26 research outputs found
Advanced fuel cell based on Perovskite La-SrTiO3 semiconductor as the electrolyte with superoxide-ion conduction
A solid oxide fuel cell’s (SOFC) performance is largely determined by the ionic-conducting electrolyte. A novel approach is presented for using the semiconductor perovskite LaR0.25RSrR0.75RTiOR3R (LST) as the electrolyte by creating surface superionic conduction, and the authors show that the LST electrolyte can deliver superior power density, 908.2 mW·cmP-2P at just 550 °C. The prepared LST materials formed a heterostructure including an insulating core and a super ionic conducting surface layer. The rapid ion transport along the surfaces or grain boundaries was identified as the primary means of oxygen ion conduction. The fuel cell-induced phase transition was observed from the insulating LST to a super OP2-P conductivity of 0.221 S·cmP-1P at 550 °C, leading to excellent current and power outputs
Solar Interface Evaporation System Assisted by Mirror Reflection Heat Collection Based on Sunflower Chasing the Sun
In
this study, a photothermal material, C-CP/MnO2, was
prepared by compounding corrugated paper (CP) and MnO2,
with excellent photothermal conversion efficiency. The porous structure
and the presence of oxygen-containing functional groups enabled the
material to have a good water transport function and a fast vapor
escape rate. The special semihollow structure also allowed C-CP/MnO2 to have better thermal management and an evaporation rate
that could reach 2.563 kg m–2 h–1 with an efficiency of 98.82% under 1 sun. The continuous arch structure
inside C-CP/MnO2 was able to induce the Marangoni effect
to achieve continuous desalination of high-concentration brine. The
mirror heat collector achieved efficient light capture on the material
surface through multiple reflections of light. This could increase
the amount of radiation on the material surface by nearly 80%, and
the evaporation rate could reach 4.314 kg m–2 h–1 under 1 sun. Moreover, this study demonstrated the
light propagation path by simulating the light using Zemax to verify
the correctness of the experimental results. Inspired by the sunflower
chasing the sun, we designed a chasing heat collection system powered
by solar panels to achieve efficient evaporation outdoors. This provided
new ideas for further development of solar interface evaporation and
also provided guidance for other industrial applications
Standard p<i>K</i><sub>a</sub> Scales of Carbon-Centered Indicator Acids in Ionic Liquids: Effect of Media and Structural Implication
Energetics of bond dissociation, especially the R–H
bond heterolysis free energy (p<i>K</i><sub>a</sub>), has
played a central role in promoting chemistry to become a rational
science. Despite the oceans of acidity studies in the literature,
the current knowledge is limited to that in the classical molecular
solvents and is unable to be extended to anticipate the acidity changes
in ionic media. As the latter is now very popular for replacing volatile
organic solvents, it becomes highly desirable to know how the driving
force of bond cleavage is varied as the medium composition is switched
from neutral <i>molecules</i> to the charged <i>ions</i>. Here we describe a general approach to measure absolute p<i>K</i><sub>a</sub>’s in pure ionic liquid (IL). The standard
conditions warranting accurate measurement were outlined. The p<i>K</i><sub>a</sub>’s of the selected 18 C–H type
indicator acids in four ILs were determined and a convenient indicator
platform was constructed for easy expansion of acidity scales. These
absolute p<i>K</i><sub>a</sub>’s make possible, for
the first time, direct comparisons of bond energies in IL with those
in molecular solvent and in the gas phase and should be able to serve
as the standard parameters for calibrating computational methods suitable
for the studies in ionic media. The effect of cation and anion in
IL in relation to structure was analyzed
Additional file 1: Table S1. of High mobility group box-1 contributes to anti-myeloperoxidase antibody-induced glomerular endothelial cell injury through a moesin-dependent route
Presenting a summary of the mass spectrometry results. (XLS 23 kb
Standard p<i>K</i><sub>a</sub> Scales of Carbon-Centered Indicator Acids in Ionic Liquids: Effect of Media and Structural Implication
Energetics of bond dissociation, especially the R–H
bond heterolysis free energy (p<i>K</i><sub>a</sub>), has
played a central role in promoting chemistry to become a rational
science. Despite the oceans of acidity studies in the literature,
the current knowledge is limited to that in the classical molecular
solvents and is unable to be extended to anticipate the acidity changes
in ionic media. As the latter is now very popular for replacing volatile
organic solvents, it becomes highly desirable to know how the driving
force of bond cleavage is varied as the medium composition is switched
from neutral <i>molecules</i> to the charged <i>ions</i>. Here we describe a general approach to measure absolute p<i>K</i><sub>a</sub>’s in pure ionic liquid (IL). The standard
conditions warranting accurate measurement were outlined. The p<i>K</i><sub>a</sub>’s of the selected 18 C–H type
indicator acids in four ILs were determined and a convenient indicator
platform was constructed for easy expansion of acidity scales. These
absolute p<i>K</i><sub>a</sub>’s make possible, for
the first time, direct comparisons of bond energies in IL with those
in molecular solvent and in the gas phase and should be able to serve
as the standard parameters for calibrating computational methods suitable
for the studies in ionic media. The effect of cation and anion in
IL in relation to structure was analyzed
sj-pdf-1-imr-10.1177_03000605221148895 - Supplemental material for Lymphoepithelial carcinoma of the head and neck: a SEER analysis of prognostic factors for survival
Supplemental material, sj-pdf-1-imr-10.1177_03000605221148895 for Lymphoepithelial carcinoma of the head and neck: a SEER analysis of prognostic factors for survival by Jing Wei, Hui Deng, Lihua Wu, Jianbo Song, Junping Zhang, Wenhui Yang, Mengxian Zhang and Hongtao Zhen in Journal of International Medical Research</p
Postsurface Selenization for High Performance Sb<sub>2</sub>S<sub>3</sub> Planar Thin Film Solar Cells
Sb<sub>2</sub>S<sub>3</sub> has attracted great research interest
very recently as a promising absorber material for thin film photovoltaics
because of their unique optical and electrical properties, binary
compound and easy synthesis. Sb<sub>2</sub>S<sub>3</sub> planar solar
cells from evaporation method without hole-transport layer (HTM) assistance
suffer from sulfur deficit vacancy and high back contact barrier.
Herein, we developed a postsurface selenization treatment to Sb<sub>2</sub>S<sub>3</sub> thin film in order to improve the device performance.
The XRD, Raman, and UV–vis spectra indicated the treated film
kept the typical characters of Sb<sub>2</sub>S<sub>3</sub>. TEM/EELS
mapping of treated Sb<sub>2</sub>S<sub>3</sub> film revealed that
only surface adjacent section was partly selenized and formed Sb<sub>2</sub>(S<sub><i>x</i></sub>Se<sub>1–<i>x</i></sub>)<sub>3</sub> alloy. In addition, XPS results further unfolded
that there was trace selenium doping in the bulk of Sb<sub>2</sub>S<sub>3</sub> film. The treated HTM-free Sb<sub>2</sub>S<sub>3</sub> based solar cells were fabricated and an improved efficiency of
4.17% was obtained. The obtained <i>V</i><sub>OC</sub> of
0.714 V was the highest and the power conversion efficiency also reached
the top value among HTM-free planar Sb<sub>2</sub>S<sub>3</sub> solar
cells. The nonencapsulated device exhibited high stability. After
storing in ambient air for up to 100 days, the device could maintain
90% efficiency. Systematic materials and device characterizations
were implemented to investigate the improvement mechanism for postsurface
selenization. The back alloying could suppress the rear contact barrier
to improve the fill factor and carrier extraction capability. The
bulk Se-doping helped to passivate the interface and bulk defects
so as to improve the CdS/Sb<sub>2</sub>S<sub>3</sub> heterojunction
quality and enhance the long-wavelength photon quantum yield. The
robust treatment method with multifunctional effect holds great potential
for new chalcogenide thin film solar cell optimization
High Quantum Yield Blue Emission from Lead-Free Inorganic Antimony Halide Perovskite Colloidal Quantum Dots
Colloidal
quantum dots (QDs) of lead halide perovskite have recently
received great attention owing to their remarkable performances in
optoelectronic applications. However, their wide applications are
hindered from toxic lead element, which is not environment- and consumer-friendly.
Herein, we utilized heterovalent substitution of divalent lead (Pb<sup>2+</sup>) with trivalent antimony (Sb<sup>3+</sup>) to synthesize
stable and brightly luminescent Cs<sub>3</sub>Sb<sub>2</sub>Br<sub>9</sub> QDs. The lead-free, full-inorganic QDs were fabricated by
a modified ligand-assisted reprecipitation strategy. A photoluminescence
quantum yield (PLQY) was determined to be 46% at 410 nm, which was
superior to that of other reported halide perovskite QDs. The PL enhancement
mechanism was unraveled by surface composition derived quantum-well
band structure and their large exciton binding energy. The Br-rich
surface and the observed 530 meV exciton binding energy were proposed
to guarantee the efficient radiative recombination. In addition, we
can also tune the inorganic perovskite QD (Cs<sub>3</sub>Sb<sub>2</sub>X<sub>9</sub>) emission wavelength from 370 to 560 nm <i>via</i> anion exchange reactions. The developed full-inorganic lead-free
Sb-perovskite QDs with high PLQY and stable emission promise great
potential for efficient emission candidates
Location of the <i>cfr</i> gene in the 10 <i>E. coli</i> strains and their corresponding transformants.
<p>(a) S1-PFGE of the <i>cfr</i>-positive strains and their transformants, (b) subsequent southern hybridization with <i>cfr</i>-specific probe. Lanes: M, Low Range PFG Marker; 1, 8ZG1D; 2, 8ZG1D-21; 3, 8ZG12D; 4, 8ZG12D-50; 5, 1ZF13D; 6, 1ZF13D-22; 7, 2ZX7S; 8, 2ZX7S-41; 9, 8ZG6D; 10, 8ZG6D-59; 11, 3ZX12D; 12, 3ZX12D-6; 13, 8ZG8D; 14, 8ZG8D-81; 15 FS-P54; 16,FS-P54-2; 17,8ZB6D; 18, 8ZB6D-30; and 19,FS13Z3C.</p
UPGMA dendrogram, PFGE patterns, phylogenetic group and isolation date of <i>cfr</i>-positive <i>E. coli</i>.
<p>UPGMA dendrogram, PFGE patterns, phylogenetic group and isolation date of <i>cfr</i>-positive <i>E. coli</i>.</p