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The electrocatalytic ethanol oxidation reaction (EOR) is a critical component for direct ethanol fuel cells, while its reactivity, stability, and selectivity toward C1 products are severely hindered by the poisoning effect of CO species on the surface of noble-metal catalysts. In this work, we developed a hybrid material of palladium nanoparticles and nickel single-atom catalyst (Pd NPs@Ni SAC) for efficient EOR. The Pd nanoparticles catalyzed the breaking of carbon-carbon bonds of ethanol, while the adsorbed CO intermediates were removed by the Ni single-atom catalyst. The Pd NPs@Ni SAC structure exhibited outstanding EOR performances, including a high mass activity, good selectivities of C1 products, and a high electrocatalytic stability. Our work suggests an attractive perspective of utilizing single-atom electrocatalysts for ethanol oxidation.

Sulfur poisoning of cathode materials is one of the important factors to cause cathode performance degradation resulting in shortening lifetime of SOFC. The sulfur attacks alkali earth components of the rare earth-transition metal perovskite oxides, such as Ba, Ca, Sr, which reacts with SO2 to form sulfates. In this work, the La(Ni0.6Fe0.4)O3 (LNF) cathode material without alkali earth elements was employed to investigate the sulfur poisoning behavior by flowing 30 ppm SO2 at different temperatures of 500 °C–800 °C. It was found that SO2 readily reacts with the La2O3 component in LNF to form La2O2SO4 at 700 °C and 800 °C. The extent of the chemical reaction is temperature dependent. These results confirm that sulfur poisoning also occurs in cathode materials free of alkali earth components. The study prompts the exploration of new materials and new strategies for the developing new cathode materials with high sulfur tolerance.

The eastern Paleo-Tethyan Jinshajiang–Ailaoshan–Song Ma orogenic belt in the Southeast Tibetan Plateau represents the tectonic boundary between the Indochina and South China blocks. Regional Cenozoic lithospheric strike-slip movements caused by the India–Asia collision have modified many of the pristine geological records associated with the Indosinian orogeny. The lack of reliable petrological evidences, particularly of high-pressure (HP) metamorphism, has hindered the tracing of the evolutionary history of the Paleo-Tethyan orogenic belt. We report the mineralogy, geochemistry, geochronology and thermodynamic modelling of eclogite lenses/blocks and their host garnet–phengite schists from the Song Ma Suture Zone of Northwest Vietnam and reveal their protolith origins and metamorphic evolution. The eclogites are geochemically similar to mid-ocean ridge basalt, showing weak depletions in high field-strength elements, positive to slightly negative whole-rock ɛNd(t) ratios (−1.69 to +5.15) and slightly high 87Sr/86Sr(t) ratios (0.70466–0.70834). The igneous protolith of the eclogites formed in the late Silurian (425.4 ± 3.6 Ma; igneous zircon dating, 638–459 Ma TDM dating), which makes them the oldest known mid-ocean ridge mafic rocks in an ancient Paleo-Tethyan Ocean. Various eclogites preserve similar peak mineral assemblages (garnet + omphacite + phengite + rutile + quartz ± epidote/clinozoisite ± kyanite ± winchite) under indistinguishable peak conditions. Their prograde P–T trajectories show a uniform pattern of progressive heating and weak compression along a geothermal gradient of 8°C–10°C/km, indicating a warm subduction setting at a low angle that contrasts with the cold oceanic subduction recorded in the adjacent Paleo-Tethyan suture zones. Combined with detrital U–Pb ages from previous studies, our geochronological data indicate that the host schists originated from continental crust within the South China Block and underwent a pervasive Triassic HP metamorphism related to the Indosinian orogeny. The eclogites and host schists yielded HP metamorphic ages of 239–234 Ma and retrogressive amphibolite-facies metamorphic ages of 231–229 Ma, suggesting rapid cooling (14.0°C–21.6°C/Myr) and exhumation (6.4 km/Myr) from the mantle to the crust. The Song Ma eclogites and their host schists formed when the final ocean closure transitioned to the initial Indochina–South China collision. The Song Ma eclogites and their host schists provide essential information on the opening and closure of the eastern Paleo-Tethys and the subsequent amalgamation of Southeast Asian continental fragments.

Relaxor ferroelectric PbMg1/3Nb2/3O3-PbTiO3 (PMN-PT) ceramics are high-performance piezoelectric materials that are widely used in many electronic devices. However, it is extremely difficult to manufacture thin piezoelectric components dozens of micrometers in size using commercial coarse-grained PMN-PT ceramics. This limits the application of PMN-PT ceramics to high-frequency ultrasonic devices. In this work, we prepared a dense, fine-grained PMN-PT ceramic at low temperature using a hot-press sintering (HPS) method. The HPS ceramic had small grains with an average size of 1 μm and maintained high performance with a large permittivity (er = 4500), piezoelectricity (d33 = 650 pC/N), and electrostrain (SE = 0.14% at 20 kV/cm). The large volume fraction of grain boundaries led to stronger relaxor behavior of the fine-grained PMN-PT ceramic than of the normal coarse-grained one. Owing to its small grains and high piezoelectric performance, this fine-grained PMN-PT ceramic meets the strict requirements of manufacturing thin piezoelectric components. Our results demonstrate that PMN-PT ceramics have great potential for developing low-cost, high-frequency ultrasonic devices by replacing expensive piezoelectric single crystals.

To explore the differences of health hazards between acetylenogen dust as two different occupational hazards of "particles not otherwise regulated" and "calcium carbide".A calcium carbide production enterprise in northwest China was selected. The occupational health survey was used to obtain the spatial distribution and population distribution of calcium carbide dust. Occupational health testing was performed to determine the time-weighted average exposure concentration(C_(TWA)) and excursion limits of calcium carbide dust in the workplace and the main exposure positions. The Singapore semi-quantitative risk matrix was used for occupational risk assessment. The "Classification of Occupational Disease Hazards in the Workplace Part 1: Productive Dust"(GBZ/T 229.1-2010) was used for the operation classification. The calcium carbide dust was regarded as two different occupational hazards: "particles not otherwise regulated" and "calcium carbide", the differences of health hazards between which were compared. PC-TWA of calcium carbide was performed at 2.28 mg/m~3. The heat amount of CaC_2 and CaO released after reacting with water was compared by using Hessapos; s law, and the reaction rates of the two reactions are compared.The concentrations of calcium carbide dust in the workplace of belt inspection position and the calcium carbide crusher was higher(14.3-15.7 mg/m~3), and the concentrations of the driver in the calcium carbide loader was higher(13.8 mg/m~3). The result of the risk assessment show that the health risks of calcium carbide dust in various positions are basically low risk. Only when the type of damage was "calcium carbide", the risk of the driver of calcium carbide loader increase to medium. The operation classification result show that the hazard classification of calcium carbide dust in each post is basically relatively harmless. Only the type of damage was "calcium carbide", the classification of the driver of the calcium carbide crusher loader increased to moderately hazardous operations. As for the "calcium carbide", the operation classification index of calcium carbide were higher than that of "particles not otherwise regulated". CaC_2 reacting with water released more heat than that of equal amount CaO.In the current production process of calcium carbide dust, except for the crushing section, its occupational health risk was low, but the health risk level of calcium carbide as "calcium carbide" was higher, indicating that the evaluation of calcium carbide dust as "particles not otherwise regulated" may underestimate its occupational hazard.

The Changning–Menglian orogenic belt (CMOB) in the southeastern Tibetan Plateau is considered as the main suture of the Paleozoic Paleo-Tethys that separates Gondwana-derived continental fragments from Eurasia-derived ones. Understanding the evolutionary history of this orogenic belt is of critical importance in the reconstruction of the tectonic history of Paleo-Tethys. The CMOB preserves well-exposed blueschist facies rocks, albeit their tectonometamorphic history and protolith signatures remain poorly constrained. Here we present, for the first time, results from a detailed investigation of lawsonite-bearing blueschist rocks, including epidote-magnesioriebeckite schist and garnet-ferroglaucophane schist from the CMOB and involving petrological, mineralogical, thermodynamic modeling, whole-rock geochemical, and geochronological studies. The epidote-magnesioriebeckite schist samples and garnet-ferroglaucophane schist samples display OIB- and E-MORB-like geochemical affinities, respectively, and have whole-rock eNd (t) values in the range of −5.4–+4.4, suggesting that their protoliths were mainly oceanic crust with limited degree of crustal assimilation. Magmatic zircon grains from the garnet-ferroglaucophane schist samples yield protolith ages of 253–250 Ma. Combined with previous data, our data represent the youngest ages of rock formation in the Paleo-Tethyan Ocean reported to date. The epidote-magnesioriebeckite schist samples show a peak assemblage of magnesioriebeckite + lawsonite + augite-aegirine + phengite + titanite + allanite, with peak P–T conditions of 12.4–16.8 kbar and 350–406 °C. In contrast, the garnet-ferroglaucophane schist samples preserve a peak assemblage of garnet + ferroglaucophane + omphacite + lawsonite + phengite + titanite/ilmenite/rutile ± allanite and yield peak P–T conditions of 19.5–22.6 kbar and 490–510 °C. The epidote-magnesioriebeckite schists and garnet-ferroglaucophane schists record a nearly complete clockwise P–T loop characterized by a steep prograde P–T path with a low thermal gradient of ~5–8 °C/km followed by cooling or overprinting by isothermal decompression. Reconstruction of the metamorphic P–T evolution, together an evaluation of previous age data, allows us to propose rapid subduction of cold oceanic lithosphere to depths of 50–75 km at a rate of ~6.3–9.3 km/Myr during Early-Middle Triassic (248–240 Ma), followed by exhumation in the Late Triassic (231–214 Ma). The short time lag (

Introduction CpG oligodeoxynucleotides (CpG ODN) play important roles in resisting inflammation and bone resorption. However, the inherent instability and rapid degradation hinder their wider application. This study aimed to evaluate whether N-acetyl-L-leucine-modified polyethyleneimine (N-Ac-L-Leu-PEI) could effectively deliver CpG ODN 2006 to RAW264.7 cells and and if it can regulate osteoclastogenesis in vitro. Materials and methods Gel retardation assay was conducted to evaluate whether N- Ac-L-Leu-PEI and CpG ODN could form a stable complex. RAW264.7 cells were divided into four groups of control group, ODN group, phosphorothioate ODN group and N-Ac-L-Leu-PEI/ODN group. Fluorescence assay was conducted to evaluate the transfection rate of ODNs in different groups. Cell viability was determined by MTT assay. Cell apoptosis was determined by live-dead cell staining and flow cytometry assay. Relative expression levels of osteoclastic differentiation factors, including Nfatc, c-fos, receptor activator of nuclear factor κB (RANK), and matrix metalloproteinase 9 (MMP9), were determined by real-time PCR and Western blot. Results N-Ac-L-Leu-PEI and CpG ODN could form a stable complex at a mass ratio of 1:1 (w:w). MTT assay showed that the cell viability of N-Ac-L-Leu-PEI was relatively high even at a mass ratio of 8 μg/mL. The transfection rate of N-Ac-L-Leu-PEI-ODN complex was higher than 90%. The cell proliferation and apoptosis was significantly enhanced in N-Ac-L-Leu-PEI- CpG ODN group when compared to those in phosphorothioate CpG ODN. The expression levels of Nfatc, c-fos, RANK, and MMP9 were significantly decreased in N-Ac-L-Leu-PEI/ODN complex group. Discussion N-Ac-L-Leu-PEI could be a potential gene vehicle for the prevention of periodontitis-mediated bone resorption.

Subduction erosion along active convergent plate margins involves arc subduction, tectonic erosion and sediment subduction. Here we investigate the metasedimentary rocks enclosing blueschists and eclogites in the Changning–Menglian orogenic belt (CMOB) of the southeastern Tibetan Plateau which marks the main suture associated with the closure of the Paleo-Tethyan Ocean between the Baoshan–Tengchong and Lanping–Simao blocks. We present an integrated study of petrology, mineral chemistry, whole-rock geochemistry, zircon U–Pb geochronology, and phengite 40Ar/39Ar isotopes. These rocks consist mainly of Ph-Qz schist, Ab-Qz-Ph schist, Grt-Ph schist, St-Ky-bearing Grt-Ms schist, and Cld-Pg-Ph schist. They display compositions similar to arkose and subarkose with trace element patterns overlapping those of the upper continental crust, and suggest immature and weak to moderate chemical weathering. The detrital zircon age spectra are dominated by two major age groups of 600–450 Ma with a peak at 550 Ma, and 1150–850 Ma with a peak at 950 Ma, suggesting that the metasedimentary rocks were sourced from a mixture of Precambrian sediments in the Lanping–Simao Block and Pan-African Orogeny-related magmatic rocks with minor Early Paleozoic Proto-Tethyan subduction- and volcanic rocks related to the onset of oceanic spreading of Paleo-Tethys. Combined with the maximum depositional age of ~428 Ma based on the youngest detrital age peaks, we infer that the Lancang Group could be the Early Paleozoic sedimentary sequence of the Lanping–Simao Block and was deposited in a foreland setting. The metasedimentary rocks display high-pressure (HP) mineral assemblages involving Ph + Ab + Qz, Grt + Ph + Qz, Grt + Ky + Ph, and Cld + Pg + Ph, and record blueschist facies to eclogite facies peak P–T conditions of 18.8–21.6 kbar at 392–553 °C (Grt-Ph schists) and 20–24.2 kbar at 592–654 °C (St-Ky-bearing Grt-Ms schists). Metamorphic zircon U–Pb and phengite 40Ar/39Ar isotopic analyses from these rocks yield consistent peak HP ages of 238–235 and 237–231 Ma, respectively, whereas 40Ar/39Ar dating for the Grt-Ph schist with low Si contents in phengite yields the post-peak age at 226.2 ± 1.3 Ma. We propose that a significant volume of sediments in Lancang Group at the western margin of the Lanping–Simao Block were off scraped by the downgoing oceanic lithosphere associated with the Paleo Tethyan ocean closure, and subducted to depths of ~60–80 km during Middle Triassic. These were subsequently rapidly exhumated at a rate of ~5.7–6.5 km/myr in the Late Triassic. The subduction erosion model proposed in our study has important implications for reconstructing the evolutionary history of the Paleo-Tethys as well as the architecture variation of the paleosubduction zone.

In industry, ammonia (NH3) is currently produced by Haber–Bosch technology, which suffers from the drawbacks of high energy consumption and CO2 emission. Artificial N2 fixation in aqueous solution ...

Manganese dioxide (MnO2) with high theoretical capacity (1380 F g−1), high natural abundance and low cost has been considered as one of the most competitive active materials for preparing the electrode of supercapacitors. However, the poor electrical conductivity limits its broad applications. To solve this problem, we design a hierarchical Cu(OH)2@MnO2 core-shell nanorods array on copper foam (CF), in which the one-dimensional (1D) Cu(OH)2 nanorod core provides the scaffold for the growth of MnO2 nanosheets and a short ion and electronic diffusion pathway and the two-dimensional (2D) MnO2 nanosheets shell provides enormous active sites due to their large surface area. The obtained Cu(OH)2@MnO2/CF nanorods array displays an excellent areal capacitance of 708.62 mF cm−2 at the current density of 2 mA cm−2 (283.45 F g−1 at 0.8 A g−1). Additionally, the assembled Cu(OH)2@MnO2/CF//activated carbon (AC) asymmetric supercapacitor shows an outstanding energy density of 18.36 Wh kg−1 at a power density of 750 W kg−1. Two such capacitors connected in series can light up a red LED bulb for over fifteen minutes.

Recently, numerous two-dimensional (2D) magnetic materials are predicted with various promising properties, whereas noncollinear antiferromagnetic 2D materials are rarely reported. In this paper, we predicted a stable 2D noncollinear antiferromagnetic triangular lattice T-FeO2. The ground state is [Formula: see text] antiferromagnetic with stronger next nearest neighbor exchange coupling than that of nearest neighbor exchange coupling because of the RKKY interaction. Our Monte Carlo simulations reveal that the magnetic phase transition is from a [Formula: see text] antiferromagnetic state to a stripy state and then to a paramagnetic state with increasing temperature. In addition, by tuning the spin direction from an in plane antiferromagnetic state to a canted weak ferromagnetic state, a nontrivial topological phase transition could be induced. Our investigation about magnetic property and nontrivial topological phase transition is very promising for antiferromagnetic spintronics.

We propose a fluid model driven by the queue length process of a working vacation queue with PH service distribution, which can be applied to the Ad Hoc network with every data group. We obtain the stationary distribution of the queue length in driving process based on a quasi-birth-and-death process. Then, we analyze the fluid model, and derive the differential equations satisfied by the stationary joint distribution of the fluid queue based on the balance equation. Moreover, we obtain some performance indices, such as, the average throughput, server utilization and the mean buffer content. These indices are relevant to pack transmission in the network, and they can be obtained by using the Laplace Transform (LT) and the Laplace-Stieltjes Transform (LST). Finally, some numerical examples have been discussed with respect to the effect of several parameters on the system performance indices.

In this paper, we research the customers' equilibrium behaviour in the single server Markovian queue with setup times and working vacation. In such an M/M/1 queueing system, the arriving customers' decision is whether to enter the system or balk based on the reward-cost structure, which includes their desire for service and their unwillingness to wait. We separately discuss the fully observable and fully unobservable cases. For each of case, we acquire the related equilibrium balking strategies of customers and the expected social benefits per time unit. Finally, we obtain some numerical examples to illustrate the effect of several parameters on the equilibrium and optimal strategy.

The Changning–Menglian orogenic belt (CMOB) in the southeastern Tibetan Plateau is an important link between the Longmu Co–Shuanghu suture (LCSS) in the northern Tibetan Plateau and the Chiang Mai–Inthanon and Bentong–Raub sutures in Thailand and Peninsular Malaysia. These belts and sutures are generally regarded as containing the remnants of the oceanic crust of the Palaeo-Tethys that formed by seafloor spreading as a result of the separation of Gondwana- and Eurasia-derived blocks during the Middle Cambrian. In this paper we report the first discovery of abundant unaltered and retrograde eclogites that occur as irregular lenses and blocks in metasedimentary rocks of the CMOB, and these eclogites form an elongate and almost north–south-trending high-pressure (HP)–ultrahigh-pressure (UHP) metamorphic belt that is ∼200 km long and ∼50 km wide. The newly discovered phengite/talc/epidote–glaucophane eclogites, lawsonite–talc–phengite eclogites, dolomite/magnesite–kyanite eclogites and phengite–kyanite-bearing retrograde eclogites have enriched (E-) and normal mid-ocean ridge basalt (N-MORB)-like affinities and mainly positive as well as some negative whole-rock εNd values (–4·34 to +7·89), which suggest an enriched and depleted oceanic lithosphere source for their protoliths. Magmatic zircons separated from the epidote–glaucophane, magnesite–kyanite and (phengite–kyanite-bearing) retrograde eclogites gave protolith ages of 317–250 Ma, which fit well within the time frame of the opening of the Palaeo-Tethys during the Middle Cambrian and its closure during the Triassic. Abundant metamorphic zircons in the eclogites indicate a Triassic metamorphic event related to the subduction of the Palaeo-Tethys oceanic crust from 235 to 227 Ma. Taking into account previous isotopic age data, we now establish the periods of Early–Middle Triassic (246–227 Ma) and Late Triassic (222–209 Ma) as the ages of subduction and exhumation of the Palaeo-Tethyan oceanic crust, respectively. Thermodynamic modelling revealed that the eclogites record distinct HP–UHP peak metamorphic conditions of 23·0–25·5 kbar and 582–610 °C for the phengite–glaucophane eclogites, 24·0–25·5 kbar and 570–586 °C for the talc–glaucophane eclogites, 29·0–31·0 kbar and 675–712 °C for the dolomite–kyanite eclogites, and 30·0–32·0 kbar and 717–754 °C for the magnesite–kyanite eclogites. These P–T estimates and geochronological data indicate that the Palaeo-Tethys oceanic slab was subducted to different mantle depths from 75 km down to 95 km, forming distinct types of eclogite with a variety of peak eclogite-facies mineral assemblages. The eclogites consistently record clockwise metamorphic P–T–t paths characterized by a heating–compression prograde loop under a low geothermal gradient of 5–10 °C km–1, indicating the rapid subduction of cold oceanic crust at a rate of 4·5–6·0 km Ma–1, followed by isothermal or cooling–decompressive retrogression and exhumation at an average rate of 3·2–4·2 km Ma–1. The newly discovered eclogites of the CMOB with their signatures of ocean-crust subduction are petrologically, geochemically and geochronologically comparable with those of the LCSS, providing powerful support for the idea that a nearly 2000 km long HP–UHP eclogite belt extends from the northern Tibetan Plateau to the southeastern Tibetan Plateau, and that it represents the main boundary suture of the Palaeo-Tethyan domain. These results have far-reaching implications for the tectonic framework and complex metamorphic evolution of the Palaeo-Tethyan domain.

H9N2 subtype low pathogenic avian influenza virus (LPAIV) is distributed worldwide and causes great economic losses in the poultry industry, especially when complicated with other bacterial infections. Tissue damages caused by virus infection provide an opportunity for bacteria invasion, but this mechanism is not sufficient for low pathogenic strains. Moreover, although H9N2 virus infection was demonstrated to promote bacterial infection in several studies, its mechanism remained unclear. In this study, infection experiments in vivo and in vitro demonstrated that the adhesion of Escherichia coli (E. coli) to host cells significantly increased after H9N2 virus infection, and this increase was not caused by pathological damages. Subsequently, we constructed a late chicken embryo infection model and used proteomics techniques to analyze the expression of proteins associated with bacterial adhesion after H9N2 virus infection. A total of 279 significantly differential expressed proteins were detected through isobaric tags for relative and absolute quantitation (iTRAQ) coupled with nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) analysis. The results of Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that differentially expressed proteins were enriched in host innate immunity; cell proliferation, differentiation, and apoptosis; and pathogenicity-related signaling pathways. Finally, we screened out several proteins, such as TGF-β1, integrins, cortactin, E-cadherin, vinculin, and fibromodulin, which were probably associated with bacterial adhesion. The study analyzed the mechanism of secondary bacterial infection induced by H9N2 virus infection from a novel perspective, which provided theoretical and data support for investigating the synergistic infection mechanism between the H9N2 virus and bacteria.

As a record of ancient subduction, eclogites preserve critical information for exploring geodynamic processes at convergent plate boundaries. The Changning–Menglian orogenic belt (CMOB) in the southeastern Tibetan Plateau is situated between the Gondwana-derived Baoshan–Tengchong Block and the Eurasia-derived Lanping–Simao Block. The belt has long been accepted as a typical cold subduction–accretion belt associated with the closure of the main Paleo-Tethys Ocean, owing to the development of oceanic-type lawsonite-bearing eclogites. However, this viewpoint is challenged by the presence of newly discovered continental-type eclogites hosted by metasedimentary rocks in the CMOB. The continental-type eclogites are depleted in high field-strength elements (e.g., Nb, Ta, and Zr), enriched in Th and U, and preserve highly negative ɛNd(t) values varying from −15.26 to −13.04, indicating derivation from continental mafic protoliths that underwent extensive crustal contamination. Inherited zircons from both the continental-type eclogites and their host schists have characteristic detrital age distributions, with dominant Pan-African age peaks at 630–505 Ma that match well with those in the Baoshan–Tengchong Block. Combined with published age data, our new geochemical and geochronological data provide convincing evidence for the presence of significant volumes of subducted continental fragments derived from the Baoshan–Tengchong Block. Thermodynamic modeling of the continental-type eclogites indicates a clockwise P–T path with a steep prograde path consistent with a geothermal gradient of 5–8 °C/km, which was followed by near-isothermal decompression. Calculations suggest the eclogite-facies assemblage of garnet + omphacite + glaucophane ± talc ± lawsonite ± phengite records peak conditions of 28.5–29.6 kbar and 580–594 °C, equivalent to depths of 85–90 km. U–Pb dating of metamorphic zircon rims from the eclogites gives an age of 234–233 Ma, which is interpreted to reflect the timing of continental subduction. The continental-type eclogites show mineral associations, paragenetic sequences and metamorphic P–T–t evolutions similar to those of low-temperature oceanic-type eclogites in the CMOB. As a result, we propose that rapid, cold subduction of continental crust, and its subsequent rapid exhumation, occurred shortly after the closure of the dense and long-lived Paleo-Tethys oceanic lithosphere. The discovery of continental-type eclogites imparts significant insights into the dynamics of Gondwana–Eurasia convergence in the Paleo-Tethyan domain. The CMOB provides a well-exposed example of the tectonic transformation from final oceanic subduction to the onset of continental subduction and collision in a cold geothermal regime.