The applications of magnetron sputtering technology on the surface coating of fabrics have attracted more and more attention from researchers. Over the past 15 years, researches on magnetron ...sputtering coated fabrics have been mainly focused on electromagnetic shielding, bacterial resistance, hydrophilic and hydrophobic properties and structural color etc. In this review, recent progress of the technology is discussed in detail, and the common target materials, technologies and functions and characterization of coated fabrics are summarized and analyzed. Finally, the existing problems and future prospects of this developing field are briefly proposed and discussed.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Single-atom electrocatalysts (SAECs) have gained tremendous attention due to their unique active sites and strong metal–substrate interactions. However, the current synthesis of SAECs mostly relies ...on costly precursors and rigid synthetic conditions and often results in very low content of single-site metal atoms. Herein, we report an efficient synthesis method to prepare metal–nitrogen–carbon SAECs based on formamide condensation and carbonization, featuring a cost-effective general methodology for the mass production of SAECs with high loading of atomically dispersed metal sites. The products with metal inclusion were termed as formamide-converted metal–nitrogen–carbon (shortened as f-MNC) materials. Seven types of single-metallic f-MNC (Fe, Co, Ni, Mn, Zn, Mo and Ir), two bi-metallic (ZnFe and ZnCo) and one tri-metallic (ZnFeCo) SAECs were synthesized to demonstrate the generality of the methodology developed. Remarkably, these f-MNC SAECs can be coated onto various supports with an ultrathin layer as pyrolysis-free electrocatalysts, among which the carbon nanotube-supported f-FeNC and f-NiNC SAECs showed high performance for the O 2 reduction reaction (ORR) and the CO 2 reduction reaction (CO 2 RR), respectively. Furthermore, the pyrolysis products of supported f-MNC can still render isolated metallic sites with excellent activity, as exemplified by the bi-metallic f-FeCoNC SAEC, which exhibited outstanding ORR performance in both alkaline and acid electrolytes by delivering ∼70 and ∼20 mV higher half-wave potentials than that of commercial 20 wt% Pt/C, respectively. This work offers a feasible approach to design and manufacture SAECs with tuneable atomic metal components and high density of single-site metal loading, and thus may accelerate the deployment of SAECs for various energy technology applications.
A hallmark of strongly correlated quantum materials is the rich phase diagram resulting from competing and intertwined phases with nearly degenerate ground-state energies
. A well-known example is ...the copper oxides, in which a charge density wave (CDW) is ordered well above and strongly coupled to the magnetic order to form spin-charge-separated stripes that compete with superconductivity
. Recently, such rich phase diagrams have also been shown in correlated topological materials. In 2D kagome lattice metals consisting of corner-sharing triangles, the geometry of the lattice can produce flat bands with localized electrons
, non-trivial topology
, chiral magnetic order
, superconductivity and CDW order
. Although CDW has been found in weakly electron-correlated non-magnetic AV
Sb
(A = K, Rb, Cs)
, it has not yet been observed in correlated magnetic-ordered kagome lattice metals
. Here we report the discovery of CDW in the antiferromagnetic (AFM) ordered phase of kagome lattice FeGe (refs.
). The CDW in FeGe occurs at wavevectors identical to that of AV
Sb
(refs.
), enhances the AFM ordered moment and induces an emergent anomalous Hall effect
. Our findings suggest that CDW in FeGe arises from the combination of electron-correlations-driven AFM order and van Hove singularities (vHSs)-driven instability possibly associated with a chiral flux phase
, in stark contrast to strongly correlated copper oxides
and nickelates
, in which the CDW precedes or accompanies the magnetic order.
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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
Fractal structures with self‐similarity are of fundamental importance in the fields of aesthetic, chemistry and mathematics. Here, by taking advantage of constructs the rational geometry‐directed ...precursor design, we report the construction of two fascinating Platonic solids, the Sierpiński tetrahedron ST‐T and the Sierpiński octahedron ST‐O, in which each possesses a fractal Sierpiński triangle on their independent faces. These two discrete complexes are formed in near‐quantitative yield from the multi‐component self‐assembly of truncated Sierpiński triangular kernel L1 with tribenzotriquinacene‐based hexatopic and anthracene‐based tetratopic terpyridine ligands (L3 and L4) in the presence of metal ions, respectively. The enhanced stabilities of the 3D discrete structures were investigated by gradient tandem mass spectrometry (gMS2). This work provides new constructs for the imitation of complex virus assemblies and for the molecular encapsulation of giant guest molecules.
A powerful multicomponent self‐assembly strategy has been developed that allows access to gorgeous 3D architectures with large cavities and high complexity. This approach has led to the synthesis of a Sierpiński tetrahedron and a Sierpiński octahedron with Sierpiński triangles as the panels. These two discrete complexes, with molecular weights up to 55 kDa and diameters up to 7.4 nm, were formed in near‐quantitative yields.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The large-scale application of blockchain technology is an expected to be an inevitable trend. This study revolves around published papers and articles related to blockchain technology, relevance ...analysis and sorting through the retrieved documents with six core layers of blockchain: Application Layer, Contract Layer, Actuator Layer, Consensus Layer, Network Layer and Data Layer. Based on the analysis results, this study found that China's research is more towards the preference and application of landing and industry and smart cities with blockchain as the underlying technology. International research is more focused on the research of finance as the underlying technology of blockchain and tries to combine crypto assets with real industries, such as crypted assets and payment systems for traditional industries. This paper studies the impact of monetary entropy on cryptocurrencies in smart cities and uses the monetary entropy formula to measure the crypto-economic entropy. We use Kolmogorov entropy to describe the degree of chaos in the cryptocurrency market in a smart city. The study illustrates the current status of blockchain technology and applications from the perspective of cryptocurrency in a smart city. We find that smart cities and cryptocurrencies have a mutually reinforcing effect.
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Although evidence on the association between per- and polyfluoroalkyl substances (PFASs) and human health outcomes has grown exponentially, specific health outcomes and their potential associations ...with PFASs have not been conclusively evaluated.
We conducted a comprehensive search through the databases of PubMed, Embase, and Web of Science from inception to February 29, 2024, to identify systematic reviews with meta-analyses of observational studies examining the associations between the PFASs and multiple health outcomes. The quality of included studies was evaluated using the A Measurement Tool to Assess Systematic Reviews (AMSTAR) tool, and credibility of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria. The protocol of this umbrella review (UR) had been registered in PROSPERO (CRD 42023480817).
The UR identified 157 meta-analyses from 29 articles. Using the AMSTAR measurement tool, all articles were categorized as of moderate-to-high quality. Based on the GRADE assessment, significant associations between specific types of PFASs and low birth weight, tetanus vaccine response, and triglyceride levels showed high certainty of evidence. Moreover, moderate certainty of evidence with statistical significance was observed between PFASs and health outcomes including lower BMI z-score in infancy, poor sperm progressive motility, and decreased risk of preterm birth as well as preeclampsia. Fifty-two (33%) associations (e.g., PFASs and gestational hypertension, cardiovascular disease, etc) presented low certainty evidence. Additionally, eighty-five (55%) associations (e.g., PFASs with infertility, lipid metabolism, etc) presented very low certainty evidence.
High certainty of evidence supported that certain PFASs were associated with the incidence of low birth weight, low efficiency of the tetanus vaccine, and low triglyceride levels.
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•High-quality evidence supports an association between PFNA as well as PFUnDA and low birthweight.•High-quality evidence supports an association between PFOA as well as PFOS and low tetanus vaccine response.•High-quality evidence supports an association between PFOS and low TG levels.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A mesoporous carbon with ultrahigh pore volume was prepared from chitosan.•The carbon was physically impregnated with polymeric amines for CO2 capture.•The amine/carbon composites showed superior ...CO2 capacities and selectivities.•The CO2 capacities were reserved very well throughout regeneration cycles.
Amine-impregnated adsorbents have promising application for selective CO2 capture from dilute sources in the industry. It is of great significance to develop a support exhibiting not only large pore width but also high pore volume, that can be prepared from renewable and low-cost raw materials. In this work, a mesoporous carbon exhibiting the total pore volume of 3.04 cm3/g was prepared from chitosan by a hard-template route. The mesoporous carbon was then physically impregnated with pentaethylenehexamine, which is rich in amine density and of extremely low volatility. It is demonstrated that the adsorption capacities for CO2 and selectivities for CO2/N2 on mesoporous carbon are significantly improved after the amine impregnation. The highest CO2 uptake of 3.72 mmol/g at 100 °C under atmospheric pressure was achieved in amine-impregnated carbons, being higher than most of other amine-impregnated adsorbents that have ever been reported in the literature. Furthermore, the CO2 adsorbed by amine-impregnated carbon can be facilely stripped out by concentration swing at 75 °C, and the amine-impregnated carbon exhibit high stability throughout consecutive adsorption-desorption cycles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Cellulose nanocrystal (CNC) materials grant abundant possibilities for insulation, however, their extensive application is hindered by the intrinsic tradeoff between their thermal insulating ...performance and mechanical properties. Here, we show that CNC aerogels with balanced thermal and mechanical performance can be fabricated
via
a 1 nm metal oxide cluster (phosphotungstic acid, PTA)-assisted unidirectional freeze-drying processing. The as-prepared hybrid aerogels with hierarchical porous structures consisting of layer-by-layer CNC nanosheets enable the decoupling of the strengthening of mechanical properties and the enhancement of thermal insulating capabilities. Within layered structures, the surface-doped nanosized PTA clusters with negative charges behave as dynamic physical cross-linking points, and continuous networks of PTA-doped CNC can be formed
via
multiple supramolecular interactions (
e.g.
, electrostatic attractions and hydrogen bonds). The afforded stable three-dimensional network structures are able to withstand externally applied forces and large deformations, endowing the aerogels with excellent mechanical performance. Moreover, the inter-layer gap is dominated by nanopores, endowing much lower thermal conductivities along the radial direction in comparison to the axial direction. The addition of PTA clusters also contributes to the obvious enhancements of the fire-retardant properties. Our discoveries provide a facile approach for the design and scalable production of CNC-based insulation materials with optimized mechanical properties and additional fire-retardant properties.
Aerogels of cellulose nanocrystals with balanced thermal and mechanical performance can be fabricated
via
a 1 nm metal oxide cluster assisted unidirectional freeze-drying processing.
Abstract
The century-long development of surface sciences has witnessed the discoveries of a variety of quantum states. In the recently proposed “obstructed atomic insulators”, symmetric charges are ...pinned at virtual sites where no real atoms reside. The cleavage through these sites could lead to a set of obstructed surface states with partial electronic occupation. Here, utilizing scanning tunneling microscopy, angle-resolved photoemission spectroscopy and first-principles calculations, we observe spectroscopic signature of obstructed surface states in SrIn
2
P
2
. We find that a pair of surface states that are originated from the pristine obstructed surface states split in energy by a unique surface reconstruction. The upper branch is marked with a striking differential conductance peak followed by negative differential conductance, signaling its localized nature, while the lower branch is found to be highly dispersive. This pair of surface states is in consistency with our calculational results. Our finding not only demonstrates a surface quantum state induced by a new type of bulk-boundary correspondence, but also provides a platform for exploring efficient catalysts and related surface engineering.
In this study, the design and asymmetric synthesis of a series of chiral targets of orientational chirality were conducted by taking advantage of
-sulfinylimine-assisted nucleophilic addition and ...modified Sonogashira catalytic coupling systems. Orientational isomers were controlled completely using alkynyl/alkynyl levers C(sp)-C(sp) axis with absolute configuration assignment determined by X-ray structural analysis. The key structural element of the resulting orientational chirality is uniquely characterized by remote through-space blocking. Forty examples of multi-step synthesis were performed, with modest to good yields and excellent orientational selectivity. Several chiral orientational amino targets are attached with scaffolds of natural and medicinal products, showing potential pharmaceutical and medical applications in the future.
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