In the last ten years, the research of solid oxide fuel cells (SOFCs) or ceramic fuel cells (CFC) had focused on reducing the working temperature through the development of novel materials, ...especially the high ionic conductive electrolyte materials. Many progresses on single-phase electrolyte materials with the enhanced ionic conductivity have been made, but they are still far from the criteria of commercialization. The studies of ceria oxide based composite electrolytes give an alternative solution to these problems because of their impressive ionic conductivities and tunable ionic conduction behaviors. Significant advances in the understanding the ceria based composite material and construction of efficient fuel cell systems have been achieved within a short period. This report reviews recent developments of ceria-based composite from different aspects: materials, fundamentals, technologies, fabrication/construction parameters, electrochemistry and theoretical studies. Particular attention is given to ceria-carbonate (nano)composite, including its fuel cell performance, multi-ionic transport properties, advanced applications, corresponding electrode material and stability concerning. Besides, several novel fuel cell (FC) concepts like nanowire FC, all-nanocomposite FC and single-component/electrolyte-free fuel cell (SC-EFFC) are presented. This mini-review emphasizes the promise of ceria-based composites for advanced FC application and highlights the breakthrough of SC-EFFC research for high efficient energy conversion.
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► Development of Ceria–salt composites with impressive ionic conductivity and tunable conduction behaviors is reviewed. ► Particular attention is given to ceria–carbonate composite, a promising electrolyte for LTCFC. ► Parameters affecting the electrical properties of ceria–carbonate composite are analyzed. ► Advanced applications, electrode materials and stability measurements development are presented. ► Novel fuel cell concepts and demonstrations such as EFFC are highlighted.
•MCMB with different pre-lithiation capacity as negative electrode in LIC.•Pre-lithiation improves the electrochemical performance of LIC.•The optimal pre-lithiation capacity has been proposed.
...Lithium ion capacitors are assembled with pre-lithiated mesocarbon microbeads (LMCMB) anode and activated carbon (AC) cathode. The effect of pre-lithiation degrees on the crystal structure of MCMB electrode and the electrochemical capacitance behavior of LIC are investigated by X-ray diffraction (XRD) and the charge-discharge test of three-electrode cell. The structure of graphite still maintained when the pre-lithiation capacity is less than 200 mAh g−1, phase transition takes place with the increase of pre-lithiation capacity from 250 mAh g−1 to 350 mAh g−1. Pre-lithiation degrees of MCMB anode greatly affect the charge-discharge process and behavior, which impact on the electrochemical performance of LIC. The LIC with pre-lithiation capacity of 300 mAh g−1 has the optimal electrochemical performance. The energy density of LIC300 is up to 92.3 Wh kg−1, the power density as high as 5.5kWkg−1 and the capacity retention is 97.0% after 1000 cycles. The excellent electrochemical performance benefits from the appropriate pre-lithiation capacity of negative electrode. The appropriate pre-lithiation ensures the working voltage of negative electrode in low and relative stable charge-discharge platform corresponding to the mutual phase transition from the second stage graphite intercalation compound (LiC12) to the first stage graphite intercalation compound (LiC6). The stable charge-discharge platform of negative electrode is conductive to the sufficient utilization of AC positive electrode.
In general object detection, scale variation is always a big challenge. At present, feature pyramid networks are employed in numerous methods to alleviate the problems caused by large scale range of ...objects in object detection, which makes use of multi-level features extracted from the backbone for top-down upsampling and fusion to acquire a set of multi-scale depth image features. However, the feature pyramid network proposed by Ghiasi et al. adopts a simple fusion method, which fails to consider the fusion feature context, and therefore, it is difficult to acquire good features. In addition, the fusion of multi-scale features directly by traditional upsampling is prone to feature misalignment and loss of details. In this paper, an adaptive feature pyramid network is proposed based on the feature pyramid network to alleviate the foregoing potential problems, which includes two major designs, i.e., adaptive feature upsampling and adaptive feature fusion. The adaptive feature upsampling aims to predict a group of sampling points of each pixel through some models, and constitute feature representation of the pixel by feature combination of sampling points, while adaptive feature fusion is to construct pixel-level fusion weights between fusion features through attention mechanism. The experimental results verified the effectiveness of the method proposed in this paper. On the public object detection dataset MS-COCO test-dev, Faster R-CNN model achieved performance improvement of 1.2 AP by virtue of the adaptive feature pyramid network, and FCOS model could achieve performance improvement of 1.0 AP. What's more, the experiments also validated that the adaptive feature pyramid network proposed herein was more accurate for object localization.
In this study, activated carbon (AC)-Fe3O4 nanoparticles asymmetric supercapacitor cells have been assembled and characterized in 6 M KOH aqueous electrolyte for the first time. The nanostructure ...Fe3O4 was prepared by the microwave method. It only cost several minutes to prepare magnetite nanoparticles with average particle size of 35 nm. The electrochemical performances of the hybrid AC-Fe3O4 supercapacitor were tested by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge−discharge tests. The results show that the asymmetric supercapacitor has electrochemical capacitance performance within potential range 0−1.2 V. The supercapacitor delivered a specific capacitance of 37.9 F/g at a current density of 0.5 mA/cm2. The result of cyclic characteristic test showed that it also can keep 82% of initial capacity over 500 cycles.
•A system photoreduction process on the principle of dye-sensitized solar cells.•Light absorption and charge separation are performed in the DSC zone.•Cr(VI) reduction with transferring electrons was ...conducted at catalysis zone.•The high efficiency reactor system can handle Cr(VI) and phenol concurrently.•The system affords a platform to realize the environment improvement.
The performance of photocatalytic reduction of chromium (VI) via a new TiO2 film and a platinum anode was systematically evaluated. The as-prepared TiO2 film is composed of a dye-sensitized zone and a catalysis zone. Charge separation was accomplished with electron transferring to the catalysis zone and positive charge transforming to an anode. A powerful reduction ability of the reaction system was achieved in the absence of any organics under visible light irradiation. Several parameters including pH, dissolved O2, the primary active species, the durability of the as-synthetized film and so on were investigated.
Lung cancer has a very high incidence rate and is one of the commonly diagnosed tumors in developed countries.
To investigate the effect of wogonin on A549 and A427 lung cancer cells and explore the ...mechanism involved.
Cell study.
The cytotoxicity effect of wogonin on A549 and A427 lung cancer and BEAS-2B cells was assessed by MTT assay. The onset of apoptosis was assessed by flow cytometry using Annexin V FITC/PI staining. Western blotting was used for the determination of changes in apoptotic protein expression.
Wogonin treatment exhibited cytotoxicity effect selectively on A549 and A427 cells without affecting BEAS-2B normal lung cells. The viability of A549 and A427 cells was reduced to 31% and 34%, respectively, on treatment with 50 μM of wogonin; however, there was no significant reduction in BEAS-2B cell viability on treatment with the same concentration of it. Moreover, the percentage of apoptotic A427 cells showed a significant (p<0.049) increase on treatment with wogonin. Furthermore, the treatment led to a marked increase in the activation of caspase 3/8/9 and the generation of reactive oxygen species (ROS) at 72 h in A427 cells. Digital tomosynthesis studies showed a marked reduction in tumor development on treatment with wogonin.
Wogonin treatment specifically exhibits a cytotoxic effect on lung cancer cells and this effect is associated with activation of apoptosis and generation of reactive oxygen species.
The rapid accumulation of clinical RNA-seq data sets has provided the opportunity to associate mRNA isoform variations to clinical outcomes. Here we report a statistical method SURVIV (Survival ...analysis of mRNA Isoform Variation), designed for identifying mRNA isoform variation associated with patient survival time. A unique feature and major strength of SURVIV is that it models the measurement uncertainty of mRNA isoform ratio in RNA-seq data. Simulation studies suggest that SURVIV outperforms the conventional Cox regression survival analysis, especially for data sets with modest sequencing depth. We applied SURVIV to TCGA RNA-seq data of invasive ductal carcinoma as well as five additional cancer types. Alternative splicing-based survival predictors consistently outperform gene expression-based survival predictors, and the integration of clinical, gene expression and alternative splicing profiles leads to the best survival prediction. We anticipate that SURVIV will have broad utilities for analysing diverse types of mRNA isoform variation in large-scale clinical RNA-seq projects.
Soft carbon materials are considered as promising anodes for potassium-ion batteries (KIBs) due to their low cost, ease of available, excellent electronic conductivity and tunable interlayer ...distance. However, they still exhibit unsatisfying performance for K-ions storage owing to the serious volume expansion and sluggish kinetics when forming potassium intercalation compounds. To date, the bulk soft carbon anodes for outstanding capacity of potassium storage have been rarely studied. Herein, a unique bulk soft carbon has been synthesized via a facile pyrolysis method, which shows a high reversible capacity of 343.2 mA h g−1, excellent rate capability, and good cycling performance (a retention of 86.2% at 100 mA g−1 after 100 cycles). The soft carbon with larger interlayer spacing and moderate defects can not only facilitate ion diffusion but also provide active sites for K-ions storage, contributing to an outstanding capacity and excellent rate performance. In addition, full cells constructed with the obtained soft carbon as anode also exhibit a good performance with a capacity of 201 mA h g−1. Considering the cost issue, practical application and electrochemical performance, this work provides a strategy for manufacturing low cost and brilliant electrochemical performance KIBs anode material.
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•Soft carbon derived from low cost pitch were obtained by a simple pyrolysis method.•Potassium-ion batteries exhibit high capacity and excellent rate performance.•The high-performance anode was applied to full cell and displayed potential application.
•MCMB with the optimal pre-lithiation capacity as negative electrode in LIC.•The capacity design of cathode affects the electrochemical performance of LIC.•The optimal designed capacity of positive ...electrode has been proposed.
Lithium-ion capacitors (LICs) are assembled with activated carbon (AC) cathode and pre-lithiated mesocarbon microbeads (MCMB) anode. The effect of AC cathode capacity design on the electrochemical performance of LIC is investigated by the galvanostatic charging-discharging and electrochemical impedance tests. As the designed capacity of AC positive electrode is lower than 50mAhg−1, the working potential of negative electrode is always in the low and stable plateau, which is conductive to the sufficient utilization and the working potential stability of positive electrode. When the designed capacity of positive electrode is higher than 50mAhg−1, the instability of negative electrode directly causes the reduced utilization and shortened working potential range of the positive electrode, which is responsible for the capacity attenuation and cycle performance deterioration of LIC. The positive electrode capacity design can realize the optimization of electrochemical performance of LIC. LIC50 exhibits the optimal electrochemical performance, high energy density up to 92.3Whkg−1 and power density as high as 5.5kWkg−1 (based on active material mass of two electrodes), excellent capacity retention of 97.0% after 1000 cycles. The power density and cycle performance of LIC can be further improved by reducing the AC positive electrode designed capacity.
Carbon coating of fine particles of Li4Ti5O12 synthesized under hydrothermal condition is carried out by amphiphilic carbonaceous material (ACM) in aqueous solution, followed by carbonization at ...800°C for 2h. The particles prepared are comprised of highly-crystalline spinel-type Li4Ti5O12 with the size in the range of 100–400nm without any agglomeration, of which surface is uniformly covered by a thin carbon layer. Their electrochemical performance as an anode in lithium-ion batteries is evaluated. The initial discharge capacity of carbon-coated Li4Ti5O12 at 20C rate is 137mAhg−1 and remains as high as 125mAhg−1 after 100 cycles (91% retention), exhibiting good rate and cyclic performance. Carbon coating by using ACM as carbon precursor gives the Li4Ti5O12 particles an enhanced performance as an anode in lithium-ion batteries, owing to the improvement in electrical conductivity, polarization and ability of dispersion. This non-organic coating process may present a new economic, facile, and green pathway for the preparation of carbon-coated Li4Ti5O12 as a high power anode material in lithium-ion batteries.
► Carbon-coated Li4Ti5Ol2 was prepared by using ACM as a carbon precursor. ► The obtained Li4Ti5Ol2 electrode presents high-rate capability and cyclic stability. ► This economic, facile, and green synthesis method enables the production on a large scale.
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