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This work investigated the corrosion resistance of AZ80 (Mg-8Al-0.5Zn alloy) with different Nd contents in alkaline solution by the mass loss test, electrochemical test, scanning electron microscope, energy spectrum analysis, and x-ray diffraction. To remove the influence of the Mg17Al12 phase, alloys were heat treated at 410°C for 10 h. Results revealed that Al2Nd and AlMnNd phases mainly exist in the alloy. The corrosion rate of the alloy increased when the Nd content was

The effect of welding current on the microstructures and mechanical properties of gas tungsten arc welding (GTAW) joints for ZLa22 (Mg-2Zn-2La, wt%) alloy was investigated. The results show that increasing the welding current gradually increases the average grain size in the fusion zone (FZ) and gradually decreases the welded joints strength. However, incomplete penetration is formed in the FZ at a low welding current of 130A, resulting in a decrease in tensile strength. The ultimate tensile strength (UTS) of the welded joint reaches the maximum value of 117 MPa at a welding current of 150A, which is only 72.22% of the base metal (BM). The rupture location occurs in the transition zone (TZ), due to the stress concentration at the junction of large and small grains, which may lead to cracks. The Mg-Zn-La phase in the welded joints precipitates at the grain boundaries in a coarse semi-continuous network, which reduces the tensile strength of the welded joints. In addition, with the increase of the welding current, the microhardness of the FZ decreases. In the welded joints, the FZ exhibits as-cast quench structure with fine grains, offering the highest hardness in this zone.

In this paper, the thermoelectric power of hypo/hyper-eutectic Al-Si alloys melt induced by electromagnetic fields has been researched, as well as the resultant microstructures evolution corresponding to different stages of thermoelectric power. The results show that the thermoelectric power of Al-Si alloy melt is strongly sensitive to electromagnetic field, showing the sharp increment. Then thermoelectric power gradually gets back to the initial value after turning off the electromagnetic field. As for the resultant microstructures during the recovery stage of the thermoelectric power, TEM are used to capture the results that smaller Si particles grow up from the combination of Si particles after treatment. SEM observation and statistical processing data results about phase size/distribution show the recovery of eutectic Si phases, as well as the α-Al phases, indicating the pseudo growth of Si and Al clusters. Further, a recovery trend of primary Si phases also indicates the pseudo growth of Si clusters. Pseudo growth of clusters is verified by both the thermoelectric power and the resultant solidification microstructures. The recovery solidification microstructures correspond well to the thermoelectric power decrement after treatment.

Background: Virus-like Particles (VLPs) are non-genetic multimeric nanoparticles synthesized through in vitro or in vivo self-assembly of one or more viral structural proteins. Immunogenicity and safety of VLPs make them ideal candidates for vaccine development and efficient nanocarriers for foreign antigens or adjuvants to activate the immune system. Aims: The present study aimed to design and synthesize a chimeric VLP vaccine of the phage Qbeta (Qβ) coat protein presenting the universal epitope of the coronavirus. Methods: The RNA phage Qβ coat protein was designed and synthesized, denoted as Qbeta. The CoV epitope, a universal epitope of coronavirus, was inserted into the C-terminal of Qbeta using genetic recombination, designated as Qbeta-CoV. The N-terminal of Qbeta-CoV was successively inserted into the TEV restriction site using mCherry red fluorescent label and modified affinity purified histidine label 6xHE, which was denoted as HE-Qbeta-CoV. Isopropyl β-D-1-thiogalactopyranoside (IPTG) assessment revealed the expression of Qbeta, Qbeta-CoV, and HE-Qbeta-CoV in the BL21 (DE3) cells. The fusion protein was purified by salting out using ammonium sulfate and affinity chromatography. The morphology of particles was observed using electron microscopy. The female BALB/C mice were immunized intraperitoneally with the Qbeta-CoV and HE-Qbeta-- CoV chimeric VLPs vaccines and their sera were collected for the detection of antibody level and antibody titer using ELISA. The serum is used for the neutralization test of the three viruses of MHV, PEDV, and PDCoV. Results: The results revealed that the fusion proteins Qbeta, Qbeta-CoV, and HE-Qbeta-CoV could all obtain successful expression. Particles with high purity were obtained after purification; the chimeric particles of Qbeta-CoV and HE-Qbeta-CoV were found to be similar to Qbeta particles in morphology and formed chimeric VLPs. In addition, two chimeric VLP vaccines induced specific antibody responses in mice and the antibodies showed certain neutralizing activity. Conclusion: The successful construction of the chimeric VLPs of the phage Qβ coat protein presenting the universal epitope of coronavirus provides a vaccine form with potential clinical applications for the treatment of coronavirus disease.

In this study, a novel multi-microalloying MgAlCoCrFeNi alloy was extruded at 300 ˚C with different extrusion speeds (0.2, 1, and 2 mm/s). The microstructure evolution, tensile properties and work-hardening behavior of the alloy were studied. Results showed that increasing the extrusion speed could improve the homogeneity of the microstructure, transitioning from a bimodal microstructure (fine recrystallized grains and elongated un-recrystallized grains) at 0.2 and 1 mm/s to a fully recrystallized one at 2 mm/s. The lower extrusion speed could improve the YS of the alloy, which possesses a maximum YS of ~213 MPa at 0.2 mm/s, an increase of ~12% compared to the YS at 2 mm/s, which was mainly attributed to the fine grain strengthening and dislocations (residual dislocations) strengthening. Moreover, the work hardening capacity of the alloy increases with the extrusion speed. As the extrusion speed increases from 0.2 mm/s to 2 mm/s, the work hardening exponent n increased from 0.08 to 0.14, and the work hardening capability Hc increased from 0.31 to 0.52. The analysis results showed that the improvement of work hardening ability was mainly due to the increase of dislocation storage rate caused by grain coarsening.

This paper investigates the microstructure, corrosion, electrochemical behavior, and the discharge performance of Gallium (Ga) alloyed Mg-Al-Zn alloys using the gravimetric method, electrochemical measurements, and battery test. The average grain size of AZ80–2.5Ga (Mg-8Al-0.5Zn-2.5Ga alloy) is 36% smaller than that of AZ80 (Mg-8Al-0.5 Zn alloy). The number and size of the Mg17Al12 phase particles are smaller and more homogeneously distributed. Ga reduces the self-corrosion rate, increases the electrochemical activity and the discharge performance. The grain refinement generates many grain boundaries on the surface and promotes discharge performance. The decrease of the self-corrosion rate is attributed to the suppression of the protective film that inhibits the anode consumption. The AZ80–2.5Ga anode has the optimal discharge capacity of 1437 mAh g− 1 and anode efficiency of 61% at 50 mA cm−2, which are 25% and 29% higher than for the AZ80 anode.

Oxidation resistance and products of the AZ80 alloys with (0, 0.32, 1.07 wt %) Y were investigated via isothermal oxidation test at temperatures between 413 °C and 445 °C. The results revealed that alloys showed linear or power law kinetics weight gain with time at each temperature. The alloying element Y facilitated the reaction of MgO + CO2 MgCO3 in the outer oxide layer of AZ80, which changed flocculent shape oxides (MgO) to granular oxides (MgCO3). Oxide layer with flocculent shape oxides is loose, while that with granular oxides is compact and can prevent alloy matrix from further oxidation. A further insight into oxidation mechanism of magnesium alloys is obtained.

Magnetic field is an effective strategy to refine microstructures, however, few researches focus on refinement efficiency over the different temperature ranges. In this paper, we develop the online thermopower measurement to provide the real-time and continuous check for the melt treated by alternating magnetic field over the selected temperature ranges. The effects of alternating magnetic field on eutectic and primary phases of Al-Fe binary alloy are discussed by both the thermopower and the solidification microstructures. Thermopower-temperature coefficient α = dS/dT turns from 0.1565 μV·K−2 to 0.0259 μV·K−2 at liquidus due to the solid particles precipitation during the direct cooling process without treatment. Relationships of thermopower and temperature are given to display the kinetics process. Thermopower increases with violent oscillation during the magnetic field. From the results of microstructures, magnetic field induces the promoted nucleation and decreased spacing of needle eutectic phases, as well as the refinement of bars and blocks primary phases, which strongly depends on the temperature ranges. Thermopower responds to nucleation and growth of eutectic and primary phases. This should be mainly attributed to the solid particles precipitation and the thermoelectric magnetic effects, respectively. Meanwhile, thermopower can be used to respond the microstructure evolution.

In this work, the effect of quasicrystal I phase (Mg3Zn6Y) on electrochemical behaviors and discharge properties of as-cast Mg–Zn–Y alloys with different Zn/Y ratio for Mg-air batteries are systematically investigated in 3.5 wt % NaCl electrolyte. The Mg–6%Zn–1%Y (wt.%) alloy is composed of Mg matrix and I phase, while the Mg7Zn3 phase appears in Mg–10%Zn–1%Y alloy. The Mg–Zn–Y anodes have higher open circuit potential, electrochemical activity and corrosion resistance than the contrasted ZK60 anode. They also have higher cell voltage, specific capacity and anodic efficiency with more stable discharge curves. The I phase is responsible for such improvements. The Mg–6%Zn–1%Y alloy achieves its best discharge capacity and anodic efficiency at the 40 mA cm−2, with the values of 1162.79 mAh·g−1 and 55.14%, respectively, which are 22.38% and 23.14% higher than ZK60 anode. Shallow pits with smooth surfaces are observed in Mg–Zn–Y anodes after discharge process. Some small holes associated with the desorption ability are detected as well.

The small screen size of a smartwatch limits user experience when watching or interacting with media. We propose a supplementary tactile feedback system to enhance the user experience with a method unique to the smartwatch form factor. Our system has a deformable surface on the back of the watch face, allowing the visual scene on screen to extend into 2.5D physical space. This allows the user to watch and feel virtual objects, such as experiencing a ball bouncing against the wrist. We devised two controlled experiments to analyze the influence of tactile display resolution on the illusion of virtual object presence. Our first study revealed that on average, a taxel can render virtual objects between 70% and 138% of its own size without shattering the illusion. From the second study, we found visual and haptic feedback can be separated by 4.5mm to 16.2mm for the tested taxels. Based on the results, we developed a prototype (called RetroShape) with 4×4 10mm taxels using micro servo motors, and demonstrated its unique capability through a set of tactile-enhanced games and videos. A preliminary user evaluation showed that participants welcome RetroShape as a useful addition to existing smartwatch output.