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The hot single point incremental forming is usually adopted to fabricate the complex part of AA2024 aluminum alloy. However, the activation mechanism of the slip system still has not been discovered at elevated temperatures. In response, the article has proposed a novel macro–micro analysis method to reveal the activation mechanism of the slip system. The shear stress model, which is demonstrated through the Schmid factor distribution of each crystal plane group, of crystal planes is established to calculate the shear stress of each slip direction. The effect of the forming process parameters on the forming limit angle is analyzed in detail, and the forming temperature is a primary factor for the increase of the forming limit angle. On this basis, the dislocation density of the material is investigated at different temperatures, and the dislocation density of the material is significantly decreased at 180 °C, which can weaken the dislocation pile-up due to the increase of the stacking fault energy. Finally, the slip system number of each crystal plane group is further analyzed at different temperatures, and the novel slip systems of the three crystal plane groups, such as {111}, {100}, and {110}, are both significantly activated at 180 °C. [ABSTRACT FROM AUTHOR]

Purpose: Orbital [99mTc]TcDTPA orbital single-photon emission computed tomography (SPECT)/CT is an important method for assessing inflammatory activity in patients with Graves' orbitopathy (GO). However, interpreting the results requires substantial physician workload. We aim to propose an automated method called GO-Net to detect inflammatory activity in patients with GO. Materials and methods: GO-Net had two stages: (1) a semantic V-Net segmentation network (SV-Net) that extracts extraocular muscles (EOMs) in orbital CT images and (2) a convolutional neural network (CNN) that uses SPECT/CT images and the segmentation results to classify inflammatory activity. A total of 956 eyes from 478 patients with GO (active: 475; inactive: 481) at Xiangya Hospital of Central South University were investigated. For the segmentation task, five-fold cross-validation with 194 eyes was used for training and internal validation. For the classification task, 80% of the eye data were used for training and internal fivefold cross-validation, and the remaining 20% of the eye data were used for testing. The EOM regions of interest (ROIs) were manually drawn by two readers and reviewed by an experienced physician as ground truth for segmentation GO activity was diagnosed according to clinical activity scores (CASs) and the SPECT/CT images. Furthermore, results are interpreted and visualized using gradient-weighted class activation mapping (Grad-CAM). Results: The GO-Net model combining CT, SPECT, and EOM masks achieved a sensitivity of 84.63%, a specificity of 83.87%, and an area under the receiver operating curve (AUC) of 0.89 (p < 0.01) on the test set for distinguishing active and inactive GO. Compared with the CT-only model, the GO-Net model showed superior diagnostic performance. Moreover, Grad-CAM demonstrated that the GO-Net model placed focus on the GO-active regions. For EOM segmentation, our segmentation model achieved a mean intersection over union (IOU) of 0.82. Conclusion: The proposed Go-Net model accurately detected GO activity and has great potential in the diagnosis of GO. [ABSTRACT FROM AUTHOR]

A crawler mobile parallel robot equipped with swing arms has been proposed to improve the parallel robot's limited workspace and poor mobility. The robot's obstacle performance in the condition of step-climbing, gap-crossing, and hill-climbing was investigated through multi-body system simulation. The flexible body finite segment model method is used to model the crawler to simulate the dynamic behaviors. The results show that the motion of the parallel manipulator along the modified path is stable and continuous. The maximum step height for the robot in the forward and backward step-climbing is 170 and 160 mm, respectively. The maximum gap widths in the forward and backward gap-crossing are 420 and 615 mm, respectively. The maximum slope gradient is 20° in the hill-climbing. In the three circumstances of obstacle-crossing, with the increase in step height, gap width, and slope gradient, the crawler slip rate increases with a more significant fluctuation, resulting in a greater force and impact on the crawler. Compared with the forward step-climbing and gap-crossing, the robot moves more smoothly with less impact in backward conditions. The initial speed is critical to improving the forward gap-crossing and hill-climbing movement. The integrated crawler mobile parallel robot has the advantages of simple structure and excellent obstacle-crossing performance. [ABSTRACT FROM AUTHOR]

An electrolytic Zn-MnO2 battery based on a deposition/dissolution mechanism has shown great prospects in energy storage applications, due to its low cost and high energy density. However, the multi-electron electrochemical reaction of the manganese-based cathode in this battery depends on the electrolyte acidity. Here, the reaction mechanism at the cathode side is investigated when electrolytes with different acidities are used. The results show that the Mn2+/MnO2 deposition/dissolution and the cation intercalation coexist in the cathode of the electrolytic Zn-MnO2 battery when the electrolyte has a pH > 0.4. The battery exhibits an unstable variation of coulombic efficiency. Upon the increase of the proton concentration in the electrolyte, the manganese-based cathode demonstrated a one-step deposition/dissolution mechanism, which benefits a high discharge voltage up to 2 V of the battery and a stable coulombic efficiency of above 90%. This work provides a useful electrolyte design for electrolytic Zn-MnO2 batteries. [ABSTRACT FROM AUTHOR]

Since the deformation region involves the interaction of electric-thermal-force coupling in electric hot incremental sheet forming, the numerical simulation of the forming process is unusually difficult. Currently, the thermal-force coupling method is adopted to simulate approximately the whole forming process, and the Joule heating effect is often ignored. Therefore, the numerical simulation of the Joule heating effect is especially significant for the prediction accuracy of forming process. In this paper, a novel numerical simulation method considering electric-thermal-force parameters was proposed to update the thermal-force condition of the forming region instantly. Meanwhile, the model of contact thermal conductance was established, combining geometrical and electric-thermal parameters. Then a high-precision finite element model was obtained to predict the Joule heating effect of the forming region. In addition to this, the impact of thermal superposition on forming temperature was further analyzed, and a modified model of contact thermal conductance was established in electric hot incremental sheet forming. [ABSTRACT FROM AUTHOR]

Fe-doped NiMnO3 nanosheet electrode material was successfully synthesized by convenient and efficient microwave-assisted hydrothermal method. The crystal structure, chemical composition, morphology, and specific surface area of the electrode material were analyzed by X-ray diffraction, Fourier transform infrared, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and Brunner-Emmet-Teller testing. Results showed that Fe doping changed not only the crystal structure but also the morphology of the NiMnO3 nanosheet electrode material. Moreover, the electrode material exhibited a high specific surface area and outstanding conductivity. Electrochemical performance was analyzed by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The outcome of these experiments demonstrated that the Fe-doped NiMnO3 electrode material exhibited optimum electrochemical performance when the mass ratio was 15 wt%. The specific capacitance reached 732.7 F g−1 at a current density of 1 A g−1, and capacitance retention was approximately 78.3% after 10,000 cycles at 3 A g−1. The Fe-doped NiMnO3 electrode material is thus a promising next-generation supercapacitor material because of its high specific capacitance and long cycle life. [ABSTRACT FROM AUTHOR]

A hot-rolled AZ31Mg alloy sheet was subjected to dynamic plastic deformation parallel to the rolling direction, and microstructural evolutions and mechanical properties of the deformed samples were examined. It has been found that dynamic strain rate could facilitate {10-12} twin nucleation and growth and leads to a lower yield stress of about 20 MPa and an early end to twinning characteristic (happening at a strain point of about 6%) shown in the stress-strain curve. {10-12} twinning mechanism dominates the early plastic deformation; but when plastic strain exceeds ~ 9%, dislocation-slip mechanism instead of {10-12} twinning dominates the later plastic deformation. And this premature transformation of the dominant deformation mechanisms from {10-12} twinning to dislocation slip is caused by dynamic strain rate. The effect of dynamic strain rate on the number of twin nucleations remains unclear, and the more systematic researches are needed in the future. [ABSTRACT FROM AUTHOR]

In present work, effect of cold rolling and aging on thermal conductivity (TC) of the as-extruded Mg-2Sn alloy was studied. Experimental results revealed that TC of as-extruded sheet decreases to value of ~105.4 W/m/K after 18% reduction rolling. TC increases with increase in aging time and regains the highest value of 126 W/m/K. Enhanced TC of cold-rolled Mg-Sn alloys is attributed to the defects annihilation, residual stress release, and precipitations. The more pronounced rolling reduction would induce more second-phase precipitations, and thus TC of the 18% rolled alloy is larger than that of 5% rolled alloys. Texture is also an important factor affecting thermal conductivity of Mg alloys, and double-peak texture is not beneficial for thermal transportation. The result would shed light on the novel design of highly conductive Mg sheet. [ABSTRACT FROM AUTHOR]

Thermal conductivity is a key parameter for thermal design and management of the electronic components in their passive cooling processes. In this work, thermal and electrical conductivities of six groups of binary Mg alloys (Mg-Al, Mg-Zn, Mg-Sn, Mg-Zr, Mg-Mn, and Mg-Ca) in as-cast, as-solution, and annealed states were measured and the corresponding microstructures were observed. In both as-cast and as-solution states, thermal/electrical conductivities of the six groups of Mg alloys decreased with composition. Effects of solution treatment and annealing on thermal/electrical conductivities of the as-cast samples were also investigated and discussed. Moreover, the specific thermal/electrical resistivity (thermal/electrical resistivity increment of the alloy derived from one atom addition) of the solute elements for Mg alloys was drawn as follows, Zn < Al < Ca < Sn < Mn < Zr. Atomic volume difference of the solute elements with Mg atom (Δ V/V), valency, and configuration of extra-nuclear electron of the solute were believed as the main reasons for the differences. [ABSTRACT FROM AUTHOR]