Replacement of precious metals with earth‐abundant electrocatalysts for oxygen evolution reaction (OER) holds great promise for realizing practically viable water‐splitting systems. It still remains ...a great challenge to develop low‐cost, highly efficient, and durable OER catalysts. Here, the composition and morphology of Ni–Co bimetal phosphide nanocages are engineered for a highly efficient and durable OER electrocatalyst. The nanocage structure enlarges the effective specific area and facilitates the contact between catalyst and electrolyte. The as‐prepared Ni–Co bimetal phosphide nanocages show superior OER performance compared with Ni2P and CoP nanocages. By controlling the molar ratio of Ni/Co atoms in Ni–Co bimetal hydroxides, the Ni0.6Co1.4P nanocages derived from Ni0.6Co1.4(OH)2 nanocages exhibit remarkable OER catalytic activity (η = 300 mV at 10 mA cm−2) and long‐term stability (10 h for continuous test). The density‐functional‐theory calculations suggest that the appropriate Co doping concentration increases density of states at the Fermi level and makes the d‐states more close to Fermi level, giving rise to high charge carrier density and low intermedia adsorption energy than those of Ni2P and CoP. This work also provides a general approach to optimize the catalysis performance of bimetal compounds.
Ni–Co bimetal phosphide nanocages as highly efficient and robust electrocatalysts are synthesized by using Cu2O nanocubes templates. Through accurate regulation of Co doping concentration, the optimum oxygen evolution reaction performance can be achieved. Theoretical analysis suggests that the Co incorporation into Ni2P effectively optimizes the electronic structures of bimetal phosphide catalysts and enhances their interaction with reactants.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Neuromorphic visual systems have considerable potential to emulate basic functions of the human visual system even beyond the visible light region. However, the complex circuitry of artificial visual ...systems based on conventional image sensors, memory and processing units presents serious challenges in terms of device integration and power consumption. Here we show simple two-terminal optoelectronic resistive random access memory (ORRAM) synaptic devices for an efficient neuromorphic visual system that exhibit non-volatile optical resistive switching and light-tunable synaptic behaviours. The ORRAM arrays enable image sensing and memory functions as well as neuromorphic visual pre-processing with an improved processing efficiency and image recognition rate in the subsequent processing tasks. The proof-of-concept device provides the potential to simplify the circuitry of a neuromorphic visual system and contribute to the development of applications in edge computing and the internet of things.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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•SNAD exhibited favorable NH4+-N, TN and refractory organics removal efficiency.•Roles of the co-existent heterotrophs in SNAD bioreactor were investigated.•SNAD bioreactor favored ...humic-like degradation from mature landfill leachate.•Metagenome of SNAD for mature leachate treatment was performed for the first time.•Anammox-based biomass was applicable inoculum of SNAD for mature leachate treatment.
In this study, a simultaneous partial nitrification, Anammox and denitrification (SNAD) bioreactor was constructed for mature landfill leachate treatment, which exhibited favorable NH4+-N (98.9–99.9%), TN (90.7–94.9%) and bio-refractory organic compounds (46.2–67.7%) removal efficiencies. Stoichiometric analysis demonstrated that the synergy of ammonium-oxidizing bacteria and Anammox bacteria dominated TN removal (96.1–97.2%). NO3−-N produced in Anammox could be further reduced through (partial) denitrification and dissimilatory nitrate reduction to ammonium (DNRA). The results highlighted that humic-like and their intermediates might serve as the electron donor for these (partial) denitrifiers and DNRA bacteria to remove NO3−-N, and could be effectively removed from mature landfill leachate in SNAD bioreactor. Metagenomic characterization further demonstrated that phyla Chloroflexi, Chlorobi and genera Nitrosomonas, Ignavibacterium and Aminiphilus might be responsible for such humic-like degradation. Overall, this work offers new insights into the metagenome-based bioinformatic roles for the previously understudied microorganisms in SNAD bioreactor for mature landfill leachate treatment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Platinum disulfide (PtS2), a new member of the group‐10 transition‐metal dichalcogenides, is studied experimentally and theoretically. The indirect bandgap of PtS2 can be drastically tuned from 1.6 ...eV (monolayer) to 0.25 eV (bulk counterpart), and the interlayer mechanical coupling is almost isotropic. It can be explained by strongly interlayer interaction from the pz orbital hybridization of S atoms.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Control of the carrier type in 2D materials is critical for realizing complementary logic computation. Carrier type control in WSe2 field‐effect transistors (FETs) is presented via thickness ...engineering and solid‐state oxide doping, which are compatible with state‐of‐the‐art integrated circuit (IC) processing. It is found that the carrier type of WSe2 FETs evolves with its thickness, namely, p‐type (<4 nm), ambipolar (≈6 nm), and n‐type (>15 nm). This layer‐dependent carrier type can be understood as a result of drastic change of the band edge of WSe2 as a function of the thickness and their band offsets to the metal contacts. The strong carrier type tuning by solid‐state oxide doping is also demonstrated, in which ambipolar characteristics of WSe2 FETs are converted into pure p‐type, and the field‐effect hole mobility is enhanced by two orders of magnitude. The studies not only provide IC‐compatible processing method to control the carrier type in 2D semiconductor, but also enable to build functional devices, such as, a tunable diode formed with an asymmetrical‐thick WSe2 flake for fast photodetectors.
In the thickness‐dependent transport behavior of WSe2 transistors, it is revealed that all p‐type, ambipolar, and n‐type characteristics are obtained by merely varying the thickness of WSe2 flakes. The layer‐dependent band structure is a determining factor in achieving this strong thickness‐dependent transport behavior in WSe2 field‐effect transistors. The unique band structure of WSe2 also enables efficient p‐type doping in WSe2 by solid‐state oxide.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A microscopic understanding of the growth mechanism of two-dimensional materials is of particular importance for controllable synthesis of functional nanostructures. Because of the lack of direct and ...insightful observations, how to control the orientation and the size of two-dimensional material grains is still under debate. Here we discern distinct formation stages for MoS2 flakes from the thermolysis of ammonium thiomolybdates using in situ transmission electron microscopy. In the initial stage (400 °C), vertically aligned MoS2 structures grow in a layer-by-layer mode. With the increasing temperature of up to 780 °C, the orientation of MoS2 structures becomes horizontal. When the growth temperature reaches 850 °C, the crystalline size of MoS2 increases by merging adjacent flakes. Our study shows direct observations of MoS2 growth as the temperature evolves, and sheds light on the controllable orientation and grain size of two-dimensional materials.
Potential risks of treatment with hydroxychloroquine (HCQ) include QT interval prolongation, hypoglycemia, a wide range of neuropsychiatric manifestations, hematotoxicity, and potential genetic ...defects. HCQ is extremely toxic when used in overdose and can lead to tachycardia, hypotension, known central nervous system, transmission defects, hypokalemia and other manifestations in individuals. The mechanism of excessive HCQ leading to these manifestations is still unclear. In this paper, overdose HCQ at different concentrations was used to treat zebrafish embryos, and the phenomena like human beings were obtained, such as increased heart rate and nervous system inhibition. With the increase of concentration to 100 μM, embryo mortality and malformation rate increased and hatching rate decreased, in situ hybridization showed abnormal differentiation of embryo germ layers and formation of vital organs. We selected embryos treated with 50 μM HCQ, in which concentration the mortality rate, hatching rate and malformation rate of the embryos were like those of the control group, for transcriptome analysis. Although the above indexes did not change significantly, the molecular changes related to the development of the heart, eye, nerve and other important organs were significant. This study provides useful information for further research on the toxicity mechanism of HCQ overdose, and provides some insight that can guide future studies in humans.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Cost-effective, highly efficient, and durable catalyst electrodes play a critical role in large-scale water splitting. Although bimetallic phosphides show great potential in electrocatalytic water ...splitting, the synergistic effect between different active sites has not been investigated to date in detail, which implies lack of an effective strategy to optimize the water splitting performance in a reasonable way. Here we realize robust oxygen evolution (OER) performance with an extremely low overpotential (500 mA cm −2 @255 mV), low Tafel slope (29.1 mV dec −1 ), and superior stability by controlling the Fe sites on the Ni–Fe–P surface. The prepared OER electrode employs non-noble metal catalysts for superior oxygen evolution performance and meets the requirements of commercial water electrolyzers. In addition, remarkable hydrogen evolution (HER) performance with prominent stability is also achieved by reducing the content of Fe dopant. Our theoretical calculations reveal that improved chemisorption of O-containing intermediates induced by Fe doping contributes to the enhanced OER performance and water molecule chemisorption, which is sensitive to the Fe content, is the primary cause affecting alkaline HER performance. This work highlights controllable water splitting performance on the Ni–Fe–P surface by precisely manipulating the surface active Fe-sites.
The aryl hydrocarbon receptor was previously known as an environmental receptor that modulates the cellular response to external environmental changes. In essence, the aryl hydrocarbon receptor is a ...cytoplasmic receptor and transcription factor that is activated by binding to the corresponding ligands, and they transmit relevant information by binding to DNA, thereby activating the transcription of various genes. Therefore, we can understand the development of certain diseases and discover new therapeutic targets by studying the regulation and function of AhR. Several autoimmune diseases, including systemic lupus erythematosus (SLE), have been connected to AhR in previous studies. SLE is a classic autoimmune disease characterized by multi-organ damage and disruption of immune tolerance. We discuss here the homeostatic regulation of AhR and its ligands among various types of immune cells, pathophysiological roles, in addition to the roles of various related cytokines and signaling pathways in the occurrence and development of SLE.
Betweenness centrality measures the centrality of nodes and edges in a graph based on the concept of shortest paths. However, such a definition is unsuitable for uncertain graphs due to the ...uncertainty of links. In the possible-world semantics, the Monte Carlo method is proposed to estimate the betweenness centrality of uncertain graphs. However, this method is computationally intensive. To address this challenging issue, in this paper, we propose the concept of possible shortest paths and develop a metric to approximate the betweenness centrality for uncertain graphs. We demonstrate that the new metric of betweenness centrality generalizes the deterministic one. Unfortunately, it is NP-hard to enumerate all possible shortest paths between two nodes exhaustively. To tackle this difficulty, we design a heuristic algorithm to explore the majority of possible shortest paths efficiently. Our method avoids the sampling process in the Monte Carlo method, and thus significantly improves the computational efficiency. We conduct extensive experiments to evaluate the effectiveness and efficiency of our method. The experimental results show that our approach can approximate the centrality of uncertain graphs accurately with high efficiency. Finally, we apply our method to the Internet network to evaluate the importance of autonomous systems.
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