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1.
J Am Chem Soc ; 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39219155

RESUMO

Martensitic transformation with volume expansion plays a crucial role in enhancing the mechanical properties of steel and partially stabilized zirconia. We believe that a similar concept could be applied to unexplored nonoxide materials. Herein, we report the stress-induced martensitic transformation of monoclinic Na3YCl6 with an ∼3.4% expansion. In situ synchrotron X-ray diffraction and atomistic simulations showed that anisotropic crystallographic transformation from monoclinic to rhombohedral Na3YCl6 occurs exclusively under uniaxial pressure; no effect is observed under hydrostatic pressure conditions. The uniaxially pressed powder compact of monoclinic Na3YCl6 showed a large indentation impression and low Young's modulus, in contrast to its high bulk modulus, suggesting that these unique mechanical properties are induced by the martensitic transformation.

2.
Chem Commun (Camb) ; 60(53): 6813-6816, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38873825

RESUMO

Cathode composites were fabricated using the nuclear growth (SEED) method. Compared to mortar mixing, the SEED method demonstrated higher cycle stability, with a 90LiNi1/3Mn1/3Co1/3O2-10Li7P2S8I composite retaining 99.7% discharge capacity after six cycles compared to 66.1%. Cross-sectional SEM-EDX images suggest that the solid electrolyte was more uniformly distributed in the cathode composite prepared using the SEED method. This study opens up the potential for higher cathode-active material loading ratios.

3.
J Phys Chem Lett ; 14(51): 11691-11696, 2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38109358

RESUMO

Photoelectrochemical (PEC) water splitting is a highly demanded technology for the realization of sustainable society. Various types of photoanodes have been developed to achieve high efficiency of PEC water splitting. Plasmonic field enhancement and light confinement effects are often adopted to improve PEC performance. However, their synergistic effects have not been studied. In this work, a mesoporous TiO2 layer was deposited on an Al plate with a nanovoid array structure, which acts as a photoanode and simultaneously exhibits a light confinement effect and surface plasmon resonance. The solo and synergy effects were investigated through experimental photocurrent measurements and theoretical simulations using the finite-difference time-domain method. The highest improvement in PEC performance was confirmed when the synergy effect occurred.

4.
Heliyon ; 9(7): e17889, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37449150

RESUMO

All-solid-state batteries, which use flame-resistant solid electrolytes, are regarded as safer alternatives to conventional lithium-ion batteries for various applications including electric vehicles. Herein, we report the fabrication of cathode composites for oxide-type all-solid-state batteries through an electrostatic assembly method. A polyelectrolyte is used to adjust the surface charge of the matrix particles to positive/negative, and the aggregation resulting from electrostatic interactions is utilized. Composites consisting of cathode active material particles (LiNi1/3Mn1/3Co1/3O2 (NMC) or LiNi0.5Mn1.5O4 (LNMO)), solid electrolyte particles Li1.3Al0.3Ti1.7(PO4)3 (LATP), and electron conductive one-dimensional carbon nanotubes (CNT) are formed via an electrostatic integrated assembly of colloidal suspensions. Electrostatic integration increases the electronic conductivity by two orders of magnitude in the NMC-LATP-CNT composite (6.5 × 10-3 S cm-1/3.2 × 10-5 S cm-1) and by six orders of magnitude in the LNMO-LATP-CNT composite (6.4 × 10-3 S cm-1/2.3 × 10-9 S cm-1). The dispersion of CNTs in the cathode composite is enhanced, resulting in percolation of e- path even at 1 wt% (approximately 2.5 vol%) CNT. This study indicates that an integrated cathode composite can be fabricated with particles uniformly mixed by electrostatic interaction for oxide-type all-solid-state batteries.

5.
Nanomaterials (Basel) ; 13(1)2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36616109

RESUMO

Despite the availability of nano and submicron-sized additive materials, the controlled incorporation and utilization of these additives remain challenging due to their difficult handling ability and agglomeration-prone properties. The formation of composite granules exhibiting unique microstructure with desired additives distribution and good handling ability has been reported using the electrostatic integrated granulation method. This study demonstrates the feasible controlled incorporation of two-dimensional hexagonal boron nitride (hBN) sheets with alumina (Al2O3) particles, forming Al2O3-hBN core-shell composite granules. The sintered artifacts obtained using Al2O3-hBN core-shell composite granules exhibited an approximately 28% higher thermal conductivity than those obtained using homogeneously hBN-incorporated Al2O3 composite granules. The findings from this study would be beneficial for developing microstructurally controlled composite granules with the potential for scalable fabrication via powder-metallurgy inspired methods.

6.
Front Aging Neurosci ; 14: 1025667, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36466607

RESUMO

This study focuses on changes in implicit motor imagery during advanced aging and these changes' co-occurrences with physical motor deficits. We administered a mental rotation (MR) task with letters, hands, and feet to 28 young adults (20-27 years) and to 71 older adults (60-87 years), and assessed motor skills (gait mobility and hand dexterity) and neuropsychological performance. Compared to young adults, older adults showed lower MR performance for all stimuli and stronger biomechanical constraint effects on both hand and foot rotation. Moreover, the foot biomechanical constraint effect continued to increase during late adulthood, and declines in hand and foot motor imagery emerged at earlier old ages than declines in visual imagery. These results first demonstrated distinct aging trajectories of hand motor imagery, foot motor imagery, and visual imagery. Exploratory partial correlation analysis for older adults showed positive associations of low-level perceptual-motor skills (Trail Making Test-A performance) with hand and foot MR performance and positive associations of mobility (Timed Up and Go test performance) with foot and letter MR performance. These associations exhibited somewhat different patterns from those of young adults and raised the possibility that age-related declines in motor (and visual) imagery co-occur with declines in motor functioning.

7.
ACS Appl Mater Interfaces ; 14(46): 52440-52447, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36332184

RESUMO

The stability of sulfide-based solid electrolytes (SEs) in ambient air is a critical criterion for the application of all-solid-state lithium-ion batteries. Air-stable Li3SbS4-LiI SEs were synthesized using a unique process in an aqueous solution under ambient air, i.e., an ion-exchange (IE) process. The crystalline structure of Li3SbS4 obtained by this process was confirmed by X-ray diffraction (XRD) patterns. The ionic conductivity of the obtained SE was 8.5 × 10-8 S cm-1 at 50 °C. The SEs of Li3SbS4-LiI were also synthesized via the IE process. The temperature dependence of the Li3SbS4-LiI SEs' ionic conductivities showed a unique behavior; for example, the conductivities of 60Li3SbS4·40LiI (LSbSI) rapidly increased upon heating from 1.8 × 10-7 S cm-1 at 26.5 °C to 8.4 × 10-3 S cm-1 at 65 °C. The LiI layers on LSbSI are responsible for the unique temperature dependence of conductivity determined by differential scanning calorimetry-XRD measurement. Further, the dehydrated LSbSI obtained by milling and annealing showed a high conductivity of 1.3 × 10-4 S cm-1 at a low temperature of 25 °C. A cathode composite containing the active material of Ti2S and the LSbSI SE obtained via the IE process was prepared by freeze-drying. The all-solid-state cell using the cathode composite, which consists of Li-In/SE/TiS2-LSbSI, showed good performance at 60 °C as a lithium-ion secondary battery.

8.
Gerontol Geriatr Med ; 8: 23337214221116226, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35937277

RESUMO

Background: Older adults were expected to experience a decline in physical activities and an increase in social isolation during the COVID-19 pandemic. Methods: We investigated the changes in living conditions of 508 older adults (79.70 years ± 0.88) before (from July to December 2019) and during (in August 2020) the pandemic. We compared the mean score for the same individual instrumental activities of daily living (IADL), frequency of going out, exercise, and social interaction at two-time points. We also examined the influence of living arrangement (living alone or not) on the frequency of exercise and social interaction. Results: The frequency of going out decreased during the pandemic (in 2020); however, there was no significant change in IADL. The frequency of exercise and social interaction increased irrespective of the living arrangement. The frequency of exercise increased more in those living alone. Conclusions: Although older adults refrained from going out, they compensated for the risks of inactivity in daily life by increasing or maintaining their frequency of exercise and social interactions. The view that "older adults have a poor ability to accommodate the lifestyle changes during the COVID-19 pandemic" may be a stereotypical assumption.

9.
Nanoscale ; 14(27): 9669-9674, 2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35766342

RESUMO

Controlled incorporation of carbon nanotubes (CNT) with alumina (Al2O3) and zirconia (ZrO2) nanoparticles using an electrostatic nano-assembly method for the fabrication of homogeneous CNT-incorporated Al2O3-ZrO2 and CNT-incorporated shell-layer Al2O3-ZrO2 composite granules is demonstrated. The spark-plasma-sintered CNT-incorporated shell-layer Al2O3-ZrO2 artifact exhibited approximately 15 times higher electrical conductivity than a homogeneous CNT-incorporating artifact. This novel composite granule fabrication method using an electrostatic integrated assembly of colloidal nanomaterials would be beneficial for the development of multiscale and multicomponent composite materials.

10.
ACS Omega ; 7(19): 16561-16567, 2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35601295

RESUMO

Li7P3S11 solid electrolytes (SEs) subjected to liquid-phase synthesis with CaS or CaI2 doping were investigated in terms of their ionic conductivity and stability toward lithium anodes. No peak shifts were observed in the XRD patterns of CaS- or CaI2-doped Li7P3S11, indicating that the doping element remained at the grain boundary. CaS- or CaI2-doped Li7P3S11 showed no internal short circuit, and the cycling continued, indicating that not only CaI2 including I- but also CaS could help increase the lithium stability. These results provide insights for the development of sulfide SEs for use in all-solid-state batteries in terms of their ionic conductivity and stability toward lithium anodes.

11.
RSC Adv ; 12(12): 7469-7474, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35424691

RESUMO

In this study, mechanical milling and liquid-phase shaking are used to synthesise 3Li2S·P2S5 LiI·xLi4SiO4 (Li7P2S8I·xLi4SiO4) solid electrolytes. When mechanical milling is used, the electrolyte samples doped with 10 mol% of Li4SiO4 (Li7P2S8I·10Li4SiO4) have the highest ionic conductivity at ∼25-130 °C. When liquid-phase shaking is used, they exhibit a relatively high conductivity of 0.85 mS cm-1 at ∼20 °C, and low activation energy for conduction of 17 kJ mol-1. A cyclic voltammogram shows that there are no redox peaks between -0.3 and +10 V, other than the main peaks near 0 V (v.s. Li/Li+), indicating a wide electrochemical window. The galvanostatic cycling test results demonstrate that the Li7P2S8I·10Li4SiO4 has excellent long-term cycling stability in excess of 680 cycles (1370 h), indicating that it is highly compatible with Li. Thus, Li7P2S8I solid electrolytes doped with Li4SiO4 are synthesised using the liquid-phase shaking method for the first time and achieve a high ionic conductivity of 0.85 mS cm-1 at 25 °C. This work demonstrates the effects of Li4SiO4 doping, which can be used to improve the ionic conductivity and stability against Li anodes with Li7P2S8I solid electrolytes.

12.
Environ Sci Pollut Res Int ; 29(40): 60600-60615, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35426025

RESUMO

In this study, nanoporous anodic film was produced by anodization of niobium, Nb in a fluoride ethylene glycol electrolyte. The effect of anodization voltage and electrolyte temperature was studied to find an optimum condition for circular, ordered, and uniform pore formation. The diameter of the pores was found to be larger when the applied voltage was increased from 20 to 80 V. The as-anodized porous film was also observed to comprise of nanocrystallites which formed due to high field-induced crystallization. The nanocrystallites grew into orthorhombic Nb2O5 after post-annealing treatment. The Cr(VI) photoreduction property of both the as-anodized and annealed Nb2O5 samples obtained using an optimized condition (anodization voltage: 60 V, electrolyte temperature: 70 °C) was compared. Interestingly, the as-anodized Nb2O5 film was found to display better photoreduction of Cr(VI) than annealed Nb2O5. However, in terms of stability, the annealed Nb2O5 presented high photocatalytic efficiency for each cycle whereas the as-anodized Nb2O5 showed degradation in photocatalytic performance when used continually.

13.
ACS Omega ; 6(42): 28203-28214, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34723018

RESUMO

Coral-like and nanowire (NW) iron oxide nanostructures were produced at 700 and 800 °C, respectively, through thermal oxidation of iron foils in air- and water vapor-assisted conditions. Water vapor-assisted thermal oxidation at 800 °C for 2 h resulted in the formation of highly crystalline α-Fe2O3 NWs with good foil surface coverage, and we propose that their formation was due to a stress-driven surface diffusion mechanism. The Cr(VI) adsorption property of an aqueous solution on α-Fe2O3 NWs was also evaluated after a contact time of 90 min. The NWs had a removal efficiency of 97% in a 225 mg/L Cr(VI) solution (pH 2, 25 °C). The kinetic characteristic of the adsorption was fitted to a pseudo-second-order kinetic model, and isothermal studies indicated that the α-Fe2O3 NWs exhibited an adsorption capacity of 66.26 mg/g. We also investigated and postulated a mechanism of the Cr(VI) adsorption in an aqueous solution of α-Fe2O3 NWs.

14.
Chemosphere ; 283: 131231, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34144283

RESUMO

An anodic film with a nanoporous structure was formed by anodizing niobium at 60 V in fluorinated ethylene glycol (fluoride-EG). After 30 min of anodization, the anodic film exhibited a "pore-in-pore" structure; that is, there were smaller pores growing inside larger pores. The as-anodized film was weakly crystalline and became orthorhombic Nb2O5 after heat treatment. The energy band gap of the annealed nanoporous Nb2O5 film was 2.9 eV. A photocatalytic reduction experiment was performed on Cr(VI) under ultraviolet (UV) radiation by immersing the nanoporous Nb2O5 photocatalyst in a Cr(VI) solution at pH 2. The reduction process was observed to be very slow; hence, ethylenediaminetetraacetic acid (EDTA) was added as an organic hole scavenger, which resulted in 100% reduction after 45 min of irradiation. The photocatalytic reduction experiment was also performed under visible light, and findings showed that complete reduction achieved after 120 min of visible light exposure.


Assuntos
Nanoporos , Nióbio , Catálise , Cromo
15.
Exp Psychol ; 68(1): 41-48, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33843256

RESUMO

People can mentally rotate objects that resemble human bodies more efficiently than nonsense objects in the same/different judgment task. Previous studies proposed that this human-body advantage in mental rotation is mediated by one's projections of body axes onto a human-like object, implying that human-like objects elicit a strategy shift, from an object-based to an egocentric mental rotation. To test this idea, we investigated whether mental rotation performance involving a human-like object had a stronger association with spatial perspective-taking, which entails egocentric mental rotation, than a nonsense object. In the present study, female participants completed a chronometric mental rotation task with nonsense and human-like objects. Their spatial perspective-taking ability was then assessed using the Road Map Test and the Spatial Orientation Test. Mental rotation response times (RTs) were shorter for human-like than for nonsense objects, replicating previous research. More importantly, spatial perspective-taking had a stronger negative correlation with RTs for human-like than for nonsense objects. These findings suggest that human-like stimuli in the same/different mental rotation task induce a strategy shift toward efficient egocentric mental rotation.


Assuntos
Navegação Espacial/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
16.
Nanomaterials (Basel) ; 11(1)2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33450938

RESUMO

In materials processing, the sol-gel method is one of the techniques that has enabled large-scale production at low cost in the past few decades. The versatility of the method has been proven as the fabrication of various materials ranging from metallic, inorganic, organic, and hybrid has been reported. In this review, a brief introduction of the sol-gel technique is provided and followed by a discussion of the significance of this method for materials processing and development leading to the creation of novel materials through sol-gel derived coatings. The controlled modification of sol-gel derived coatings and their respective applications are also described. Finally, current development and the outlook of the sol-gel method for the design and fabrication of nanomaterials in various fields are described. The emphasis is on the significant potential of the sol-gel method for the development of new, emerging technologies.

17.
Behav Processes ; 182: 104279, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33189797

RESUMO

Group-living animals gain fitness benefits from intergroup aggression, but also incur costs. Advertisement behaviors, such as long-distance calls and scent marking, help animals avoid disadvantageous, or less rewarding, fights. However, it remains unclear how species that lack advertisement behaviors respond to auditory information from other groups. We hypothesized that such species use auditory information prior to visual contact with the opponent group to determine its relative resource holding potential. Here, we aimed to identify the behavioral responses of Japanese macaques to simulated intergroup encounters. We conducted a vocal playback experiment and behavioral observations of 11 adult males and females from two groups intermittently from October 2015 to June 2017. In response to vocalizations of other groups, the macaques stopped feeding, decreased contact calling, and increased visual scanning, which could enable them to make timely and accurate decisions as to whether to fight or flee. The spatial cohesion of the group did not change. These results partly support our hypothesis and suggest that the onset of increased vigilance to opponents is prior to visual contact with them. The present study highlights the importance of investigating early phases of intergroup encounters in species lacking advertisement behaviors to obtain new insights on intergroup conflicts in animals.


Assuntos
Macaca fuscata , Macaca , Agressão , Animais , Feminino , Masculino , Vocalização Animal
18.
ACS Omega ; 5(40): 26287-26294, 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33073156

RESUMO

All-solid-state lithium batteries using inorganic sulfide solid electrolytes have good safety properties and high rate capabilities as expected for a next-generation battery. Presently, conventional preparation methods such as mechanical milling and/or solid-phase synthesis need a long time to provide a small amount of the product, and they have difficult in supplying a sufficient amount to meet the demand. Hence, liquid-phase synthesis methods have been developed for large-scale synthesis. However, the ionic conductivity of sulfide solid electrolytes prepared via liquid-phase synthesis is typically lower than that prepared via solid-phase synthesis. In this study, we have controlled three factors: (1) shaking time, (2) annealing temperature, and (3) annealing time. The factors influencing lithium ionic conductivity of Li3PS4 prepared via liquid-phase synthesis were quantitatively evaluated using high-energy X-ray diffraction (XRD) measurement coupled with pair distribution function (PDF) analysis. It was revealed from PDF analysis that the amount of Li2S that cannot be detected by Raman spectroscopy or XRD decreased the ionic conductivity. Furthermore, it was revealed that the ionic conductivity of Li3PS4 is dominated by other parameters, such as remaining solvent in the sample and high crystallinity of the sample.

19.
Nanomaterials (Basel) ; 10(1)2020 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-31940902

RESUMO

Micro/nanoscale design of composite materials enables alteration of their properties for advanced functional materials. One of the biggest challenges in material design is the controlled decoration of composite materials with the desired functional additives. This study reports on and demonstrates the homogeneous decoration of hexagonal boron nitride (hBN) on poly(methylmethacrylate) (PMMA) and vice versa. The formation of the composite materials was conducted via a low environmental load and a low-energy-consuming, electrostatic nano-assembly method which also enabled the efficient usage of nano-sized additives. The hBN/PMMA and PMMA/hBN composites were fabricated in various size combinations that exhibited percolated and layer-oriented structures, respectively. The thermal conductivity behaviors of hBN/PMMA and PMMA/hBN composites that exhibited good microstructure were compared. The results showed that microstructural design of the composites enabled the modification of their heat-conducting property. This novel work demonstrated the feasibility of fabricating heat-conductive PMMA matrix composites with controlled decoration of hBN sheets, which may provide a platform for further development of heat-conductive polymeric materials.

20.
J Nanosci Nanotechnol ; 20(1): 359-366, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383179

RESUMO

Novel decoration of high aspect ratio zinc oxide nanowires (ZnO NWs) with noble metals such as Ag and Au nanoparticles (NPs) was demonstrated in this work. A facile method of chemical deposition with good controllability, as well as good homogeneity would be a huge advantage towards large scale fabrication. The highlight of this work is the feasibility of multiple component decoration such as a hybrid (co-exist) Ag-Au NPs decorated ZnO NWs formation that could be beneficial towards the development of nanoarchitectured materials with the most desired properties. The local surface plasmon effect (LSPR) of Ag and Au NPs were confirmed using extinction spectra and significant photoelectrochemical conversion efficiency (PCE) enhancement of dye-sensitized solar cells (DSSCs) was achieved. The Ag-NPs and hybrid Ag-Au NPs decorated ZnO NWs marked an impressive 125 and 240% efficiency improvement against pure ZnO NWs. The improved dye light extinction resulted from the LSPR effect that had enabled greater electron generation leading to improved PCE. As the complex design of oxides' nanoarchitectures have reached a point of saturation, this novel method would enable further enhancement in their photoelectrochemical properties through decoration with noble metals via a simple chemical deposition route.

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