A flexible Li–S battery based on an integrated structure of sulfur and graphene on a separator is developed. The internal graphene current collector offers a continuous conductive pathway, a modified ...interface with sulfur, and a good barrier to and an effective reservoir for dissolved polysulfides, consequently improving the capacity and cyclic life of the Li–S battery.
Developing cost‐efficient multifunctional electrocatalysts is highly critical for the integrated electrochemical energy‐conversion systems such as water electrolysis based on hydrogen/oxygen ...evolution reactions (HER/OER) and metal‐air batteries based on OER/oxygen reduction reactions (ORR). The core–shell structured materials with transition metal phosphide as the core and nitrogen‐doped carbon (NC) as the shell have been known as promising HER electrocatalysts. However, their oxygen‐related electrocatalytic activities still remain unsatisfactory, which severely limits their further applications. Herein an effective strategy to improve the core and shell performances of core–shell Co2P@NC electrocatalysts through secondary metal (e.g., Fe, Ni, Mo, Al, Mn) doping (termed M‐Co2P@M‐N‐C) is reported. The as‐synthesized M‐Co2P@M‐N‐C electrocatalysts show multifunctional HER/OER/ORR activities and good integrated capabilities for overall water splitting and Zn‐air batteries. Among the M‐Co2P@M‐N‐C catalysts, Fe‐Co2P@Fe‐N‐C electrocatalyst exhibits the best catalytic activities, which is closely related to the configuration of highly active species (Fe‐doping Co2P core and Fe‐N‐C shell) and their subtle synergy, and a stable carbon shell for outstanding durability. Combination of electrochemical‐based in situ Fourier transform infrared spectroscopy with extensive experimental investigation provides deep insights into the origin of the activity and the underlying electrocatalytic mechanisms at the molecular level.
By incorporating various secondary metals (e.g., Fe, Ni, Mo, Mn, and Al) into core–shell Co2P@NC system, the trifunctional catalytic activities of core and shell of Co2P@NC toward HER/OER/ORR is enhanced simultaneously, leading to an advanced catalytic system (Fe‐Co2P@Fe‐N‐C) with high catalytic efficiency and remarkable stability for efficient water electrolysis and rechargeable liquid/all‐solid‐state Zn‐air batteries.
Alginate oligosaccharides produced by enzymatic degradation show versatile physiological functions and biological activities. In this study, a new alginate lyase encoding gene
from
sp. S02 was ...recombinantly expressed at a high level in
, with the highest extracellular activity in the supernatant reaching 36.8 ± 2.1 U/mL. AlyS02 was classified in the polysaccharide lyase (PL) family 7. The optimal reaction temperature and pH of this enzyme were 30 °C and 7.6, respectively, indicating that AlyS02 is a cold-adapted enzyme. Interestingly, AlyS02 contained more than 90% enzyme activity at 25 °C, higher than other cold-adapted enzymes. Moreover, AlyS02 is a bifunctional alginate lyase that degrades both polyG and polyM, producing di- and trisaccharides from alginate. These findings suggest that AlyS02 would be a potent tool for the industrial applications.
Electrolyte engineering via fluorinated additives is promising to improve cycling stability and safety of high‐energy Li‐metal batteries. Here, an electrolyte is reported in a porous lithium fluoride ...(LiF) strategy to enable efficient carbonate electrolyte engineering for stable and safe Li‐metal batteries. Unlike traditionally engineered electrolytes, the prepared electrolyte in the porous LiF nanobox exhibits nonflammability and high electrochemical performance owing to strong interactions between the electrolyte solvent molecules and numerous exposed active LiF (111) crystal planes. Via cryogenic transmission electron microscopy and X‐ray photoelectron spectroscopy depth analysis, it is revealed that the electrolyte in active porous LiF nanobox involves the formation of a high‐fluorine‐content (>30%) solid electrolyte interphase layer, which enables very stable Li‐metal anode cycling over one thousand cycles under high current density (4 mA cm−2). More importantly, employing the porous LiF nanobox engineered electrolyte, a Li || LiNi0.8Co0.1Mn0.1O2 pouch cell is achieved with a specific energy of 380 Wh kg−1 for stable cycling over 80 cycles, representing the excellent performance of the Li‐metal pouch cell using practical carbonate electrolyte. This study provides a new electrolyte engineering strategy for stable and safe Li‐metal batteries.
Electrolyte engineering via fluorinated additives is promising to improve the cycling stability and safety of high‐energy Li‐metal batteries. The electrolyte in an active porous LiF nanobox involves the formation of a high‐fluorine‐content (>30%) solid electrolyte interphase layer to achieve a ≈3.5 Ah Li || LiNi0.8Co0.1Mn0.1O2 pouch cell with a specific energy of 380 Wh kg−1 under a practical carbonate electrolyte.
•Conduct 3D profile and fatigue test to investigate the effects of corrosion pits on fatigue life.•Analyze pitting characterizations and establish a qualitative relationship with fatigue ...life.•Propose a nondestructive method based on 3D profile and AFGROW to predict fatigue life.
The effects of corrosion pits on the fatigue life of pre-corroded Q235 steel plates were investigated. 3D profile measurements were conducted to obtain the distribution and morphology characterization of corrosion pits. Three types of pits were observed and categorized for thoroughly understanding their effects on fatigue behavior. Results indicate that corrosion pits reduce the fatigue life significantly, particularly the sharp pits and the interacting pits. A nondestructive methodology based on 3D profile data for fatigue life prediction has been presented. This method (a) provides a finite element method (FEM) to determine the dimensions of critical pits, (b) considers pit-to-crack transition and (c) considers the effect of multiple critical pits. The predictions are shown to compare well against experimental results.
This study assessed the diversity and distribution of fungal communities in thirteen marine seawater samples from four sites (L1, L3, L4 and L7) of the Mariana Trench, with a depth range of 1000-4000 ...meters, using Illumine Hiseq sequencing with fungal-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Sedimentary fungal communities showed high diversity with 209 880 reads belonging to 91 operational taxonomic units (OTUs). Of these OTUs, 45 belonged to the Ascomycota, 37 to Basidiomycota, 3 to Chytridiomycota, 1 to Glomeromycota, 1 to Cryptomycota, and 4 to unknown fungi. The major fungal orders included Saccharomycetales and Sporidiobolales. The commonly found fungal genera were
,
and
. These results suggest the existence of diverse fungal communities in the Mariana Trench marine seawater, which can be considered as a useful community model for further ecological and evolutionary study of fungi in the trench.
Similar materials play an important role in model testing. In order to meet the demand for similar materials in modeling tests, such as those on coal mining, coal system rocky similar materials were ...formulated using yellow sand as a coarse aggregate, heavy calcium carbonate as a fine aggregate, and cement and gypsum as binders. Based on the orthogonal experimental design method, four influencing factors, namely the aggregate–binder ratio, heavy calcium carbonate content, cement–gypsum ratio, and moisture content, were selected. Each factor was designed at five levels. Through weighing, uniaxial compression, Brazilian splitting, and variable-angle plate shear tests on 225 specimens under 25 different ratios, five physico-mechanical property indicators of the material, including density, compressive strength, tensile strength, cohesion, and internal friction angle, were obtained under different ratios. The test results indicate that the similar materials formulated with the above raw materials had a wide range of mechanical properties, which met the simulation needs of different types of coal rocks, such as main coking coal, anthracite, shale, etc., in the similar model test. Range analysis was adopted to analyze the sensitivities to each factor, which showed that the density and internal friction angle of similar materials are mainly controlled by the aggregate–binder ratio; the cement–gypsum ratio mainly controls the compressive strength, tensile strength, and cohesion of the material. Analysis of variance (ANOVA) was adopted to analyze the sensitivities to each factor, which showed that the aggregate–binder ratio had a highly significant effect on the density of the material, the cement–gypsum ratio had a highly significant effect on the compressive and tensile strength of the material, the cement–gypsum ratio had a significant effect on the cohesion and density of the material, and the moisture content had a significant effect on the compressive strength of the material. The remaining factors did not significantly affect the material parameters. The results of this study can provide some reference for the selection of coal system rocky similar materials in subsequent physical modeling tests.
Circular RNAs (circRNAs) represent a class of non-coding RNAs (ncRNAs) which are widely expressed in mammals and tissue-specific, of which some could act as critical regulators in the atherogenesis ...of cerebrovascular disease. However, the underlying mechanisms by which circRNA regulates the ectopic phenotype of endothelial cells (ECs) in atherosclerosis remain largely elusive.
CCK-8, transwell, wound healing and Matrigel assays were used to assess cell viability, migration and tube formation. QRT-qPCR and Immunoblotting were used to examine targeted gene expression in different groups. The binding sites of miR-370-3p (miR-370) with TGFβR2 or hsa_circ_0003204 (circ_0003204) were predicted using a series of bioinformatic tools, and validated using dual luciferase assay and RNA immunoprecipitation (RIP) assay. The localization of circ_0003204 and miR-370 in ECs were investigated by fluorescence in situ hybridization (FISH). Gene function and pathways were enriched through Metascape and gene set enrichment analysis (GSEA). The association of circ_0003204 and miR-370 in extracellular vesicles (EVs) with clinical characteristics of patients were investigated using multiple statistical analysis.
Circ_0003204, mainly located in the cytoplasm of human aorta endothelial cells (HAECs), was upregulated in the ox-LDL-induced HAECs. Functionally, the ectopic expression of circ_0003204 inhibited proliferation, migration and tube formation of HAECs exposed to ox-LDL. Mechanically, circ_0003204 could promote protein expression of TGFβR2 and its downstream phosph-SMAD3 through sponging miR-370, and miR-370 targeted the 3' untranslated region (UTR) of TGFβR2. Furthermore, the expression of circ_0003204 in plasma EVs was upregulated in the patients with cerebral atherosclerosis, and represented a potential biomarker for diangnosis and prognosis of cerebrovascular atherogenesis.
Circ_0003204 could act as a novel stimulator for ectopic endothelial inactivation in atherosclerosis and a potential biomarker for cerebral atherosclerosis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Carbon based materials as one promising cathode to accommodate the insoluble and insulating discharge products (Li2O2) for lithium oxygen (Li‐O2) batteries have attracted great attention due to their ...large energy density store ability compared with the other carbon‐free cathodes. However, the side reaction occurring at carbon/Li2O2 interfaces hinders their large‐scale application in Li‐O2 batteries. Herein, a simple and cost‐effective strategy is developed for the growth of core‐shell‐like Co/CoO nanoparticles on 3D graphene‐wrapped carbon foam using 3D melamine foam as the initial backbone. This unique 3D hierarchical carbonized melamine foam‐graphene‐Co/CoO hybrid (CMF‐G‐Co/CoO) with a continuous conductive network and elastic properties is used as binder‐free oxygen electrode for Li‐O2 batteries. Electrochemical and structural measurements show that a synergistic effect is observed between Co/CoO and graphene, where Li2O2 grows on the Co/CoO surfaces instead of the carbon surfaces at the initial discharge state (500 mAh gtotal−1), indicating the reduced carbon/Li2O2 interfaces and alleviative side reactions during the electrochemical process. Importantly, the CMF‐G‐Co/CoO electrode can achieve greatly improved cycle life over the electrode without aid of the Co/CoO. Furthermore, it delivers a large capacity of ≈7800 mAh gtotal−1 and outstanding rate capability, exhibiting the great potential for the application in Li‐O2 batteries.
Core–shell structured Co/CoO with high LiO2 adsorption energy is proven to be a superior preservative for carbon‐based Li‐O2 batteries. The design is based on a 3D Co/CoO‐graphene‐carbonized polymer foam. The preservative reduces the side reaction and improves the cycle stability of Li‐O2 batteries by inducing Li2O2 growth on itself instead of the carbon surfaces.
Abstract
The grand challenge in the development of atomically dispersed metallic catalysts is their low metal-atom loading density, uncontrollable localization and ambiguous interactions with ...supports, posing difficulty in maximizing their catalytic performance. Here, we achieve an interface catalyst consisting of atomic cobalt array covalently bound to distorted 1T MoS
2
nanosheets (SA Co-D 1T MoS
2
). The phase of MoS
2
transforming from 2H to D-1T, induced by strain from lattice mismatch and formation of Co-S covalent bond between Co and MoS
2
during the assembly, is found to be essential to form the highly active single-atom array catalyst. SA Co-D 1T MoS
2
achieves Pt-like activity toward HER and high long-term stability. Active-site blocking experiment together with density functional theory (DFT) calculations reveal that the superior catalytic behaviour is associated with an ensemble effect via the synergy of Co adatom and S of the D-1T MoS
2
support by tuning hydrogen binding mode at the interface.
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