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The morphology advantage and modified electronic structure of amorphous FeCoSx-PBA hetero-nanoframes enhances the electron transfer and alleviates the overbinding effect of OH*, leading to the improved OER and Al–air battery performance.

Microstructure and dislocations were observed for Ti-600 alloy crept at the temperature of 600°C with the stress of 200MPa and 300 MPa. The results indicate that more precipitation phases could be found both in β phases and at phase boundaries for the alloy after creep tests, and the width of the phase boundary become broader obviously. Also more dislocations could be seen at or around the precipitation phases for the alloy crept at 600°Cwith the stress of 200MPa. Dislocation density is rather big in some regions, dislocations aggregate in precipitation phases, phase boundaries and sub-grain boundaries. Some tangled dislocations or regular arranged dislocations could also be found around precipitation phases. Condensed three-dimensional dislocation meshes could be found in the alloy crept for the alloy crept at 600°Cwith two stresses. For the alloy crept at 600°Cwith the stress of 200MPa, faults originated from boundaries of α lamellar could be found in α lamellar. Some of these faults extend to boundaries of α lamellar, and some stop or end off in α lamellar. While for the alloy crept at 600°Cwith the stress of 300MPa, dislocation tend to arrange in dislocation walls, form bamboo-like structure along the direction of α lamellar, which would expand and penetrate the whole grain of elongated dislocation walls, and at last stop at grain boundaries.

Metal–organic frameworks (MOFs) have been considered as versatile materials for applications in energy fields. For improving reactivity, structural collapse will cut the important advantage of frameworks and hinder the exposure to reactive centers. Herein, we constructed rich structural vacancies in MOFs by the thermal decomposition of specific functional groups, which will not only expose more reactive sites and modulate the electronic structure on the premise of maintaining the frame structure but also benefit in situ derivations to form uniformly along the defect interface. After integrating metal phosphides with defective MOFs, the electrocatalyst shows a low overpotential of 295 mV at 10 mA cm−2 and long-term OER stability, both of which are primarily attributed to the enlarged electrochemically active surface area and accelerated charge-transfer rate in the unique structure.

In this work, the same formulations of Nano-Silica/intumescent fire retardant polypropylene nanocomposites were prepared via a novel vane extruder and a tri-screw extruder, which represented elongational flow field and shearing flow field, respectively. Not only the synergistic combustion mechanisms of Kissinger method and Flynn-Wall-Ozawa method were revealed, but also the combustion effect and efficiency were compared. Both two methods proved specimens that processed by TE exhibited higher thermal stability. The smaller aggregates of physical initial Nano-Silica, the better dispersivity of aggregates in specimens that processed by VE. Such property broke the compactness degree of char layer.

Two-dimensional (2D) porous materials with high specific surface area and ordered morphology exhibit great potential as supercapacitor electrodes. The fundamental understanding of the charge storage and charging dynamics of 2D porous materials can help the optimal design of supercapacitors. Herein, we investigated the energy storage, including the double layer and quantum capacitances, of supercapacitors with typical 2D porous graphynes in the ionic liquid electrolyte by combining molecular dynamics simulation and density functional theory. Simulations revealed that supercapacitors with porous graphyne electrodes could obtain excellent double-layer capacitances, but their total capacitances are limited by the low quantum capacitances. We further predicted boron-/nitrogen-doped graphynes and found that the new porous graphynes turn into good conductors after doping and could achieve a quite high quantum capacitance. The charging dynamics in nanoscale and capacitive performance in macroscale based on the predicted graphyne electrodes were evaluated by combining molecular simulation and transmission line model. Results demonstrate that both outstanding gravimetric and volumetric energy and power densities could be obtained in doped porous graphyne supercapacitors. These findings pave the way for understanding energy storage mechanisms and designing high-performance supercapacitors.

MoS2 has emerged as an attractive electrocatalyst for hydrogen evolution reaction (HER) although its performance still needs to be further enhanced, especially in alkaline solution due to inferior ability for water dissociation. Herein, we discover that coupling water-dissociation-active FeOOH with MoS2 grown on Ni3S2 nanowire arrays to achieve a core-shell Ni3S2@MoS2/FeOOH heterostructure can not only significantly accelerate the HER of MoS2, but also appreciably promote the OER activity of the catalyst. Systematic investigations on Ni3S2@MoS2/FeOOH and a series of delicately designed control catalysts reveal that such synergistically enhanced electrocatalytic performance for both OER and HER should be ascribed to the coupling effect and electronic modulation between FeOOH and MoS2. As a result, the prepared Ni3S2@MoS2/FeOOH exhibits small overpotentials of 95 mV for HER and 234 mV for OER at 10 mA cm−2. The alkaline electrolyzer using it as both anode and cathode only need a cell voltage of 1.57 V to output a stable current density of 10 mA cm−2, enabling it as an efficient bifunctional electrocatalyst for alkaline overall water splitting. The present strategy opens up opportunities to develop new efficient electrocatalysts for diverse applications by coupling OER-active electron-modulating component with highly-active HER electrocatalyst or vice versa.

Transition-metal nitrides (TMNs), especially iron-based TMNs, have high electrical conductivity, superior chemical stability and unique oxygen-reaction ability, and have emerged as a new form of noble metal-free electrocatalysts. In this paper, we demonstrate that the ORR-active/OER-inert single function catalyst Fe-N can be made as the OER/ORR-active bifunctional catalyst Co-Fe-N by controlled substitution of Fe with Co. To obtain atomic insights of the Co-enhanced OER catalysis, we develop a new exfoliation method to prepare atomically thin (1.1 nm) nanosheets (NSs) of CoxFe1-xN0.5 (x = 0, 0.05, 0.1, 0.15 and 0.2). Our studies show that both electronic structure and local binding environment of Fe are modified by Co substitution and the Co-Fe-N NSs show a volcano−like OER catalysis with Co0.15Fe0.85N0.5 NSs being the most efficient OER catalyst, showing the lowest overpotential of 266 mV at 10 mA cm−2, a Tafel slope of ∼30 mV dec−1, and excellent stability in the 1.0 M KOH OER condition. Density functional theory (DFT) calculations suggest that the Co-Fe sites in the Co0.15Fe0.85N0.5 structure are optimized to promote OH* to O* conversion, O*-O* coupling and O2 formation. The Co0.15Fe0.85N0.5 NSs are a class of new noble-metal-free catalyst for OER.

Creep tests were carried out on one kind of near alpha titanium alloy named after Ti-600 alloy at the temperature of 650°C, and with the stresses of 150MPa, 200MPa, 250 MPa, 300 MPa and 350 MPa, respectively. The alloy ingot was conventionally forged and rolled to diameter 18mm bars. The creep samples were cut from the rolling bars and were solutioned at 1020°C for 1 h, air cooling, then aged at 650°C for 8 h, air cooling (STA). Steady state creep rate and the stress exponent n at different stresses were calculated for the alloy. Threshold stress σ0 was introduced to get the true stress exponent p. Creep deformation mechanism was also investigated. The results indicated that the steady state creep rate will increase with the rise of stress, and the creep time will also be shortened at the same time. At 650°C, the threshold stress is 83.8MPa. The value of n and p is 7.7 and 3.3 respectively for the alloy crept at lower stress region (150-200MPa); and which is 2.1 and 4.7 respectively for the alloy crept at relatively higher stress region (200-350MPa). Constitutive equations of steady state creep rate were also established for the alloy crept at 650°C. The creep deformation for the alloy is controlled by dislocation slipping at lower stress region, and which is mainly controlled by dislocation climbing and subordinately controlled by dislocation slipping at higher stress region.

Altres ajuts: ICN2 is funded by the CERCA Programme/Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Autònoma de Barcelona Materials Science PhD program. TZ has received funding from the CSC-UAB PhD scholarship program. Non-enzymatic glucose sensors based on different Co-Ni-C composite materials were developed by pyrolysis of bimetallic or single metal based metal-organic frameworks (MOFs). The structure and composition of the resulting materials were explored by XRD, nitrogen adsorption/desorption isotherms, SEM, HRTEM and STEM-EELS. The electrochemical performance of the bimetallic MOF derived novel yolk-albumen-shell structure of Ni-Co@C (YASNiCo@C) stands out from these materials. The YASNiCo@C electrode exhibited a sensitivity of 1964 μA cm-2 mM-1 with the detection limit of 0.75 μM, a linear range from 5 μM to 1000 μM and good stability for the detection of glucose. These promising electrochemical performances prove that YASNiCo@C is a promising material for glucose sensors. Moreover, the strategy outlined in this work for the design of MOF based nanomaterials can also be used beyond glucose sensors.

Developing high-performance biomass-derived carbons and understanding the relationship between their structures and performance are highly desired for carbon-based supercapacitors. Herein, a wheat gluten-derived carbon with porous sheet-like structure, high specific surface area, and oxygen- and nitrogen-based heteroatom groups is fabricated. Their pore properties and heteroatom doping amount are adjusted through controlling the activation temperature. In aqueous electrolyte there is a significant synergistic effect between pore properties and heteroatom amount on the electrochemical performance of the gluten-derived carbon; while their performance is mainly determined by their pore properties in ionic liquid electrolytes. Besides, whatever in the aqueous and ionic liquid electrolytes ion sieving effect also affects their capacitive performance. The gluten-derived carbon prepared at 700 °C with reasonable pore properties and heteroatom amount shows the highest specific capacitance of 350 F g−1 at 0.5 A g−1 in 6 mol L−1 KOH. But the gluten-derived carbon prepared at 800 °C with the highest specific surface area of 2724 m2 g−1 possesses a high specific capacitance of 197 F g−1 at 0.25 A g−1 in the ionic liquid electrolyte. This work can provide a guideline for optimizing the performance of biomass-derived carbons through matching their pore properties and heteroatom with different electrolytes.

Metal organic frameworks (MOFs), an emerging class of nanoporous crystalline materials, have become increasingly attractive for solar energy applications. In this work, we report a newly designed mixed-node MOF catalyst, CoxFe1–x-MOF-74 (0 < x ≤ 1), which acts as a highly efficient electrocatalyst for oxygen evolution reaction (OER) in alkaline solution with remarkably low overpotential (280 mV at a current density of 10 mA/cm2), small Tafel slope (56 mV/dec), and high faradic efficiency (91%) and can deliver a current density of 20 mA/cm2 at 1.58 V for overall water splitting. Moreover, using the combination of multiple spectroscopic methods, including X-ray absorption, electron spin resonance, and X-ray photoelectron spectroscopy, etc., we unraveled the mechanistic origin of the enhanced catalytic performance of CoxFe1–x-MOF-74 compared to its single-metal counterparts. We show the mixed-node MOF can provide more open metal sites and an enhanced electron-rich environment, which facilitates efficient cha...

The poor surface performance of titanium alloys substantially limits their application in many fields, such as the petrochemical industry. To overcome this weakness, the Cu and Ni double layers were deposited on the surface of TC4 alloy by the electroplating method, and the isothermal diffusion process was performed at 700 &deg, C to enhance the binding ability between Cu and Ni layers. The isothermal diffusion behavior and microstructure of the coating were systematically analyzed, and tribological property and corrosion resistance of the coating were also evaluated to reveal the influence of isothermal diffusion on the surface performance. It was shown that multiple diffusion layers appeared on the Cu/Ni and Ni/Ti interface, and that NixTiy and CuxTiy phases were formed in the coating with the increase of diffusion time. More importantly, Kirkendall diffusion occurred when the diffusion time increased, which led to the formation of continuous microvoids and cracks in the diffusion layer, weakening the surface performance of the Cu/Ni coatings. This paper unveils the relationship between the microstructure of the Cu/Ni coatings and isothermal diffusion behavior, providing guidelines in preparing high performance surface coatings.

Designing highly-efficient and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) in an alkaline solution is more complex and sluggish than for an acidic one. Herein, we report a controllable N-doping strategy to synthesize a series of N-doped porous metallic NiMoO4 nanowires with concomitant oxygen vacancy defects (N-Vo-NiMoO4 NWs) for promoting the alkaline HER ability and durability. Both experimental and theoretical results demonstrate that the doped-N at NiO6 octahedral sites and the abundant oxygen vacancy defects confined in N-Vo-NiMoO4 NWs with modified electronic arrangement could enhance the metallic conductivity, affect the surface areas, and lower the adsorption energy of hydrogen, resulting in an increased HER property. However, the excess doped-N leads to an opposite effect due to the reduced valence state of Ni centres. Therefore, alkaline HER ability of N-Vo-NiMoO4 NWs exhibits a volcano-like trend vs. the nitrogen content, with N3-Vo-NiMoO4 NWs being the best one. As a result, the N3-Vo-NiMoO4 NWs show nearly zero onset overpotential, an overpotential of 55 mV at 10 mA cm-2, and a Tafel slope of only 38 mV dec-1 in 1.0 M KOH, which are superior to those of state-of-the-art platinum-free electrocatalysts.

A novel CoSe/FeSe2 nanohybrid electrocatalyst was prepared by a simple one-step hydrothermal method. Owing to the unique interface structure, abundant internal defects, good hydrophilia and electrical coupling effects between different components, the hybrid shows enhanced oxygen evolution reaction (OER) performances, better than those of the individual CoSe and FeSe2.

The isothermal compression dynamics of ternary Ti-6Al-4V alloy with initial martensitic structures were investigated in the high temperature range 1083–1173 K and moderate strain rate regime 0.01–10 s−1. Shear banding was found to still dominate the deformation mechanism of this process, despite its nonadiabatic feature. The constitutive equation was derived with the aid of Zener–Hollomon parameter, which predicted the apparent activation energy as 534.39 kJ/mol. A combination of higher deformation temperature and lower strain rate suppressed the peak flow stress and promoted the evolution of shear bands. Both experiments and calculations demonstrated that a conspicuous temperature rise up to 83K could be induced by severe plastic deformation. This facilitated the dynamic recrystallization of deformed martensites, as evidenced by the measured microhardness profiles across shear bands.

A series of Ni0.37Co0.63S2-reduced graphene oxide nanocomposites with different graphene contents (NCS@rGO-x) has been successfully prepared via a facile one-step hydrothermal method and applied as the catalysts for the oxygen evolution reaction (OER) and degradation of organic pollutants. The XRD and FESEM analyses revealed that the phase structure and morphology of NCS nanoparticles were substantially influenced by the graphene contents. The phase structure of NCS nanoparticles gradually transformed from primary NiCo2S4 to Ni0.37Co0.63S2 and the morphology and size of NCS nanoparticles were found to become more regular and homogeneous with the increase of graphene concentration. On the NCS@rGO-x nanocomposites, the NCS@rGO-2 sample demonstrated the best catalytic activity toward the OER, which delivers a stable current density of 10 mA cm−2 at a small overpotential of ∼276 mV (vs. RHE) with a Tafel slope as low as 48 mV dec−1. Furthermore, the NCS@rGO-2 sample showed the remarkable photocatalytic activity for degradation of methylene blue (MB), which may be attributed to the increased reaction sites and high separation efficiency of photogenerated charge carries due to the electronic interaction between NCS nanoparticles and rGO. All these impressive performances indicate that the NCS@rGO-2 nanocomposite is a promising catalyst in energy and environmental fields.

There is a growing need for the electrode with high mass loading of active materials, where both high energy and high power densities are required, in current and near-future applications of supercapacitor. Here, an ultrathin Co3S4 nanosheet decorated electrode (denoted as Co3S4/NF) with mass loading of 6 mg cm−2 is successfully fabricated by using highly dispersive Co3O4 nanowires on Ni foam (NF) as template. The nanosheets contained lots of about 3∼5 nm micropores benefiting for the electrochemical reaction and assembled into a three-dimensional, honeycomb-like network with 0.5∼1 μm mesopore structure for promoting specific surface area of electrode. The improved electrochemical performance was achieved, including an excellent cycliability of 10,000 cycles at 10 A g−1 and large specific capacitances of 2415 and 1152 F g−1 at 1 and 20 A g−1, respectively. Impressively, the asymmetric supercapacitor assembled with the activated carbon (AC) and Co3S4/NF electrode exhibits a high energy density of 79 Wh kg−1 at a power density of 151 W kg−1, a high power density of 3000 W kg−1 at energy density of 30 Wh kg−1 and 73 % retention of the initial capacitance after 10,000 charge-discharge cycles at 2 A g−1. More importantly, the formation process of the ultrathin Co3S4 nanosheets upon reaction time is investigated, which is benefited from the gradual infiltration of sulfide ions and the template function of ultrafine Co3O4 nanowires in the anion-exchange reaction.

The recrystallization behavior of deformed Ti40 alloy during a heat-treatment process was studied using electron backscatter diffraction and optical microscopy. The results show that the microstructural evolution of Ti40 alloy is controlled by the growth behavior of grain-boundary small grains during the heating process. These small grains at the grain boundaries mostly originate during the forging process because of the alloy’s inhomogeneous deformation. During forging, the deformation first occurs in the grain-boundary region. New small recrystallized grains are separated from the parent grains when the orientation between deformation zones and parent grains exceeds a certain threshold. During the heating process, the growth of these small recrystallized grains results in a uniform grain size and a decrease in the average grain size. The special recrystallization behavior of Ti40 alloy is mainly a consequence of the alloy’s high β-stabilized elemental content and high solution strength of the β-grains, which partially explains the poor hot working ability of Ti–V–Cr-type burn-resistant titanium alloys. Notably, this study on Ti40 burn-resistant titanium alloy yields important information related to the optimization of the microstructures and mechanical properties.

A novel tobacco rods-derived carbon (TC) has been prepared by hydrothermal carbonization and potassium hydroxide activation strategy for supercapacitors application. The physicochemical properties of TC are investigated by X-ray diffraction, Raman spectra, Scanning electron microscopy, Nitrogen adsorption–desorption isotherms, X-ray photoelectron spectroscopy, and four-probe tests. Results show TC derived from different tobacco rods possesses similar properties, such as amorphous state, high specific surface area, hierarchical porous structure, numerous heteroatom groups, and good electrical conductivity. The electrochemical characteristics of TC are examined via cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy measurements. In a three-electrode system, TC exhibits high capacitance with 286.6 F g−1 at 0.5 A g−1, excellent rate performance with 212.1 F g−1 even at 30 A g−1, and outstanding cyclic stability with 96% capacitance retention after 10,000 cycles at 5 A g−1. Furthermore, TC supercapacitor devices can deliver an energy density of 31.3 Wh kg−1 at 0.5 A g−1 and power density of 11.8 kW kg−1 at 15 A g−1. Therefore, this novel concept of tobacco use, namely tobacco rods from cigarette (the harmful) to high-performance carbon for supercapacitors (the beneficial), is an extremely promising strategy for developing high-performance carbon from renewable sources, and supporting the tobacco control.

To investigate the effect of Panax NotoginSeng Saponins(PNS) on functional recovery of rats with spinal cord injury (SCI) after exercise.SD normal rats were randomly divided into normal control group (Normal) and control group (Sham), spinal cord injury (SCI) and spinal cord injury (SCI) + panax notoginseng saponins group (PNS) (After operation, the BBB scores of Sham group, PNS group, SCI group were lower than that of normal; MEP amplitude was lower than that of normal group; the incubation time was prolonged compared with that in normal group. In PNS group compared with that in the SCI group, BBB scores at 7,14,21 and 28 days was significantly different(PNS can promote the recovery of motor function after SCI in rats.

Optimized catalysts show great potential for renewable energy storage and conversion. Herein, we report metallic CuCo2S4 nanosheets (NSs) of atomic thickness as efficient bifunctional electrocatalysts for use in portable, flexible Zn-air batteries. The metallic CuCo2S4 NSs of atomic thickness with 4-atom-thick to 6-atom-thick layers are confirmed by temperature-dependent electrical resistance measurements and atomic force microscopy. Furthermore, extended X-ray absorption fine structure spectroscopy confirms that CuCo2S4 NSs with sulfur vacancies can further increase the OER activity. Due to high electrical conductivity and ultrathin nanosheet structure with abundant defects, CuCo2S4 NSs exhibit excellent reversible oxygen catalytic performance with an overpotential of 287 mV (at j = 10 mA cm-2) for the oxygen evolution reaction (OER) and an onset potential of 0.90 V for the oxygen reduction reaction (ORR). Additionally, the portable, flexible Zn-air battery using CuCo2S4 NSs as the air-cathode displays a high open circuit voltage and strong rechargeable capacity for 18 h. The present study highlights the importance of designing metallic catalysts having atomic thickness with surface defects for highly efficient and stable renewable energy storage and conversion.

The vane plasticating extruder (VPE) is a novel polymer processing equipment which is based upon elongational rheology. According to the basic structural analysis and movement interpretation, generation mechanism of elongational flow field was derived. Elongational effects during the controlled recovery of immiscible polymer blends, containing polystyrene (PS) matrix and linear low density polyethylene (LLDPE) as dispersed phase, were studied. The morphological results revealed the elongational effect of vane extruder. LLDPE morphology evolution was precisely predicted by a mathematical model. Elongational ratio and elongational strain via VPE were calculated separately, both of which established that the VPE does imposed elongational force field on polymer blends. DOI: http://dx.doi.org/10.5755/j01.mech.23.6.19855

The semisolid compressive deformation behavior of Ti230 titanium alloy at the temperature range of 1273 K to 1573 K and strain rate range of 0.005 to 5 s−1 has been investigated by hot compressive testing. The relationship between flow stress and deformation parameters and microstructure were discussed. The results show that the alloy expresses obvious yield point in semisolid state. The maximum decreased with decreasing solid phase fraction and/or decreasing strain rate, and a transition in stress occurred at a solid phase fraction close to 0.95, which is considered to be associated with the decrease in amount of solid bridges between grains and the decomposing effects of the liquid on α-Ti matrix. A deformation constitutive equation for Ti230 alloy in semisolid state was established considering high-temperature deformation activation energy Q. Furthermore, microstructural analysis confirmed that increasing temperature could reduce the deformation-resistant stress and lead to the transformation of softening mechanism from plastic deformation of solid particles (PDS) to sliding between the solid particles (SS).

The effect of compatibilizer types and concentrations on the mechanical properties and morphology of Pithecellobium Clypearia Benth Fiber (PCBF)/recycled ABS composites prepared by a vane extruder were characterized. In addition, the percentage of compatibilizer was fixed at 8%, and the effect of lubricant concentrations on the mechanical properties and torque behaviors of the composites was also studied. Maleic anhydride grafted ABS (ABS-g-MAH) and maleic anhydride grafted PS (PS-g-MAH) were used as compatibilizers; the lubricant used was Struktol TPW 604 (blend of aliphatic carboxylic acid salts and mono diamides). The composite with 8% ABS-g-MAH showed superior mechanical properties compared to the composite without compatibilizer and the 8% PS-g-MAH compatibilized composites. Compared with PS-g-MAH, ABS-g-MAH was more effective for the composites to improve the interfacial interaction and mechanical properties. The comprehensive mechanical properties of PCBF/recycled ABS composite filled with 4% lubri...

Context: Tea (Camellia sinensis (L.) Kuntze [Theaceae]) is used to induce urination and inducing nervous excitation. Green and black teas have multifarious physiological functions. The different effects of green and black tea aqueous extracts (GTEs and BTEs) on hyperuricemia are not definitely reported. Objective: The different effects of GTEs and BTEs on lowering serum uric acid (UA) in hyperuricemic mice were determined. Materials and methods: Kunming mice were divided into nine groups (n = 6/each group). GTEs and BTEs at the doses of 0.5, 1 and 2 g/kg were orally administrated to mice for seven days, respectively. Hepatic xanthine oxidase (XOD) and adenosine deaminase (ADA) activities as mechanisms of actions were assessed. Results: Research indicated that the LD50 of tea extract is greater than 2 g/kg in mice. UA levels were suppressed significantly with dose-dependent treatment of 0.5, 1 and 2 g/kg BTEs (up to 25.5%, 28.7% and 29.8%, respectively); the serum UA levels were decreased by GTEs but not significant. The activities of XOD and ADA in high dose (2 g/kg) groups of both GTEs and BTEs were notably lower than those of the model group. Discussion and conclusions: The results suggested that both GTEs and BTEs have hypouricaemic and renal protective effects on hyperuricemic mice and the latter one was better. Our study sheds light on the research and development of anti-hyperuricemic functional foods and drugs from tea.

The development of highly efficient bifunctional catalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is crucial for improving the efficiency of the Zn–air battery. Herein, we report porous NiO/CoN interface nanowire arrays (PINWs) with both oxygen vacancies and a strongly interconnected nanointerface between NiO and CoN domains for promoting the electrocatalytic performance and stability for OER and ORR. Extended X-ray absorption fine structure spectroscopy, electron spin resonance, and high-resolution transmission electron microscopy investigations demonstrate that the decrease of the coordination number for cobalt, the enhanced oxygen vacancies on the NiO/CoN nanointerface, and strongly coupled nanointerface between NiO and CoN domains are responsible for the good bifunctional electrocatalytic performance of NiO/CoN PINWs. The primary Zn–air batteries, using NiO/CoN PINWs as an air–cathode, display an open-circuit potential of 1.46 V, a high power density of 79.6 mW cm–2, a...

In this paper, it was addressed a hydrogen absorbing and desorbing thermodynamics in α+β type TC21 titanium alloy with high strength and toughness based on thermodynamic experiments and calculation. The relationship between concentration (C), temperature (T), and pressure (P) of TC21 alloy is shown by P–C–T curves during hydrogen absorption and desorption process, which were measured by multistep hydrogenation/dehydrogenation methods from 625 to 750 °C. The P–C–T isotherms at a given temperature were separated into three regions. The partial thermodynamic functions of hydrogen reaction were evaluated by a modified form of Sievert’s law and P–C–T relation of different regions was expressed by the modified Sievert’s law. The results show that the enthalpy of hydrogen reaction in the first and third region relies on hydrogen content. According to Vant’s Hoff law, enthalpy and entropy of hydrogenation platform in TC21 alloys are −53.58 kJ·mol−1 and −127.41 J·K·mol−1, respectively. Compared with P–C–T curves of hydrogen absorption, that of hydrogen desorption exists hysteresis.

On the basis of the forces on the differential element in the solids bed, a function between bulk density and pressure, and the nonisotropic pressure distribution in the element, an expression of pressure in the circumferential direction is derived. And the total power introduced through the positive conveying and the friction dragging conveying is also deduced. Experimental data are obtained using a self-developed and simplified vane extruder with an adjustable rotor eccentricity. The solids conveying mechanism in the solids compaction zone of a vane extruder is theoretically and semiempirically confirmed. Besides, the various portions of total power consumption including the power dissipated on the surfaces of the stator and baffles, the power used to build pressure and the power converted into rotational kinetic energy are derived. The effects of the eccentricity on the solids conveying are also discussed theoretically and semiempirically. POLYM. ENG. SCI., 55:719–728, 2015. © 2014 Society of Plastics Engineers

The melt blends of recycled polycarbonate and recycled poly(acrylonitrile-butadiene-styrene) were performed by using a novel vane extruder. The morphology, mechanical, and thermal properties of the RPC/RABS blends in the whole composition range were investigated. When the concentration of RABS was 20 wt%, the blend presented the best comprehensive mechanical properties, especially for the impact strength which was significantly improved compared with RPC and RABS individuals. The blend with 90 wt% RABS also presents better mechanical properties compared with the adjacent blending ratio. With the increase of RABS concentration in blends, Tg of the RABS phase decreases slightly, but Tg of the RPC phase increases. The DSC and SEM results indicate that RPC are partial miscible with RABS.

The semi-solid deformation behavior of Ti14 was investigated using compression tests at deformation temperatures between 1 273 and 1 423 K with strain rate of 5×10−2 s−1. Moreover, the fraction solid at different temperatures was also measured by image analysis. The results showed that the deformation temperature had strong effects on the flow stress, and the stress increased with the decrease of deformation temperature. The maximum stress depended greatly on the fraction solid, and a sharp decrease in stress occurred at a solid fraction between 0.94 and 0.98 (temperature from 1 323 to 1 373 K). This decrease was related to the decrease in the amount of solid bridges between grains. Because of the partial solid/liquid segregation during deformation, the experimental strain rates were much lower than those calculated by the flow of liquid incorporating solid particles, which suggested that the main deformation mechanism between 1 323 and 1 373 K was still plastic deformation of solid particles.

Pithecellobium Clypearia Benth fibre (PCBF) comes from steam-exploded Chinese medicine residue was filled in polypropylene (PP) matrix to prepare for PCBF/PP composites using vane extruder based on elongational deformation. The testing technologies related to the structure and morphology of PCBF with different times of steam explosion treatment were conducted by nuclear magnetic resonance (NMR), automatic surface area analyser and scanning electron microscopy (SEM). The effects of different times of steam explosion treatment, PCBF content, coupling agent content and extruding speed on the comprehensive mechanical properties of PCBF/PP composites were studied in this paper. The results showed that the PCBF has a higher content of cellulose, an increased aspect ratio and an enlarged specific surface area after third time steam explosion treatment. The tensile strength, tensile modulus, flexural strength and flexural modulus of PCBF/PP composites increase with the increasing times of steam explosion treatment when the times not more than three, and then decrease with increasing times of steam explosion treatment when the times exceed three. The tensile properties and flexural properties of PCBF/PP composites change with the increasing of PCBF content, coupling agent content and extruding speed nonlinearly. Furthermore, the SEM of PCBF/PP composites showed better interfacial interaction between the fibre and the matrix.

Adding caulis spatholobi residue fiber (CSRF) to reinforce biodegradable poly (propylene carbonate) (PPC) as a reinforcement was investigated. The morphology of CSRF before and after continuous steam explosion, the mechanical and morphological properties of PPC/CSRF bio-composites with different fiber content were investigated using scanning electron microscopy (SEM), mechanical tests and infrared spectroscopy. The tensile strength and modulus, and impact strength of the bio-composites increased as the content of fiber increased in composites, the elongation at break declined. It was found that a small stay-segment in the stress–strain curves and pulled-out fibers on fractured surfaces of the composites. Infrared spectra result showed esterification and formation of hydrogen bonds between the matrix and CSRF. The fractured surface of the composites addressed a promotion of the interfacial interactions. POLYM. COMPOS., 35:208–216, 2014. © 2013 Society of Plastics Engineers

This work reports the synthesis of novel nanocomposite electrodes based on MnO2 nanosheets, Pt, Au, or Pd nanoparticles (NPs), exfoliated carbon nanotubes (CNTs), and Ni foam (NF) substrates. The MnO2–Pd–CNT–NF electrode in 1-butyl-3-methyl-imidazolium hexafluorophosphate (BMIM-PF6)/N, N-dimethylformamide (DMF) electrolyte exhibits a high specific capacitance of 559.1 F/g based on MnO2 with a wide potential window (2.1 V). To the best of our knowledge, this is one of the highest capacitance for MnO2 in ionic liquid (IL) electrolytes ever reported. The IL hybrid supercapacitors are assembled using MnO2–Pd–CNTs–NF positive electrode, activated carbon (AC) negative electrode, and BMIM-PF6/DMF electrolyte displaying high operating voltage (3 V), high energy density (78.4 Wh/kg) and high power density (12.7 kW/kg). The superior performances of the MnO2 IL hybrid supercapacitors suggest their potential application for the future generation of electrochemical power sources.

The damage and fracture behavior was researched in hot compression of as-cast Ti40 titanium alloy with single β phase. The main fracture modes consist of 45° shear fracture, inner cracking and longitudinal fracture on free-surface, which occur at 850°C/10s-1, 900~950°C/10s-1 and other deformation conditions respectively. Moreover, 45° transgranular cracking is the combination result of adiabatic shear bands due to local temperature rise and shear stress, the inner intergranular cracking is induced by the microvoids near the adiabatic shear bands propagted along grain boundry under shear stress, the surface longitudinal intergranular cracking is caused by the vaporization of oxide and function of hoop tensile stress. In addition, the material undergoes the complex fracture which has to be avoided or decreased in hot processing for obtaining satisfactory properties.

The flammable and the mechanical effects of silica (SiO2) on the halogen-free, flame-retarded ethylene–octene copolymer (POE)/polypropylene (PP) composites were investigated. Through the thermal stability analysis and the combustion test, it was found that the SiO2 had a synergistic effect on the intumescent flame retardant (IFR), especially when the SiO2 content was 3 wt%. According to the results of mechanical properties, the tensile strength of composites increased with the rising SiO2 content and most of the impact strength is retained. The fracture morphology showed the state of SiO2/IFR particles in the POE/PP blends, which reflected that with the increasing SiO2 content and the decreasing IFR content, the aggregates became less compact and the size of aggregates became smaller.

A 30 wt % high-density polyethylene (HDPE)/70 wt % polystyrene (PS) blends and 5 wt % HDPE/95 wt % PS blends were prepared via polymer vane plasticating extruder, which can generate elongational force field, in different rotation speeds. The fracture surface of the HDPE/PS blends was observed by a scanning electron microscope, and the dispersion of the HDPE in the PS matrix was evaluated by multifractal programs. The multifractal spectrum width , and the dimension difference of maximum and minimum probability subset were defined to discuss the homogeneity and the diameter of the HDPE particles. The results showed that the multifractal method was an effective tool to quantitatively describe the special distribution and diameter of the dispersed particles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2328–2335, 2013

Polymer granules are conveyed and plasticized using an innovational vane extruder composed of several vane plasticizing and conveying units (VPCUs). This study developed a mathematic model to analyze the bulk density of polymer granules in a VPCU, as well as conducted an experiment to investigate the effects of device geometry, polymer properties, and operating conditions on the model. By comparing the theoretical model data with the experiment data, the proposed model of bulk density is found to be aligned with actual conditions, thus providing a basis for device and process optimization. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 842-850, 2013

The present work is focused on the microstructure and mechanical properties of Ti14 alloy with different semisolid deformation ratios during forging tests. The results revealed that the forging ratio had a significant effect on the precipitation of the alloy. Fewer plate-shaped Ti2Cu tended to precipitate on grain boundaries with higher forging ratios, and finally the plate-shaped Ti2Cu formed precipitate-free zones along grain boundaries with a forging ratio of 75%. The precipitation on grain boundaries was found to be controlled by a peritectic reaction. Large forging ratios accelerated the extrusion of liquid and resulted in less liquid along the prior grain boundaries, which reduced the peritectic precipitation in this region and formed precipitate-free zones during re-solidification. In addition, increasing the forging ratio could accelerate dynamic recrystallization, which is favorable for improving the semisolid formability. The tensile ductility increased with increasing forging ratio, and a mixed fracture mode, involving both cleavage and dimple fracture, was observed after forging with a forging ratio of 75%, which is attributed to the presence of precipitate-free zones formed along grain boundaries during semisolid processing.

An asymmetric supercapacitor based on manganese dioxide/Au/nickel foam (MANF) electrode as positive electrode and graphene or commercial activated carbons (AC) as negative electrode was fabricated. The effect of different negative electrode materials and mass ratios of negative/positive electrodes on the electrochemical properties of the asymmetric supercapacitor was carefully investigated. The results suggest that the mass ratio of negative/positive electrode has a significant impact on the specific capacitance of the asymmetric supercapacitor. Especially, it is found that the optimal mass ratio of the negative/positive electrode is slightly lower than that calculated according to charge balance. On the other hand, the asymmetric supercapacitor with commercialized AC as negative electrode possesses higher specific capacitance and better rate capability than that of the asymmetric supercapacitor with graphene as negative electrode. The negative material has slight impact on the cycle stability of the asymmetric supercapacitor. In addition, the optimized asymmetric supercapacitor with MANF composite as positive electrode and AC as negative electrode can obtain an energy density as high as 65.9 Wh kg−1 at a power density of 180 W kg−1 and a cell voltage of 1.8 V in the neutral Na2SO4 aqueous solution.

OM, XRD, SEM, EDS were used to test. and analyze the combustion products of TC4 and Ti40 alloys by layer-by-layer from reaction frontier to matrix The result shows that: titanium alloy can be divided into 4 sections, combustion surface (CS), molten zone (MZ), transitional zone (TZ) and influence zone (IZ). The CS is mainly consist of TiO2, and with oxide of V. Cr2O3 and SiO2 are detected on CS of Ti40. MZ of TC4 is in loose and porous state. There are lots of cracks and holes in the TZ and IZ; MZ of Ti40 is compact, between MZ and IZ there is a TZ which is rich of V and Cr, it can stop oxygen diffusing effectively. From the MZ to matrix, oxygen content reduces gradually, and oxide of Ti with different valence state is detected. Because of effect of oxygen, the hardness of the two alloy increase after combustion, increment of Ti40 is much greater than that of TC4.

A class of novel composite electrodes based on poly(3,4-ethylenedioxythiophene) (PEDOT) and manganese dioxide (MnO2) was assembled by step-by-step anodic deposition on nickel foam for supercapacitor application. The effect of the distribution and loading of PEDOT on the electrochemical performance of composite electrodes was studied carefully. Among these composite electrodes, the optimized PEDOT/MnO2/PEDOT sandwich electrode shows excellent capacitive behavior, and MnO2 species in the optimized sandwich electrode possesses a high specific capacitance of 487.5 F g−1 at 1 A g−1. Furthermore, an asymmetric supercapacitor cell with the optimized sandwich composite as positive electrode and active carbon (AC) as negative electrode also exhibits outstanding performance at a cell voltage of 1.8 V in a 0.5 M Na2SO4 aqueous electrolyte. It has a high energy density of 30.2 Wh kg−1 with a power density of 180 W kg−1. And even at a high power density of 2.7 kW kg−1, the asymmetric supercapacitor can deliver a high energy density of 13.1 Wh kg−1. Moreover, the asymmetric supercapacitor displays impressive electrochemical cycling stability with 99.5% initial capacitance remained after 1000 continuous cycles.

Some research results are introduced briefly in this paper. A new kind of titanium alloy was designed based on nine elements system, which belongs to (a+b) type. Bars with diameter of 14 mm were produced via Vacuum Arc Remelting (VAR) melting and conventional forging and rolling facilities. Influence of alloy elements contents and heat treatments on microstructure and mechanical properties of the new alloy were studied. The results show that Ultimate Tensile Strength (UTS) is about 1200~1700MPa and Elongation (EL) is normally less than 5% at R.T., though Electron Beam (EB) welding can be proceeded, but the toughness of the alloy is poor at R.T.High temperature (HT) short-term strength of the alloy is also acceptable up to 600. Based on the above performances, the new material can be applied in the corresponding circumstances.