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1.
Proc Natl Acad Sci U S A ; 120(10): e2206619120, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36848552

RESUMO

Selective oxidation of methane to organic oxygenates over metal-organic frameworks (MOFs) catalysts at low temperature is a challenging topic in the field of C1 chemistry because of the inferior stability of MOFs. Modifying the surface of Cu-BTC via hydrophobic polydimethylsiloxane (PDMS) at 235 °C under vacuum not only can dramatically improve its catalytic cycle stability in a liquid phase but also generate coordinatively unsaturated Cu(I) sites, which significantly enhances the catalytic activity of Cu-BTC catalyst. The results of spectroscopy characterizations and theoretical calculation proved that the coordinatively unsaturated Cu(I) sites made H2O2 dissociative into •OH, which formed Cu(II)-O active species by combining with coordinatively unsaturated Cu(I) sites for activating the C-H bond of methane. The high productivity of C1 oxygenates (CH3OH and CH3OOH) of 10.67 mmol gcat.-1h-1 with super high selectivity of 99.6% to C1 oxygenates was achieved over Cu-BTC-P-235 catalyst, and the catalyst possessed excellent reusability.

2.
Water Sci Technol ; 88(11): 2849-2861, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38096073

RESUMO

Capacitive deionization (CDI) is considered a promising technology for desalination of sea or brackish water. In this study, a ZnS/g-C3N4 composite was synthesized through a one-step high-temperature method and used as the main material to fabricate CDI electrodes. The results of SEM and TEM showed that spherical-like nanoparticles of ZnS were uniformly distributed on the g-C3N4 sheet. The g-C3N4 phase facilitates the ZnS particles precipitate and restrain their agglomeration, which contributes to a high specific surface area of ZnS. Furthermore, the electrochemical test results indicated that ZnS/g-C3N4 composite had a good capacitance characteristic, low resistance, and high electrochemical stability. Finally, the desalinization performance of the ZnS/g-C3N4 composite electrodes was tested in traditional mode and membrane capacitive deionization (MCDI) mode. The results showed that ZnS/g-C3N4//ZnS/g-C3N4 (MCDI) exhibited an optimal desalination capacity. The adsorption amount was 27.65, 50.26, and 65.34 mg/g for NaCl initial concentration of 200, 400, and 600 mg/L, respectively, with the voltage of 1.2 V and flow rate of 5 mL/min. Increasing initial concentration enhanced the conductivity and ion migration rate so as to increase the NaCl adsorption amount. ZnS/g-C3N4 composite can be used as potential electrode material for high performance of MCDI.


Assuntos
Cloreto de Sódio , Purificação da Água , Purificação da Água/métodos , Condutividade Elétrica , Águas Salinas , Eletrodos
3.
Arch Microbiol ; 204(6): 293, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35507236

RESUMO

A Gram-stain-negative, cocci-to-oval-shaped bacterial strain, designated XZZS9T, was isolated from the rhizosphere soil of Pinus sylvestris var. mongolica and characterized taxonomically using a polyphasic approach. Growth occurred at 20-35 °C (optimum, 28 °C), pH 6.0-11.0 (optimum, pH 7.0), and in 0-1% NaCl (optimum, 0%). Phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain XZZS9T was related to members of the genus Roseococcus, with the highest sequence identity to Roseococcus microcysteis NIBR12T (96.9%). The major cellular fatty acids (> 5% of the total) were C18:1 ω7c and C19:0 cyclo ω8c. The major isoprenoid quinone was Q-9 and the polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, an unidentified glycophospholipid, and an unidentified phospholipid. Genome sequencing revealed that had a genome size of 4.79 Mbp with a G + C content of 69.5%. Comparative genomic analyses clearly separated strain XZZS9T from the known species of the genus Roseococcus based on average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values below the thresholds for species delineation. Genome annotations did not find pufL and pufM genes in strain XZZS9T, suggesting a possible lack of photosynthetic reaction. Based on genotypic and phenotypic characteristics, strain XZZS9T represents a novel species of the genus Roseococcus, for which we propose the name Roseococcus pinisoli sp. nov. The type strain is XZZS9T (= KCTC 82435T = JCM 34402T = GDMCC 1.2158T).


Assuntos
Acetobacteraceae , Bacterioclorofila A , Acetobacteraceae/genética , Técnicas de Tipagem Bacteriana , Bacterioclorofila A/genética , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
4.
Environ Res ; 205: 112434, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34856169

RESUMO

Photocatalytic removal of NH3-N is expected to be an alternative to the biological method that accompanied with high energy consumption and secondary pollution. However, NH3-N is always oxidized into nitrate and nitrite during the photocatalytic processes, which also need to be removed from the water. Herein, the g-C3N4/rGO/TiO2 Z-scheme photocatalytic system was prepared and used for the NH3-N removal. The results showed the rate constant of NH3-N conversion on it was 0.705 h-1, 1.7 times as high as that on g-C3N4/TiO2, and most of the NH3-N were converted into gaseous products. And the experiment result indicated NH3-N and NO3- in water could enhance the removal of each other. According to the results, the main reaction mechanism is speculated as: ·OH radicals and ·O2- radicals were generated on TiO2 and oxidized the NH3-N into NO3-, and the latter was reduced into non-toxic N2 on the conduction band of g-C3N4. Finally, NH3-N removal performance for actual coking wastewater was investigated, and the stability of the photocatalyst was tested. This work provides some theoretical basis for the two-step degradation of pollutants by Z-scheme photocatalytic system.


Assuntos
Amônia , Água , Catálise , Desnitrificação , Grafite , Nitrificação , Titânio
5.
Curr Microbiol ; 79(4): 122, 2022 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-35239058

RESUMO

Strain XMGL2T, isolated from rhizosphere soil of Quercus mongolica in China, was characterized using a polyphasic taxonomic approach. Cells were Gram-negative, aerobic, non-spore-forming, and rod-shaped. Growth occurred at 20-37 °C (optimum, 28 °C), pH 5.0-10.0 (optimum, pH 6.0), and with 0-1% NaCl (optimum, 1%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain XMGL2T was related to members of the genus Sphingomonas and had the highest 16S rRNA gene sequence identity to Sphingomonas oleivorans FW-11 T (96.4%). The average nucleotide identity and digital DNA-DNA hybridization values between strain XMGL2T and the closely related taxa Sphingomonas oleivorans FW-11 T and Sphingomonas fennica K101T were 75.3/19.8% and 75.8/20.2%, respectively. The major cellular fatty acids were C18:1 ω7c, C14:0 2-OH, and C16:0. The major isoprenoid quinone was Q-10 and the polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, an unidentified glycophospholipid and an unidentified phospholipid. The genomic DNA G + C content was 67.9%. Based on the phenotypic and genotypic properties and phylogenetic inference, strain XMGL2T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas quercus sp. nov. is proposed. The type strain is XMGL2T (= JCM 34441 T = GDMCC 1.2153 T).


Assuntos
Quercus , Sphingomonas , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , Filogenia , Quercus/genética , RNA Ribossômico 16S/genética , Rizosfera , Análise de Sequência de DNA , Solo , Microbiologia do Solo
6.
Arch Microbiol ; 204(1): 50, 2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-34935074

RESUMO

Strain XQZ8T, isolated from the rhizosphere soil of a Populus popularis plant in China, was characterized using a polyphasic taxonomic approach. Cells were Gram-negative, aerobic, non-spore-forming, and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain XQZ8T was related to members of the genus Rhizobium and had the highest 16S rRNA gene sequence similarity to Rhizobium smilacinae PTYR-5T (96.6%). The average nucleotide identity and digital DNA-DNA hybridization value between strain XQZ8T and R. smilacinae PTYR-5T were 77.5% and 21.4%, respectively. TYGS whole-genome-based taxonomic and multi-locus sequence analyses of three concatenated housekeeping genes (atpD-recA-glnII) further indicated that strain XQZ8T was a new member of the genus Rhizobium. The major cellular fatty acids included summed feature 8 (C18:1 ω7c/C18:1 ω6c), summed feature 2 (C12:0 aldehyde/unknown 10.928), C16:0, and C19:0 cyclo ω8c. The major respiratory quinones were Q-9 and Q-10. The polar lipids were phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, an unidentified glycophospholipid, and three unidentified lipids. The genomic DNA G + C content of the strain was 60.1 mol%. Based on the phylogenetic, phenotypic, and genotypic characteristics, strain XQZ8T represents a novel species of the genus Rhizobium, for which the name Rhizobium populisoli sp. nov. is proposed. The type strain is XQZ8T (= JCM 34442T = GDMCC 1.2201T).


Assuntos
Populus , Rhizobium , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Ácidos Graxos/análise , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Rhizobium/genética , Rizosfera , Análise de Sequência de DNA , Solo , Microbiologia do Solo
7.
BMC Microbiol ; 20(1): 67, 2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-32216749

RESUMO

BACKGROUND: Daqu, the saccharification, fermentation, and aroma-producing agents for Baijiu brewing, is prepared using a complex process. Aging is important for improving the quality of Daqu, but its impact has rarely been studied. This study investigated changes in the physicochemical properties, flavor compounds, and microbial communities during aging of Daqu with a roasted sesame-like flavor. RESULTS: The physicochemical properties changed continuously during aging to provide a high esterifying activity. Aging removed unpleasant flavor compounds and helped to stabilize the flavor compounds in mature Daqu. A high-throughput sequencing approach was used to analyze the changing composition of the microbial communities during aging. Aging helped to modify the microbial population to produce better Baijiu by eliminating low-abundance microbial communities and optimizing the proportion of predominant microbial communities. Nine genera of prokaryotic microbes formed the core microbiota in Daqu after aging. Regarding eukaryotic microbes, Zygomycota, the predominant community, increased in the first 2 months, then decreased in the third month of aging, while Ascomycota, the subdominant community, showed the opposite behavior. Absidia, Trichocomaceae_norank and Rhizopus were the predominant genera in the mature Daqu. CONCLUSIONS: Significant correlations between microbiota and physicochemical properties or flavor compounds were observed, indicating that optimizing microbial communities is essential for aging Daqu. This study provides detailed information on aging during Daqu preparation.


Assuntos
Bebidas Alcoólicas/microbiologia , Ascomicetos/classificação , Bactérias/classificação , Aromatizantes/análise , Bebidas Alcoólicas/análise , Ascomicetos/isolamento & purificação , Bactérias/isolamento & purificação , Indústria Alimentícia , Microbiologia de Alimentos , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Análise de Sequência de DNA
8.
Langmuir ; 34(25): 7479-7487, 2018 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-29860837

RESUMO

Stimuli-responsive hydrogels have been considered to have various applications in numerous fields. In the present work, a double-network (DN) hydrogel has been synthesized. The copolymers of 2-acrylamide-2-methylpropane sulfonic acid (AMPS) and acrylamide (AM) [P(AMPS- co-AM)] are prepared as the 1st network and poly(acrylic acid) as the 2nd network. This DN hydrogel is sensitive to glucose by introducing the glucose-sensitive group phenylboronic acid to the network. The tribological properties of this glucose-sensitive DN hydrogel have been investigated using a universal mechanical tester (UMT-5). The tribological results show that the friction coefficient varied with the glucose solution. The friction coefficient increased to a maximum of 0.06, and finally decreased to 0.025 with the increase in the glucose concentration. An adjustable friction coefficient of the hydrogel, between 0.025 and 0.056, was achieved along with the change of lubricant. According to the tribological experimental results and the analysis of the DN structure, it can be deduced that a hydrated layer exists in the interface of the hydrogel. The hydrated layers consisting of water molecules are bounded with the hydrophilic group of the hydrogel network by hydrogen bonds. The change in the number of water molecules leads to the difference in the water content of the hydrogel, which further resulted in the various tribological properties. In addition, the hydrogel's mesh size also has an impact on the change in friction coefficient. In general, the adjustable friction of the hydrogel in a glucose environment is achieved.

9.
Langmuir ; 30(13): 3811-6, 2014 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-24645739

RESUMO

In the present work, an excellent biological lubricant extracted from an aquatic plant called Brasenia schreberi (B.s) is reported. With a rotary cylinder-on-ring tribometer, the lubrication properties of the B.s mucilage between quartz glass surfaces have been investigated under different rotation velocity, and an ultralow friction coefficient between 0.004 and 0.006 is obtained. It is observed that the ultralow friction coefficient is independent of the rotation speed, when it is less than 0.1 m/s. SEM images indicate that the mucilage surrounding B.s is composed of polysaccharide gels with a layered structure, which are called nanosheets in the following work. Moreover, it can be deduced that the liquid superlubricity is closely related to the B.s mucilage layer absorbed on the quartz glass surface by hydrogen bonds and the superlubricity behavior only occurs when the adsorption layer stably forms between the quartz glass surface and the B.s mucilage. It is also found that superlubricity is closely dependent upon the sheet structure of the B.s mucilage and water molecules in the mucilage. According to these results, a layered nanosheets lubrication mechanism has been revealed, i.e., the ultralow friction coefficient is due to the adsorption layer of polysaccharide on the quartz glass surface and the hydration layers of water molecules bonded on the polysaccharide nanosheets between the sliding surfaces.


Assuntos
Lubrificantes/química , Magnoliaceae/química , Mucilagem Vegetal/química , Polissacarídeos/química , Organismos Aquáticos , Fricção , Géis , Vidro/química , Lubrificação , Quartzo/química , Propriedades de Superfície , Água/química
10.
Artigo em Inglês | MEDLINE | ID: mdl-38968215

RESUMO

The main challenge in the preparation of MOF-based mixed matrix membranes is to construct a good interface morphology to improve the gas separation performance and stability of the membranes. Herein, high-aspect-ratio ZIF-8 nanoplates for H2/CO2 separation membranes were synthesized by direct template conversion. The ZIF-8 nanoplates were prepared with the commercial Matrimid polymer to form MMMs by the flat scraping method. The homogeneous dispersion of high-aspect-ratio nanoplates in the membrane and the good compatibility between the filler and the matrix caused by the thermal annealing operation improve the gas separation performance and mechanical properties of MMMs. The H2/CO2 selectivity of MMMs loaded with 30 wt % ZIF-8 nanoplates increased to 10.3, and the H2 permeability was 330.1 Barrer. This synthesis method can be extended to prepare various ZIF nanoplates with elevated aspect ratios to obtain excellent performance fillers for gas separation of MMMs. In addition, the thermal annealing operation allows more efficient gas separation in polymer membranes and is a feasible way to design excellent and stable MMMs.

11.
Waste Manag ; 162: 55-62, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36940644

RESUMO

As one of the main methods for sludge treatment, recovery of renewable biogas energy by anaerobic digestion (AD) is a promising strategy to deal with the conflict between carbon neutralization and sharply increase of sewage sludge. Humic acid (HA) in sludge is a major inhibitor of biogas yields and needs to be removed or pretreated. However, as the graphene oxide-like material, HA is an ideal precursor for the preparation of energy storage materials with high performance. Based on that, this study i) proposes the extraction and utilization of HA in sludge, ii) discusses the feasibility of HA-based materials after thermal reduction as electrodes for supercapacitor, and iii) investigates the factors with positive influences on the structure and electrochemical performance. It reveals that, with a synergistic effect of purification and activation at a low mass ratio, the HA-based material exhibits superior capacitive performance with the highest specific capacitance of 186.7 F/g (at 0.05 A/g), as well as excellent rate capability and cycling stability. Sludge is verified a cheaper and more abundant precursor resource of HA for energy storage application. The results of this study are expected to provide a new green, energy-efficiency and sustainability way for sludge treatment, which has the double benefits: efficient conversion and capture of bio-energy during AD process, and high value-added utilization of HA for supercapacitor.


Assuntos
Substâncias Húmicas , Esgotos , Esgotos/química , Biocombustíveis , Carbono , Eletrodos
12.
Heliyon ; 9(3): e14184, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36923906

RESUMO

Cordycepin (3 '-deoxyadenosine) is the main active component of Cordyceps militaris, which is a chemical marker for quality detection of Cordyceps militaris and has important medicinal development value. Existing methods for obtaining cordycepin are complex and costly. In this study, an economical and simple method for separation and purification of cordycepin from Cordyceps militaris fermentation liquid through physical crystallization was explored. First, lyophilized powdered fermentation liquid (LPFL) and pure methanol (1 g/100 mL, w/v) were mixed, and then repeatedly dissolved and crystallized until the precipitation was white. Purified product was obtained by freeze-drying the precipitate. The substance was determined to be cordycepin by high performance liquid chromatography, mass spectrometry and infrared spectroscopy, and the purity was 94.26%. Compared with the existing methods, this method is simple and low cost. In addition, the functional activity of cordycepin was determined by in vitro test. The results exhibited that cordycepin caused death and morphological changes in human colon cancer Caco-2 cells, and significantly inhibited the proliferation of Caco-2 cells, with a half-maximal inhibitory concentration (IC50) of 107.2 µg/mL. Cordycepin could induce early apoptosis of Caco-2 and caused cell cycle arrest in the G2 phase. Caco-2 cell apoptosis and cell cycle arrest showed dose dependence to cordycepin over a certain range. These results improved cordycepin purification method, provided insights into the mechanism of cordycepin in cancer inhibition, and would provide important reference for further development and clinical application of cordycepin.

13.
Langmuir ; 28(20): 7797-802, 2012 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-22548346

RESUMO

The present work reports an excellent lubrication property of an aquatic plant called Brasenia schreberi (BS). To investigate the lubrication characteristics of the BS mucilage, a novel measuring system is designed, and an ultralow friction coefficient about 0.005 between the mucilage and glass surface has been obtained. It is found that the ultralow friction is closely related to the structure of mucilage and water molecules in the mucilage. The microstructure analysis indicates that the mucilage surrounding BS forms a kind of polysaccharide gel with many nanosheets. A possible lubrication mechanism is proposed that the formation of hydration layers among these polymer nanosheets with plenty of bonded water molecules causes the ultralow friction. The excellent lubrication property has a potential application for reducing the friction between a glossy pill coated with such layer of mucilage and people's throats.


Assuntos
Adesivos , Gleiquênias/química , Lubrificantes , Adesivos/química , Fricção , Vidro , Lubrificantes/química , Modelos Moleculares , Conformação Molecular , Propriedades de Superfície
14.
Sci Total Environ ; 814: 152569, 2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-34973325

RESUMO

Two membrane bioreactors with and without adding an electric circuit (named as MFC-MBR and C-MBR, respectively) were established to investigate the effects of micro-electric field on membrane fouling. With the aeration rate of 1.5 L/min, the synergistic effect of aeration and micro-electric field was the best in reducing membrane fouling and COD in treatment of a simulated phenol wastewater. Compared with C-MBR, the running time of MFC-MBR was extended for 16 days. Scanning electron microscope (SEM) and energy-dispersive X-ray detector (SEM-EDX) demonstrated that less foulants were attached to the membrane and the attachment was loosend in MFC-MBR. The decreased absolute value of zeta potential indicated repulsion among the negatively-charged sludge particles was reduced and flocculation of the sludge was improved, which alleviated the membrane fouling. The soluble microbial products (SMP) and loosely-bound extracellular polymeric substances (LB-EPS) were also decreased in MFC-MBR. It was found that migration and neutralization of the negatively-charged particles, and degradation of microorganisms contributed to the alleviation of membrane fouling. Moreover, the decreases of carbohydrates in LB-EPS led to higher protein/carbohydrates (PN/PS) ratio, which was a key parameter for alleviating membrane fouling. Meanwhile, the increase of tightly bound extracellular polymeric substances (TB-EPS) could also slow down membrane fouling. Because TB-EPS can be used as a binder to strengthen the flocculation of sludge particles.


Assuntos
Fontes de Energia Bioelétrica , Reatores Biológicos , Matriz Extracelular de Substâncias Poliméricas , Membranas Artificiais , Esgotos
15.
Bioresour Technol ; 338: 125504, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34274582

RESUMO

This study evaluated the feasibility of phenol degradation in microbial fuel cell (MFC) and membrane bioreactor (MBR) coupling system, and explored the mechanism of MBR membrane fouling. Four aspects were researched in open and closed circuit conditions: the degradation capacity of the coupling system, the increase of trans-membrane pressure (TMP), and the adhesion of phenol degradation products and microorganisms on the membrane. The results showed that the degradation of phenol and COD in the closed circuit coupling system was higher than that in the open circuit. The micro-electric field can inhibit the growth of TMP and keep dodecamethylcyclohexasiloxane away from the membrane, meanwhile can also reduce the abundance and species diversity of microorganisms. Nevertheless, the micro-electric field could not completely eliminate the membrane fouling due to the fact that the phenol degradation product of ethanethiol, microorganisms of Proteobacteria and Actinobacteria were more favorable on the membrane.


Assuntos
Fontes de Energia Bioelétrica , Reatores Biológicos , Membranas Artificiais , Fenóis , Esgotos , Águas Residuárias
16.
Front Microbiol ; 12: 663744, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34135875

RESUMO

Baijiu is an important fermented product in China. A yeast named YX3307 that is capable of producing a large amount of ethyl caproate (EC) was isolated from Daqu, a crude fermentation starter for Baijiu. This yeast was identified as Clavispora lusitaniae on the basis of its morphological properties, physiological and biochemical characteristics, and 26S rDNA sequence. Single-factor experiments were conducted to obtain the optimum fermentation conditions for EC production by YX3307. The highest EC yield (62.0 mg/L) from YX3307 was obtained with the following culture conditions: inoculum size 7.5% (v/v), seed cell age 30 h, sorghum hydrolysate medium (SHM) with a sugar content of 10 Brix and an initial pH of 6.0; incubation at 28°C with shaking at 180 rpm for 32 h; addition of 10% (v/v) anhydrous ethanol and 0.04% (v/v) caproic acid at 32 and 40 h, respectively, static culture at 20°C until 72 h. YX3307 synthesized more EC than ethyl acetate, ethyl lactate, ethyl butyrate, and ethyl octanoate. An intracellular enzyme or cell membrane enzyme was responsible for EC synthesis. YX3307 can produce many flavor compounds that are important for high-quality Baijiu. Thus, it has potential applications in improving the flavor and quality of Baijiu.

17.
J Neural Eng ; 17(1): 016066, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-31614342

RESUMO

OBJECTIVE: This study aimed to design and evaluate a high-speed online steady-state visually evoked potential (SSVEP)-based brain-computer interface (BCI) in an optical see-through (OST) augmented reality (AR) environment. APPROACH: An eight-class BCI was designed in an OST-AR headset which is wearable and allows users to see the user interface of the BCI and the device to be controlled in the same view field via the OST head-mounted display. The accuracies, information transfer rates (ITRs), and SSVEP signal characteristics of the AR-BCI were evaluated and compared with a computer screen-based BCI implemented with a laptop in offline and online cue-guided tasks. Then, the performance of the AR-BCI was evaluated in an online robotic arm control task. MAIN RESULTS: The offline results obtained during the cue-guided task performed with the AR-BCI showed maximum averaged ITRs of 65.50 ± 9.86 bits min-1 according to the extended canonical correlation analysis-based target identification method. The online cue-guided task achieved averaged ITRs of 65.03 ± 11.40 bits min-1. The online robotic arm control task achieved averaged ITRs of 45.57 ± 7.40 bits min-1. Compared with the screen-based BCI, some limitations of the AR environment impaired BCI performance and the quality of SSVEP signals. SIGNIFICANCE: The results showed the potential for providing a high-performance brain-control interaction method by combining AR and BCI. This study could provide methodological guidelines for developing more wearable BCIs in OST-AR environments and will also encourage more interesting applications involving BCIs and AR techniques.


Assuntos
Realidade Aumentada , Interfaces Cérebro-Computador , Eletroencefalografia/métodos , Potenciais Evocados Visuais/fisiologia , Estimulação Luminosa/métodos , Adulto , Feminino , Humanos , Masculino , Robótica/instrumentação , Robótica/métodos , Adulto Jovem
18.
Environ Sci Pollut Res Int ; 27(32): 40837-40847, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32677015

RESUMO

In this work, removal of antipyrine was studied through two-dimensional (2D) and three-dimensional (3D) electrolysis. 2D electrolysis was firstly studied with the Ti/SnO2-Ta2O5-IrO2 anode as working electrode. Operating parameters affecting antipyrine removal, such as current density, electrode distance, and initial concentration of antipyrine, were investigated and optimized. As the limited antipyrine removal efficiency of 48.0% was not satisfying, 3D electrolysis with γ-Al2O3 as particle electrodes was introduced in the purpose of improving the antipyrine removal. An obviously enhanced removal efficiency of 78.3% was obtained, which seemingly validated the effect of particle electrodes in improving antipyrine removal. Hence, an effort to further enhance the antipyrine removal efficiency was made through improving the electrochemical characteristics of γ-Al2O3 as particle electrodes. Modified Sn-Sb-Bi/γ-Al2O3 particles were thus prepared through impregnation method. And a desirable antipyrine removal efficiency of 94.4% and energy consumption of 0.18 kWh/g antipyrine were achieved in the 3D electrolysis with Sn-Sb-Bi/γ-Al2O3 as particle electrodes. Furthermore, possible mechanism and pathway of antipyrine degradation in 3D electrolysis were explored through detection of ·OH using terephthalic acid fluorescent probe method and detection of antipyrine degradation intermediates using LC-MS.


Assuntos
Antipirina , Poluentes Químicos da Água , Eletrodos , Eletrólise , Oxirredução , Titânio
19.
Sci Total Environ ; 708: 134773, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31753491

RESUMO

In this study, corn straw biomass was co-pyrolyzed with a clay mineral (montmorillonite) in the presence of iron-bearing materials (FeCl3, magnetite and iron acetylacetone) and the prepared iron-montmorillonite biochars were characterized for their interfacial behavior. The results showed that, by adding iron to the pyrolysis process, organometallic complexes such as Fe-O-C were generated on the surface of biochars. All the iron-montmorillonite biochars were also shown to enhance the oxidation resistance likely by the increased relative contents of CO and COOH from 0% and 3.7% to 6.5-8.4% and 5.5-6.3%, respectively, compared with the iron-absent biochar. The measured carbon recalcitrance index (R50, bicohar) of iron-montmorillonite biochars in thermogravimetric analysis (TGA) also increased from 46.9% to 48.6-56.9%. Among the three types of added iron materials, magnetite showed the best performance in improving biochar stability. The study indicated that, when added together, montmorillonite and iron were effective in improving the stability of biochar, which displays an important environmental significance of carbon sequestration.


Assuntos
Zea mays , Bentonita , Carvão Vegetal , Ferro
20.
Bioelectrochemistry ; 128: 291-297, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31059969

RESUMO

A biocathode microbial fuel cell was constructed to investigate Congo red decolorization and power generation under different cathode operational parameters. The results showed that the suspended sludge in the cathode could improve the performance of the microbial fuel cell for electricity generation but had a negligible effect on the Congo red decolorization. The maximum voltage increased as the aeration rate was increased up to 100 mL/min. At aeration rates of 150 and 200 mL/min, the maximum voltage was lower than that at 100 mL/min. In the meantime, the Congo red decolorization efficiency decreased with increasing cathode aeration rate. These results showed that excessive aeration is not favorable in a bio-cathode microbial fuel cell used for simultaneous Congo red decolorization and electricity generation. The addition of Mn2+ to the biocathode resulted in a 74.5% increase in maximum power density but had no effect on Congo red decolorization. SEM and 16S rRNA sequencing analysis confirmed that Mn2+ was involved in the electrochemical reaction of the biocathode as an electron mediator, and it could induce a difference in the biocathode-attached populations.


Assuntos
Fontes de Energia Bioelétrica , Cor , Corantes/química , Vermelho Congo/química , Eletricidade , Eletrodos , Biofilmes , Manganês/química , Microscopia Eletrônica de Varredura , RNA Ribossômico 16S/metabolismo , Esgotos
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