Potassium‐ion batteries (PIBs) are promising alternatives to lithium‐ion batteries because of the advantage of abundant, low‐cost potassium resources. However, PIBs are facing a pivotal challenge to ...develop suitable electrode materials for efficient insertion/extraction of large‐radius potassium ions (K+). Here, a viable anode material composed of uniform, hollow porous bowl‐like hard carbon dual doped with nitrogen (N) and phosphorus (P) (denoted as N/P‐HPCB) is developed for high‐performance PIBs. With prominent merits in structure, the as‐fabricated N/P‐HPCB electrode manifests extraordinary potassium storage performance in terms of high reversible capacity (458.3 mAh g−1 after 100 cycles at 0.1 A g−1), superior rate performance (213.6 mAh g−1 at 4 A g−1), and long‐term cyclability (205.2 mAh g−1 after 1000 cycles at 2 A g−1). Density‐functional theory calculations reveal the merits of N/P dual doping in favor of facilitating the adsorption/diffusion of K+ and enhancing the electronic conductivity, guaranteeing improved capacity, and rate capability. Moreover, in situ transmission electron microscopy in conjunction with ex situ microscopy and Raman spectroscopy confirms the exceptional cycling stability originating from the excellent phase reversibility and robust structure integrity of N/P‐HPCB electrode during cycling. Overall, the findings shed light on the development of high‐performance, durable carbon anodes for advanced PIBs.
A viable anode material composed of nitrogen/phosphorus co‐doped hollow porous bowl‐like hard carbon is developed for potassium ion batteries. The resulting anode manifests prominent merits in structure, endowing it with extraordinary K+ storage capability. The K+ storage mechanisms are revealed through in‐depth studies by combining in situ TEM studies, ex situ microscopic, and Raman spectroscopy in conjunction with DFT calculations.
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•The typical lamellar structure made COFTDBA-TPA have a larger specific surface area.•COFTDBA-TPA had a large number of catalytically active sites (–CO, –NH2, –CN).•The adsorption ...kinetic equilibrium of COFTDBA-TPA was reached at 10 min.•COFTDBA-TPA can detect and remove HMIs in sewage and soil.
Here, tripolycyanamide (TPA) and 2,4,6-triformyl pyrogallol (TDBA) are used to prepare a highly crystalline covalent-organic frameworks based on imine linkages (COFTDBA-TPA) for heavy metal ions (HMIs) detection and removal. Each unit of COFTDBA-TPA had 6 adsorption sites for HMIs (–CO, –NH2, –CN), which could selectively capture HMIs. The typical lamellar structure made COFTDBA-TPA have a larger specific surface area, and the mesoporous structure provided numerous channels for the adsorption of HMIs. Therefore, the COFTDBA-TPA-based electrochemical sensor could realize the detection of Cd2+, Cu2+, Pb2+, Hg2+ and Zn2+ in drinking water, simultaneously. The limits of detection for five HMIs were as low as 0.922 nM, 0.450 nM, 0.309 nM, 0.208 nM and 0.526 nM, respectively. The adsorption capacity of COFTDBA-TPA for each HMI was as high as 711.6 mg/g, 716.9 mg/g, 603.7 mg/g and 618.3 mg/g, respectively. Compared with other adsorbents, it had higher capacity and faster adsorption kinetics. After being recycled five times, the adsorption performance was maintained. This not only provides a reliable platform for the removal of HMIs in wastewater, but also provides new ideas for the use of COFs in the electrochemical field.
The deterioration of flaxseed oil (FSO) during heating greatly influences the quality of fried foods. FSOs heated at different temperatures (120 °C, 150 °C, 180 °C, and 210 °C) were investigated for ...volatile organic compound (VOC) and fatty acid compositions and physicochemical indices. In total, 84 VOCs were identified, including 20 aldehydes (37.43%–66.17%), 20 alcohols (31.19%–42.90%), 9 esters (0.28%–1.27%), 8 ketones (0.4%–1.58%), 19 alkanes (1.15%–19.96%), and 8 heterocyclics (0.68%–6.16%). Furthermore, 1-nonanal, 2,4-decadienal, hexanal, and trans,trans-2,4-heptadienal were identified as the characteristic aroma compounds to estimate the oxidation degree of heated FSO through the calculation of odor activity values. The polyunsaturated fatty acid content in FSO significantly (p < 0.05) decreased by 5.75 μg/g after heating at 210 °C. The physicochemical indices of FSO increased during heating with acid, peroxide, p-anisidine and thiobarbituric acid values ranging from 0.26 to 0.55 mg NaOH/g, 0.041–0.066 g/100 g, 0.12–0.88, and 0.025–0.088, respectively. Results of Pearson correlation analysis indicate that 2,4-decadienal and hexanal may be oxidation deterioration markers in FSO. This study provides a theoretical basis for evaluation of the suitability of FSO for household food preparation.
•Most volatile compound types (45) were found in flaxseed oil (FSO) heated at 210 °C.•Aldehydes were dominant among the volatile compounds in the FSO samples.•Characteristic aroma compounds were identified in the FSO samples during heating.•During heating, 2,4-decadienal and hexanal could be the markers of FSO oxidation.
The SARS-CoV-2 Omicron (B.1.1529) variant was designated as a variant of concern (VOC) by the World Health Organization (WHO) on November 26, 2021. Within two months, it had replaced the Delta ...variant and had become the dominant circulating variant around the world. The Omicron variant possesses an unprecedented number of mutations, especially in the spike protein, which may be influencing its biological and clinical aspects. Preliminary studies have suggested that increased transmissibility and the reduced protective effects of neutralizing antibodies have contributed to the rapid spread of this variant, posing a significant challenge to control the coronavirus disease 2019 (COVID-19) pandemic. There is, however, a silver lining for this wave of the Omicron variant. A lower risk of hospitalization and mortality has been observed in prevailing countries. Booster vaccination also has ameliorated a significant reduction in neutralization. Antiviral drugs are minimally influenced. Moreover, the functions of Fc-mediated and T-cell immunity have been retained to a great extent, both of which play a key role in preventing severe disease.
Triggering receptor expressed on myeloid cells (TREM)-1 is a transmembrane receptor embedded in the intrinsic immune cell membrane that amplifies inflammation by increasing inflammatory signalling ...triggered by toll-like receptors as well as transcript levels in the NF-κB signalling pathway. The soluble form of TREM-1 is obtained by cleavage of the extracellular portion of TREM-1 by matrix metalloprotease-9 and can be used as a biomarker for the diagnosis and prognosis of TREM-1 pathway activation in many acute and chronic inflammatory diseases. The present review aims to summarise the latest research and insights on TREM-1 in inflammatory and non-inflammatory diseases.
The variations in flavor compounds of flaxseed oil (FSO) processed under different roasting conditions were studied using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) combined ...with principal component analysis (PCA). A total of 81 typical target compounds were identified, including 27 aldehydes, 16 ketones, 14 alcohols, 9 heterocycles, 6 esters, 5 acids, 3 hydrocarbons, and one sulfur compound (dimethyl disulfide). After roasting process at 120 °C, 2-propanol, methylpropanal, (E)-2-pentenal, (E)-2-hexenal, and 1-hexanol were the major volatile components, while furfural, 3-(methylthio)propanal, 2-pentanone, 2-heptanone, and 2-ethyl-6-methylpyrazine were the predominant compounds of hot-pressed FSO roasting at 180 °C; (E,E)-2,4-nonadienal, (E)-2-nonenal, propanal, 1-octen-3-one, methyl salicylate, propyl hexanoate, ethyl propanoate-M, and ethyl hexanoate were the main volatile compounds at 240 °C. Additionally, the results of PCA and the Euclidean distance showed the similarity of FSO and its flavor compounds under different roasting conditions. This method could be helpful for the quick and thorough analysis of volatile compounds in FSO.
Graphical Abstract
Here, tripolycyanamide (TPA) and 2,5-dihydroxyterephthalic acid (DDTA) were used to synthesize crystalline covalent organic framework (COF
DDTA-TPA
) which was employed to detect and remove heavy ...metal ions (HMIs). COF
DDTA-TPA
has abundant N-O-O and N-N-O sites and large specific surface area, which can be used as an excellent adsorbent for HMIs. The detection limits for Zn
2+
, Cd
2+
, Pb
2+
, Cu
2+
, and Hg
2+
were 0.85 nM, 0.096 nM, 0.14 nM, 0.072 nM, and 0.084 nM, respectively. The COF
DDTA-TPA
was controllably grown on both melamine foam (MF) and macroporous carbon to remove Cd
2+
, Pb
2+
, Cu
2+
, and Hg
2+
effectively, which avoided some defects of traditional COFs powder such as random orientation, easy accumulation, and poor reproducibility. The COF
DDTA-TPA
/MF was further prepared as a water filter device for the removal of HMIs. In addition, the proposed material can detect and remove HMIs in sewage, soil, and blood serum real samples and showed great potential in environmental remediation.
Prussian blue analogues (PBA) are promising cathode materials because of their low-cost and wide diffusion tunnels for sodium ion batteries. However, several key challenges, such as low actual ...capacity and high voltage instability, restrain their further development. Here, we investigate the influence of pH value on the electrochemical performances of Na2MnFe(CN)6 cathodes during co-precipitation process. When the pH equals to 3.0, the sample shows the high content of sodium, low contents of interstitial water molecules and Fe(CN)6 defects, which achieves a high discharge capacity (~130.6 mAh g−1) and a capacity retention of 72% after 100 cycles at 1C. As the pH becomes 9.0, the sample exhibits an excellent high-rate capability, and the discharge capacity can still remain about 92% when the rate goes back to 0.1C from 5C. Besides, the sample also reveals capacity retention of about 80% after 100 cycles at 1C, which shows the best stability among all samples. The enhanced performances could be mainly ascribed to two aspects: on the one hand, the high content of Na+ contributes to high specific capacity; on the other hand, less Fe(CN)6 defects are beneficial to Na+ ion diffusion and stabilize the structure during the Na+ insertion/extraction process.
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•The different PBM samples are successfully prepared by controlling pH value.•The effects of different pH value on the properties of PBM are discussed in detail.•The PBM-3 sample exhibits the highest content of sodium and discharge capacity.•The PBM-9 sample reveals capacity retention of about 80% after 100 cycles at 1C.
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•Anti-site defects and properties of the γ′ phase in Co-Al-Nb alloys were studied by first-principles calculations.•Properties of the γ′ phase depend on the Al/Nb ratio, and Nb ...content exceeding 0.8125 facilitates phase transition.•Stoichiometry variations affect elastic constants, and anti-site defects reduce Gibbs free energy at elevated temperatures.•High-temperature precipitate is proved to be cobalt-rich γ′ phase with anti-site defects by experiments.
The design of the composition for two-phase superalloys of γ/γ′ has always been key to achieving a breakthrough in their mechanical performance. However, the underlying mechanism of the anti-site defects in γ′ precipitates that severely affect stability and performance have rarely been explored. The present work therefore specifically investigated the structural stability and mechanical properties of strictly stoichiometric and off-stoichiometric γ′-Co3(Al, Nb) phases by using the first-principles calculations. The results show that the change in the Al/Nb ratios in the compounds could induce the instability of the L12 structure, while an increase of Nb atoms leads to compounds with predominantly covalent bonds exhibiting stronger mechanical properties. After evaluating the Gibbs free energy of these γ′-Co3(Al, Nb) phases at finite temperature, it is found that Co29Al2Nb1 and Co29Al1Nb2 compounds with anti-site defects can be thermodynamically stable at greater than 710 and 905 K, respectively. Accordingly, Co-10Al-2Nb and Co-2.5Al-3Nb alloys were successfully prepared experimentally, further confirming that the γ′-Co3(Al, Nb) phase with anti-site defects can precipitate preferentially and remain stable during the 168 h annealing treatment.
Diffusion coefficient play a crucial role in material designing, and physical phenomenon explaining during the material preparation and post-treatment. However, it is unavailable in some metallic ...systems. In this paper, based on basic physical properties (including atom properties, lattice parameters, melting temperature, elastic stiffness constant and etc.), the diffusion activate energy model were developed by machine-learning methods. First, the melting temperature (Tm) and elastic stiffness constant (Cij) models were built by machine-learning methods to fill the absent values in properties. Second, the diffusion activate energy (Q) model was built, and a hybrid features selection method was used to decrease features from 73 to 11 in the model. The Tm, Cij and Q models showed a good predictive ability and goodness of fit. Finally, features in the models were analyzed and compared with the parameters in various prior models. This work provides further understanding on the mechanism of the melting process, elastic deformation and diffusion process. Moreover, the models could be able to provide an easy and reliable method to obtain the diffusion coefficients in bcc, fcc, and hcp alloys when they are needed but unavailable.
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•Machine-learning models of melting temperature, elastic constants and diffusion coefficients were constructed.•A hybrid features selection method were developed to decrease the number of features in the models.•Diffusion coefficients in bcc, fcc and hcp alloys remained the stable and metastable were well predicted.•The effects of features on melting temperature, elastic constants and diffusion coefficients were discussed.
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