Influences on Distribution of Solute Atoms in Cu-8Fe Alloy Solidification Process Under Rotating Magnetic Field

A rotating magnetic field (RMF) was applied in the solidification process of Cu-8Fe alloy. Focus on the mechanism of RMF on the solid solution Fe(Cu) atoms in Cu-8Fe alloy, the influences of RMF on solidification structure, solute distribution, and material properties were discussed. Results show that the solidification behavior of Cu–Fe alloy have influenced through the change of temperature and solute fields in the presence of an applied RMF. The Fe dendrites were refined and transformed to rosettes or spherical grains under forced convection. The solute distribution in Cu-rich phase and Fe-rich phase were changed because of the variation of the supercooling degree and the solidification rate. Further, the variation in solute distribution was impacted the strengthening mechanism and conductive mechanism of the material.     

Effects of Solution Treatment Temperatures on Microstructure and Mechanical Properties of TIG–MIG Hybrid Arc Additive Manufactured 5356 Aluminum Alloy

A novel additive manufacturing method with TIG–MIG hybrid heat source was applied for fabricating 5356 aluminum alloy component. In this paper the microstructure evolution, mechanical properties and fracture morphologies of both as-deposited and heat-treated component were investigated, and how these were affected by different heat-treated temperature. The as-deposited microstructure showed dominant equiaxed grains with second phase, and the size of them is coarse in the bottom region, medium in the middle region and fine in the top region owing to different thermal cycling conditions. Compared with as-deposited microstructure, the size of grain becomes large and second phases gradually dissolve in the matrix as heat-treated temperature increase. Different microstructures determine the mechanical properties of component. Results show that average ultimate tensile strength enhances from 226 to 270 MPa and average microhardness increases from 64.2 to 75.3 HV0.1 but ductility decreases from 33 to 6.5% with heat-treated temperature increasing. For all components, the tensile properties are almost the same in the vertical direction (Z) and horizontal direction (Y) due to equiaxed grains, which exhibits isotropy, and the mechanisms of these are analyzed in detailed. In general, the results demonstrate that hybrid arc heat source has the potential to fabricate aluminum alloy component.     

Electrodeposition of nano-nickel in deep eutectic solvents for hydrogen evolution reaction in alkaline solution

The electrodeposition of nano-Ni films on a Cu substrate from NiCl₂ precursors in choline chloride (ChCl)/urea or ethylene glycol (EG) based deep eutectic solvent (DES) was illustrated. Voltammetric study demonstrates that the electrodeposition of Ni(Ⅱ) in both ChCl/urea and ChCl/EG systems is a simple one-step reaction process, and the electrochemical process is a typical diffusion-controlled irreversible process. The obtained Ni films can be controlled to form nanostructures depending on the DES and the electrodeposition conditions. The nanostructured Ni films were investigated as electrodes for hydrogen evolution reaction (HER) in an alkaline medium. The enhanced catalytic activity toward the HER was confirmed, which is mainly attributed to the formation of needles morphology and the improved electrochemical surface area. The result reveals that the electrodeposition process may provide a promising strategy for the production of nano-Ni at low temperature for HER.     

Synthesis of a N-doped mesoporous carbon as an efficient electrocatalyst for oxygen reduction

A facile and effective approach was developed for the preparation of mesoporous Fe-NC by pyrolyzing the mixture of FeCl₂, urea, (NH₄)₂MoO₇, phthalic anhydride and SBA-15, during which the in-situ formation of iron phthalocyanine is confirmed. The obtained catalyst exhibits high catalytic activity towards ORR, whose half-wave potential can be 53 mV more positive than that of commercial Pt/C catalyst. Besides, the catalyst also exhibits high selectivity of four electron path, along with excellent stability and methanol tolerance in alkaline media. Based on the characterization results, we suggest, the higher surface areas, highly porous structures induced by SBA-15 addition, as well as high graphitic N content should be the proper origins for its outstanding catalytic performance.     

Improvement of tenderness and water holding capacity of spiced beef by the application of ultrasound during cooking

The aim of this study was to assess the effects of power ultrasound‐assisted (0, 400, 600, 800 and 1000 W, frequency of 20 kHz) cooking (80, 100, 120 min) on spiced beef. The results showed that power ultrasound could significantly increase the salt content (P < 0.05). For water holding capacity, the ultrasonic treatment could significantly reduce the pressure loss and free water content while improving the immobilised water content (P < 0.05). And ultrasonic treatment improved hardness compared with control (P < 0.05). However, the effects on the springiness, the chewiness and the resilience of the spiced beef were not significant (P > 0.05). As for microstructure, the myofibrils of beef were ruptured by ultrasonic treatment along with the Z‐lines leading to the muscle swelling. The results indicated that the application of ultrasound during cooking could effectively promote the penetration of salt, improve the water holding capacity and ameliorate the tenderness of spiced beef.     

Study on migration characteristics of heavy metals during oil sludge incineration

Experimental and simulation studies on the migration characteristics of heavy metals during the incineration of OS were conducted with a tube furnace reactor and thermodynamic equilibrium calculation software FactSage, respectively. The results showed that when the incineration temperature increased from 800°C to 1100°C, the release rates of heavy metals such as Cr, Pb, Cu, Zn and Ni increased gradually and reached the maximum at 1000°C. When the excess air ratio increased from 1.0 to 1.4, the release rates of heavy metals such as Cr, Pb, Cu, Zn and Ni first decreased and then became steady. The content of gaseous hydroxide of Cr and gaseous chlorides of Pb and Cu increased while the chemical forms of Zn and Ni did not change obviously with the increase of combustion temperature or excess air ratio.     

Convolutional neural network feature maps selection based on LDA

Convolutional neural network (CNN), as widely applied to vision and speech, has developed lager and lager network size in last few years. In this paper, we propose a CNN feature maps selection method which can simplify CNN structure on the premise of stabilize the classifier performance. Our approach aims to cut the feature map number of the last subsampling layer and achieves shortest runtime on the basis of Linear Discriminant Analysis (LDA). We rebuild feature maps selection formula based on the between-class scatter matrix and within-class scatter matrix, because LDA can lead to information loss in the dimension-reduction process. Our experiments measure on two standard datasets and a dataset made by ourselves. According to the separability value of each feature map, we suggest the least number of feature maps which can keep the classifier performance. Furthermore, we prove that separability value is an effective indicator for reference to select feature maps.     

Effect of comb-type copolymer on crystallization of paraffin from waxy oils and methyl ethyl ketone (MEK) -toluene dewaxing

In this research, maleic anhydride-α-octadecene copolymer and its derivative with phenylethylamine was synthesized and its effect on the crystallization of paraffins was investigated. This derivative, when added into second cut of vacuum gas oil and forth cut of vacuum gas oil, increases the size and improves aggregation of paraffin crystals observed by polarizing light microscopy, increases onset temperature and enthalpy of paraffin crystallization determined by differential scanning calorimetry, improves the dewaxing efficiency with dosage of 100?ppm explored by MEK-toluene dewaxing.     

Discrete-time neural network with two classes of bias noises for solving time-variant matrix inversion and application to robot tracking

Neural Computing and Applications - It is well known that noise is inevitable in real world, especially in the case of solving time-variant matrix inversion. Therefore, it is more necessary to...     

Revisiting the Parallel Strategy for DOACROSS Loops

Journal of Computer Science and Technology - DOACROSS loops are significant parts in many important scientific and engineering applications, which are generally exploited pipeline/wave-front...