Ruthenium single-atom doping-driven modulation of CoO spinel tetrahedral site 3d-orbital occupancy in lithium-oxygen batteries.

Metal single-atom catalysts have attracted widespread attention in the field of lithium-oxygen batteries due to their unique active sites, high catalytic selectivity, and near total atomic utilization efficiency. Isolated metal atoms not only serve as the active sites themselves, but also function as modulators, reversely regulating the surface electronic structure of the support to enhance its inherent electrocatalytic activities. Despite the potential of isolated metal atom-driven active sites, understanding the structure-activity relationship remains a challenge.

Effect of cell settlement on the electrochemical collision behaviors of single microbes.

Electrochemical collision technique has emerged as a powerful approach to detect the intrinsic properties of single entities. The diffusion model, together with migration and convection processes are generally used to describe the transport and collision processes of single entities. However, things become more complicated concerning microbes because of their relatively large size, inherent motility and biological activities.

Artificial bi-functional layers promoting Zn desolvation and homogeneous deposition for reversible zinc metal anodes.

Rechargeable aqueous zinc-ion hybrid supercapacitors (ZHSs) are drawing extensive attention because of their cost-effectiveness and diminished safety hazards. Nevertheless, large-scale application of ZHSs has been hindered by the severe side reactions and rampant dendrites growth on the surface of Zn metal anodes. Herein, we propose a three-dimensional organic-inorganic composite frame material as an artificial bi-functional layer coated on the zinc foil, featuring nitrogenous functional groups with zincophilicity (abbreviated as NCFM@Zn).

Cross-organ single-cell transcriptome profiling reveals macrophage and dendritic cell heterogeneity in zebrafish.

Tissue-resident macrophages (TRMs) and dendritic cells (DCs) are highly heterogeneous and essential for immunity, tissue regeneration, and homeostasis maintenance. Here, we comprehensively profile the heterogeneity of TRMs and DCs across adult zebrafish organs via single-cell RNA sequencing. We identify two macrophage subsets: pro-inflammatory macrophages with potent phagocytosis signatures and pro-remodeling macrophages with tissue regeneration signatures in barrier tissues, liver, and heart.

Chromium-doped inverse spinel electrocatalysts with optimal orbital occupancy for facilitating reaction kinetics of lithium-oxygen batteries.

Tailored electrocatalysts that can modulate their electronic structure are highly desirable to facilitate the reaction kinetics of oxygen evolution reaction (OER) and oxidation reduction reaction (ORR) in lithium-oxygen batteries (LOB). Although octahedron predominant inverse spinels (e.g.

Precisely Controllable Artificial Muscle with Continuous Morphing based on "Breathing" of Supramolecular Columns.

Skeletal muscles are natural motors executing sophisticated work through precise control of linear contraction. Although various liquid crystal polymers based artificial muscles have been designed, the mechanism based on mainly the order-disorder transition usually leads to discrete shape morphing, leaving arbitrary and precise deformation a huge challenge. Here, one novel photoresponsive hemiphasmidic side-chain liquid crystal polymer with a unique "breathing" columnar phase that enables continuous morphing is presented.

Band engineering in heterostructure catalysts to achieve High-Performance Lithium-Oxygen batteries.

The electronic structure of cathode catalysts dominates the electrochemistry reaction kinetics in lithium-oxygen batteries. However, conventional catalysts perform inferior intrinsic activity due to the low d-band level of the active sites makes it difficult to bond with the reaction intermediates, which results in poor electrochemical performance of lithium-oxygen batteries. Herein, NiFeO/MoS heterostructures are elaborately constructed to reach an electronic state balance for the active sites, which realizes the upper shift of the d-band level and enhanced adsorption of intermediates.

Feasibility investigation and development of microbial electrochemical biosensors for marine pollution monitoring.

Electrochemical biosensor, as a real-time and rapid detection method, has rarely been explored in marine monitoring. In present work, microbial electrochemical biosensors based on two design strategies: disperse system and integrated microbial electrode, were systematically discussed and their feasibility in marine biotoxicity assessment were investigated. An isolation method was initially investigated to eliminate the potential interference and detect the biological response accurately.

Boron nitride materials as emerging catalysts for oxidative dehydrogenation of light alkanes.

Light olefins (C-C) play a crucial role as basic ingredients in chemical industry, and oxidative dehydrogenation (ODH) of light alkanes to olefins has been one of the popular routes since the shale gas revolution. ODH of light alkanes has advantages on energy-and-cost saving as compared with traditional direct dehydrogenation, but it is restricted by its overoxidation which results in the relatively low olefin selectivity. Boron nitride (BN), an interesting nanomaterial with an analogous structure to graphene, springs out and manifests the superior performance as advanced catalysts in ODH, greatly improving the olefin selectivity under high alkane conversion.

The "Parallel Pandemic" in the Context of China: The Spread of Rumors and Rumor-Corrections During COVID-19 in Chinese Social Media.

Although studies have investigated cyber-rumoring previous to the pandemic, little research has been undertaken to study rumors and rumor-corrections during the COVID-19 (coronavirus disease 2019) pandemic. Drawing on prior studies about how online stories become viral, this study will fill that gap by investigating the retransmission of COVID-19 rumors and corrective messages on Sina Weibo, the largest and most popular microblogging site in China. This study examines the impact of rumor types, content attributes (including frames, emotion, and rationality), and source characteristics (including follower size and source identity) to show how they affect the likelihood of a COVID-19 rumor and its correction being shared.

Chameleon-Inspired Variable Coloration Enabled by a Highly Flexible Photonic Cellulose Film.

Due to spontaneous organization of cellulose nanocrystals (CNCs) into the chiral nematic structure that can selectively reflect circularly polarized light within a visible-light region, fabricating stretching deformation-responsive CNC materials is of great interest but is still a big challenge, despite such a function widely observed from existing creatures, like a chameleon, because of the inherent brittleness. Here, a flexible network structure is introduced in CNCs, exerting a bridge effect for the rigid nanomaterials. The as-prepared films display high flexibility with a fracture strain of up to 39%.

Triphenylphosphine-Based Covalent Organic Frameworks and Heterogeneous Rh-P-COFs Catalysts.

The synthesis of phosphine-based functional covalent organic frameworks (COFs) has attracted great attention recently. Herein, we present two examples of triphenylphosphine-based COFs (termed P-COFs) with well-defined crystalline structures, high specific surface areas, and good thermal stability. Furthermore, rhodium catalysts with these P-COFs as support material show high turnover frequency for the hydroformylation of olefins, as well as excellent recycling performance.

Encapsulation and release of drug nanoparticles in functional polymeric vesicles.

We investigated the co-assembly of amphiphilic diblock copolymers in solutions containing drugs and functional nanoparticles using the dissipative particle dynamics (DPD) method. By controlling the size and the concentration of the functional nanoparticles, the length of the hydrophobic blocks, and the interaction parameters between the hydrophobic block/solvent and the functional nanoparticles, we obtained the desired aggregates to load drugs. The aggregates loaded with drugs can be disk-like micelles, sphere-like micelles and vesicles with functional nanoparticles on the surface.

Accelerated polysulfide conversion on hierarchical porous vanadium-nitrogen-carbon for advanced lithium-sulfur batteries.

With high theoretical specific density, low cost, and non-toxicity, Li-S batteries are regarded as a promising candidate for next-generation energy storage systems. However, the shuttling of soluble Li polysulfides (LiPSs) results in self-discharge and rapid capacity degradation. Herein, nitrogen-doped hierarchical porous carbon with embedded highly dispersed vanadium (v)-N sites (V-N-C) is developed as a high-performance Li-S battery cathode for the first time.

Stabilizing the active phase of iron-based Fischer-Tropsch catalysts for lower olefins: mechanism and strategy.

Fischer-Tropsch synthesis of lower olefins (FTO) is a classical yet modern topic of great significance in which the supported Fe-based nanoparticles are the most promising catalysts. The performance deterioration of catalysts is a big challenge due to the instability of the nanosized active phase of iron carbides. Herein, by mass spectrometry, theoretical analysis, and atmospheric- and high-pressure experimental examinations, we revealed the Ostwald-ripening-like growth mechanism of the active phase of iron carbides in FTO, which involves the cyclic formation-decomposition of iron carbonyl intermediates to transport iron species from small particles to large ones.

Efficient entrapment and catalytic conversion of lithium polysulfides on hollow metal oxide submicro-spheres as lithium-sulfur battery cathodes.

Li-S battery technology, with high theoretical capacity and energy density, has drawn much attention in recent years as a possible replacement for current Li-ion battery technologies. A major drawback of Li-S batteries is a severe capacity fading effect which, to a large extent, stems from the dissolution and diffusion of lithium polysulfides (LiPS) that are formed during both charge and discharge cycles. The self-discharge caused by the LiPS migration during the charge process (the so-called "shuttle effect") often leads to the capacity decay of Li-S batteries.

Immobilization of Carbonylcobalt Catalyst by Poly(4-vinylpyridine) (P4VP) through N→Co Coordination Bonds: The Promotional Effect of Pyridine and the Reusability of Polymer Catalyst.

A carbonylcobalt catalyst, immobilized by poly(4-vinylpyridine) (P4VP) through N→Co coordination bonds, has been prepared by solvothermal method. It has been revealed that the pyridine fragments in the polymer catalyst act not only as promoters to improve the catalytic performance of the carbonylcobalt catalyst for alkoxycarbonylation of ethylene oxide to methyl 3-hydroxypropanoate but also as stabilizers to enhance the reusability of the polymer catalyst. Furthermore, the polymer catalyst could be easily separated by filtration and reused with only a slight loss of catalytic efficiency.

Selective hydrogenolysis of raw glycerol to 1,2-propanediol over Cu-ZnO catalysts in fixed-bed reactor.

The catalytic properties of Cu-ZnO catalysts for glycerol hydrogenolysis to 1,2-propanediol (1,2-PDO) were tested in a fixed-bed reactor at 250 °C and 2.0 MPa H2. The relation between composition, surface properties, and catalytic performance of glycerol hydrogenation of Cu-ZnO catalysts was studied using nitrogen adsorption (BET methods), XRD, H2 temperature-programmed reduction, and N2O chemisorptions.

Novel mesoporous NiO/HTiNbO5 nanohybrids with high visible-light photocatalytic activity and good biocompatibility.

Mesoporous nanohybrids of NiO nanoparticles and HTiNbO(5) nanosheets have been successfully synthesized by first exfoliating layered HTiNbO(5) in tetrabutylammonium hydroxide (TBAOH) to obtain HTiNbO(5) nanosheets, then reassembling with a nickel precursor and finally heating with urea. The resulting samples were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, photoluminescence spectroscopy (PL) and N(2) adsorption-desorption measurements. It was found that the as-prepared nanohybrids had a relatively large interlayer spacing of 1.

The structure and catalytic activity of anatase and rutile titania supported manganese oxide catalysts for selective catalytic reduction of NO by NH3.

The structure and catalytic properties of anatase and rutile supported manganese oxide catalysts prepared by impregnation method have been studied by using X-ray diffraction (XRD), laser Raman spectroscopy (LRS), X-ray photoelectron spectroscopy (XPS), H(2) temperature-programmed reduction (H(2)-TPR) and BET surface area measurements combined with activity testing of selective catalytic reduction (SCR) of NO by NH(3). It has been shown that the manganese oxide loadings on the two TiO(2) supports exert great influences on the SCR activity. For the rutile supported manganese oxide catalysts, increasing manganese oxide loading leads to the increase of reducibility of dispersed manganese oxide species and the rate constant k, which reaches a maximum around 9.

Highly dispersed Pt-Ni nanoparticles on nitrogen-doped carbon nanotubes for application in direct methanol fuel cells.

Binary Pt-Ni alloyed nanoparticles supported on nitrogen-doped carbon nanotubes (NCNTs) have been facilely constructed without pre-modification by making use of the active sites in NCNTs due to the N-participation. So-obtained binary Pt-Ni alloyed nanoparticles have been highly dispersed on the outer surface of the support with the size of about 3-4 nm. The electrochemical properties of the catalysts for methanol oxidation have been systematically evaluated.