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The limited adsorption and activation of CO2 on catalyst and the high energy barrier for intermediate formation hinder the development of electrochemical CO2 reduction reactions (CO2RR). Herein, this work reports a boron (B) doping engineering in AgCd bimetals to alleviate the above limitations for efficient CO2 electroreduction to CO and aqueous Zn-CO2 batteries. Specifically, the B-doped AgCd bimetallic catalyst (AgCd-B) is prepared via a simple reduction reaction at room temperature. A combination of in situ experiments and density functional theory (DFT) calculations demonstrates that B-doping simultaneously enhances the adsorption and activation of CO2 and reduces the binding energy of the intermediates by moderating the electronic structure of bimetals. As a result, the AgCd-B catalyst exhibits a high CO Faraday efficiency (FECO) of 99% at -0.8 V versus reversible hydrogen electrode (RHE). Additionally, it maintains a FECO over 92% at a wide potential window of 600 mV (-0.6 to -1.1 V versus RHE). Furthermore, the AgCd-B catalyst coupled with the Zn anode to assemble aqueous Zn-CO2 batteries shows a power density of 20.18 mW cm-2 and a recharge time of 33 h.
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In this work, a novel porous-structure electrochemical PbO2 filter (PEF-PbO2) was developed to achieve the reuse of bio-treated textile wastewater. The characterization of PEF-PbO2 confirmed that its coating has a variable pore size that increases with depth from the substrate, and the pores with a size of 5 µm account for the largest proportion. The study on the role of this unique structure illustrated that PEF-PbO2 possesses a larger electroactive area (4.09 times) than the conventional electrochemical PbO2 filter (EF-PbO2) and enhanced mass transfer (1.39 times) in flow mode. The investigation of operating parameters with a special discussion of electric energy consumption suggested that the optimal conditions were a current density of 3 mA cm-2, Na2SO4 concentration of 10 g L-1 and pH value of 3, which resulted in 99.07% and 53.3% removal of Rhodamine B and TOC, respectively, together with an MCETOC of 24.6%. A stable removal of 65.9% COD and 99.5% Rhodamine B with a low electric energy consumption of 5.19 kWh kg-1 COD under long-term reuse of bio-treated textile wastewater indicated that PEF-PbO2 was durable and energy-efficient in practical applications. Mechanism study by simulation calculation illustrated that the part of the pore of the PEF-PbO2's coating with small size (5 µm) plays an important role in this excellent performance which provides the advantage of rich ·OH concentration, short pollutant diffusion distance and high contact possibility.
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Águas Residuárias , Poluentes Químicos da Água , Óxidos/química , Porosidade , Eletrodos , Poluentes Químicos da Água/análise , Têxteis , Oxirredução , Titânio/químicaRESUMO
The intramuscular fat (IMF) content in sheep is associated with IMF deposition, which is affected by intramuscular adipocyte hypertrophy. In this study, we established an in vitro high glucose model of intramuscular adipocytes of sheep to investigate the expression of cannabinoid receptor 1 (CB1) gene, fatty acid-binding protein 4 (FABP4) gene, lipid metabolism-associated genes (acetyl-CoA carboxylase [ACC], fatty acid synthase [FAS], and stearoyl-CoA desaturase 1 [SCD1]), and transcription factors (liver X receptor [LXRα]), sterol regulatory element-binding transcription factor 1 [SREBF-1], and carbohydrate-responsive element-binding protein [ChREBP]) as well as the changes in the lipid and triglyceride (TG) levels in intramuscular adipocytes. The results showed that the differentiated mature adipocytes had a spherical shape, and the number and volume of the lipid droplets gradually increased over time under high glucose conditions. The lipid and TG levels in intramuscular adipocytes of sheep continuously increased under high glucose conditions. Furthermore, CB1, FABP4, ACC, FAS, SCD1, LXRα, SREBF-1, and ChREBP were highly expressed under high glucose conditions, suggesting that the energetic nutrients also affect the expression of the CB1 gene, which works in coordination with lipid metabolism-associated genes and are beneficial for lipid deposition in the intramuscular adipocytes of sheep.
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Adipócitos , Metabolismo dos Lipídeos , Ovinos , Animais , Metabolismo dos Lipídeos/genética , Glucose/metabolismo , LipídeosRESUMO
BACKGROUND: Anthocyanins have distinct biological functions in plant coloring, plant defense against strong light, UV irradiation, and pathogen infection. Aromatic hydroxyl groups and ortho-dihydroxyl groups in anthocyanins are able to inhibit free-radical chain reactions and hydroxyl radicals. Thus, anthocyanins play an antioxidative role by removing various types of ROS. Pepper is one of the solanaceous vegetables with the largest cultivation area in China. The purple-fruited pepper is rich in anthocyanins, which not only increases the ornamental nature of the pepper fruit but also benefits the human body. In this experiment, light-induced regulatory pathways and related specific regulators of anthocyanin biosynthesis were examined through integrative transcriptomic and metabolomic analysis. RESULTS: Results revealed that delphinium 3-O-glucoside significantly accumulated in light exposed surface of pepper fruit after 48 h as compared to shaded surface. Furthermore, through strand-specific sequencing technology, 1341 differentially expressed genes, 172 differentially expressed lncRNAs, 8 differentially expressed circRNAs, and 28 differentially expressed miRNAs were identified significantly different among both surfaces. The flavonoid synthesis pathway was significantly enriched by KEGG analysis including SHT (XM_016684802.1), AT-like (XM_016704776.1), CCoAOMT (XM_016698340.1, XM_016698341.1), CHI (XM_016697794.1, XM_016697793.1), CHS2 (XM_016718139.1), CHS1B (XM_016710598.1), CYP98A2-like (XM_016688489.1), DFR (XM_016705224.1), F3'5'H (XM_016693437.1), F3H (XM_016705025.1), F3'M (XM_016707872.1), LDOX (XM_016712446.1), TCM (XM_016722116.1) and TCM-like (XM_016722117.1). Most of these significantly enriched flavonoid synthesis pathway genes may be also regulated by lncRNA. Some differentially expressed genes encoding transcription factors were also identified including MYB4-like (XM_016725242.1), MYB113-like (XM_016689220.1), MYB308-like (XM_016696983.1, XM_016702244.1), and EGL1 (XM_016711673.1). Three 'lncRNA-miRNA-mRNA' regulatory networks with sly-miR5303, stu-miR5303g, stu-miR7997a, and stu-miR7997c were constructed, including 28 differentially expressed mRNAs and 6 differentially expressed lncRNAs. CONCLUSION: Possible light regulated anthocyanin biosynthesis and transport genes were identified by transcriptome analysis, and confirmed by qRT-PCR. These results provide important data for further understanding of the anthocyanin metabolism in response to light in pepper.
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Antocianinas/biossíntese , Capsicum/genética , Capsicum/metabolismo , MicroRNAs/genética , Antocianinas/análise , Antocianinas/genética , Capsicum/fisiologia , Frutas/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Luz , Pigmentação , Proteínas de Plantas/genética , RNA Longo não Codificante/genética , Fatores de Transcrição/genéticaRESUMO
Light is the key factor affecting the synthesis of anthocyanins in pepper. In this study, pepper fruit under different light days was used as experimental material to explore the synthesis of anthocyanins in purple pepper. A total of 38 flavonoid metabolites were identified in the purple pepper germplasm HNUCA21 by liquid chromatography-tandem mass spectrometry (LC-MS/MS), of which 30 belong to anthocyanins. The detected anthocyanin with the highest content was Delphinidin-3-O-glucoside (17.13 µg/g), which reached the maximum after 168 h of light treatment. Through weighted gene co-expression network analysis (WGCNA), the brown module was identified to be related to the early synthesis of anthocyanins. This module contains many structural genes related to flavonoid synthesis, including chalcone synthase (CHS 107871256, 107864266), chalcone isomerase (CHI 107871144, 107852750), dihydroflavonol 4-reductase (DFR 107860031), flavonoid 3' 5'-hydroxylase (F3'5'H 107848667), flavonoid 3'-monooxygenase (F3M 107862334), leucoanthocyanidin dioxygenase (LDOX 107866341), and trans-cinnamate 4-monooxygenase (TCM 107875406, 107875407). The module also contained some genes related to anthocyanin transport function, such as glutathione S-transferase (GST 107861273), anthocyanidin 3-O-glucosyltransferase (UDPGT 107861697, 107843659), and MATE (107863234, 107844661), as well as some transcription factors, such as EGL1 (107865400), basic helix-loop-helix 104 (bHLH104 107864591), and WRKY44 (107843538, 107843524). The co-expression regulatory network indicated the involvement of CHS, DFR, CHI, and EGL1, as well as two MATE and two WRKY44 genes in anthocyanin synthesis. The identified genes involved in early, middle, and late light response provided a reference for the further analysis of the regulatory mechanism of anthocyanin biosynthesis in pepper.
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Antocianinas , Capsicum , Antocianinas/metabolismo , Capsicum/genética , Capsicum/metabolismo , Cromatografia Líquida , Flavonoides/metabolismo , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Espectrometria de Massas em TandemRESUMO
Advanced fabrication of surface metal-organic complexes with specific coordination configuration and metal centers will facilitate to exploit novel nanomaterials with attractive electronic/magnetic properties. The precise on-surface synthesis provides an appealing strategy for in situ construction of complex organic ligands from simple precursors autonomously. In this paper, distinct organic ligands with stereo-specific conformation are separately synthesized through the well-known dehalogenative coupling. More interestingly, the exo-bent ligands promote the mono-iron chelated complexes with the Fe center significantly decoupled from the surface and of high spin, while the endo-bent ligands lead to bi-iron chelated ones instead with ferromagnetic properties.
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Complexos de Coordenação , Ferro , Ligantes , Modelos Moleculares , Conformação MolecularRESUMO
Thermally induced non-equilibrium gas flows have been simulated in the present study by coupling kinetic and extended thermodynamic methods. Three different types of thermally induced gas flows, including temperature-discontinuity- and temperature-gradient-induced flows and radiometric flow, have been explored in the transition regime. The temperature-discontinuity-induced flow case has shown that as the Knudsen number increases, the regularised 26 (R26) moment equation system will gradually loss its accuracy and validation. A coupling macro- and microscopic approach is employed to overcome these problems. The R26 moment equations are used at the macroscopic level for the bulk flow region, while the kinetic equation associated with the discrete velocity method (DVM) is applied to describe the gas close to the wall at the microscopic level, which yields a hybrid DVM/R26 approach. The numerical results have shown that the hybrid DVM/R26 method can be faithfully used for the thermally induced non-equilibrium flows. The proposed scheme not only improves the accuracy of the results in comparison with the R26 equations, but also extends their capability with a wider range of Knudsen numbers. In addition, the hybrid scheme is able to reduce the computational memory and time cost compared to the DVM.
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A large number of molecules are usually required to model atomic walls in molecular dynamics simulations. A virtual-wall model is proposed in this study to describe fluid-wall molecular interactions, for reducing the computational time. The infinite repetition of unit cell structures within the atomic wall causes the periodicity of the force acting on a fluid molecule from the wall molecules. This force is first calculated and then stored in the memory. A fluid molecule appearing in the wall force field is subjected to the force from the wall molecules. The force can then be determined by the position of the molecule relative to the wall. This model avoids excessive calculations of fluid-wall interactions and reduces the computational time drastically. The time reduction is significant for small fluid density and channel height. The virtual-wall model is applied to Poiseuille and Couette flows, and to a flow in a channel with a rough surface. Results of the virtual and atomic wall simulations agree well with each other, thereby indicating the usefulness of the virtual-wall model. The appropriate bin size and cut-off radius in the virtual-wall model are also discussed.
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Simulação de Dinâmica MolecularRESUMO
This paper addresses the critical issue of leading edge erosion (LEE) on modern wind turbine blades (WTBs) caused by solid particle impacts. LEE can harm the structural integrity and aerodynamic performance of WTBs, leading to reduced efficiency and increased maintenance costs. This study employs a novel particle-based approach called hybrid peridynamics-discrete element method (PD-DEM) to model the impact of solid particles on WTB leading edges and target material failure accurately. It effectively captures the through-thickness force absorption and the propagation of stresses within the leading edge coating system composed of composite laminates. The amount of mass removed and the mean displacement of the target material points can be reliably calculated using the current method. Through a series of tests, the research demonstrates the method's ability to predict impact force changes with varying particle size, velocity, impact angles and positions. Moreover, this study offers a significant improvement in erosion prediction capability and the development of design specifications. This work contributes to the advancement of WTB design and maintenance practices to mitigate LEE effectively.
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OBJECTIVE: The purpose of this study was to explain the internal mechanism of attention focus affecting performance of countermovement jump based on muscle synergy theory. METHODS: Participants involved untrained group(N = 10) and high-level group(N = 11). Subjects performed countermovement jump with internal attention focus instruction (IF), external distal attention focus instruction (EDF), and external proximal attention focus instruction (EPF). The electromyography (EMG) signals of the dominant vastus lateralis muscle (VL), semitendinosus muscle (ST), tibial anterior muscle (TA), rectus femoris muscle (RF), and medial gastrocnemius (MG) were recorded. The non-negative matrix factorization was used to extract muscle synergy. RESULTS: 1) Attention focus did not affect countermovement jump performance and the number of muscle synergy in the high-level group (P>0.05). 2) Attention focus instructions affected the untrained group countermovement jump (P<0.05). and EDF and EPF reduced the number of muscle synergy. 3)The Cohen's d of EDF (0.269) was less than EPF (0.377) in untrained group. CONCLUSION: For the untrained people, the improved motor performance caused by attention focus resembled the adaptive changes that occur with long-term training. The reason why an EDF is superior to EPF is that the former produces more thorough changes in muscle synergy.
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Atenção , Eletromiografia , Músculo Esquelético , Humanos , Masculino , Músculo Esquelético/fisiologia , Atenção/fisiologia , Adulto Jovem , Adulto , Feminino , Desempenho Atlético/fisiologiaRESUMO
OBJECTIVE: Kushen (Sophora flavescens Ait.) has a long history of medicinal use in China due to its medicinal values, such as antibacterial, antiviral, and anti-inflammatory. Rapid discovery of the components and the medicinal effects exerted by Kushen will help elucidate the science of Kushen in curing diseases. GSK3ß (glycogen synthase kinase-3 beta) is a protein kinase with a wide range of physiological functions, such as antibacterial, antiviral, and anti-inflammatory. The discovery of inhibitors targeting GSK3ß from Kushen was not only helpful for the rapid discovery of the components responsible for the efficacy of Kushen but also important for the development of novel drugs. METHODS: In this study, the chemical composition of Kushen was extracted from the TMSCP database. Molecular docking, GSK3ß enzyme assay, and molecular dynamics simulations were used to discover the GSK3ß inhibitors from the chemical composition of Kushen. RESULTS: A total of 113 chemical compositions of Kushen were extracted from the TMSCP database. Molecular docking indicated that 15 chemical compositions of Kushen scored better than -8 kcal/mol against GSK3ß. GSK3ß enzyme assay demonstrated several inhibitory activities of kushenol I and kushenol F with IC50 values of 7.53 ± 2.55 µM and 4.96 ± 1.29 µM, respectively. Molecular dynamics simulations were used to reveal the interactions of kushenol I and kushenol F with GSK3ß from structural and energetic perspectives. CONCLUSION: Kushenol I and kushenol F could be the material basis for the antibacterial, antiviral, and anti-inflammatory properties of Kushen.
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MicroRNAs (miRNAs) are promising biomarkers for the early detection of disease, and many miRNA-based diagnostic models have been constructed to distinguish patients and healthy individuals. To thoroughly utilize the miRNA-profiling data across different sequencing platforms or multiple centers, the models accounting the batch effects were demanded for the generalization of medical application. We conducted transcription factor (TF)-mediated miRNA-miRNA interaction network analysis and adopted the within-sample expression ratios of miRNA pairs as predictive markers. The ratio of the expression values between each miRNA pair turned out to be stable across multiple data sources. A genetic algorithm-based classifier was constructed to quantify risk scores of the probability of disease and discriminate disease states from normal states in discovery, with a validation dataset for COVID-19, renal cell carcinoma, and lung adenocarcinoma. The predictive models based on the expression ratio of interacting miRNA pairs demonstrated good performances in the discovery and validation datasets, and the classifier may be used accurately for the early detection of disease.
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Moderate traumatic brain injury (mTBI) involves a series of complex pathophysiological processes in not only the area in direct contact with mechanical violence but also in other brain regions far from the injury site, which may be important factors influencing subsequent neurological dysfunction or death. The medulla oblongata (MO) is a key area for the maintenance of basic respiratory and circulatory functions, whereas the pathophysiological processes after mTBI have rarely drawn the attention of researchers. In this study, we established a closed-head cortical contusion injury model, identified 6 different time points that covered the acute, subacute, and chronic phases, and then used nontargeted metabolomics to identify and analyze the changes in differential metabolites (DMs) and metabolic pathways in the MO region. Our results showed that the metabolic profile of the MO region underwent specific changes over time: harmaline, riboflavin, and dephospho-coenzyme A were identified as the key DMs and play important roles in reducing inflammation, enhancing antioxidation, and maintaining homeostasis. Choline and glycerophospholipid metabolism was identified as the key pathway related to the changes in MO metabolism at different phases. In addition, we confirmed increases in the levels of inflammatory factors and the activation of astrocytes and microglia by Western blot and immunofluorescence staining, and these findings were consistent with the nontargeted metabolomic results. These findings suggest that neuroinflammation plays a central role in MO neuropathology after mTBI and provide new insights into the complex pathophysiologic mechanisms involved after mTBI.
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Lesões Encefálicas Traumáticas , Bulbo , Metabolômica , Camundongos Endogâmicos C57BL , Doenças Neuroinflamatórias , Animais , Camundongos , Metabolômica/métodos , Lesões Encefálicas Traumáticas/metabolismo , Bulbo/metabolismo , Masculino , Doenças Neuroinflamatórias/metabolismo , Modelos Animais de DoençasRESUMO
BACKGROUND: EP300 (E1A binding protein p300) played a significant role in serial diseases such as cancer, neurodegenerative disease. Therefore, it became a significant target. METHODS: Targeting EP300 discovery of a novel drug to alleviate these diseases. In this paper, 17 candidate compounds were obtained using a structure-based virtual screening approach, 4449-0460, with an IC50 of 5.89 ± 2.08 uM, which was identified by the EP300 bioactivity test. 4449-0460 consisted of three rings. The middle benzene ring connected the 5-ethylideneimidazolidine-2,4-dione group and the 3-F-Phenylmethoxy group. RESULTS: Furthermore, the interaction mechanism between 4449-0460 and EP300 was explored by combining molecular dynamics (MD) simulations and binding free energy calculation methods. CONCLUSION: The binding free energy of EP300 with 4449-0460 was -10.93 kcal/mol, and mainly came from the nonpolar energy term (ΔGnonpolar). Pro1074, Phe1075, Val1079, Leu1084, and Val1138 were the key residues in EP300/4449-0460 binding with more -1 kcal/mol energy contribution. 4449-0460 was a promising inhibitor targeting EP300, which had implications for the development of drugs for EP300-related diseases.
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Descoberta de Drogas , Proteína p300 Associada a E1A , Simulação de Dinâmica Molecular , Proteína p300 Associada a E1A/antagonistas & inibidores , Proteína p300 Associada a E1A/metabolismo , Humanos , Estrutura Molecular , Avaliação Pré-Clínica de Medicamentos , Relação Estrutura-Atividade , Relação Dose-Resposta a DrogaRESUMO
Emerging evidence indicates a significant role of remnant cholesterol in contributing to the residual risk associated with major adverse cardiovascular events (MACE). This study aims to evaluate the dose-response relationship between remnant cholesterol and the risk of MACE. PubMed, Embase and Cochrane databases were reviewed to identify cohort studies published in English up to 1 August 2023. Twenty-eight articles were selected. Pooled hazard ratios (HR) and their 95% confidence intervals (CIs) were calculated using fixed or random-effects models to evaluate the association between remnant cholesterol and the risk of MACE. The dose-response relationship between remnant cholesterol levels and the risk of MACE was analyzed using the linear model and restricted cubic spline regression models. For calculated remnant cholesterol levels, the pooled HR (95% CI) of MACE for per 1-SD increase was 1.13 (1.08, 1.17); HR (95% CI) for the second quartile (Q2), the third quartile (Q3) and the highest quartile (Q4) of remnant cholesterol levels were 1.14 (1.03, 1.25), 1.43 (1.23, 1.68) and 1.68 (1.44, 1.97), respectively, compared with the lowest quartile (Q1). For measured remnant cholesterol levels, the pooled HR (95% CI) of MACE per 1-SD increase was 1.67 (1.39, 2.01). The dose-response meta-analysis showed a dose-response relationship between remnant cholesterol levels and the risk of MACE, both on a linear trend (Pâ <â 0.0001) and a nonlinear trend (Pâ <â 0.0001). The risk of MACE is associated with increased levels of remnant cholesterol, and the dose-response relationship between remnant cholesterol levels and the risk of MACE showed both linear and nonlinear trends.
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Doenças Cardiovasculares , Colesterol , Humanos , Colesterol/sangue , Doenças Cardiovasculares/epidemiologia , Fatores de Risco , Medição de Risco/métodos , Biomarcadores/sangueRESUMO
Dyes contaminating the sewages have seriously threatened the living beings and their separation from wastewater in terms of potential resource recovery is of high value. Herein, both of metal node doping and ligand group grafting were taken into account to enhance the adsorption selectivity of Fe-MOFs towards cationic dyes. The positive correlation between copper doping amount and selective coefficient (∂MOMB) for methylene blue (MB) over methyl orange (MO) within a certain range was mainly attributed to the increased surface negative charges via partial replacement of Fe(III) with Cu(II). Moreover, the amount of surface negative charges was further increased after amino functionalization and there was a synergism between Cu(II) and -NH2 in selectivity enhancement. As a result, Fe0.6Cu0.4-BDC-NH2 exhibited a 22.5-times increase in ∂MOMB and other cationic dyes including malachite green (MG) and rhodamine B (Rh. B) could also be selectively separated from binary and quaternary mixed dye systems. Moreover, Fe0.6Cu0.4-BDC-NH2 showed many superiorities like a wide pH range of 4.0-8.0, strong anti-interference ability over various inorganic ions, good recyclability, and stability. The adsorption kinetics and isotherm suggested that the MB adsorption process was a homogeneous single-layer chemisorption. Additionally, the thermodynamics manifested that the overall process was exothermic and spontaneous. According to the FT-IR and XPS spectra analysis, the electrostatic interaction and hydrogen bonding were determined as the main driving forces, and π-π interaction also contributed to the adsorption process.
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In this work, an electric field-enhanced heterogeneous catalytic ozonation (EHCO) was systematically investigated using a prepared FeOx/PAC catalyst. The EHCO process exhibited high sulfadiazine (SDZ) and TOC removal efficiency compared with electrocatalysis (EC) and heterogeneous catalytic ozonation (HCO) process. Almost 100% of SDZ was removed within 2 min, and the TOC removal reached approximately 85% within 60 min. Quenching experiments and EPR analysis suggested that the prominent SDZ and TOC removal performance is supported by the enhanced ·OH generation ability. Further study proved that H2O2 formed by O2 electrochemical reduction, peroxone reaction and electrochemical reduction of ozone contributed to improving ·OH generation. Furthermore, the EHCO system showed satisfactory stability and recyclability compared to conventional HCO systems, and the SDZ and TOC removal rates were maintained at ≥95% and ≥70% in 16 consecutive recycles, respectively. Meanwhile, XPS analysis and Boehm's titration for the FeOx/PAC catalyst used in HCO and EHCO process confirmed that the external electron supply could restrain the oxidation of surface functional groups of PAC and maintain a balance of the Fe(II)/Fe(III) ratio, which proved the critical role of cathode reduction in catalyst in situ regeneration during long consecutive recycles. In addition, the EHCO system could achieve more than 80% SDZ removal within 2 min in different water matrices. These results confirmed that the EHCO process has a wide application perspective for refractory organics removal in actual wastewater.
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Ozônio , Poluentes Químicos da Água , Purificação da Água , Peróxido de Hidrogênio , Compostos Férricos , Sulfadiazina/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Ozônio/análise , CatáliseRESUMO
We use molecular dynamics (MD) simulations to investigate the dynamic wetting of nanoscale water droplets on moving surfaces. The density and hydrogen bonding profiles along the direction normal to the surface are reported, and the width of the water depletion layer is evaluated first for droplets on three different static surfaces: silicon, graphite, and a fictitious superhydrophobic surface. The advancing and receding contact angles, and contact angle hysteresis, are then measured as a function of capillary number on smooth moving silicon and graphite surfaces. Our results for the silicon surface show that molecular displacements at the contact line are influenced greatly by interactions with the solid surface and partly by viscous dissipation effects induced through the movement of the surface. For the graphite surface, however, both the advancing and receding contact angles values are close to the static contact angle value and are independent of the capillary number; i.e., viscous dissipation effects are negligible. This finding is in contrast with the wetting dynamics of macroscale water droplets, which show significant dependence on the capillary number.
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Simulação de Dinâmica Molecular , Nanoestruturas/química , Grafite/química , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Silício/química , Propriedades de SuperfícieRESUMO
Bismuth (Bi) is a promising material as the anode for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) due to its characteristics such as reasonable price and high theoretical volumetric capacity (3800 mAh cm-3). Nevertheless, considerable drawbacks have hindered the practical applications of Bi, including its relatively low electrical conductivity and inevitable volumetric change during the alloying/dealloying processes. To solve these problems, we proposed a novel design:Bi nanoparticles were synthesized via a single-step low-pressure vapor-phase reaction and embedded onto the surfaces of multi-walled carbon nanotubes (MWCNTs). After being vaporized at 650â and 10-5 Pa, Bi nanoparticles less than 10 nm were uniformly distributed in the three-dimensional (3D) MWCNT networks to form a Bi/MWNTs composite. In this unique design, the nanostructured Bi can reduce the risk of structural rupture during cycling, and the structure of the MWCMT network is beneficial in shortening the electron/ion transport path. In addition, MWCNTs can improve the overall conductivity of the Bi/MWCNTs composite and prevent particle aggregation, thus improving the cycling stability and rate performance. As an anode material for SIB, the Bi/MWCNTs composite has demonstrated excellent fast charging performance with a reversible capacity of 254 mAh/g at 20 A/g. A capacity of 221mAhg-1 after cycling at 10 A/g for 8000 cycles has also been achieved for SIB. As an anode material for PIB, the Bi/MWCNTs composite has delivered excellent rate performances with a reversible capacity of 251 mAh/g at 20 A/g. A specific capacity of 270mAhg-1 after cycling at 1Ag-1 for 5000 cycles has also been achieved for PIB.
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Membrane fouling and regeneration are the key issues for the application of membrane separation (MS) technology. Reactive electrochemical membranes (REMs) exhibited high, stable permeate flux and the function of chemical-free electrochemical regeneration. This study fabricated a micro-filtration REM characterized by a PbO2 layer (PbO2-REM) to investigate the electro-triggered anti-fouling and regeneration progress within REMs. The PbO2-REM exhibited a three-dimensional porous structure with a few branch-like micro-pores. The PbO2-REM could alleviate Humic acid (HA) and Bisphenol A (BPA) fouling through electrochemical degradation combined with bubble migration, which achieved the best anti-fouling performance at current density of 4 mA cm-2 with 99.2% BPA removal. Regeneration in the electro-backwash (e-BW) mode was found as eight times that in the forward wash and full flux recovery was achieved at a current density of 3 mA cm-2. EIS and simulation study also confirmed complete regeneration by e-BW, which was ascribed to the air-water wash formed by bubble migration and flow. Repeated regeneration tests showed that PbO2-REM was stable for more than five cycles, indicating its high durability for practical uses. Mechanism analysis assisted by finite element simulation illustrated that the high catalytic PbO2 layer plays an important role in antifouling and regeneration.