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In this paper, the plastic behavior of metal sandwich beams with foam-filled sinusoidal corrugation is studied theoretically and numerically. The yield criterion of foam-filled sinusoidal corrugation sandwich cross-section is established, considering the effects of metal foam strength and sinusoidal corrugation strength. Based on the yield criterion, an analytical model for the plastic behavior of fully clamped foam-filled sinusoidal corrugation sandwich beams under transverse loading is developed, considering the interaction of axial force and bending moment. Finite element calculations are carried out to verify the analytical model. The influences of geometrical and material parameters on the load-carrying capacity and energy absorption of foam-filled sinusoidal corrugation sandwich beams are discussed. The results show that, with the increase of foam strength, face-sheet thickness, sinusoidal corrugation strength, sinusoidal corrugation sheet thickness, sinusoidal amplitude, sinusoidal half wavelength and punch width, the load-carrying capacity and energy absorption of foam-filled sinusoidal corrugation sandwich beams increase. In addition, when the loading position moves from the midspan to the clamped ends, the load and absorbed energy for the same deflection increase obviously. [ABSTRACT FROM AUTHOR]

[Display omitted] Global warming during the Miocene Climate Optimum (MCO, ∼17–14 million years ago) is associated with massive carbon emissions sourced from the flood basalt volcanism and ocean crustal production. However, the perturbation of tectonic carbon degassing on the interaction between climate change and carbon cycle remains unclear. Here, through time-evolutive phase analysis of new and published high-resolution benthic foraminiferal oxygen (δ 18O) and carbon (δ 13C) isotope records from the global ocean, we find that variations in the marine carbon cycle lead the climate-cryosphere system (δ 13C-lead- δ 18O) on 405,000-year eccentricity timescales during the MCO. This is in contrast to the previously reported climate-lead-carbon (δ 18O-lead- δ 13C) scenario during most of the Oligo-Miocene (∼34–6 million years ago). Further sensitivity analysis and model simulations suggest that the elevated atmospheric CO 2 concentrations and the resulting greenhouse effect strengthened the low-latitude hydrological cycle during the MCO, accelerating the response of marine carbon cycle to eccentricity forcing. Tropical climate processes played a more important role in regulating carbon-cycle variations when Earth's climate was in a warm regime, as opposed to the dominant influence of polar ice-sheet dynamics during the Plio-Pleistocene (after ∼6 million years ago). [ABSTRACT FROM AUTHOR]

Sepsis is mainly caused by infection, and inflammation plays a vital role in the progression of sepsis. Increasing evidence shows the regulatory mechanism of long non-coding RNA growth arrest-specific 5 (GAS5) in inflammatory response. However, the potential role of GAS5 in sepsis was not really clear. Here, we set to investigate the role and mechanism of GAS5 in the inflammatory response of lipopolysaccharide (LPS)-induced macrophages in vitro. Levels of GAS5, microRNA-520-3p, suppressor of cytokine signaling 3 (SOCS3) and inflammatory cytokines tumor necrosis factor-α (TNF-α), and interleukin (IL)-6 and IL-1β were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Nitric oxide (NO) release was measured through flow cytometry. The levels of TNF-α, IL-6, and IL-1β were also detected using ELISA. Dual-luciferase reporter and RNA pull-down assays were performed to clarify the relationship between miR-520-3p and GAS5 or SOCS3. Western blot was carried out to assess SOCS3 protein expression in macrophages. GAS5 level was remarkably decreased in sepsis serum and it was inversely related to the severity of sepsis. Upregulation of GAS5 repressed inflammatory response in LPS-induced macrophages, and the inhibitory effect was returned by miR-520-3p mimics. Moreover, miR-520-3p inhibitor downregulated the levels of inflammatory factors of TNF-α, IL-6, and IL-1β, as well as suppressed NO release. Mechanically, GAS5 functioned as a sponge of miR-520-3p and miR-520-3p directly targeted SOCS3. GAS5 regulated inflammatory response by the miR-520-3p/SOCS3 axis in LPS-induced macrophages, which furnished a novel therapeutic idea in clinical treatment of inflammation-induced sepsis. [ABSTRACT FROM AUTHOR]

Among mechanisms accounting for atmospheric pCO2 drawdown during glacial periods, processes operating in the North Atlantic (NA) and Southern Ocean (SO) have been proposed to be critical. Their individual and synergic effects during a course of glaciation, however, remain enigmatic. We conducted simulations to examine these effects at idealized glacial stages. Under early‐glacial‐like conditions, cooling in the SO can trigger an initial pCO2 drawdown while the associated sea ice expansion has little impact on air‐sea gas exchange. Under later glacial‐like conditions, further cooling in the NA enhances ocean carbon uptake due to a stronger solubility pump, and the SO‐induced stronger deep stratification prevents carbon exchange between the deep and upper ocean. Meanwhile, strengthened dust deposition increases the SO contribution to the global biological pump, and CO2 outgassing is suppressed by fully extended sea ice cover. More carbon is then stored in the deep Pacific, acting as a passive reservoir. Plain Language Summary: CO2 is one of the most important "greenhouse" gases that drive global climate changes. Tens of thousands of years ago, during the glacial time (known as the "ice age"), atmospheric CO2 was much lower than today. Research has shown that processes in different ocean regions, such as the Southern Ocean (SO) and North Atlantic (NA), made essential contributions to the glacial CO2 drawdown. However, the interplay between these processes remains unclear. Here, using an ocean general circulation model coupled with an atmospheric box that includes active air‐sea CO2 exchange, we examined the key processes at idealized stages of a glacial cycle. We found that: at an early stage, surface cooling in the SO triggers the CO2 decrease by shortening the time for air‐sea CO2 exchange; during a late stage, the SO and NA cooling act collaboratively to store more carbon in the deep ocean, where the SO plays a more determining role. Pacific seems to be a passive carbon pool during glaciation. Sea ice expansion hinders CO2 outgassing increasingly over the course of glaciation. Further CO2 decrease is achieved by a larger contribution of the SO to the global biological carbon pump. Key Points: The stepwise glacial atmospheric pCO2 decrease is linked to a Southern Ocean (SO)‐controlled synergy of interhemispheric mechanismsSea ice prevents CO2 outgassing increasingly from the early‐ to later‐glacial timeThe SO contribution to the global biological carbon pump might increase from interglacial to glacial periods [ABSTRACT FROM AUTHOR]

In this paper, analytical and experimental methods are used to study the deformation mechanisms of metal foam-filled circular tubes in axial splitting and curling modes. Metal foam-filled tubes with prefabricated cracks are placed on a die, and axial compressive experiments are conducted. In the experiments, the force–displacement curves of metal foam-filled tubes are measured, and the deformation modes of metal foam-filled tubes are observed. An analytical model is established for metal foam-filled circular tubes in axial splitting and curling modes. In the analytical model, energy is dissipated by splitting, curling, and plastic bending of the tubes, as well as by friction between the tubes and die and foam compression. The analytical, numerical and experimental results are compared. The analytical model captures the experimental results reasonably well, and the numerical results are in good agreement with experimental ones. It is found that, in the stage of steady deformation, the axial compressive force increases with the increase in the number of prefabricated cracks, the ratio of radius to the wall-thickness and the semi-angle of conical die. The axial compressive force decreases with the increase in the ratio of the prefabricated-crack length to the wall-thickness. Foam-filled tubes have a higher specific energy absorption than sandwich tubes. [ABSTRACT FROM AUTHOR]

In the process of direct use and upgrading of rubber seed oil (RSO), coke formation is a severe problem. Therefore, evolution of the cokes structure is a key factor affecting the efficient utilization of RSO. This study investigates the production of coke during RSO pyrolysis. All cokes are analyzed and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectroscopy, CHNS/O analysis, and Raman. The results indicate that cokes on the surface of copper slag (SCS-cokes) are coral-like and the surfaces are relatively rough while cokes on the quartz tube wall (QTW-cokes) have a flat structure. According to FT-IR (500–4000 cm−1), QTW-cokes and SCS-cokes contain a variety of O-containing functional groups. Raman spectra indicate a decrease in the total band area with increasing temperature due to the loss of O-containing functional groups at high temperature. The small aromatic ring systems in cokes are transformed into the large aromatic ring systems. In addition, the yields of pyrolysis gas and cokes increase with increasing temperature, while the opposite is true for tar. RSO pyrolysis products also have value for further processing. Therefore, there is great potential for the co-treatment of CS with RSO. [Display omitted] • The yields of pyrolysis gases during the pyrolysis of rubber seed oil are promoted by copper slag. • Different types of cokes are produced by rapid heating of rubber seed oil at high temperature. • The O-containing functional groups in cokes are unstable at high temperature. [ABSTRACT FROM AUTHOR]

This study investigates the fast catalytic pyrolysis of rubber seed oil over a CO 2 -activated biochar catalyst in the temperature range of 600–800 °C, producing high-value products. The effect of activation time on the catalytic performance and the possibility of using the deactivated catalyst as fuel are also examined. The results indicate that extending the activation time can increase the specific surface area and oxygen active sites of biochar catalyst, thereby improving the catalytic performance. At optimum temperature (800 °C), the biochar catalysts increase the syngas yield from 507.90 mL/g to 634.51 mL/g while facilitating the conversion of polycyclic aromatic hydrocarbons to monocyclic aromatic hydrocarbons. Consequently, the yield of monocyclic aromatic hydrocarbons is increased from 3.72 wt% to 55.77 wt%. Out of the monocyclic aromatic hydrocarbons, benzene and its derivatives are important chemicals, with a yield of 46.80 wt%. Besides, microporous channels in biochar catalysts inhibit the generation of coke, reducing the coke yield from 13.57 to 5.59 wt%; the coke deposit on biochar catalyst is pyrolytic coke. The high heating value of the deactivated biochar catalyst reach 28.605 MJ/kg, and it can be used as a solid fuel. Finally, a mechanism for converting polycyclic aromatic hydrocarbons to monocyclic aromatic hydrocarbons during the fast catalytic pyrolysis of the rubber seed oil is proposed. • The rubber seed oil catalytic pyrolysis over biochar catalyst is performed for the first time. • The catalytic pyrolysis of rubber seed oil produces over 55 wt% monocyclic aromatic compounds. • The microporous channels in the activated carbon has a negative effect on the production of coke. • The mechanism of catalytic pyrolysis of rubber seed oil over biochar catalyst is proposed. [ABSTRACT FROM AUTHOR]

Industrial hemp stems and polyvinyl chloride are heat-treated at 400–800 °C to prepare cylindrical biochar-based briquette. The results show that the co -pyrolysis of industrial hemp stems and Polyvinyl chloride degrade at 205–519 °C with a mass loss of 84.173 wt%. According to the TG-FTIR, the co -pyrolysis of industrial hemp stems and polyvinyl chloride produces large amounts of volatiles such as CH 4 , CO, CO 2 and HCl. With the increase of pyrolysis temperature and holding time, industrial hemp stems can produce biochar-based briquette with a lower O/C-H/C ratio. Polyvinyl chloride can significantly improve the durability of biochar-based briquette. Besides, polyvinyl chloride can significantly increase the high heating value of biochar-based briquette due to the HCl gas increases the fixed carbon content of biochar-based briquette in the preparation process. When industrial hemp stems and polyvinyl chloride at the ratio of 1:1, the maximum high heating value of biochar-based briquette can reach 29.475 MJ/kg. The concentration of Cl in biochar briquettes is 9.260 mg/g, mainly in the form of metal chloride. Therefore, biochar-based briquette has a potential application prospect in bioenergy production due to the remarkable improvement of its properties. [Display omitted] • Co-pyrolysis of PVC and industrial hemp stem has synergistic effects. • The durability and high heating value of biochar-based briquette is significantly improved via the PVC. • The maximum high heating value of biochar-based briquette can reach 29.475 MJ/kg higher than that of standard coal. • A reaction mechanism for the preparation of biochar-based briquette by co-pyrolysis is proposed. [ABSTRACT FROM AUTHOR]

Abstract The Mo/Pt/Ag laminated metal matrix composites (LMMCs) have been used as interconnected materials of solar cell array of spacecraft at low-Earth orbit (LEO), where the interconnectors are vulnerable to the combined effects of atomic oxygen (AO) and thermal cycles. To enhance its resistance to LEO environment, the metallurgical bonding Mo/Pt/Ag LMMCs was prepared in this work with optimized processing parameters. During the process, the multiple calenderings and annealing at a protecting atmosphere were performed to improve the surface activity of Mo and Pt. Consequently, the expectant metallurgical bonding interfaces of Mo/Pt and Pt/Ag were successfully constructed through the atomic diffusion accelerated by the improvement of surface activity. Additionally, the resulting microstructure of the Mo/Pt interface was confirmed to be composed of MoPt and Mo 3 Pt alloy phases, and the Pt/Ag interface consisted of distorted and tangled Pt and Ag lattices. Besides, the interfacial type and the orientation relationships of constituent phases were determined. Lastly, the as-obtained Mo/Pt/Ag LMMCs is assessed to have good resistance to thermal fatigue and AO erosion by the thermal cycling and AO exposure experiments. [ABSTRACT FROM AUTHOR]

The mechanism of radiation-induced detwinning is different from that of deformation detwinning as the former is dominated by supersaturated radiation-induced defects while the latter is usually triggered by global stress. In situ Kr ion irradiation was performed to study the detwinning mechanism of nanotwinned Cu films with various twin thicknesses. Two types of incoherent twin boundaries (ITBs), so-called fixed ITBs and free ITBs, are characterized based on their structural features, and the difference in their migration behavior is investigated. It is observed that detwinning during radiation is attributed to the frequent migration of free ITBs, while the migration of fixed ITBs is absent. Statistics shows that the migration distance of free ITBs is thickness and dose dependent. Potential migration mechanisms are discussed. [ABSTRACT FROM AUTHOR]

Composite molecular sieves, FAU/SBA-15, having core-shell structure were synthesized. The synthesized composite sieves were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), pyrolysis fourier transform infrared (Py-FTIR) spectroscopy, temperature programmed desorption spectra (NH3-TPD), UV Raman spectroscopy, nuclear magnetic resonance (NMR) and other techniques. XRD, SEM, TEM, N2 adsorption-desorption, mass spectrometry, NMR and EDS results showed that the composite molecular sieve contained two pore channels. Py-FTIR results showed that the addition of HY molecular sieves improved the acidity of the composite zeolite. The crystallization mechanism during the growth of FAU/SBA-15 shell was deduced from the influence of crystallization time on the synthesis of FAU/SBA-15 core-shell structured composite molecular sieve. HY dissociated partially in H2SO4 solution, and consisted of secondary structural units. This framework structure was more stable than its presence in the isolated form on the same ring or in the absence of Al. Thus it played a guiding role and connected with SBA-15 closely through the Si-O bond. This resulted in the gradual covering of the exterior surface of FAU phase by SBA-15 molecular sieves. The presence of SBA-15 restricted the formation of the other high mass components and increased the selectivity towards ethylbenzene. [ABSTRACT FROM AUTHOR]

MoS 2 /C nanocomposite with a multilayered sandwich structure based on few-layered MoS 2 and carbon layers in an alternating sequence, was successfully synthesized through a one-step synchronized carbonization and sulfuration method. The hybrids were characterized by X-ray diffraction, High-resolution transmission electron microscopy, Atomic force microscope, Raman and X-ray photoelectron spectroscopic methods. The as-obtained MoS 2 /C nanocomposite applied as lithium-ion batteries anode materials, showed a high initial discharge and charge capacities of 1678.5 and 1386.0 mAh g −1 , respectively. High specific reversible capacity is maintained at fast C rates, e.g., 1390, 1223, 1017, 566, and 450 mAh g −1 at 0.1C, 0.6C, 3C, 10C and 20C, respectively. The good performance of the composite is mainly attributed to the unique few layered composite architectures, which can improve ion/electron transportation and prevent aggregation and restacking during the lithiation/delithiation process. [ABSTRACT FROM AUTHOR]

Composite molecular sieves, FAU/SBA-15, having core-shell structure were synthesized. The synthesized composite sieves were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), pyrolysis fourier transform infrared (Py-FTIR) spectroscopy, temperature programmed desorption spectra (NH3-TPD), UV Raman spectroscopy, nuclear magnetic resonance (NMR) and other techniques. XRD, SEM, TEM, N2adsorption-desorption, mass spectrometry, NMR and EDS results showed that the composite molecular sieve contained two pore channels. Py-FTIR results showed that the addition of HY molecular sieves improved the acidity of the composite zeolite. The crystallization mechanism during the growth of FAU/SBA-15 shell was deduced from the influence of crystallization time on the synthesis of FAU/SBA-15 core-shell structured composite molecular sieve. HY dissociated partially in H2SO4solution, and consisted of secondary structural units. This framework structure was more stable than its presence in the isolated form on the same ring or in the absence of Al. Thus it played a guiding role and connected with SBA-15 closely through the Si-O bond. This resulted in the gradual covering of the exterior surface of FAU phase by SBA-15 molecular sieves. The presence of SBA-15 restricted the formation of the other high mass components and increased the selectivity towards ethylbenzene. [ABSTRACT FROM AUTHOR]

Copper slag has potential economic and environmental benefits and there is a need for further clean utilization. The traditional recovery methods have the disadvantages of high energy consumption and low Fe recovery ratio. A strategy is proposed for the clean and efficient recovery of Fe from copper slag by deep reduction using rubber seed oil as a reductant. The reduction experiments and thermokinetics analysis are conducted to explore the reaction behavior between rubber seed oil and copper slag. The results show that the Fe recovery ratio of the copper slag is 91.85% and the Fe grade is 95.66% under the optimal conditions for roasting reduction. The process of recycling Fe from copper slag produces new secondary waste residue. Secondary waste residue can be used as a partial starting material for the synthesis of glass-ceramics. The reduction reaction mechanism of copper slag is transformed with increasing temperature. Limiting surface reaction (n = 2) is the restrictive step for the direct reduction reaction region and one-dimension diffusion is the restrictive step for the smelting reduction reaction region. The activation energy of the direct reduction reaction region and smelting reduction reaction region are 16.64 kJ/mol and 13.68 kJ/mol, respectively. This research provides an important approach to the clean utilization of copper slag. [Display omitted] • Using rubber seed oil as a reductant to recover iron from copper slag is very effective. • Secondary waste residue can be used as a partial starting material for the synthesis of glass-ceramics. • The reduction reaction of copper slag is identified into five reaction stages. • Limiting surface reaction (n = 2) is the restrictive step in the direct reduction reactions region. • One-dimension diffusion is the restrictive step in the smelting reduction reaction region. [ABSTRACT FROM AUTHOR]

In this paper, the plastic behavior of fully clamped circular sandwich tubes with metal foam core under transverse loading is analytically, experimentally and numerically studied. Considering the strength of the filled foam, the yield criterion of the compressed sandwich tube is proposed. Using the yield criterion, an analytical model for the plastic behavior of the fully clamped circular sandwich tube is proposed, in which the effects of local denting and the interaction of bending and stretching are considered. The bending experiment of clamped circular sandwich tubes is conducted. The load–deflection and energy–deflection relations are obtained by numerical calculation for the sandwich tubes at different loading positions. The analytical results are in good agreement with numerical and experimental results. Finally, the influences of foam strength, tube-wall thickness, loading position and radius of inner tubes on the plastic behavior of sandwich tubes are studied based on the analytical model. • Plastic behavior of circular sandwich tubes with metal foam core under transverse loading is studied. • An analytical model for plastic behavior of clamped circular sandwich tubes considering the effect of local denting is proposed. • Analytical results capture experimental and numerical results reasonably. • The load-carrying capacity of sandwich tubes increases with increase of foam strength and tube-wall thickness. [ABSTRACT FROM AUTHOR]

As the most significant carbon isotope excursion in the past ∼10 Ma, the Late Miocene Carbon Isotope Shift (LMCIS, ∼7.65 to 6.5 Ma) offers a great opportunity to investigate the carbon-climate dynamics in a warmer-than-today world. However, the driving mechanisms of the LMCIS remain controversial. In this study, we used a 7-box biogeochemical model to simulate the long-term sea water δ 13 C and atmospheric CO 2 changes during the late Miocene. Based on quantitative parameterization of two terrestrial processes (C 4 -grasses expansion and enhanced weathering input) during the late Miocene, our results show that the synergy between the two terrestrial processes may ultimately result in the LMCIS via the perturbation of the land-sea carbon fluxes. Moreover, our results reveal that the re-partitioning of alkalinity and nutrients between the land and the ocean may have influenced the long-term atmospheric CO 2 change during the late Miocene. • Late Miocene C 4 -grass expansion can cause a limited decrease of sea water δ 13 C. • Enhanced weathering input in the late Miocene contributed to the δ 13 C shift too. • The synergy of the two terrestrial forcings could be the major driver of the LMCIS. • Late Miocene p CO 2 decline was linked to land-ocean carbon redistribution. [ABSTRACT FROM AUTHOR]

Attached masses are utilized in this work to improve the performance of circular cylindrical piezoelectric transformers operating in thickness-shear mode. An exact solution based on the linear theory of piezoelectricity is obtained to verify the concept. The transforming ratio, displacement and stress fields of the transformer are investigated. Numerical results based on the theoretical analysis show the noticeable influences of the attached masses on the behavior of the transformer. The desirable load impedance for a high transforming ratio is also obtained in this study. [ABSTRACT FROM AUTHOR]

In this paper, the large deflection of the slender circular metal foam-filled tube (FFT) under transverse loading is studied theoretically and numerically. The yield criterion of the circular foam-filled tube is proposed. Using the yield criterion, the analytical solution for the plastic behavior of slender circular metal foam-filled tube under transverse loading is obtained considering the interaction between bending and stretching and foam strength. Large deflection of the circular metal foam-filled tube is numerically calculated. The analytical model captures numerical results. Influences of tube-wall thickness, punch width, foam strength, loading position and the radius of filled foam on the load-carrying capacity and energy absorption (EA) of foam-filled tubes are discussed in detail. The results show the load-carrying capacity and energy absorption of the foam-filled tubes increase with the increase of tube-wall thickness, foam strength, punch width and the radius of filled foam. • Large deflection of the slender circular metal foam-filled tube under transverse loading is studied. • The analytical solution of the plastic behavior of the circular foam-filled tube is obtained considering foam strength. • The analytical model captures the numerical results reasonably. • Load-carrying capacity and energy absorption increase with increase of tube-wall thickness, foam strength and radius of foam. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a new technique of shifting the phase of a low-frequency AC voltage. The technique is derived from the multioutput piezoelectric transformer. The piezoelectric phase shifter is made of a piezoelectric ceramic plate operating at the thickness shear vibration mode. The ceramic plate consists of input, output and control parts. The control part is connected to a tunable inductor or capacitor, which can tune the phase shift between the output and input voltages smoothly. The phase shift can be increased by decreasing the inductance or capacitance at the control part. Tuning a DC bias voltage applied to the input part may also change the phase shift. A maximum phase shift of 128° and minimum phase shift of −10° are achieved by the prototype of the phase shifter. The phase shifter has a wide phase shift range, good ability to manage high power and relatively high energy transmission efficiency. [Copyright &y& Elsevier]

In this study, a high power-density dual-output piezoelectric transformer is proposed and experimentally investigated. This transformer consists of a lead zirconate titanate (PZT) ceramic plate with a size of 30 mm×5 mm×1 mm. It has a high mechanical quality factor Qm and high electromechanical coupling coefficient keff. The PZT ceramic plate is poled along the width direction. The electrodes of input and output parts are on the top and bottom surfaces of the ceramic plate and separated by narrow gaps. Lead wires are pressed on the electrodes by a proper elastic force. At a temperature rise lower than 20 °C, the piezoelectric transformer has a maximum output power density of 52.7 W/cm3 with an efficiency of 88%. The maximum efficiency of this piezoelectric transformer is 95%. Voltage gains larger than one and smaller than one are obtained in one transformer. By using a parallel combination of the two outputs of the proposed transformer, a higher output power density of 57.3 W/cm3 can be achieved at the temperature rise lower than 20 °C. [Copyright &y& Elsevier]

Under lateral load, this article aims to discuss the large deflection and yield criterion of Y-shape sandwich beams filled with foam. Considering the effect of metal foam strength, a yield criterion of Y-shape sandwich structure filled with foam is proposed. An analytical solution for large deflection of clamped foam-filled Y-shape sandwich beam under lateral load is derived using yield criterion, considering the interaction between stretching and bending due to large deflection. The corresponding numerical calculation of sandwich beams under lateral load is carried out. It is shown that the theoretical results are in good agreement with the calculated results. The effects of metal foam strength, face-sheet thickness and punch width on large deflection are studied in detail. The results show that the analytical model could predict the large deflection of foam-filled Y-shaped sandwich beam under lateral load really well. [ABSTRACT FROM AUTHOR]

This paper provides a new method to compare and then reveal the vacancy sink efficiencies quantitively between different hetero-interfaces with a shared Cu layer in one sample, in contrast to previous studies, which have compared the vacancy sink efficiencies of interfaces in different samples. Cu-Nb-Cu-V nanoscale metallic multilayer composites (NMMCs) containing Cu/V and Cu/Nb interfaces periodically were prepared as research samples and bombarded with helium ions to create vacancies which were filled by helium bubbles. A special Cu layer shared by adjoining Cu/V and Cu/Nb interfaces exists, in which the implanted helium concentration reaches its maximum and remains nearly constant with a well-designed incident energy. The results show that bubble-denuded zones (BDZ) close to interfaces exist, and that the width of the BDZ close to the Cu/V interface is less than that of Cu/Nb interface. This result is explained by one-dimensional diffusion theory, and the ratio of vacancy sink efficiency between Cu/V and Cu/Nb interfaces is calculated. Conclusively, Cu/Nb interfaces are more efficient than Cu/V interfaces in eliminating vacancies induced by radiation. [ABSTRACT FROM AUTHOR]

Abstract Direct alloying is very difficult for immiscible alloy systems owing to the absence of driving force at equilibrium. To realize alloying for immiscible alloy systems, a method, named as irradiation damage alloying (IDA), is developed and used to prepare W/Ag, Mo/Ag and Mo/Cu laminated metal composites (LMCs) in this work. The IDA process mainly includes three steps: firstly, the multi-energy Ag (or Cu) ions were implanted into the surface of the W (or Mo) matrix; secondly, an Ag (or Cu) coating layer was deposited on the damaged W (or Mo) matrix by vacuum evaporation; thirdly, the obtained W/Ag (Mo/Ag or Mo/Cu) laminated bimetallic samples were annealed at 950 °C in hydrogen for 8 h. It is confirmed that diffusion alloying of immiscible metal atoms indeed takes place and metallurgical bonding interfaces have been constructed successfully. Additionally, to reveal the underlying mechanism of IDA, a thermodynamic model is introduced. It is shown that the storage energy caused by irradiation damage in the matrix metal and the surface energy of the coating layer dominate the thermodynamic driving force. Besides, the storage energy has been confirmed to play a decisive role for the microstructure development of the metallurgical bonding interface. Graphical abstract Unlabelled Image Highlights • The newly developed IDA is a feasible way to realize direct alloying for immiscible systems. • W/Ag, Mo/Ag and Mo/Cu metallurgical bonding interfaces have been constructed successfully by means of IDA. • The storage energy caused by irradiation damage and surface energy of coating layer dominate thermodynamic driving force. • The decisive role for the microstructure development is the storage energy caused by irradiation damage. [ABSTRACT FROM AUTHOR]

The lattice defects in graphene-based carbon materials have been proven to play a critical role for improving the hydrogen evolution reaction (HER) behavior of supported metal catalysts. Nevertheless, accurately manipulating the intensity and distribution of defects for the optimal carbon structure still remains a significant challenge. Here, the microstructures of graphene nanospheres (GNs), in the form of defects distribution and graphitization degree, are accurately regulated by annealing. The optimal electrocatalyst (Ru@GNs300) was achieved by annealing at 300 °C, giving an overpotential of 40 mV at a current density of 10 mA cm−2 together with superior durability in the HER performance test in 1 M KOH. Particularly, the Ru@GNs catalyst has been annealed in situ in transmission electron microscope to monitor its structural evolution. The results indicate that the aggregation of Ru nanoparticles have not been observed up to 900 °C, while the graphitization degree of carbon support increased with elevated temperature. It is worth noting that the optimized electrocatalytic activity of Ru@GNs300 originates from the annealing induced defects regulating of GNs. Thus, the structural optimizing of carbon supports by defect engineering provides an efficient approach to improve the catalytic performance for HER. Image 1 [ABSTRACT FROM AUTHOR]

Tungsten (W), as a promising plasma-facing material for fusion nuclear reactors, exhibits ductility reduction. Introducing high-density coherent nano-dispersoids into the W matrix is a highly efficient strategy to break the tradeoff of the strength–ductility performance. In this work, we performed helium (He) ion irradiation on coherent oxide-dispersoids strengthened (ODS) W to investigate the effect of coherent nanoparticle interfaces on the behavior of He bubbles. The results show that the diameter and density of He bubbles in ODS W are close to that in W at low dose of He ion irradiation. The radiation-induced hardening increment of ODS W, being 25% lower than that of pure W, suggests the involvement of the coherent interface in weakening He ion irradiation-induced hardening and emphasizes the potential of coherent nano-dispersoids in enhancing the radiation resistance of W-based materials. [ABSTRACT FROM AUTHOR]

• Plastic behavior of foam-filled negative Poisson's ratio beam is studied by numerical and theoretical methods. • Considering the effect of the metal foam, the yield criterion of the foam-filled negative Poisson's ratio structure is established. • Based on the yield criterion, the analytical model of plastic behavior of the clamped foam-filled negative Poisson's ratio beam under lateral loading is established. • Analytical results are in good agreement with numerical ones. In this paper, the plastic behavior of foam-filled negative Poisson's ratio (NPR) beams is studied by numerical and theoretical methods. The yield criterion of foam-filled NPR structure is established. On this basis, the plastic behavior of the clamped foam-filled NPR beam under lateral loading is developed considering the interaction between axial force and moment. To make sure the correctness of the theoretical model, the finite element simulation of foam-filled NPR beam is conducted, and the consistency of the results of theoretical analysis and numerical calculation is good. Finally, the effects of material and geometrical parameters, loading location and punch width about the load-bearing capability and energy-absorbing capability of the foam-filled NPR beam are considered by the theoretical model. The result shows that with increasing foam strength, the angular size of the structure, wall thickness and punch width, the load-bearing capability and energy-absorbing capability of foam-filled NPR beams also improve. In addition, when the loading location is nearer to the clamped end, the load and energy absorption is higher. [ABSTRACT FROM AUTHOR]

• Plastic behavior of foam-filled sandwich beams with circular tube core under transverse loading is studied. • Analytical model for the plastic behavior of the foam-filled sandwich beam with circular tube core is developed. • Analytical results are in good agreement with numerical ones. • Load-carrying capacity of sandwich beams increase with increase of foam strength, face-sheet thickness, tube-wall thickness. Under transverse loading, the plastic behaviour of the foam-filled sandwich beam with circular tube core is researched by numerical and analytical ways in this paper. The yield condition of the foam-filled sandwich section with circular tube core is proposed firstly. Based on the yield condition, the analytical model for the plastic behaviour of the foam-filled sandwich beam with circular tube core under transverse loading is developed, in consideration of the interaction of stretching and bending moment and the strength effect. To make ensure the correctness of the analytical model, the finite element analysis is carried out, and the analytical results are in good agreement with numerical ones. On the basis, the influences of structural and material parameters about load-bearing ability and energy-absorbing ability of foam-filled sandwich beams with circular tube core are discussed by analytical solutions. The results show that, with the increase of foam strength, face-sheet thickness, tube-wall thickness and the width of punch, the load-bearing ability and energy-absorbing ability of the foam-filled sandwich beams with circular tube core increase. In addition, when the loading location is close to the clamped end, the load-bearing ability and energy-absorbing ability of the foam-filled sandwich beam with circular tube core increases significantly. [ABSTRACT FROM AUTHOR]

The paper used the analytical and numerical methods to analyze large deflection of multilayer sandwich beams with foam-filled trapezoidal corrugated and foam cores. Considering both the strength of metal foam and corrugated core, we obtained a yield criterion for the multilayer sandwich structure foam-filled trapezoidal corrugated and foam cores. Based on proposed yield criterion, we further presented an analytical solution for large deflection of such multilayer sandwich beam under transverse loading. Well agreement is achieved between analytical and numerical results. What is more, we discussed the effects of foam strength, punch size, face-sheet thickness and middle foam thickness on the plastic behaviors. • Large deflection of multilayer sandwich beams with foam-filled trapezoidal corrugated and foam cores is studied. • The yield criterion for multilayer sandwich structures with foam-filled trapezoidal corrugated and foam cores is obtained. • Analytical solutions are derived for large deflection of multilayer sandwich beams under transverse loading. • Good agreement is achieved between analytical and numerical results. • Foam strength, punch size and face-sheet thickness have significant effects on plastic behavior of sandwich beams. [ABSTRACT FROM AUTHOR]

We report a novel in-situ symbiosis method to prepare reduced graphene oxide wrapped Mn 3 O 4 nanoparticles (rGO/Mn 3 O 4) with uniform size about 50 nm as anodes for lithium-ion batteries (LIBs), which can simplify the preparation process and effectively reduce pollution. The rGO/Mn 3 O 4 nanocomposite exhibited a reversible specific capacity of 795.5 mAh g−1 at 100 mA g−1 after 200 cycles (capacity retention: 87.4%), which benefits from the unique structural advantages and the synergistic effect of rGO and Mn 3 O 4. The Mn 3 O 4 nanoparticles encapsulated among the rGO nanosheets exhibited good electrochemical activity, and the multilayer wrinkled rGO sheets provided a stable 3D conduction channel for Li+/e− transport. The rGO/Mn 3 O 4 nanocomposite is a promising anode candidate for advanced LIBs with excellent cycling performance and rate performance. Furthermore, this new preparation method can be extended to green and economical synthesis of advanced graphene/manganese-based nanocomposites. [ABSTRACT FROM AUTHOR]

Casing deformation problem caused by hydraulic fracturing treatments has seriously reduced the number of fracturing stages. A well understanding of the mechanism and controlling method for this problem is very necessary. Based on the detected results, shear deformation is the main type of casing deformation in Weirong shale gas field, Sichuan province of China. According to the analysis on the special geological condition in this area, the reactivation and slip of natural fractures in shale gas formation are treated as the main reason for causing deformation in shale gas well. Model for calculating fracture reactivation and slippage are established. The shear reactivity trend factors in different condition are calculated to judge the reactivation of fractures. Based on the slippage calculation model, the slippages of fractures in four shale gas wells are calculated. Compared with the geological conditions and hydraulic fracturing treatment in Fuling and Yongchuan shale gas field with no casing deformation in China, the existence of dominant natural fracture is one of the most important factors for casing deformation. The results coincide with the field detected casing deformation incidents which certifies the theory that reactivation and slip of dominant fractures induced the casing deformation. In the end, the useful methods for controlling casing deformation in shale gas wells, including temporary plugging, fracture identification, and changing casing size are proposed. The research in this paper provides reference values for controlling casing deformation in exploiting unconventional oil and gas with hydraulic fracturing treatment and reservoirs contains plenty of activated dominant natural fractures. [ABSTRACT FROM AUTHOR]

Vacuum diffusion bonding (VDB)-prepared 304 austenite stainless steel (SS)/Q235 carbon steel (CS) clad plates were the focus of this study. Specifically, the metallurgically bonded interfaces, which are known to have good mechanical properties, were investigated. The microstructures of the interfaces were extensively investigated using transmission electron microscopy (TEM). The characterization results revealed the existence of annealing twins and lath martensite precipitates at the interface; the high strength and plasticity at the interface were determined to be attributed to these features. In addition, the distribution and Burgers vector of dislocations at the ferrite–austenite interfaces were investigated by using two-beam method of TEM electron diffraction contrast image (EDCI) technology and high-resolution TEM imaging. As a result, the coordination mechanisms at the ferrite–austenite interfaces during the deformation of the SS/CS clad plates were clarified; the observations include: (1) the perfect dislocation with the Burgers vector a 2 ⟨ 111 ⟩ in the ferrite moved across the interface and formed a perfect dislocation with the Burgers vector a 2 ⟨ 110 ⟩ in the austenite; (2) the ferrite lattice was joined to the perfect dislocation with the Burgers vector a 2 ⟨ 110 ⟩ in the austenite; and (3) the ferrite lattice continuously extended across the interface, and was connected to the austenite lattice. According to the results on the Burgers vector of dislocations, two types of dislocation reactions occurred at the ferrite–austenite interfaces during the deformation. Lastly, the transfer matrix of the orientation relationship (OR) between austenite and ferrite was calculated. The results revealed that the OR differed from that of the conventional OR between body-centered cubic and face-centered cubic structures; thus, it can be concluded that the preparation of SS/CS clad plates via VDB technology may lead to the formation of a unique OR between ferrite and austenite. [ABSTRACT FROM AUTHOR]

Axial splitting and curling collapse of square sandwich metal tubes with metal foam core is investigated analytically and experimentally. The square sandwich metal tube split axially and curl outward along prefabricated cracks. Axial compressive tests of square sandwich metal tubes with prefabricated cracks are conducted and deformation modes are observed. An analytical model for axial splitting and curling behavior of square sandwich metal tube considering plastic bending, crack tearing, curling, foam compression, friction is proposed. It is demonstrated the analytical predictions are in good agreement with experimental results. Influences of foam thickness, tube thickness, die angle, prefabricated crack length, and foam strength are of vital importance to axial splitting and curling of square sandwich metal tube. • A theoretical model is proposed to predict splitting and curling of sandwich tubes. • Axial compression experiments are carried out and deformation modes are found. • Analytical solution captures the experimental results reasonably. • Effects of foam thickness, die angle are of importance to splitting and curling. • The specific energy absorption of the sandwich tube is higher than single tube. [ABSTRACT FROM AUTHOR]

The short-range repulsive interactions of any force field must be modified to be applicable for high energy atomic collisions because of extremely far from equilibrium state when used in molecular dynamics (MD) simulations. In this work, the short-range repulsive interaction of a reactive force field (ReaxFF), describing Fe–Ni–Al alloy system, is well modified by adding a tabulated function form based on Ziegler–Biersack–Littmark (ZBL) potential. The modified interaction covers three ranges, including short range, smooth range, and primordial range. The short range is totally predominated by ZBL potential. The primordial range means the interactions in this range is the as-is ReaxFF with no changes. The smooth range links the short-range ZBL and primordial-range ReaxFF potentials with a taper function. Both energies and forces are guaranteed to be continuous, and qualified to the consistent requirement in LAMMPS. This modified force field is applicable for simulations of energetic particle bombardments and reproducing point defects' booming and recombination effectively. [ABSTRACT FROM AUTHOR]

• The extractable multi-dimensional information from the 4D-EELS technique. • Parallelly acquired phonon dispersion at nanoscale via 4D-EELS technique. • Visualizing local inhomogeneity by extracted momentum and energy filtered images. • The flexible mathematical combinations of spectra at different momentum via 4D-EELS. Recent advances in scanning transmission electron microscopy have enabled atomic-scale focused, coherent, and monochromatic electron probes, achieving nanoscale spatial resolution, meV energy resolution, sufficient momentum resolution, and a wide energy detection range in electron energy-loss spectroscopy (EELS). A four-dimensional EELS (4D-EELS) dataset can be recorded with a slot aperture selecting the specific momentum direction in the diffraction plane and the beam scanning in two spatial dimensions. In this paper, the basic principle of the 4D-EELS technique and a few examples of its application are presented. In addition to parallelly acquired dispersion with energy down to a lattice vibration scale, it can map the real space variation of any EELS spectrum features with a specific momentum transfer and energy loss to study various locally inhomogeneous scattering processes. Furthermore, simple mathematical combinations associating the spectra at different momenta are feasible from the 4D dataset, e.g., the efficient acquisition of a reliable electron magnetic circular dichroism (EMCD) signal is demonstrated. This 4D-EELS technique provides new opportunities to probe the local dispersion and related physical properties at the nanoscale. [ABSTRACT FROM AUTHOR]

• Create Ti 3 C 2 T x MXene coupled CdS nanostructures by radiation-induced reduction. • Derive amorphous TiO 2 -C nanosheet cocatalysts from Ti 3 C 2 T x /CdS by alkaline treatment. • Achieve the highest H 2 generation rate by aTiO 2 -C/CdS composites at 2.5 wt% Ti 3 C 2 T x. • Unravel the mechanisms mediating the growth and photocatalysis of aTiO 2 -C/CdS. • Pave the way to fabricate viable cocatalysts for solar-to-chemical energy conversion. Developing non-noble-metal cocatalysts is essential for the large-scale implementation of solar-driven H 2 production technology, but still remains a great challenge. In this work, Ti 3 C 2 T x MXene coupled CdS nanostructures are fabricated via one-step gamma-ray radiation-induced reduction in ambient conditions. By subsequent alkaline treatment, a novel cocatalyst of carbon supported amorphous TiO 2 nanosheets (denoted as aTiO 2 -C) is derived from Ti 3 C 2 T x /CdS to form aTiO 2 -C/CdS nanocomposites. The prepared aTiO 2 -C/CdS nanocomposites with cyclability achieve a H 2 evolution rate of 1.48 mmol·g−1·h−1 under visible-light illumination, which is 6.4 and 7.0 times greater than that of pristine Ti 3 C 2 T x /CdS and P-CdS, respectively. The oxygen vacancies in aTiO 2 -C cocatalysts are revealed to act as electron trapping sites to facilitate the transfer of photoexcited electrons and boost photoactivity. Further, the electronic interaction between CdS and aTiO 2 -C prevents Cd2+ from leaching and thus enhances photostability. The results of this work may guide the rational design of viable cost-effective cocatalysts in solar-to-chemical energy conversion and beyond. [ABSTRACT FROM AUTHOR]

Continuous gas leakage paths of cement sheath during hydraulic fracturing were investigated in this study. The finite‐element models of a casing–cement‐sheath–formation assembly for the whole wellbore were established, the integrity of the cement sheath of the whole wellbore during single‐stage fracturing was analyzed firstly, and the factors affecting the integrity were examined. Furthermore, a cyclic compression test was conducted. Then, test results for the accumulative plastic strain of the cement sheath under the intermediate casing shoe during multistage fracturing were analyzed. Finally, the mechanism of dilatancy of cement stone in cyclic compression tests was analyzed. The results show that the radial and tangential stresses of the cement sheath increase and decrease, respectively, with depth. The cement sheath above the intermediate casing shoe had a risk of tensile failure, which could result in tangential tensile cracks. The cement sheath below the intermediate casing shoes had cumulative plastic strain, resulting in a microannulus. Reducing Young's modulus, increasing the Poisson ratio of the cement sheath, and reducing the pump pressure were beneficial to relieve the stress state. When the cyclic compressive stress exceeded the dilatation yield stress, the permeability increased with cycle numbers, and the increase in permeability provided another leakage path for gas migration. [ABSTRACT FROM AUTHOR]

As a popular material synthesis method, spatially confined reactions have been gradually recognised for their excellent performance in the field of current materials synthesis. In recent years, molybdenum-based catalysts have gradually gained recognition due to high natural reserves of Mo, its low cost, and many other advantages, and they have wide applications in the area of functional materials, especially in topical areas such as batteries and electrocatalysts. In this context, spatially confined reactions have become widely to obtain various types of molybdenum-based electrode materials and electrocatalysts which result in an excellent morphology, structure, and performance. In this review, the concept of a spatially confined reaction system and the electrochemical application (electrode materials and electrocatalyst) of molybdenum-based materials synthesised in this way are comprehensively discussed. The current problems and future development and application of molybdenum-based materials are also discussed in this review. The classification of spatially confined reactions and their electrochemical applications of molybdenum nanocomposites (MoO3, MoS2, MoC x , MoC x N y , and MoP) are summarised and discussed. [ABSTRACT FROM AUTHOR]

• Low-velocity impact of sandwich beams with multilayer sandwich beams is analytically and numerically studied. • Analytical solutions for low-velocity impact of multilayer sandwich beams are developed. • Analytical solution captures the numerical results reasonably. • Impact position, foam strength and face-sheet thickness have significant effects on the dynamic response. The paper focuses on the dynamic response of multilayer sandwich beams with foam-filled trapezoidal corrugated and foam cores under low-velocity impact with heavy-mass using analytical and numerical methods. Based on the yield criterion for the multilayer sandwich structure, the circumscribing and inscribing loci of sandwich structure are obtained. Considering the interaction of bending and stretching, the analytical solution and "bound" solution for the dynamic response of multilayer sandwich beams with foam-filled trapezoidal corrugated and foam cores are developed. The numerical calculations are used to verify the analytical solutions, and all lie within the analytical "bound" predications. Then, the influences of impact position, foam strength and face-sheet thickness on the dynamic response of multilayer sandwich beams are discussed in detail by theoretical model. For a given deflection, the impact force decreases with impact position closer to the midspan, the impact force increases with the increase of foam strength and face-sheet thickness. The present analytical model can effectively predict the dynamic response of fully clamped multilayer sandwich beams with foam-filled trapezoidal corrugated and foam cores under low-velocity impact. [ABSTRACT FROM AUTHOR]

Background/Aims: Increasing evidences suggest that dysregulated expression of miRNAs contributes to the progression of various tumors. However, the underlying function of miR-423-5p in osteosarcoma remains unexplored. Methods: The expression of miR-423-5p and STMN1 were determined in osteosarcoma samples and cell lines via quantitative real-time PCR. Colony formation and Cell Counting Kit-8 (CCK-8) assays were performed to measure cell proliferation ability and transwell analysis was used to detect cell invasion, and dual luciferase reporter assay was perform to analysis the interaction between the miR-423-5p and STMN1. Results: The expression levels of miR-423-5p and STMN1 in the osteosarcoma tissues and cell lines were measured by qRT-PCR. Cell viability was determined using the clone formation and CCK-8 assays. A dual-luciferase reporter and Western blot were performed to stdudy the target gene of miR-423-5p. Here, we showed that miR-423-5p expression was downregulated in osteosarcoma tissues and cell lines. However, the expression of stathmin1 (STMN1) was downregulated in osteosarcoma tissues and cell lines. Moreover, STMN1 expression level was negatively correlated with the miR-423-5p expression in the osteosarcoma tissues. We identified STMN1 was a direct target gene of miR-423-5p in osteosarcoma cell. Overexpression of miR-423-5p inhibited osteosarcoma cell proliferation, colony formation and invasion. Furthermore, we demonstrated that STMN1 was involved in miR-423-5p-mediated cell behavior such as cell proliferation, colony formation and invasion in the osteosarcoma cell. Conclusion: Our present study indicated that miR-423-5p acted as a tumor suppressor gene in osteosarcoma partly through inhibiting STMN1 expression. [ABSTRACT FROM AUTHOR]

A gradient Fe-Si alloy was prepared by solid powder siliconizing and diffusion annealing using Fe-3.0 wt% Si alloy as raw material. Solid powder siliconizing was carried out at 800 °C for 10–20 min, and siliconized samples with Fe 3 Si phase and FeSi phase were obtained. Then, the siliconized sample was subjected to diffusion annealing at 1050 °C for 1–2 h, and the Fe 3 Si phase and FeSi phase were transformed into single α-Fe phase. The magnetic properties of gradient Fe-Si alloys are higher than those of Fe-Si alloys with uniform Si content distribution (even Fe-6.5 wt%Si alloy). When the surface Si content is 12.3 wt% and the core Si content is 5.0 wt%, the iron loss of the gradient Fe-Si alloy at high frequency is reduced by 97.3% compared with Fe-3.0 wt%Si alloy. Moreover, gradient Fe-Si alloys show excellent magnetic induction intensity and mechanical properties after solid powder siliconizing and diffusion annealing process. This work proposes a solid powder siliconizing and diffusion annealing method to prepare high-performance gradient Fe-Si alloys, which is simple, low-cost, and can control the distribution of Si content in the thickness direction, providing a new idea for the realization of large-scale industrial production of high-performance Fe-Si alloys. • High-performance Fe-Si alloy can be obtained by solid powder siliconizing and diffusion annealing. • Phase transformations in the siliconized layer are detected as follows: α-Fe→FeSi＋Fe 3 Si→α-Fe. • Gradient Fe-Si alloy shows low iron loss, excellent magnetic and mechanical properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • RGO-modified Al foils are facilely prepared. • RGO-modified Al foils are used as a current collector in lithium-ion battery. • RGO layer can enhance the adhesion, conductivity and corrosion resistance. • The inserted RGO layer improves rate and cycling performance. Aluminum (Al) foil current collector is easily corroded by the electrolyte during long-term cycling and damages the electrochemical performance of the lithium-ion batteries (LIBs), especially at high operating voltages, this limits the development of next-generation high operating voltage (5 V) LIBs. Here, we successfully fabricated reduced graphene oxide (RGO) modified Al foils with high electrical conductivity and corrosion resistance as current collectors, which significantly enhanced the corrosion resistance of current collectors in LiPF 6 -based electrolytes and improved the long-term cycling stability and safety of LiMn 2 O 4 batteries at high voltages. The LiMn 2 O 4 (LMO) cells with RGO modified Al foils as the current collector (LMO/GA) exhibit a discharge capacity retention rate of 88.7 % after 200 cycles at a current density of 100 mA g−1, which is much higher than that of the cells with pristine Al foils as the current collector (LMO/PA). The reversible capacity, rate capability, and thermal stability of the LMO/GA cells have also been significantly improved with RGO mediations. This work provides a new idea for the development of long-life corrosion-resistant current collector materials for high-performance LIBs at high operating voltages. [ABSTRACT FROM AUTHOR]

• Dynamic response of sandwich plates with GLARE face-sheets under metal foam projectile impact is studied. • Effects of impulse and thickness on dynamic response are studied by single impact experiments. • The ability of resisting multiple impacts and the ultimate failure mode are measured. • The numerical results are in good agreement with experimental ones. Aluminum honeycomb sandwich plate with fiber metal laminate (FML) as panel can combine the advantages of FML face-sheet and honeycomb core, and has advantages of high specific strength / specific stiffness, lightweight and good energy absorption performance. In this paper, the dynamic response of aluminum honeycomb sandwich plates with Glass Laminate Aluminum Reinforced Epoxy (GLARE) face-sheets under metal foam projectile impact is studied. The single foam projectile impact test is conducted to study the dynamic response of honeycomb sandwich plates with GLARE face-sheets. The debonding between metal and composite layers of the front face-sheet, the fiber fracture, buckling, shear and fracture of core are observed. Also, the multiple foam projectile impact test is carried out to study the impact resistance of the sandwich plate. The numerical calculation is conducted, numerical results are compared with experimental ones. Influences of the impulse, face-sheet thickness, fiber laying angle, honeycomb height, wall thickness of core and cell length of honeycomb on impact resistance and energy absorption of sandwich plates are discussed. It is found that the improvement range of the maximum deflection of back face-sheet gradually decreases with the increase of face-sheet thickness. In addition, by increasing the impulse, decreasing the face-sheet thickness and decreasing the core stiffness, the energy absorption of sandwich plates under metal foam projectile impact can be enhanced. These findings can be used to guide the optimal design of FML sandwich structures under metal foam projectile impact. [ABSTRACT FROM AUTHOR]

In this paper, the plastic behavior of a fully clamped sandwich beam with fiber metal laminate (FML) face-sheets and metal foam core under transverse loading is analytically and numerically studied. Based on the modified rigid plastic model, the analytical solution for large deflection of FML sandwich beams under transverse loading is given, in which the local denting deformation is considered. Finite element results are conducted, and analytical solutions capture numerical results reasonably. The influences of material and geometrical parameters on the plastic behavior of FML sandwich beams are considered. The results show that the present analytical model can be used to predict the plastic behavior of fully clamped FML sandwich beams considering the local denting deformation. • Plastic behavior of sandwich beams with fiber metal laminate (FML) face-sheets is studied. • A simplified formula for plastic behavior of FML sandwich beams is obtained considering local denting. • Analytical solutions capture numerical results reasonably. [ABSTRACT FROM AUTHOR]

Understanding the effect of water activity on shale is of major importance for the exploration and development of shale gas reservoirs, especially in the drilling and completion processes. Deep brittle shale samples from the lower Silurian Longmaxi Formation located in Southwest China were characterized using X-ray diffraction (XRD), swelling ratio tests, computerized tomography (CT), Field Emission Scanning Electron Microscope (FE-SEM) and uniaxial compressive strength (UCS) tests. Because of the physical characteristics of the samples, the relationship between water activity and swelling ratio could be approximated by the Frenkel–Halsey–Hill (FHH) equation. The relationships between clay minerals, UCS and water activity were investigated. Based on the physical description of the internal structure, the impact of water activity on micro-fractures was also discussed. The results showed that multilayer adsorption was the main contributor to the swelling of the deep brittle shale samples. The swelling ratio of brittle shale samples was described by the water activity of external environment via a logarithmic expression of the FHH equation, with fractal dimensions ranging from 2.71 to 2.75. The mineralogical composition was a controlling factor on water activity, as shown by the positive correlation between water activity and the total content of clay minerals (TCCM), especially the amount of montmorillonite in illite/smectite mixed layer clay. When soaking in a solution with a water activity above the critical water activity, the brittle samples developed micro-fractures because the clay swelled, acting as cementing material in the weakened planes. The environmental water activity was used to evaluate mechanical properties of the hydrated brittle shale. Brittle shale samples with larger water activity had a higher critical water activity. Water activity analysis led to a better understanding of the characteristics of the brittle shale and the performance of the downhole fluid. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a new method of extracting biologic particles from a mixture of particles. The method is based on the pumping effect in a π-shaped ultrasonic actuator, which has a gap between its two vibrating metal plates. An adhesive tape is placed at a proper position in the gap. Due to the pumping effect which is induced by the sound field in the gap, the particles with smaller mass and radius in the mixture can be pumped up to reach the adhesive tape; while the ones with larger mass cannot. Therefore, the particles with smaller mass and radius can be extracted from the mixture. A theoretical model which can well explain the operation principle and experimental phenomena is developed. By the experimental results and the theoretical analyses based on the model, the validity of the method in extracting small particles from a mixture of solid particles in air is confirmed, and the effects of the actuator’s vibration, adhesive tape height, contents of the mixture and viscosity of fluid on the extraction are clarified. Also, it is theoretically predicted that the method will work under the microgravity condition in air. [Copyright &y& Elsevier]

The temperature field in small piezoelectric vibrators is investigated experimentally. First of all, the effects of the solder points and internal loss of small piezoelectric vibrators on the non-uniformity of the temperature field are investigated. It is found that the solder points increase the temperature of adjacent piezoelectric material, and the non-uniformity of the temperature field increases as the internal loss increases. Then, the placement method of the piezoelectric vibrators on the temperature field is investigated. It is found that the placement method has a remarkable effect on the maximum temperature rise of the piezoelectric vibrators. Finally, the transient temperature field and its effect on the operation of the vibrators are investigated. It is found that the input power of the vibrators may fluctuate greatly during the transient process of the temperature field. [Copyright &y& Elsevier]

The low-velocity impact via a heavy mass on clamped square sandwich plates (SSP) composed of metal foam core and fibre-metal laminate (FML) face-sheets is studied by analytical and numerical methods. Low-velocity impact (LVI) is formulated on square FML sandwich plates based on modified rigid-plastic material approximation (RPMA). Numerical simulations are conducted, and then compared with analytical results reasonably. Influences of the material parameters and impact location on the dynamic behaviors are discussed in detail. This work provides an efficient and simply analytical method to predict low-velocity impact for square FML sandwich plates. [ABSTRACT FROM AUTHOR]