Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 111
Filtrar
1.
ACS Nano ; 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38904995

RESUMO

Flexible tactile sensors show promise for artificial intelligence applications due to their biological adaptability and rapid signal perception. Triboelectric sensors enable active dynamic tactile sensing, while integrating static pressure sensing and real-time multichannel signal transmission is key for further development. Here, we propose an integrated structure combining a capacitive sensor for static spatiotemporal mapping and a triboelectric sensor for dynamic tactile recognition. A liquid metal-based flexible dual-mode triboelectric-capacitive-coupled tactile sensor (TCTS) array of 4 × 4 pixels achieves a spatial resolution of 7 mm, exhibiting a pressure detection limit of 0.8 Pa and a fast response of 6 ms. Furthermore, neuromorphic computing using the MXene-based synaptic transistor achieves 100% recognition accuracy of handwritten numbers/letters within 90 epochs based on dynamic triboelectric signals collected by the TCTS array, and cross-spatial information communication from the perceived multichannel tactile data is realized in the mixed reality space. The results illuminate considerable application possibilities of dual-mode tactile sensing technology in human-machine interfaces and advanced robotics.

2.
J Hazard Mater ; 475: 134871, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38876020

RESUMO

Many studies have shown that Peroxymonosulfate (PMS) works synergistically with ferrate (Fe(VI)) to remove refractory organic compounds in a few minutes. However, little has been reported on the combined effects of peroxydisulfate (PDS) and Fe(VI). Since PDS is stable and cost effective, it is of practical significance to study the reaction mechanism and conditions of the PDS/Fe(VI) system. The results of the study indicate that the intermediate Fe(II) is formed during the decomposition of Fe(VI), which is then rapidly oxidized. Due to the asymmetry of the PMS molecular structure, PMS can rapidly trap Fe(II) (kPMS/Fe(II)= 3 × 104 M-1∙s-1), whereas PDS cannot (kPDS/Fe(II)= 26 M-1∙s-1). Hydroxylamine hydrochloride (HA) can reduce Fe(VI) and Fe(III) to Fe(II) to excite PDS to produce SO4•-. Acetate helps to detect Fe(II), but does not help PDS to trap Fe(II). Active species such as SO4•-, •OH, 1O2, and Fe(IV), Fe(V) are present in both systems, but in different amounts. In the PMS/Fe(Ⅵ) system, all these active species react with ibuprofen (IBP) and degrade IBP within several minutes. The effects of the initial pH, PMS or Fe(VI) dosage, and different amounts of IBP on the removal rate of IBP were investigated. According to the intermediates detected by the GC-MS, the degradation process of IBP includes hydroxylation, demethylation and single bond breakage. The degradation pathways of IBP were proposed. The degradation of IBP in tap water and Songhua River was also investigated. In actual water treatment, the dosage needs to be increased to achieve the same results. This study provides a basis and theoretical support for the application of PMS/Fe(Ⅵ) and PDS/Fe(VI) system in water treatment.

3.
Front Pharmacol ; 15: 1379058, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38895617

RESUMO

Ulcerative colitis (UC), a subtype of inflammatory bowel disease, manifests with symptoms such as abdominal pain, diarrhea, and mucopurulent, bloody stools. The pathogenesis of UC is not fully understood. At present, the incidence of UC has increased significantly around the world. Conventional therapeutic arsenals are relatively limited, with often poor efficacy and many adverse effects. In contrast, traditional Chinese medicine (TCM) holds promise due to their notable effectiveness, reduced recurrence rates, and minimal side effects. In recent years, significant progress has been made in the basic research on TCM for UC treatment. It has been found that the inhibition of ferroptosis through the intervention of TCM can significantly promote intestinal mucosal healing and reverse UC. The mechanism of action involves multiple targets and pathways. Aim of the review: This review summarizes the experimental studies on the targeted regulation of ferroptosis by TCM and its impact on UC in recent years, aiming to provide theoretical basis for the prevention, treatment, and further drug development for UC. Results: Ferroptosis disrupts antioxidant mechanisms in intestinal epithelial cells, damages the intestinal mucosa, and participates in the pathological process of UC. TCM acts on various pathways such as Nrf2/HO-1 and GSH/GPX4, blocking the pathological progression of ferroptosis in intestinal epithelial cells, inhibiting pathological damage to the intestinal mucosa, and thereby alleviating UC. Conclusion: The diverse array of TCM single herbs, extracts and herbal formulas facilitates selective and innovative research and development of new TCM methods for targeting UC treatment. Although progress has been made in studying TCM compound formulas, single herbs, and extracts, there are still many issues in clinical and basic experimental designs, necessitating further in-depth scientific exploration and research.

4.
Angew Chem Int Ed Engl ; : e202405839, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38801294

RESUMO

Triggering the lattice oxygen oxidation mechanism is crucial for improving oxygen evolution reaction (OER) performance, because it could bypass the scaling relation limitation associated with the conventional adsorbate evolution mechanism through the directly formation of oxygen-oxygen bond. High-valence transition metal sites are favorable for activating the lattice oxygen, but the deep oxidation of pre-catalysts suffers from a high thermodynamic barrier. Here, taking advantage of the Jahn-Teller (J-T) distortion induced structural instability, we incorporate high-spin Mn3+ (t2g3eg1) dopant into Co4N. Mn dopants enable a surface structural transformation from Co4N to CoOOH, and finally to CoO2, as observed by various in-situ spectroscopic investigations. Furthermore, the reconstructed surface on Mn doped Co4N triggers the lattice oxygen activation, as evidenced experimentally by pH-dependent OER, tetramethylammonium cation adsorption and on-line electrochemical mass spectrometry measurements of 18O-labelled catalysts. In general, this work not only offers the introducing J-T effect approach to regulate the structural transition, but also provides an understanding about the influence of catalyst's electronic configuration on determining the reaction route, which may inspire the design of more efficient catalysts with activated lattice oxygen.

5.
Adv Healthc Mater ; 13(16): e2303474, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38458151

RESUMO

Electrotherapy is of great interest in the field of tissue repair as an effective, well-tolerated, and noninvasive treatment. Triboelectric nanogenerator (TENG) has shown advantages in promoting wound healing due to its peak output characteristic and low Joule heating effect. However, it is limited in infected wound healing due to poor antimicrobial capacity. Here, a wearable triboelectric stimulator (WTS) is developed that consists of a flexible TENG (F-TENG) and a triboelectric-responsive drug delivery hydrogel (TR-DDH) for healing of bacterium-infected wounds. F-TENG can generate pulsed current to wounds by converting mechanical energy from body movements. Polypyrrole is prone to reduction and volume contraction under electrical stimulation, resulting in desorption of curcumin nanoparticles (CUR NPs) from the polypyrrole in TR-DDH. Therefore, the highly efficient and controllable release of CUR NPs can be achieved by triboelectric stimulation. According to the in vitro and in vivo experiments, WTS has the greatest antimicrobial effect and the fastest promotion of infected wound healing compared to treatment with electrical stimulation or curcumin. Finally, the safety assessment demonstrates that the WTS has excellent tissue safety for chronic wound healing. Synergistic therapy with WTS provides an efficient strategy for chronic wound healing and smart-responsive drug delivery systems.


Assuntos
Curcumina , Sistemas de Liberação de Medicamentos , Hidrogéis , Pirróis , Cicatrização , Cicatrização/efeitos dos fármacos , Curcumina/química , Curcumina/farmacologia , Hidrogéis/química , Animais , Sistemas de Liberação de Medicamentos/métodos , Pirróis/química , Polímeros/química , Nanopartículas/química , Camundongos , Terapia por Estimulação Elétrica/métodos , Dispositivos Eletrônicos Vestíveis , Humanos , Antibacterianos/química , Antibacterianos/farmacologia , Masculino
6.
Sci Rep ; 14(1): 4754, 2024 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-38413689

RESUMO

This study is nationwide multicenter epidemiological research, aimed at investigating the distribution changes and seasonal patterns of various airborne allergens among preschool children with allergic rhinitis (AR) in different regions of China, and analyzing the clinical correlation between sensitization to various airborne allergens and AR symptoms in children. Information on children was collected through standard questionnaires, and total IgE (tIgE) and specific IgE (sIgE) for 11 inhalant allergens were tested. The results showed that dust mites are the primary allergens for preschool AR children (39%). Among pollen allergens, Amb a had the highest positivity rate (8.1%), followed by Art v (7.8%). The sensitization rates for two mites peaked in May (46.9% and 40.6%). Art v peaked in August (21.5%), while Amb a had peaks in May (12.7%) and August (17.8%). The sensitization peaks for various tree pollens mainly occurred in August. In the Eastern monsoon region, the sensitization rate to mites was significantly higher than in the Northwest arid and semi-arid regions; whereas, for pollen allergens, the sensitization rates to Amb a, Pla a, Pin a, Pop d, and Bet v were significantly higher in the Northwest arid and semi-arid regions than in the Eastern monsoon region. The correlation among various tree pollens, specifically between Pla a, Pin r, Pop d, and Bet v was strong (0.63 ~ 0.79), with a cross-overlapping percentage of 53.9%. Children with multiple pollen sensitizations had higher cumulative nasal symptom scores than those negative for pollen (P < 0.01). Children with only pollen sensitization had higher cumulative rhinitis symptom scores than the all-negative group (P < 0.0001) and the mite-only sensitization group [P < 0.05], while the mite-only sensitization group also had higher scores than the all-negative group [P < 0.05], and the group sensitized to both pollen and mites had lower scores than the pollen-only group [P < 0.05]. This study indicates that sensitization to mites and grass pollens exhibits significant regional differences, with grass pollen allergies primarily occurring in autumn, sensitization to pollens in general exhibits a pronounced seasonal pattern. Moreover, pollen sensitization aggravates nasal and ocular symptoms in AR children.


Assuntos
Rinite Alérgica , Rinite , Pré-Escolar , Humanos , Estações do Ano , Alérgenos , Rinite Alérgica/epidemiologia , Rinite/diagnóstico , China/epidemiologia , Imunoglobulina E
7.
RSC Adv ; 14(8): 5566-5576, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38352687

RESUMO

An in situ synthesis approach is used to directly grow a microsphere of melamine-glutaraldehyde (MAGA) polymer over three-dimensional (3D) nickel foam (NF). The materials are used to produce nitrogen-doped carbon (NC) with and without NF. These precursors undergo carbonization at various temperatures, namely 400 °C, 500 °C, and 700 °C. The electrochemical properties of the materials would be significantly improved by directly growing MAGA polymer on the surface of NF. The electrochemical performance of NC/NF-400 was excellent, with a capacitance of 297 F g-1 achieved at a current density of 1 A g-1. The in situ growing approach does not necessitate the use of additional chemical agents, such as binders or conductive compounds when preparing the electrode. In addition, the material exhibits only 10% reduction in capacitance after undergoing 5000 cycles, indicating excellent cycling performance. The outstanding electrochemical performance achieved by using the in situ method of MAGA microsphere polymer on NF may be attributed to the rapid transit of ions to the electrode surfaces, facilitating effortless redox reactions.

8.
Medicine (Baltimore) ; 103(3): e36862, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38241586

RESUMO

BACKGROUND: To explore the relationship between specific immunoglobulin E levels in response to prevalent pollen and food allergens among patients suffering from localized allergic diseases in the Dongying area of China, and to analyze the interconnectivity among these factors. METHODS: This research encompassed allergic patients who visited the Allergy Department of Shengli Oilfield Central Hospital from January 2022 to January 2023. We examined the specific immunoglobulin E levels in the blood of 230 patients utilizing the Fobock platform provided by Jiangsu Haoeubo Company. Statistical analysis was conducted with SPSS 25.0 statistical software. The chi-square test evaluated the relevance of differences in gender and age. A value of P < .05 was considered statistically significant. RESULTS: In this study, eggs emerged as the allergen with the highest number of sensitized individuals, closely followed by dust mite. Conversely, the least sensitized allergen was the cypress tree, closely followed by mango. Notably, male patients exhibited higher sensitivities to cottonwood (P < .05) and egg (P < .001) compared to female patients. Children aged 0 to 10 years showed increased sensitivity to variety of allergens. A significant correlation was observed among different allergens. The top ten allergen pairs with the highest correlation included Birch Tree and Cottonwood (0.88, P < .001), Cottonwood and Pine Tree (0.86, P < .001), Birch Tree and Pine Tree (0.84, P < .001), Pine Tree and Paulownia (0.81, P < .001), Dust Mite and House Dust Mite (0.76, P < .001), Birch Tree and Paulownia (0.73, P < .001), Cashew and Pistachio (0.71, P < .001), Apple and Hazelnut (0.71, P < .001), Cottonwood and Paulownia (0.71, P < .001), and Pine Tree and Ordinary Ragweed (0.70, P < .001). CONCLUSION: This research sheds light on the patterns of allergen sensitization in Dongying, Shandong, highlighting that egg is the most prevalent sensitizing allergen. A notably high correlation was observed between Birch Tree and Cottonwood. This study enhanced the understanding of allergic diseases, explored the causes and mechanisms of allergies, strengthened the management of allergic diseases. Furthermore, it offers valuable insights for the clinical diagnosis and prevention of allergic diseases.


Assuntos
Alérgenos , Hipersensibilidade Alimentar , Criança , Animais , Humanos , Hipersensibilidade Alimentar/epidemiologia , Estudos Epidemiológicos , Pyroglyphidae , Betula , China/epidemiologia , Imunoglobulina E
9.
ACS Appl Mater Interfaces ; 16(4): 5168-5182, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38234121

RESUMO

Metal coordination hydrogels (MC-HGs) that introduce dynamically coordinate bonds together with metal ionic conduction have attracted considerable attention in flexible electronics. However, the traditional soaking method alleged to have technical scalability faces the challenge of forming MC-HGs with a "core-shell" structure, which undoubtedly reduces the whole mechanical properties and ionic stimulation responsiveness required for flexible electronics materials. Herein, a novel strategy referred to as "masking" has been proposed based on the theory of the valence bond and coordination chemistry. By regulating the masking agents and their concentrations as well as pairing mode with the metal ions, the whole mechanical properties of the resulting composites (MC-HGsMasking) show nearly double the values of their traditional soaking samples (MC-HGsSoaking). For example, the fracture stress and toughness of Fe-HGsMasking(SA, 5.0 g/L) are 1.55 MPa and 2.14 MJ/m3, almost twice those of Fe-HGsSoaking (0.83 MPa and 0.93 MJ/m3, respectively). Microstructure characterization combined with finite element analysis, molecular dynamics, and first-principles simulations demonstrates that the masking strategy first facilitating interfacial permeation of metal complexes and then effective coordination with functional ligands (carboxylates) of the hydrogels is the mechanism to strengthen the mechanical properties of composites MC-HGsMasking, which has the potential to break through the limitations of current MC-HGs in flexible electronic sensor applications.

10.
Carbohydr Polym ; 327: 121656, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38171677

RESUMO

In recent years, renewable cellulose-based ion exchange membranes have emerged as promising candidates for capturing green, abundant osmotic energy. However, the low power density and structural/performance instability are challenging for such cellulose membranes. Herein, cellulose-molecule self-assembly engineering (CMA) is developed to construct environmentally friendly, durable, scalable cellulose membranes (CMA membranes). Such a strategy enables CMA membranes with ideal nanochannels (∼7 nm) and tailored channel lengths, which support excellent ion selectivity and ion fluxes toward high-performance osmotic energy harvesting. Finite element simulations also verified the function of tailored nanochannel length on osmotic energy conversion. Correspondingly, our CMA membrane shows a high-power density of 2.27 W/m2 at a 50-fold KCl gradient and super high voltage of 1.32 V with 30-pair CMA membranes (testing area of 22.2 cm2). In addition, the CMA membrane demonstrates long-term structural and dimensional integrity in saline solution, due to their high wet strength (4.2 MPa for N-CMA membrane and 0.5 MPa for P-CMA membrane), and correspondingly generates ultrastable yet high power density more than 100 days. The self-assembly engineering of cellulose molecules constructs high-performance ion-selective membranes with environmentally friendly, scalable, high wet strength and stability advantages, which guide sustainable nanofluidic applications beyond the blue energy.

11.
Small ; 20(11): e2305459, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37922532

RESUMO

Electrocatalyst engineering from the atomic to macroscopic level of electrocatalysts is one of the most powerful routes to boost the performance of electrochemical devices. However, multi-scale structure engineering mainly focuses on the range of atomic-to-particle scale such as hierarchical porosity engineering, while catalyst engineering at the macroscopic level, such as the arrangement configuration of nanoparticles, is often overlooked. Here, a 2D carbon polyhedron array with a multi-scale engineered structure via facile chemical etching, ice-templating induced self-assembly, and high-temperature pyrolysis processes is reported. Controlled phytic acid etching of the carbon precursor introduces homogeneous atomic phosphorous and nitrogen doping, as well as a well-defined mesoporous structure. Subsequent ice-templated self-assembly triggers the formation of a 2D particle array superstructure. The atomic-level doping gives rise to high intrinsic activity, while the well-engineered porous structure and particle arrangement addresses the mass transport limitations at the microscopic particle level and macroscopic electrode level. As a result, the as-prepared electrocatalyst delivers outstanding performance toward oxygen reduction reaction in both acidic and alkaline media, which is better than recently reported state-of-the-art metal-free electrocatalysts. Molecular dynamics simulation together with extensive characterizations indicate that the performance enhancement originates from multi-scale structural synergy.

12.
Small ; 20(16): e2306453, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38032174

RESUMO

Colloidal quantum dots (QDs) are shown to be effective as light-harvesting sensitizers of metal oxide semiconductor (MOS) photoelectrodes for photoelectrochemical (PEC) hydrogen (H2) generation. The CdSe/CdS core/shell architecture is widely studied due to their tunable absorption range and band alignment via engineering the size of each composition, leading to efficient carrier separation/transfer with proper core/shell band types. However, until now the effect of core size on the PEC performance along with tailoring the core/shell band alignment is not well understood. Here, by regulating four types of CdSe/CdS core/shell QDs with different core sizes (diameter of 2.8, 3.1, 3.5, and 4.8 nm) while the thickness of CdS shell remains the same (thickness of 2.0 ± 0.1 nm), the Type II, Quasi-Type II, and Type I core/shell architecture are successfully formed. Among these, the optimized CdSe/CdS/TiO2 photoelectrode with core size of 3.5 nm can achieve the saturated photocurrent density (Jph) of 17.4 mA cm-2 under standard one sun irradiation. When such cores are further optimized by capping alloyed shells, the Jph can reach values of 22 mA cm2 which is among the best-performed electrodes based on colloidal QDs.

13.
Opt Express ; 31(16): 26410-26417, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37710503

RESUMO

We propose and investigate a class of aperiodic grating structure which can achieve perfect Talbot effect under certain conditions. The aperiodic grating structure is obtained by the superposition of two or more sine terms. In the case of two sine terms, the Talbot effect can be realized when the period ratio of two terms is arbitrary. While in the case of more than two sine terms, the period ratios of each term must meet certain extra conditions. The theory has been further verified by numerical simulations. It expands the field of Talbot effect and is of potential significance for subsequent research applications such as optical imaging and measurement.

14.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 40(9): 1155-1159, 2023 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-37643965

RESUMO

OBJECTIVE: To explore the genetic characteristics of a child with Focal segmental glomerulosclerosis and neurodevelopmental syndrome (FSGSNEDS). METHODS: A child with FSGSNEDS who had visited Shengli Oilfield Central Hospital on September 15, 2019 was selected as the study subject. Clinical data of the child was collected, and trio-whole exome sequencing (trio-WES), Sanger sequencing, chromosomal karyotyping analysis, and copy number variation sequencing (CNV-seq) were used to analyze the child and his parents. RESULTS: The child, a 3-year-old boy, had manifested developmental delay, nephrotic syndrome, and epilepsy. Trio-WES and Sanger sequencing showed that he has carried a heterozygous c.1375C>T (p.Q459*) variant of the TRIM8 gene, for which both his parents were of the wild type. Based on guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be pathogenic. No abnormality was found in the chromosomal karyotyping and CNV-seq results of the child and his parents. CONCLUSION: The child was diagnosed with FSGSNEDS, for which the c.1375C>T variant of the TRIM8 gene may be accountable.


Assuntos
Variações do Número de Cópias de DNA , Glomerulosclerose Segmentar e Focal , Masculino , Humanos , Criança , Pré-Escolar , Glomerulosclerose Segmentar e Focal/genética , Genômica , Heterozigoto , Cariotipagem , Proteínas de Transporte , Proteínas do Tecido Nervoso
15.
Nanomicro Lett ; 15(1): 170, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37407863

RESUMO

Cutting-edge heat spreaders for soft and planar electronics require not only high thermal conductivity and a certain degree of flexibility but also remarkable self-adhesion without thermal interface materials, elasticity, arbitrary elongation along with soft devices, and smart properties involving thermal self-healing, thermochromism and so on. Nacre-like composites with excellent in-plane heat dissipation are ideal as heat spreaders for thin and planar electronics. However, the intrinsically poor viscoelasticity, i.e., adhesion and elasticity, prevents them from simultaneous self-adhesion and arbitrary elongation along with current flexible devices as well as incurring high interfacial thermal impedance. In this paper, we propose a soft thermochromic composite (STC) membrane with a layered structure, considerable stretchability, high in-plane thermal conductivity (~ 30 W m-1 K-1), low thermal contact resistance (~ 12 mm2 K W-1, 4-5 times lower than that of silver paste), strong yet sustainable adhesion forces (~ 4607 J m-2, 2220 J m-2 greater than that of epoxy paste) and self-healing efficiency. As a self-adhesive heat spreader, it implements efficient cooling of various soft electronics with a temperature drop of 20 °C than the polyimide case. In addition to its self-healing function, the chameleon-like behavior of STC facilitates temperature monitoring by the naked eye, hence enabling smart thermal management.

16.
Nanomicro Lett ; 15(1): 109, 2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37071340

RESUMO

Realizing real-time monitoring of physiological signals is vital for preventing and treating chronic diseases in elderly individuals. However, wearable sensors with low power consumption and high sensitivity to both weak physiological signals and large mechanical stimuli remain challenges. Here, a flexible triboelectric patch (FTEP) based on porous-reinforcement microstructures for remote health monitoring has been reported. The porous-reinforcement microstructure is constructed by the self-assembly of silicone rubber adhering to the porous framework of the PU sponge. The mechanical properties of the FTEP can be regulated by the concentrations of silicone rubber dilution. For pressure sensing, its sensitivity can be effectively improved fivefold compared to the device with a solid dielectric layer, reaching 5.93 kPa-1 under a pressure range of 0-5 kPa. In addition, the FTEP has a wide detection range up to 50 kPa with a sensitivity of 0.21 kPa-1. The porous microstructure makes the FTEP ultra-sensitive to external pressure, and the reinforcements endow the device with a greater deformation limit in a wide detection range. Finally, a novel concept of the wearable Internet of Healthcare (IoH) system for real-time physiological signal monitoring has been proposed, which could provide real-time physiological information for ambulatory personalized healthcare monitoring.

17.
Sensors (Basel) ; 23(5)2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36904636

RESUMO

The sensitivity and selectivity profiles of gas sensors are always changed by sensor drifting, sensor aging, and the surroundings (e.g., temperature and humidity changes), which lead to a serious decline in gas recognition accuracy or even invalidation. To address this issue, the practical solution is to retrain the network to maintain performance, leveraging its rapid, incremental online learning capacity. In this paper, we develop a bio-inspired spiking neural network (SNN) to recognize nine types of flammable and toxic gases, which supports few-shot class-incremental learning, and can be retrained quickly with a new gas at a low accuracy cost. Compared with gas recognition approaches such as support vector machine (SVM), k-nearest neighbor (KNN), principal component analysis (PCA) +SVM, PCA+KNN, and artificial neural network (ANN), our network achieves the highest accuracy of 98.75% in five-fold cross-validation for identifying nine types of gases, each with five different concentrations. In particular, the proposed network has a 5.09% higher accuracy than that of other gas recognition algorithms, which validates its robustness and effectiveness for real-life fire scenarios.

18.
ACS Appl Mater Interfaces ; 15(6): 7978-7986, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36727599

RESUMO

The promotion of magnetic field on catalytic performance has attracted extensive attention. However, little research has been reported on the performance of the oxygen evolution reaction (OER) for the modulating intrinsic magnetism of the catalyst under a magnetic field. Herein, we adjusted the intrinsic magnetism of the CoxNi1-xFe2O4-nanosheet by adjusting the ratio of Co and Ni, and researched the relationship between the OER activity and the intrinsic magnetism. The results indicate that the CoFe2O4-nanosheet has the most OER activity increases in the magnetic field due to the optimal intrinsic magnetism. The required overpotential of CoFe2O4-nanosheet@NF to reach a current density of 10 mA cm-2 was reduced by 21 mV under about 100 mT magnetic field compared with no magnetic field, and the degree of improvement of OER activity of different magnetic catalysts in the same magnetic field is positively correlated with the intrinsic magnetism of the catalyst. Therefore, magnetic field assistance provides a new, effective, and general strategy to improve the activity of electrodes for water splitting.

19.
Small ; 19(15): e2206316, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36642852

RESUMO

Manipulating the separation and transfer behaviors of charges has long been pursued for promoting the photoelectrochemical (PEC) hydrogen generation based on II-VI quantum dot (QDs), but remains challenging due to the lack of effective strategies. Herein, a facile strategy is reported to regulate the recombination and transfer of interfacial charges through tuning the surface stoichiometry of heterostructured QDs. Using this method, it is demonstrated that the PEC cells based on CdSe-(Sex S1- x )4 -(CdS)2 core/shell QDs with a proper Ssurface /Cdsurface ratio exhibits a remarkably improved photocurrent density (≈18.4 mA cm-2 under one sun illumination), superior to the PEC cells based on QDs with Cd-rich or excessive S-rich surface. In-depth electrochemical and spectroscopic characterizations reveal the critical role (hole traps) of surface S atoms in suppressing the recombination of photogenerated charges, and further attribute the inferior performance of excessive S-rich QDs to the impeded charge transfer from QDs to TiO2 and electrolyte. This work puts forward a simple surface engineering strategy for improving the performance of QDs PEC cells, providing an efficient method to guide the surface design of QDs for their applications in other optoelectronic devices.

20.
ACS Nano ; 17(1): 346-354, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36574462

RESUMO

Elastic strains in metallic catalysts induce enhanced selectivity for carbon dioxide reduction (CO2R) toward valuable multicarbon (C2+) products. However, under working conditions, the structure of catalysts inevitably undergoes reconstruction, hardly retaining the initial strain. Herein, we present a metal/metal oxide synthetic strategy to introduce and maintain the tensile strain in a copper/ceria heterostructure, enabled by the presence of a thin interface layer of Cu2O/CeO2. The tensile strain in the copper domain and deficient electron environment around interfacial Cu sites resulted in strengthened adsorption of carbonaceous intermediates and promoted *CO dimerization. The strain effect in the copper/ceria heterostructure leads to an improved C2+ selectivity with a maximum Faradaic efficiency of 76.4% and a half-cell power conversion efficiency of 49.1%. The fundamental insights gained from this system can facilitate the rational design of heterostructure catalysts for CO2R.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA