Particle swarm optimization (PSO) has been employed to solve numerous real-world problems because of its strong optimization ability and easy implementation. However, PSO still has some shortcomings ...in solving complicated optimization problems, such as premature convergence and poor balance between global exploration and local exploitation. A novel hybrid particle swarm optimization using adaptive strategy (ASPSO) is developed to address associated difficulties. The contribution of ASPSO is threefold: (1) a chaotic map and an adaptive position updating strategy to balance exploration behavior and exploitation nature in the search progress; (2) elite and dimensional learning strategies to enhance the diversity of the population effectively; (3) a competitive substitution mechanism to improve the accuracy of solutions. Based on various functions from CEC 2017, the numerical experiment results demonstrate that ASPSO is significantly better than the other 16 optimization algorithms. Furthermore, we apply ASPSO to a typical industrial problem, the optimization of melt spinning progress, where the results indicate that ASPSO performs better than other algorithms.
Pure phase bismuth nanospheres have been successfully prepared by thermolysis of bismuth acetate in oleylamine. The size distribution of the bismuth nanospheres was improved by quickly quenching the ...reaction as revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The ultraviolet–near-infrared (UV-NIR) absorbance spectrum of the bismuth nanospheres showed camel-like shapes located at 425 and 575 nm, which could be ascribed to the effect of the surface plasmon resonance and light scattering. Due to the absorption in the visible range, the prepared bismuth nanospheres showed good photocatalytic properties to the degradation of RhB.
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•Photothermocatalytic synergistic oxidation overcomes the negative effect of H2O.•Photothermocatalytic synergistic oxidation enhances VOCs oxidation efficiency.•Relative dominance of ...photocatalysis and thermocatalysis is identified.
Thermocatalytic oxidation over supported noble metal catalysts shows a promising application prospect in eliminating VOCs. However, the high consumption of the expensive noble metals and input energy as well as catalyst deactivation from H2O poisoning limit its practical application. Herein, we report that photothermocatalytic synergistic oxidation over bifunctional supported noble metal catalysts can attenuate the negative effect of H2O vapour and achieve efficient mineralization of aromatic VOCs with high concentration at a low Pt loading and a mild temperature. Photothermocatalytic synergistic oxidation of aromatic VOCs was performed over bifunctional Pt/SrTiO3-x with a low 0.1 wt% Pt loading in the co-presence of visible-light illumination and mild thermal energy input (≤150 °C), achieving much more effective mineralization of toluene in high concentrations than the pristine thermocatalytic or photocatalytic oxidation. The introduction of photocatalysis lowers the activation energy and attenuates the negative H2O effect in the conventional thermocatalytic process through activating oxygen and consuming H2O for oxidative species O2− and OH production with photogenerated charges. Such a finding may provide some new insight into the construction of robust photothermocatalytic process and catalysts for efficient and economic VOCs elimination.
With the rapid development of the new energy vehicle market, the demand for extruded profiles for battery trays, mainly characterized by significant wall thickness differences in multiple chambers, ...is increasing, posing new challenges to production and quality control. This study examines the multi-objective optimization problem in the design process of aluminum profile dies with multi-cavity profiles and significant wall thickness differences. Using QFORM-extrusion professional aluminum extrusion finite element analysis software and the response surface analysis method, the standard deviation of the velocity (SDV), standard deviation of the pressure (SDP), and thick wall hydrostatic pressure (TWHP) on the profile section at the die exit are optimized. By analyzing the functional relationship between the key die structure parameters (the height of the baffle plates, the length of the bearing, and the height of the false mandrel) and the optimization objective, the optimal combination scheme of die structure parameters was obtained using the NSGA2 (non-dominated sorting genetic algorithm-2) multi-objective genetic optimization algorithm. The results show that, compared with the initial design scheme, the standard deviation of profile section velocity was reduced by 5.33%, the standard deviation of pressure was reduced by 11.16%, and the thick wall hydrostatic pressure was increased by 26.47%. The die designed and manufactured using this scheme successfully completed the hot extrusion production task, and the profile quality met the predetermined requirements, thus verifying the effectiveness of this study in optimizing the design of a multi-cavity aluminum profile die with significant differences in wall thickness for complex structures.
Phosphorous doped carbon dots (P-CDs) are prepared by a one-step hydrothermal method. The phenomenon of aggregation induced red shift emission (AIRSE) is observed in the obtained P-CDs. The emission ...wavelength of a P-CD solution can be tuned in the range from 455 nm to 595 nm by changing the solution concentration.
A neuromorphic visual system integrating optoelectronic synapses to perform the in‐sensor computing is triggering a revolution due to the reduction of latency and energy consumption. Here it is ...demonstrated that the dwell time of photon‐generated carriers in the space‐charge region can be effectively extended by embedding a potential well on the shoulder of Schottky energy barrier. It permits the nonlinear interaction of photocurrents stimulated by spatiotemporal optical signals, which is necessary for in‐sensor reservoir computing (RC). The machine vision with the sensor reservoir constituted by designed self‐powered Au/P(VDF‐TrFE)/Cs2AgBiBr6/ITO devices is competent for both static and dynamic vision tasks. It shows an accuracy of 99.97% for face classification and 100% for dynamic vehicle flow recognition. The in‐sensor RC system takes advantage of near‐zero energy consumption in the reservoir, resulting in decades‐time lower training costs than a conventional neural network. This work paves the way for ultralow‐power machine vision using photonic devices.
In this work, photovoltaic devices are innovatively used as self‐powered reservoirs. Ultralow‐power machine vision is achieved by the self‐powered sensor reservoir with Cs2AgBiBr6 photonic devices. Both image processing and dynamic video analysis are energy‐efficiently achieved in this in‐sensor reservoir computing system. The accuracy is 99.67% for face classification and 100% for dynamic vehicle flow recognition.
This paper focuses on the position control of the quadruped robot hydraulic drive unit (HDU). The proposed control strategy has the advantages of excellent output tracking performance, strong ...robustness, no chattering and low computational complexity. HDU has the characteristics of nonlinearity and parameter uncertainty, coupled with unpredictable external interference, which makes it difficult to achieve precise position control. In this paper, we first establish the mathematical model of the HDU based on the actual parameters and obtain the state space of the system. Through the pole placement, the simplified system can easily achieve the expected control goal. Then, the state equation of the error system is constructed, and the nonlinearity, parameter uncertainty and external interference of the HDU are summarized as the matched and unmatched uncertainties of the system. The integral sliding mode control (ISMC) is used to derive the control law, and the response characteristics of the system when pole placement and state feedback
H
∞
control are used for the nominal control are compared. It can be concluded that the system with state feedback
H
∞
control for nominal control has stronger robustness and can resist the unmatched uncertainties. Finally, the control law of the simplified system is used as feedforward and combined with the ISMC of the error system, the output tracking control framework of the HDU is proposed. Simulations and experiments show that the proposed control method has excellent tracking performance and strong robustness.
Inspired by the collaborative mechanism among biological nervous, endocrine and immune systems, this paper proposes an algorithm of adaptive evolutionary based on biological cooperation (BCAE). This ...method can solve the dynamic multi-objective optimization problem of Industrial Internet of Things (IIoT) services to reduce the total service cost and service time. The BCAE algorithm consists of two parts: bottom level and top level. In the bottom level, different Pareto frontiers are obtained by coevolution of multiple subpopulations. In the top level, according to the distance between the service request and the service provider and the unit energy consumption of the service provider, the connection weight sequence is designed, and then the affinity matrix is constructed according to the connection weight sequence. Finally, the multi factor genetic algorithm (MFEA-II) is used to mate and imitate the service providers with different affinity, and the total service cost and total service time of the optimal solution are obtained, which are recorded in the top-level optimal antigen solution set. On the basis of single service strategy and collaborative service strategy, the IIoT services with dynamic requests are studied under different distributions. The obtained simulation results show that the performance of BCAE is better than the performance of the four existing algorithms, especially when solving high-dimensional problems.
The arc plasma behavior for gas metal arc welding (GMAW) with an external compound magnetic field was numerically investigated. A three-dimensional finite element model for the external magnetic ...field (EMF) and a three-dimensional finite volume model for the arc plasma were established. The effects of the EMF on the redistribution of the temperature, fluid flow, pressure, and electromagnetic force in the arc plasma were compared with traditional GMAW under the same welding parameters. The control mechanism of the external compound magnetic field on the arc plasma behavior was analyzed. The results show that the magnitude of the additional electromagnetic force was much lower than that of the self-induced electromagnetic force, but it caused forward inclination and periodic swinging of the arc plasma. When an EMF was applied, the peak temperature decreased, and the temperature distribution was more uniform. The peak pressure was also much smaller than that without an applied EMF.
Electrocatalytic water splitting to produce hydrogen is a promising route to provide green hydrogen on a large scale. To explore non-noble metal electrocatalysts with high performance is still a ...challenge. Herein, a one-step electrodeposition way is developed to construct the heterostructural (NiO-La
2
O
3
)/(Ni-La)/NiO/Ni electrocatalysts on Ni foam. The dark Ni-La coating was prepared by co-electrodeposition from an aqueous solution containing LaCl
3
and NiCl
2
with a molar concentration ratio of 1:5. Among these heterostructural Ni-based electrocatalysts, an excellent HER activity is achieved: an overpotential of 22 mV at the current density of 10 mA cm
−2
in 1 M KOH solution. It is demonstrated that the introduction of La significantly reduces the overpotential for HER. The higher the La content in the Ni-La coating of these electrocatalysts, the better the electrocatalytic HER performance was exhibited. This work provides a facile and inexpensive route to prepare Ni-La coating on electrodes in an aqueous solution.
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