.
•Electrolyte oxidation products diffuse away or accumulate at the electrode.•Metal-ion doped fluorescence compounds form at potentials above 4.2V.•Formation of fluorescent species coincides with the oxidation of Ni2+ in LNMO.•Chemical cross-talk in Li-ion cells affects the electrochemical performance.
We report the synthesis of colloidal Mn(2+)-doped ZnO (Mn(2+):ZnO) quantum dots and the preparation of room-temperature ferromagnetic nanocrystalline thin films. Mn(2+):ZnO nanocrystals were prepared ...by a hydrolysis and condensation reaction in DMSO under atmospheric conditions. Synthesis was monitored by electronic absorption and electron paramagnetic resonance (EPR) spectroscopies. Zn(OAc)(2) was found to strongly inhibit oxidation of Mn(2+) by O(2), allowing the synthesis of Mn(2+):ZnO to be performed aerobically. Mn(2+) ions were removed from the surfaces of as-prepared nanocrystals using dodecylamine to yield high-quality internally doped Mn(2+):ZnO colloids of nearly spherical shape and uniform diameter (6.1 +/- 0.7 nm). Simulations of the highly resolved X- and Q-band nanocrystal EPR spectra, combined with quantitative analysis of magnetic susceptibilities, confirmed that the manganese is substitutionally incorporated into the ZnO nanocrystals as Mn(2+) with very homogeneous speciation, differing from bulk Mn(2+):ZnO only in the magnitude of D-strain. Robust ferromagnetism was observed in spin-coated thin films of the nanocrystals, with 300 K saturation moments as large as 1.35 micro(B)/Mn(2+) and T(C) > 350 K. A distinct ferromagnetic resonance signal was observed in the EPR spectra of the ferromagnetic films. The occurrence of ferromagnetism in Mn(2+):ZnO and its dependence on synthetic variables are discussed in the context of these and previous theoretical and experimental results.
A search for supersymmetry in all-hadronic events with missing transverse momentum is presented. The data were collected in proton-proton collisions at a center-of- mass energy of 13 TeV with the CMS ...detector at the LHC and correspond to an integrated luminosity of 2.3 fb-1. Search regions are defined using the properties of reconstructed jets, the presence of b quark and t quark candidates, and missing transverse momentum. No statistically significant excess of events above the expected contribution from standard model processes is observed. Exclusion limits are set on the masses of potential new particles in the context of simplified models of direct and gluino-mediated top squark production.
This study was designed to characterize the release of available P from different ratios of mono-ammonium phosphate:struvite (MAP:struvite) in soils as affected by the season in which it was applied, ...representing field conditions. A 63-day soil incubation evaluated release of soil test P (STP) as Olsen P from MAP:struvite ratios (0:0, 100:0, 75:25, 50:50, 37.5:62.5, 25:75, 12.5:87.5, 0:100) as temperature decreased (26 to 15 °C) and increased (12.4 to 22.6 °C) to mimic fall and spring temperatures, respectively. All treatments decreased in STP concentration from the beginning to end of both fall and spring incubations. The amount of decrease in STP during the incubation period was greater for the fall incubation compared to the spring incubation. After 63 days of the fall incubation, treatments 100:0 and 0:100 decreased the most from 22.9 to 12.1 mg STP kg
−1
and 21.2 to 7.7 mg STP kg
−1
, respectively. After 63 days in the spring incubation, 100:0 and 0:100 decreased from 20.2 to 11.8 mg STP kg
−1
and 18.1 to 14.0 mg STP kg
−1
. Overall results suggest that soil STP decreased in the range of 12 to 26 °C for soils fertilized with MAP:struvite mixtures, regardless of season.
Background
The health‐related quality of life (HRQOL) of tonsillar carcinoma survivors was explored to investigate any HRQOL differences associated with tumor stage and treatment. The survivors' ...HRQOL was also compared to reference scores from the population.
Methods
In this exploratory cross‐sectional study patients were invited 15 months after their diagnosis and asked to answer two quality of life questionnaires (EORTC QLQ‐ C30, EORTC QLQ‐ HN35), 405 participated.
Results
HRQOL was associated with gender, with males scoring better than females on a few scales. Patients' HRQOL was more associated with treatment than tumor stage. Patients' HRQOL was worse than that in an age‐ and sex‐matched reference group from the normal population, the largest differences were found for problems with dry mouth followed by problems with sticky saliva, senses, swallowing and appetite loss.
Conclusions
The tonsillar carcinoma patients had a worse HRQOL compared to the general population one year after treatment.
The structural properties of anion deficient ceria, CeO
2−
δ
, have been studied as a function of oxygen partial pressure,
p(O
2), over the range 0≥log
10
p(O
2)≥−18.9 at 1273(2)
K using the neutron ...powder diffraction technique. Rietveld refinement of the diffraction data collected on decreasing
p(O
2) showed increases in the cubic lattice parameter,
a, the oxygen nonstoichiometry,
δ, and the isotropic thermal vibration parameters,
u
Ce and
u
O, starting at log
10
p(O
2)~−11. The increases are continuous, but show a distinct kink at log
10
p(O
2)~−14.5. Analysis of the total scattering (Bragg plus diffuse components) using reverse Monte Carlo (RMC) modelling indicates that the O
2− vacancies preferentially align as pairs in the
〈
111
〉
cubic directions as the degree of nonstoichiometry increases. This behaviour is discussed with reference to the chemical crystallography of the CeO
2–Ce
2O
3 system at ambient temperature and, in particular, to the nature of the long-range ordering of O
2− vacancies within the crystal structure of Ce
7O
12.
Partial radial distribution function for oxygen vacancies within CeO
1.710 at 1273
K (solid line) showing the increased tendency for local ordering in
〈
111
〉
directions compared to a random distribution (dashed line).
Abstract
The high accuracy of detector simulation is crucial for modern particle physics experiments. However, this accuracy comes with a high computational cost, which will be exacerbated by the ...large datasets and complex detector upgrades associated with next-generation facilities such as the High Luminosity LHC. We explore the viability of regression-based machine learning (ML) approaches using convolutional neural networks (CNNs) to “denoise” faster, lower-quality detector simulations, augmenting them to produce a higher-quality final result with a reduced computational burden. The denoising CNN works in concert with classical detector simulation software rather than replacing it entirely, increasing its reliability compared to other ML approaches to simulation. We obtain promising results from a prototype based on photon showers in the CMS electromagnetic calorimeter. Future directions are also discussed.
Inhibitors of VEGF signaling can block angiogenesis and reduce tumor vascularity, but little is known about the reversibility of these changes after treatment ends. In the present study, regrowth of ...blood vessels in spontaneous RIP-Tag2 tumors and implanted Lewis lung carcinomas in mice was assessed after inhibition of VEGF receptor signaling by AG-013736 or AG-028262 for 7 days. Both agents caused loss of 50%-60% of tumor vasculature. Empty sleeves of basement membrane were left behind. Pericytes also survived but had less alpha-SMA immunoreactivity. One day after drug withdrawal, endothelial sprouts grew into empty sleeves of basement membrane. Vessel patency and connection to the bloodstream followed close behind. By 7 days, tumors were fully revascularized, and the pericyte phenotype returned to baseline. Importantly, the regrown vasculature regressed as much during a second treatment as it did in the first. Inhibition of MMPs or targeting of type IV collagen cryptic sites by antibody HUIV26 did not eliminate the sleeves or slow revascularization. These results suggest that empty sleeves of basement membrane and accompanying pericytes provide a scaffold for rapid revascularization of tumors after removal of anti-VEGF therapy and highlight their importance as potential targets in cancer therapy.
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