The Ca2+ and Ba2+ solubility on Nd3+ sites in new layered perovskite NdBaInO4 mixed oxide ionic and hole conductor and their effect on the oxide ion conductivity of NdBaInO4 were investigated. Among ...the alkaline earth metal cations Ca2+, Sr2+, and Ba2+, Ca2+ was shown to be the optimum acceptor–dopant for Nd3+ in NdBaInO4 showing the largest substitution for Nd3+ up to 20% and leading to oxide ion conductivities ∼3 × 10–4–1.3 × 10–3 s/cm within 600–800 °C on Nd0.8Ca0.2BaInO3.9 composition, exceeding the most-conducting Nd0.9Sr0.1BaInO3.95 in the Sr-doped NdBaInO4. Energetics of defect formation and oxygen vacancy migration in NdBaInO4 were computed through the atomistic static-lattice simulation. The solution energies of Ca2+/Sr2+/Ba2+ on the Nd3+ site in NdBaInO4 for creating the oxygen vacancies confirm the predominance of Ca2+ on the substitution for Nd3+ and enhancement of the oxygen vacancy conductivity over the larger Sr2+ and Ba2+. The electronic defect formation energies indicate that the p-type conduction in a high partial oxygen pressure range of the NdBaInO4-based materials is from the oxidation reaction forming the holes centered on O atoms. Both the static lattice and molecular dynamic simulations indicate two-dimensional oxygen vacancy migration within the perovskite slab boundaries for the acceptor-doped NdBaInO4. Molecular dynamic simulations on the Ca-doped NdBaInO4 specify two major vacancy migration events, respectively, via one intraslab path along the b axis and one interslab path along the c axis. These paths are composed by two terminal oxygen sites within the perovskite slab boundaries.
Tetrahedral units can transport oxide anions via interstitial or vacancy defects owing to their great deformation and rotation flexibility. Compared with interstitial defects, vacancy-mediated ...oxide-ion conduction in tetrahedra-based structures is more difficult and occurs rarely. The isolated tetrahedral anion Scheelite structure has showed the advantage of conducting oxygen interstitials but oxygen vacancies can hardly be introduced into Scheelite to promote the oxide ion migration. Here we demonstrate that oxygen vacancies can be stabilized in the BiVO
Scheelite structure through Sr
for Bi
substitution, leading to corner-sharing V
O
tetrahedral dimers, and migrate via a cooperative mechanism involving V
O
-dimer breaking and reforming assisted by synergic rotation and deformation of neighboring VO
tetrahedra. This finding reveals the ability of Scheelite structure to transport oxide ion through vacancies or interstitials, emphasizing the possibility to develop oxide-ion conductors with parallel vacancy and interstitial doping strategies within the same tetrahedra-based structure type.
The aggregation-induced emission (AIE) effect exhibits a significant influence on the development of luminescent materials and has made remarkable progress over the past decades. The advancement of ...high-performance AIE materials requires fast and accurate predictions of their photophysical properties, which is impeded by the inherent limitations of quantum chemical calculations. In this work, we present an accurate machine learning approach for the fast predictions of quantum yields and wavelengths to screen out AIE molecules. A database of about 563 organic luminescent molecules with quantum yields and wavelengths in the monomeric/aggregated states was established. Individual/combined molecular fingerprints were selected and compared elaborately to attain appropriate molecular descriptors. Different machine learning algorithms combined with favorable molecular fingerprints were further screened to achieve more accurate prediction models. The simulation results indicate that combined molecular fingerprints yield more accurate predictions in the aggregated states, and random forest and gradient boosting regression algorithms show the best predictions in quantum yields and wavelengths, respectively. Given the successful applications of machine learning in quantum yields and wavelengths, it is reasonable to anticipate that machine learning can serve as a complementary strategy to traditional experimental/theoretical methods in the investigation of aggregation-induced luminescent molecules to facilitate the discovery of luminescent materials.
Abstract
CeNbO
4+δ
, a family of oxygen hyperstoichiometry materials with varying oxygen content (CeNbO
4
, CeNbO
4.08
, CeNbO
4.25
, CeNbO
4.33
) that shows mixed electronic and oxide ionic ...conduction, has been known for four decades. However, the oxide ionic transport mechanism has remained unclear due to the unknown atomic structures of CeNbO
4.08
and CeNbO
4.33
. Here, we report the complex (3 + 1)D incommensurately modulated structure of CeNbO
4.08
, and the supercell structure of CeNbO
4.33
from single nanocrystals by using a three-dimensional electron diffraction technique. Two oxide ion migration events are identified in CeNbO
4.08
and CeNbO
4.25
by molecular dynamics simulations, which was a synergic-cooperation knock-on mechanism involving continuous breaking and reformation of Nb
2
O
9
units. However, the excess oxygen in CeNbO
4.33
hardly migrates because of the high concentration and the ordered distribution of the excess oxide ions. The relationship between the structure and oxide ion migration for the whole series of CeNbO
4+
δ
compounds elucidated here provides a direction for the performance optimization of these compounds.
Mutations in
CSNK2B
lead to Poirier-Bienvenu neurodevelopmental syndrome (POBINDS), a rare neurodevelopmental disorder. Only 14 cases of POBINDS have been reported worldwide. The main manifestations ...are seizures, often tonic–clonic, with or without intellectual disability, growth retardation, and developmental language retardation. We conducted a comprehensive phenotypic mining and trio-whole exome sequencing on six children with POBINDS for gene diagnosis and analyzed the different variants using bioinformatics analysis software and related experiments. This paper reviews previous literature and discusses two common missense variants that lead to structural changes. Among the six patients, four, one, and one had tonic–clonic, myoclonic, and febrile seizures, respectively. Language development disorder, motor development disorder, and developmental delay/intellectual disability (DD/ID) are the main clinical features. All children had de novo mutations in
CSNK2B
, including three missense variants (c.410G > T/p.(Cys137Phe), c.494A > G/p.(His165Arg), and c.3G > A/p.(Met1Ile)), two splice variants (c.292-2A > T, c.558-3 T > G), and one frameshift variant (c.499delC/p.(Leu167Serfs*60)). Three missense variants were predicted to be harmful by various software programs, and two splicing variants were found to produce new exonic splicing enhancers by the minigene assay. Western blot analysis showed that the frameshift variant resulted in decreased protein expression. According to a literature review, c.3G > A/p.(Met1Ile), c.292-2A > T, c.558-3 T > G, and c.499delC/p.(Leu167Serfs*60) are novel variants of
CSNK2B
. The decrease or loss of protein function caused by CSNK2B mutations may be a pathogenic factor in this cohort. The severity of the POBINDS phenotype differs, and refractory epilepsy may be accompanied by a more serious DD/ID, language disorder, and motor retardation. At present, there is no specific treatment, and antiepileptic therapy usually requires the combination of two or more anti-epileptic drugs.
Here, we demonstrate an effective strategy to constitutionally increase the conductivity and electrocatalytic property of NiFe2O4 by phosphate ion functionalization. The phosphate-ion-modified ...NiFe2O4 (P-NiFe2O4) nanosheets are readily grown on a carbon cloth by a simple hydrothermal method and followed by a phosphating process. The introduction of phosphate ions on the NiFe2O4 surface is highly beneficial for increasing the charge transport rate and electrocatalytic active sites. As a result, the as-prepared P-NiFe2O4 nanosheets show outstanding electrocatalytic activity toward oxygen evolution reaction (OER), with a low overpotential (231 mV at 10 mA/cm2) and Tafel slope (49 mV/dec). Furthermore, the P-NiFe2O4 electrode has a remarkable stability with no activity fading after 50 h. In addition, the as-fabricated water electrocatalysts exhibit excellent flexibility at the foldable state. These features make the phosphate-ion-functionalized NiFe2O4 electrodes open a new way to develop OER electrocatalysts with high electrochemical property.
All-solid-state sodium-ion batteries are promising candidates for renewable energy storage applications, owing to their high safety, high energy density, and the abundant resources of sodium. The ...critical factor for an all-solid-state battery is having a sodium solid electrolyte that has high Na ion conductivity at room temperature and outstanding thermal stability, low flammability, and long battery lifespan. Herein, a new Na ion solid-state electrolyte, Na3VS4, is prepared by a solid state reaction. It shows conductivity of ∼1.16 × 10−8 to 1.46 × 10−6 S cm−1 from 25 to 100 °C. The sodium ion conductivity was enhanced to ∼1.49 × 10−7 to 1.20 × 10−5 S cm−1 through P substitution for V in the composition Na3P0.1V0.9S4. Such sodium ion conduction enhancement could be attributed to P substitution for V leading to a wider Na migration path and the generation of sodium vacancies.
Zero thermal expansion (ZTE) alloys with high mechanical response are crucial for their practical usage. Yet, unifying the ZTE behavior and mechanical response in one material is a grand obstacle, ...especially in multicomponent ZTE alloys. Herein, we report a near isotropic zero thermal expansion (α
= 1.10 × 10
K
, 260-310 K) in the natural heterogeneous LaFe
Co
Si
alloy, which exhibits a super-high toughness of 277.8 ± 14.7 J cm
. Chemical partition, in the dual-phase structure, assumes the role of not only modulating thermal expansion through magnetic interaction but also enhancing mechanical properties via interface bonding. The comprehensive analysis reveals that the hierarchically synergistic enhancement among lattice, phase interface, and heterogeneous structure is significant for strong toughness. Our findings pave the way to tailor thermal expansion and obtain prominent mechanical properties in multicomponent alloys, which is essential to ultra-stable functional materials.
Rapid progress in modern technologies demands zero thermal expansion (ZTE) materials with multi-property profiles to withstand harsh service conditions. Thus far, the majority of documented ZTE ...materials have shortcomings in different aspects that limit their practical utilization. Here, we report on a superior isotropic ZTE alloy with collective properties regarding wide operating temperature windows, high strength-stiffness, and cyclic thermal stability. A boron-migration-mediated solid-state reaction (BMSR) constructs a salient "plum pudding" structure in a dual-phase Er-Fe-B alloy, where the precursor ErFe
phase reacts with the migrated boron and transforms into the target Er
Fe
B (pudding) and α-Fe phases (plum). The formation of such microstructure helps to eliminate apparent crystallographic texture, tailor and form isotropic ZTE, and simultaneously enhance the strength and toughness of the alloy. These findings suggest a promising design paradigm for comprehensive performance ZTE alloys.
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