CoCoNet: Coupled Contrastive Learning Network with Multi-level Feature Ensemble for Multi-modality Image Fusion

Infrared and visible image fusion targets to provide an informative image by combining complementary information from different sensors. Existing learning-based fusion approaches attempt to construct various loss functions to preserve complementary features from both modalities, while neglecting to discover the inter-relationship between the two modalities, leading to redundant or even invalid information on the fusion results. To alleviate these issues, we propose a coupled contrastive learning network, dubbed CoCoNet, to realize infrared and visible image fusion in an end-to-end manner. Concretely, to simultaneously retain typical features from both modalities and remove unwanted information emerging on the fused result, we develop a coupled contrastive constraint in our loss function.In a fused imge, its foreground target/background detail part is pulled close to the infrared/visible source and pushed far away from the visible/infrared source in the representation space. We further exploit image characteristics to provide data-sensitive weights, which allows our loss function to build a more reliable relationship with source images. Furthermore, to learn rich hierarchical feature representation and comprehensively transfer features in the fusion process, a multi-level attention module is established. In addition, we also apply the proposed CoCoNet on medical image fusion of different types, e.g., magnetic resonance image and positron emission tomography image, magnetic resonance image and single photon emission computed tomography image. Extensive experiments demonstrate that our method achieves the state-of-the-art (SOTA) performance under both subjective and objective evaluation, especially in preserving prominent targets and recovering vital textural details.Comment: 25 pages, 16 figure

Identification and manipulation of dynamic active site deficiency-induced competing reactions in electrocatalytic oxidation processes

A detrimental competition between the urea oxidation reaction (UOR) and oxygen evolution reaction is identified. Strategies are proposed to alleviate such competition and boost the performance of the UOR and other organic compound oxidation reactions

Approaching theoretical performances of electrocatalytic hydrogen peroxide generation by cobalt‐nitrogen moieties

Electrocatalytic oxygen reduction reaction (ORR) has been intensively studied for environmentally benign applications. However, insufficient understanding of ORR 2 e−‐pathway mechanism at the atomic level inhibits rational design of catalysts with both high activity and selectivity, causing concerns including catalyst degradation due to Fenton reaction or poor efficiency of H2O2 electrosynthesis. Herein we show that the generally accepted ORR electrocatalyst design based on a Sabatier volcano plot argument optimises activity but is unable to account for the 2 e−‐pathway selectivity. Through electrochemical and operando spectroscopic studies on a series of CoN x /carbon nanotube hybrids, a construction‐driven approach based on an extended “dynamic active site saturation” model that aims to create the maximum number of 2 e− ORR sites by directing the secondary ORR electron transfer towards the 2 e− intermediate is proven to be attainable by manipulating O2 hydrogenation kinetics

Towards a global partnership model in interprofessional education for cross-sector problem-solving

Objectives A partnership model in interprofessional education (IPE) is important in promoting a sense of global citizenship while preparing students for cross-sector problem-solving. However, the literature remains scant in providing useful guidance for the development of an IPE programme co-implemented by external partners. In this pioneering study, we describe the processes of forging global partnerships in co-implementing IPE and evaluate the programme in light of the preliminary data available. Methods This study is generally quantitative. We collected data from a total of 747 health and social care students from four higher education institutions. We utilized a descriptive narrative format and a quantitative design to present our experiences of running IPE with external partners and performed independent t-tests and analysis of variance to examine pretest and posttest mean differences in students’ data. Results We identified factors in establishing a cross-institutional IPE programme. These factors include complementarity of expertise, mutual benefits, internet connectivity, interactivity of design, and time difference. We found significant pretest–posttest differences in students’ readiness for interprofessional learning (teamwork and collaboration, positive professional identity, roles, and responsibilities). We also found a significant decrease in students’ social interaction anxiety after the IPE simulation. Conclusions The narrative of our experiences described in this manuscript could be considered by higher education institutions seeking to forge meaningful external partnerships in their effort to establish interprofessional global health education

Design of metal-carbon hybrids for electrosynthesis

Electrocatalytic devices are of great importance for promoting global electrification and solving renewable energy intermittency problem by enabling efficient and flexible conversion between electrical and chemical energy. For instance, green hydrogen, which refers to hydrogen gas produced by renewable energy, is considered an ideal candidate to replace fossil fuels as energy carriers and raw materials for domestic and industrial applications. Green hydrogen can be generated by water electrolyser through catalytic hydrogen evolution reaction and then be utilized as the fuel of fuel cells to power electronics. Hydrogen economy is currently hindered by the high production (due to the large overpotential and low economic value of the anodic product of the water splitting process) and utilization (due to the expensive fuel cell cathode material) cost, thus requires the electrocatalytic systems/catalysts to be further studied and designed. Here, this thesis firstly aims at minimising the operation potential of a H2 generator by replacing the sluggish anodic oxygen evolution reaction of conventional water electrolysers with advanced anodic reactions (i.e. organic compound oxidation reactions) which either requires lower overpotential (i.e. urea oxidation reaction) or generates high value products (i.e. methanol upgrading reaction). Step-by-step research is carried out by firstly investigating the products, selectivity and active site of organic compound oxidation reactions governed by nickel-carbon catalyst, then evaluating the activity limitations, finally optimising the electrocatalyst design. The second objective of this thesis is to design oxygen reduction reaction electrocatalysts made of earth-abundant elements such as carbon and transition metals. Attention is laid on correlating oxygen reduction reaction selectivity with catalytic active moiety at atomic level to accommodate the demand for fuel cell application or green hydrogen peroxide synthesis. The details of these two main work in this PhD thesis are as follows: (1) Electrocatalytic organic compound oxidation reactions have been intensively studied for energy and environmentally benign applications. However, relatively little effort has been devoted to developing a fundamental understanding of the electrooxidation of organic compounds, including the detailed competition with side reactions and activity limitations, thus inhibiting the rational design of high-performance electrocatalysts. Herein, by taking NiWO4-catalysed urea oxidation reaction in aqueous media as an example, the competition between the organic compound oxidation reaction and the oxygen evolution reaction within a wide potential range was examined. It is shown that the root of the competition can be ascribed to insufficient surface concentration of dynamic Ni3+, an active site shared by both UOR and OER. Similar problems are observed in other OCOR electrocatalysts and systems. To address the issue, a “controllable reconstruction of pseudo-crystalline bimetal oxides” design strategy is proposed to maximise the dynamic Ni3+ population and manipulate the competition between urea oxidation and oxygen evolution reactions. The optimised electrocatalyst delivers best-in-class performance and a ~10-fold increase in current density at 1.6 V versus the reversible hydrogen electrode for alkaline urea electrolysis compared to that of the pristine materials. (2) Electrochemical oxygen reduction reaction (ORR), in which O2 is either reduced to H2O for fuel cell/metal air battery applications; or undergone a 2e- pathway to produce green H2O2, is critical for global electrification and decarbonisation thanks to its multi-pathway character. Nevertheless, holding multiple reaction channels can be a double-edge sword which raises difficulty in selectivity control. This work firstly identified the limitations of the popular Sabatier principle-driven ORR catalyst design, owing to which current ORR electrocatalysts are restricted by a activity-selectivity dilemma. A “O2 hydrogenation kinetics modification” strategy was then predicted for synergising the activity and selectivity. By designing and examining a series of Co-Nx-C samples, ORR selectivity was correlated with Co-N coordination at atomic level. The most optimised sample exhibits a ~100% H2O2 selectivity and a high onset which is comparable to the thermodynamic limit. Through operando spectroscopic studies, the excellent 2e- ORR activity and selectivity can be attributed to the seemly O2 hydrogenation kinetics, validating the as-proposed hypothesis. Finally, a redox-induced electron delocalisation mechanism was identified via analysing the pseudocapacitive and ORR behaviours of the Co-Nx-C samples. Such mechanism was then applied for regulating the H2O2 formation of ORR 4e- catalysts. The above discoveries provide fresh insights for electrocatalyst design in both fuel cell and H2O2 generation applications

Two Metagenome-Assembled Genome Sequences of Magnetotactic Bacteria in the Order Magnetococcales

International audienceMagnetotactic bacteria represent a valuable model system for the study of microbial biomineralization and magnetotaxis. Here, we report two metagenome-assembled genome sequences of uncultivated magnetotactic bacteria belonging to the order Magnetococcales. These genomes contain nearly complete magnetosome gene clusters responsible for magnetosome biomineralization

Insights into the effect of metal ratio on cooperative redox enhancement effects over au- and pd-mediated alcohol oxidation

The aerobic oxidation of alcohols and aldehydes over supported heterogeneous catalysts can be considered as comprising two complementary and linked processes: dehydrogenation and oxygen reduction. Significant rate enhancements can be observed when these processes are catalyzed by independent active sites, coupled by electron transport between the two catalysts. This effect, termed cooperative redox enhancement (CORE), could significantly influence how researchers approach catalyst design, but a greater understanding of the factors which influence it is required. Herein, we demonstrate that the Au/Pd ratio used in physical mixtures of monometallic catalysts and phase-separated Au and Pd bimetallic catalysts dramatically influences the degree to which CORE effects can promote alcohol oxidation. Perhaps more interestingly, the roles of Au and Pd in this coupled system are determined to be interchangeable. Preliminarily, we hypothesize that this is attributed to the relative rates of the coupled reactions and demonstrate how physical properties can influence this. This deeper understanding of the factors which influence CORE is an important development in bimetallic catalysis

Towards a global partnership model in interprofessional education for cross-sector problem-solving

Abstract Objectives A partnership model in interprofessional education (IPE) is important in promoting a sense of global citizenship while preparing students for cross-sector problem-solving. However, the literature remains scant in providing useful guidance for the development of an IPE programme co-implemented by external partners. In this pioneering study, we describe the processes of forging global partnerships in co-implementing IPE and evaluate the programme in light of the preliminary data available. Methods This study is generally quantitative. We collected data from a total of 747 health and social care students from four higher education institutions. We utilized a descriptive narrative format and a quantitative design to present our experiences of running IPE with external partners and performed independent t-tests and analysis of variance to examine pretest and posttest mean differences in students’ data. Results We identified factors in establishing a cross-institutional IPE programme. These factors include complementarity of expertise, mutual benefits, internet connectivity, interactivity of design, and time difference. We found significant pretest–posttest differences in students’ readiness for interprofessional learning (teamwork and collaboration, positive professional identity, roles, and responsibilities). We also found a significant decrease in students’ social interaction anxiety after the IPE simulation. Conclusions The narrative of our experiences described in this manuscript could be considered by higher education institutions seeking to forge meaningful external partnerships in their effort to establish interprofessional global health education