Electrochemically reduced graphene oxides (ERGO) are obtained under various reducing potentials in the phosphate buffer solution (PBS). Different characterization methods are used to analyse the ...changes of structure and surface chemical condition for graphene oxide (GO). The results show that GO could be reduced controllably to certain degree and its electrochemical activity towards VO2+/VO2+ and V3+/V2+ redox couples is also tunable using this environmentally friendly method. The catalytic mechanism of the ERGO is discussed in detail, the CO functional groups other than the C–O functional groups on the surface of ERGO more likely provide reactive sites for those redox couples, leading to a more comprehensive understanding about the catalytic process than previous relevant researches. This controllable modification method and the ERGO as electrode reaction catalyst with enhanced battery performance are supposed to have promising applications in the all vanadium redox flow battery.
► SWCNT shows excellent electrochemical catalytic activity towards VO2+/VO2+ and V3+/V2+ redox couples. ► The anodic reactions are more sensitive to the surface oxygen atom content change compared ...with the cathodic reactions. ► The enhanced battery performance clearly demonstrated that the SWCNT is suitable to be used as an electrode catalyst for VRFB.
Single-walled carbon nanotube (SWCNT) was used as an electrode catalyst for an all vanadium redox flow battery (VRFB). The electrochemical property of SWCNT towards VO2+/VO2+ and V3+/V2+ was carefully characterized by cyclic voltammetric (CV) and electrochemical impedance spectroscopy (EIS) measurements. The peak current values for these redox pairs were significantly higher on the modified glassy carbon electrode compared with those obtained on the bare electrode, suggesting the excellent electrochemical activity of the SWCNT. Moreover, it was proved that the anodic process was more dependent on the surface oxygen of the SWCNT than the cathodic process through changing its surface oxygen content. Detailed EIS analysis of different modified electrodes revealed that the charge and mass transfer processes were accelerated at the modified electrode–electrolyte interface, which could be ascribed to the large specific surface area, the surface defects and the oxygen functional groups of the SWCNT. The enhanced battery performance effectively demonstrated that the SWCNT was suitable to serve as an electrode catalyst for the VRFB.
Three-dimensional (3D) image reconstruction is an important field of computer vision for restoring the 3D geometry of a given scene. Due to the demand for large amounts of memory, prevalent methods ...of 3D reconstruction yield inaccurate results, because of which the highly accuracy reconstruction of a scene remains an outstanding challenge. This study proposes a cascaded depth residual inference network, called DRI-MVSNet, that uses a cross-view similarity-based feature map fusion module for residual inference. It involves three improvements. First, a combined module is used for processing channel-related and spatial information to capture the relevant contextual information and improve feature representation. It combines the channel attention mechanism and spatial pooling networks. Second, a cross-view similarity-based feature map fusion module is proposed that learns the similarity between pairs of pixel in each source and reference image at planes of different depths along the frustum of the reference camera. Third, a deep, multi-stage residual prediction module is designed to generate a high-precision depth map that uses a non-uniform depth sampling strategy to construct hypothetical depth planes. The results of extensive experiments show that DRI-MVSNet delivers competitive performance on the DTU and the Tanks & Temples datasets, and the accuracy and completeness of the point cloud reconstructed by it are significantly superior to those of state-of-the-art benchmarks.
► A new composite electrode is designed for vanadium redox flow battery (VRB). ► The graphite oxide (GO) is used as electrode reactions catalyst. ► The excellent electrode activity is attributed to ...the oxygen-containing groups attached on the GO surface. ► A catalytic mechanism of the GO towards the redox reactions is presumed.
A graphite/graphite oxide (GO) composite electrode for vanadium redox battery (VRB) was prepared successfully in this paper. The materials were characterized with X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. The specific surface area was measured by the Brunauer–Emmett–Teller method. The redox reactions of VO2+/VO2+ and V3+/V2+ were studied with cyclic voltammetry and electrochemical impedance spectroscopy. The results indicated that the electrochemical performances of the electrode were improved greatly when 3wt% GO was added into graphite electrode. The redox peak currents of VO2+/VO2+ and V3+/V2+ couples on the composite electrode were increased nearly twice as large as that on the graphite electrode, and the charge transfer resistances of the redox pairs on the composite electrode are also reduced. The enhanced electrochemical activity could be ascribed to the presence of plentiful oxygen functional groups on the basal planes and sheet edges of the GO and large specific surface areas introduced by the GO.
IntroductionAs a prevalent psychiatric disease, depression is a life-threatening mental disorder that may cause work disability and premature death. Transcranial magnetic stimulation (TMS) is a ...non-invasive neuromodulation procedure, which has been reported to have a significant effect on antidepressant treatment in recent years. However, the parameters of TMS for depression that can produce the best clinical benefits remain unknown. In the present study, we will evaluate the effect of TMS treatment for depression from the perspective of functional neuroimaging by performing a meta-analysis based on included studies.Methods and analysisTwo independent reviewers will search published studies in the following five databases: PubMed, Web of Science, Embase, China National Knowledge Infrastructure and WANGFANG DATA from inception to 1 June 2020. Then we will select studies according to predesigned inclusion and exclusion criteria. After extracting data from included studies, activation likelihood estimation will be applied to data synthesis. Any disagreement will be checked by the third reviewer who will also make the final decision.Ethics and disseminationThis work does not require ethics approval as it will be based on published studies. This review will be published in peer-reviewed journals.PROSPERO registration numberCRD42020165436.
Biomass-derived porous carbon materials are effective electrocatalysts for oxygen reduction reaction (ORR), with promising applications in low-temperature fuel cells and metal–air batteries. Herein, ...we developed a synthesis procedure that used spinach as a source of carbon, iron, and nitrogen for preparing porous carbon nanosheets and studied their ORR catalytic performance. These carbon sheets showed a very high ORR activity with a half-wave potential of +0.88 V in 0.1 M KOH, which is 20 mV more positive than that of commercial Pt/C catalysts. In addition, they showed a much better long-term stability than Pt/C and were insensitive to methanol. The remarkable ORR performance was attributed to the accessible high-density active sites that are primarily from Fe–N x moieties. This work paves the way toward the use of metal-enriching plants as a source for preparing porous carbon materials for electrochemical energy conversion and storage applications.
Advanced microscopy and/or spectroscopy tools play indispensable roles in nanoscience and nanotechnology research, as they provide rich information about material processes and properties. However, ...the interpretation of imaging data heavily relies on the “intuition” of experienced researchers. As a result, many of the deep graphical features obtained through these tools are often unused because of difficulties in processing the data and finding the correlations. Such challenges can be well addressed by deep learning. In this work, the optical characterization of 2D materials is used as a case study, and a neural‐network‐based algorithm is demonstrated for the material and thickness identification of 2D materials with high prediction accuracy and real‐time processing capability. Further analysis shows that the trained network can extract deep graphical features such as contrast, color, edges, shapes, flake sizes, and their distributions, based on which an ensemble approach is developed to predict the most relevant physical properties of 2D materials. Finally, a transfer learning technique is applied to adapt the pretrained network to other optical identification applications. This artificial‐intelligence‐based material characterization approach is a powerful tool that would speed up the preparation, initial characterization of 2D materials and other nanomaterials, and potentially accelerate new material discoveries.
Microscopy data of nanomaterials often contains rich yet complicated information that reflects the material properties, but is mostly overlooked by researchers. Deep learning is an ideal approach to finding these highly correlated and non‐linear features. As a case study, a neural network model called “2DMOINet” is trained for optical identification and characterization of exfoliated 2D materials.
Despite orientationally variant tears of the meniscus, suture repair is the current clinical gold treatment. However, inaccessible tears in company with re-tears susceptibility remain unresolved. To ...extend meniscal repair tools from the perspective of adhesion and regeneration, we design a dual functional biologic-released bioadhesive (S-PIL10) comprised of methacrylated silk fibroin crosslinked with phenylboronic acid-ionic liquid loading with growth factor TGF-β1, which integrates chemo-mechanical restoration with inner meniscal regeneration. Supramolecular interactions of β-sheets and hydrogen bonds richened by phenylboronic acid-ionic liquid (PIL) result in enhanced wet adhesion, swelling resistance, and anti-fatigue capabilities, compared to neat silk fibroin gel. Besides, elimination of reactive oxygen species (ROS) by S-PIL10 further fortifies localized meniscus tear repair by affecting inflammatory microenvironment with dynamic borate ester bonds, and S-PIL10 continuously releases TGF-β1 for cell recruitment and bridging of defect edge. In vivo rabbit models functionally evidence the seamless and dense reconstruction of torn meniscus, verifying that the concept of meniscus adhesive is feasible and providing a promising revolutionary strategy for preclinical research to repair meniscus tears.
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