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Cellulose‐based separator exhibits excellent electrolyte affinity, thermal stability, and mechanical strength, which acts as a promising alternative to commercial polyolefin separators in lithium metal batteries (LMBs). Fiber size in cellulose‐based separators plays a crucial role in determining their physicochemical structure and mechanical strength, as well as the electrochemical performance of corresponding LMBs. Herein, the fiber size in cellulose‐based separators was first time regulated to optimize their mechanical stability and the related battery performance. The influences of fiber size in the separator on chemical structure, mechanical properties, surface morphology, electrochemical behavior were investigated in detail, in which the underlying mechanism between separator structure and the related performance was elucidated. As a result, the separator optimized by fiber size regulation exhibited excellent thermal stability under 180 °C, good tensile strengths of 6.0 MPa and Young's moduli of 315.9 MPa, superior room temperature ionic conductivity of 1.87 mS cm−1, as well as significantly improved electrochemical performance of corresponding batteries. It can be concluded that structure optimization for cellulose‐based separator through fiber size regulation is an effective and indispensable approach towards high safety and high performance LMBs. [ABSTRACT FROM AUTHOR]

To further improve the cooling performance and operation stability of system, the gas-liquid separator enhanced loop thermosyphon/vapor compression hybrid system was proposed. In the thermosyphon mode, the separator was used to reduce the pressure drop of fluid in the two-phase tube for improving the performance of steady-state heat transfer and start-up and the operation stability of system. In the vapor compression mode, the separator was used to make the saturated vapor into the condenser for increasing the mass flow rate in the condenser and enhancing the system coefficient of performance (COP). The simulation model of the hybrid system was developed to investigate the impact of structural parameters on thermosyphon mode performance. The difference of refrigeration performance between the new system and the conventional system in vapor compression mode was comparatively analyzed under the given structural condition of system. The results show that the system performance is the best when the inner diameters of two-phase tube and gas tube are respective 10 mm and 9 mm with separator height and total system height of respective 1.05 m and 1.45 m. Compared with the conventional system, the new system can achieve better performance under any operating condition, and the maximum COP of the new system is improved by 19. 70％. [ABSTRACT FROM AUTHOR]

Variable flow emitters are used in subsurface drip irrigation to address challenges in soil moisture transport. This study investigates the impact of flow channel structural parameters on the hydraulic performance and anticlogging ability of emitters using computational fluid dynamics (CFD) simulations and experimental tests. The results show that the realizable k–ε turbulence model can be used to simulate the flow field inside the variable flow emitter flow channel. The nRMSE between the measured (qm) and simulated (q) values of the flow rate is 11.23%, and the relative error between the measured (xm) and simulated (x) values of the flow index is 4.66%, which gives a high simulation accuracy. A polar analysis shows that the tooth angle (A) has the smallest effect on the effluent flow rate at 0.1 MPa (q0.1), x, and particle passage rate (η) of the variable flow emitter. Flow channel depth (D), tooth spacing (B), and tooth height (E) have a different order of precedence in the influence of the three indices, which are D > B > E > A, B > E > D > A and E > B > D > A, respectively. The value of η is positively correlated with the mean flow velocity (v) and the mean turbulent kinetic energy (k) in the flow channel, and η tends to increase and then decrease with the increase of x. The retention time of the particles in the flow channel is closely related to the magnitude of v and k. Three multivariate lin ear regression equations (R2 = 0.883–0.995) were constructed for q0.1, x, and η versus the flow channel structural parameters. The optimal design combination of channel structure parameters for different scenarios was determined using the scipy.optimize.minimize function in Python 3.8.0. The research results provide a reference for the optimal design of variable flow emitters. [ABSTRACT FROM AUTHOR]

Zinc‐based batteries are emerging as the most promising candidates for large‐scale energy storage devices due to their low cost, high safety, and long‐term storage. However, zinc‐based batteries encounter challenges stemming from undesirable side reactions and zinc dendrites on the anode, as well as dissolution on the cathode. Owing to their extremely small size, substantial surface functional groups, and adjustable structure, carbon dots (CDs) present considerable benefits in augmenting coulombic efficiency, expanding cycle life, and enhancing the rate functionality of zinc‐based batteries. Herein, this review delves into the surface modification and morphological regulation of batteries elements by CDs, CDs composites, and CDs derivatives. Moreover, it systematically encapsulates the application of CDs in zinc‐based batteries, underscoring the pivotal role of CDs in the advancement of electrode technology. Finally, the review highlights the impediments and proposes potential avenues for utilizing CDs in zinc‐based batteries. This review aims to facilitate the development of superior solutions and provide scientific insights into energy storage technologies. [ABSTRACT FROM AUTHOR]

Environmental pollution and global warming caused by fossil fuels have become increasingly serious issues. Therefore, it is urgent to explore novel strategies to obtain sustainable, renewable and clean energy. Fortunately, ambient energy harvesting technologies, which are receiving increasing attention, provide an optimal solution. Additionally, the investigation of two-dimensional (2D) materials represented by transition metal dichalcogenides (TMDs) significantly facilitates the advancement of ambient energy harvesting technologies due to their unique properties, enabling the application of ambient energy harvesting. Herein, we summarized recent advances in the application of TMDs in thermal energy harvesting, osmotic energy harvesting, mechanical energy harvesting, water energy harvesting and radiofrequency energy harvesting respectively. In the meanwhile, we listed some representative structure and device optimization strategies for enhancing the energy conversion performance of these ambient energy harvesters, aiming to provide valuable insights for future investigations towards further optimization. Finally, we highlight the pressing issues currently faced in the application of the TMDs ambient energy harvesting technologies and propose some potential solutions to these challenges. We aimed to provide a comprehensive review in the applications of the energy harvesting technologies, in order to provide innovative insights for optimizing existing TMDs-based technologies. [ABSTRACT FROM AUTHOR]

The rapid development of high-speed railway bridges in China has brought enormous challenges to the ballast bed stability on the bridge. With the increase in the bridge span, the bridge deformation under the temperature load increases gradually, as well as the stability difference of ballast bed between different regions. Moreover, the track vibration response under high-speed driving conditions is larger, which can easily cause differential settlement, flying ballast, and deterioration of the ballast bed, thereby affecting the bearing capacity and stability of the ballast bed. In view of this, this article summarizes relevant research work on a ballast bed on the bridge from the perspectives of the resistance, deformation, and acceleration response of the ballast bed. In addition, this study discusses the existing measures for improving the ballast bed stability on the bridge, including the optimization of the sleeper and ballast bed structures. Finally, the main issues that need to be addressed to improve the ballast bed stability on the bridge are pointed out, and ideas for future research on ballast beds on bridges with different spans and structures are proposed. [ABSTRACT FROM AUTHOR]

Nowadays, magnetic bearing has been used in more and more fields. Displacement sensor is one of the most important functional components of a magnetic bearing system and have attracted more and more attentions. Inductance displacement sensor, which shows merits in maintainability, lifetime, sensitivity, environmental interference ability, and cost, is a potential displacement sensor for magnetic bearing systems. While, usually, for a certain application, installation space of displacement is limited, increasing the difficulty of sensitivity improvement by stator structure optimization. This paper presents a novel approach for axial inductance displacement sensor to improve sensitivity by decreasing the armature depth. In the experiment part, three armature with different depth have been fabricated and their performance are tested. The results show that sensitivity is improved from 2.34 mV/µm to 3.15 mV/µm when the depth of armature decreases from 24 mm to 18 mm, validating the feasibility of sensitivity improvement by decreasing the armature depth. With the improvement of sensitivity, resolution also improves from 5.1 µm to 3.8 µm. Negative effect of this approach is that measuring range is decreased when the armature depth is reduced. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Automobile Technology & Material is the property of Automobile Technology & Material Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Under partial load operating conditions, vortex rope generation in the draft tube of a Francis turbine is considered one of the main reasons for hydro unit vibration. In this paper, a Francis turbine HLA551-LJ-43 in the laboratory was taken as a prototype. Numerical simulations of the entire flow passage were carried out. Four different hydro-turbines were chosen to analyze the effect of vortex suppression, which were named the prototype turbine (N-J), the turbine with J-grooves installed on its conical section (W-J), the one with extending runner cone (C), and the one that considered the J-grooves and the extending runner cone at the same time (J+C). Under the part load conditions in which the vortex rope is easily generated (0.4–0.8 times design flow QBEP), the spectrum characteristics of pressure fluctuation, the morphology of vortex rope, and the energy dissipation based on the entropy production theory in the draft tube were studied. The results show that the three optimized structures W-J, C, and J+C could reduce the pressure pulsation in the conical section of the draft tube, weaken the eccentricity of the vortex rope, and decrease the energy losses in the runner and draft tube. It is worth mentioning that the turbine with a J+C optimized structure had the most potent effect on vortex suppression and energy dissipation. Primarily when operating in deep partial load (DPL) conditions, the efficiency of the turbine with a J+C optimized structure was increased by 13.7% compared to the prototype turbine, and the main frequency amplitude of the pressure pulsation in the draft tube was reduced to 32% of the prototype. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Donghua University (Natural Science Edition) is the property of Journal of Donghua University (Natural Science) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Power Generation Technology is the property of Power Generation Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ObjectivesThe localization of core components of heavy-duty gas turbines holds significant importance for technological innovation, industrial upgrading, and even national security. As a typical hot-end component of heavy-duty gas turbines, the performance of the turbine first-stage rotor blade directly determines the efficiency and reliability of the gas turbine. Therefore, the structure of the first-stage turbine blades of a certain heavy-duty gas turbine was optimized.MethodsBy increasing the number of bamboo nodes in the blade body, the blade cooling hole structure was optimized, and the thermal barrier coating was used to improve the blade coating. The temperature, stress distribution and aerodynamic efficiency of the blades before and after optimization under the service condition of the blade were compared and analyzed by fluid calculation and finite element calculation.ResultsHeat transfer efficiency inside the blade is enhanced by optimization of turbulent structure. Under the condition of the same inlet pressure of the cooling air, the surface temperature of the optimized blade is reduced by more than 50 ℃. Since the shape of the blade is not changed, there is little influence on the aerodynamic efficiency. Compared with the blades without optimization, the maximum equivalent stress and equivalent total strain of the optimized blade during service are significantly reduced.ConclusionsBy optimizing the cooling structure and upgrading the protective coatings, the reliability of the blades in high-temperature can be significantly improved. The research results provide a theoretical basis for the localization of gas turbines.

In order to solve the problems of low loading efficiency and large load fluctuation of traditional thin seam shearer, taking the spiral blade of the drum as the research object, the variation law of the loading performance of the drum under different spiral lift angle was studied through discrete element simulation test. The results show these as follows When the spiral angle of the drum with a diameter of 1 200 mm is gradually increased, the loading efficiency of the drum is gradually increased from 73. 31% to 76. 56%. When the spiral angle reaches 18°, the optimal loading efficiency is obtained. When the spiral angle continues to increase from 18° to 30°, the loading efficiency of the drum is negatively correlated with the spiral angle. Based on the optimal spiral lifting angle, the structure of the spiral blades was optimized, and the simulation results showed that the loading efficiency of the drum was increased by 9. 94% and the load fluctuation was reduced by 22. 59%. [ABSTRACT FROM AUTHOR]

Enhancing the activity of oxygen evolution reaction (OER) is crucial for improving the efficiency of electrochemical water splitting (EWS). The highly adjustable electronic structure and potential high conductivity of transition metal sulfides (TMSs) make them promising candidates for OER electrocatalysts. Herein, we have synthesized trimetallic sulfides Fe 2 Ni 1 Zn 1 –S(II) based on layered double hydroxides (LDHs) precursor employing a facile and efficient two-step solvothermal approach. Benefitting from the multi-metallic synergistic effect and the distinctive interfacial structure, Fe 2 Ni 1 Zn 1 –S(II) shows excellent electrocatalytic OER performance (η 10 = 252 mV, Tafel slope = 64.2 mV∙dec−1). Meanwhile, it has outstanding stability (50 h) in 1 M KOH, which is better than RuO 2 and many other metal sulfide electrocatalysts. Furthermore, it was found that the structure of the catalyst was still retained after OER test, which further verified its catalytic stability. This work supplies an effective route for the preparation of LDHs derived multi-metallic sulfides. [Display omitted] • Modulation of the surface electronic structure of catalysts through multi-metal synergistic effect. • Layered double hydroxides offer a unique layered structure and high electrochemical activity. • Transition metal sulfides provide high electrical conductivity. • This study provides an effective way to further optimize the structure of transition metal sulfides. [ABSTRACT FROM AUTHOR]

This research uses a new method called the Modified Adolescent Identity Search Algorithm (MAISA) to solve optimization problems. The identity of a teenager is a different combination of thoughts, beliefs, and abilities that are obtained by him. He communicates with other people in society and tries to use the positive or negative feedback from these social interactions to shape his identity and become an independent person. Mathematical simulation of how adolescents' personality is formed during the mentioned process causes the emergence of this algorithm. The purpose of this research is to improve the performance of the AISA algorithm in the balance between exploration and exploitation. This algorithm isn't trapped in the optimal local points due to the appropriate convergence rate and reaches the universal optimal answer quickly. One of the features of this algorithm that we can mention is its simplicity and having few setting parameters. To show the effectiveness of this algorithm, results of solving two types of problems of mathematical functions and practical examples such as large-scale truss 120, 244, 942, and 72-bar truss, are measured by other similar algorithms. The results show that this algorithm has a good performance in the optimal solution of such problems, compared to other similar algorithms. [ABSTRACT FROM AUTHOR]

Accurate measurement of the pretightening stress for bolts has great significance for improving the assembly quality and safety, especially in severe environments. In this study, AlN thin film transducers were deposited on GH4169 nickel base alloy bolts using the RF magnetron sputtering, enabling a systematic investigation into the correlation between structures and the intensity of ultrasonic echo signals. Employing the finite element method resulted in consistency with the experimental data, enabling further exploration of the enhancement mechanism. With the increasing thickness of both the piezoelectric layer and the electrode layer, the intensity of the ultrasonic echo signals saw a great enhancement. The maximum-intensity observed increase is 14.7 times greater than that of the thinnest layers. Specifically, the thicker piezoelectric layer improves its mechanical displacement, while the increased thickness of the electrode layer contributes to better densification. An electrode diameter of nearly 4 mm is optimal for an AlN thin film transducer of M8 bolts. For pretightening the stress measurement, the sample with a strong and stable echo signal shows a low measurement error of pretightening below ±2.50%. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The shovel face inclination angle is a crucial parameter of the potato harvester digging shovel. Currently, there is limited research on the relationship between the inclination angles of curved digging shovel surfaces. The purpose of this study was to investigate the impact of the shovel face inclination angle on its soil crushing capacity in hilly terrain. A simulation model for the contact between the digging shovel and the soil was developed. The digging process of the shovel was simulated and analyzed under different shovel face inclination angles (α2). The analysis included comparisons of stress, Plastic Equivalent Strain (PEEQ), and energy. The results show that the larger the angle, the stronger its soil crushing ability; however, if the angle difference is too large, the phenomenon of soil flipping back occurs. When α2 = 16-17 °, the shovel length becomes excessive. When α2 = 18 °, the stress is too small. When α2 = 19 °, the energy is too large, and when α2 = 23-24 °, the PEEQ is too small. Therefore, the optimal shovel face inclination angle α2 is between 20 and 22 °, with fixed angles α1 = 15 ° and α3 = 13 °. [ABSTRACT FROM AUTHOR]

The development of novel nitride-based phosphors is always a significant work, especially for AlON system because of their rigid crystal structure, which is similar to the promising host material of β-SiAlON. In this work, Mg2+ ion was introduced into AlON-related phase Al 5 O 3 N 3 along with co-doped Si4+ ion used to keep charge neutrality, and thus a novel Mg-based nitroaluminosilicate MgAl 3 SiO 3 N 3 (MASON) was successfully synthesized under a mild preparation condition due to the high reactivity of MgO. Benefiting from its special crystal structure optimized by the introduction of Mg2+ ion, Eu2+-activated MASON performs significant photoluminescence (PL) and cathodoluminescence (CL) properties. In contrast to most Eu2+-activated AlON related phosphors that commonly emit high-energy blue light, the as-prepared sample emits a high-bright green light along with good thermal stability. Moreover, its broad emission band with the full width at half maximum (FWHM) of 134 nm well compensates the "cyan cavity", which leads to a full spectrum light-emitting diode. The structure-property relation of Eu2+ in MASON was established in this work, which confirms the significant role of the introduced Mg2+ ion in the structure optimization of AlON system. The result may pave an efficient way to explore more promising AlON-based phosphors. High-brightness green light emission was achieved in Eu2+-activated nitroaluminosilicate MgAl 3 SiO 3 N 3. [Display omitted] [ABSTRACT FROM AUTHOR]

Numerous efforts in the additive manufacturing literature have been made toward in-situ defect prediction for process control and optimization. However, the current work in the literature is limited by the need for multi-sensory data in appropriate resolution and scale to capture defects reliably and the need for systematic experimental and data-driven modeling validation to prove utility. For the first time in literature, we propose a data-driven neural network framework capable of in-situ micro-porosity localization for laser powder bed fusion via exclusively within hatch strip of sensory data, as opposed to a three-dimensional neighborhood of sensory data. We further propose using prior-guided neural networks to utilize the often-abundant nominal data in the form of a prior loss, enabling the machine learning structure to comply more with process physics. The proposed methods are validated via rigorous experimental data sets of high-strength aluminum A205 parts, repeated k-fold cross-validation, and prior-guided validation. Using exclusively within hatch stripe data, we detect and localize porosity with a spherical equivalent diameter (SED) smaller than 50.00 μ m with a classification accuracy of 73.13 ± 1.57 % This is the first work in the literature demonstrating in-situ localization of porosities as small as 38.12 μ m SED and is more than a five-fold improvement on the smallest SED porosity localization via spectral emissions sensory data in the literature. In-situ localizing micro-porosity using exclusively within hatch-stripe data is a significant step towards within-layer defect mitigation, advanced process feedback control, and compliance with the reliability certification requirements of industries such as the aerospace industry. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The high-power laser diode (HPLD) has witnessed increasing application in space, as the aerospace industry is developing rapidly. To cope with the space environment, optimizing the heat-dissipation structure and improving the heat-dissipation ability via heat conduction have become key to researching the thermal reliability of the HPLD in space environments. Based on a theoretical analysis of the HPLD, a simulation model of the HPLD was constructed for numerical simulation, and it was found that the maximum temperature and thermal resistance of lasers were efficaciously decreased by changing the packaging position of laser bars. The packaging position of the bars and the cutting angle of the microchannel heat sink (MCHS) were determined based on the light-emitting angle of the light-emitting unit and the internal structure of the MCHS. The internal structure of the MCHS was optimized through a single-factor experiment, an orthogonal experiment, and the combination of neural networks and genetic algorithms (GAs), using three key structural parameters, namely the MCHS ridge width, W1, the channel width, W2, and the channel length, L1. After optimization, the performance of the MCHS was obviously improved. Finally, an analysis was carried out on the applicability of the optimized MCHS to bars with a higher power. [ABSTRACT FROM AUTHOR]

This study introduces an integrated structural optimization design method based on a BP neural network and NSGA-II multi-objective genetic algorithm. Initially, a two-dimensional axisymmetric finite element model of the Giant Magnetostrictive Actuator (GMA) was established, and the coupling simulation of the electromagnetic field, structural field, and temperature field was conducted to obtain the GMA's performance parameters. Subsequently, the structural parameters of the GMA magnetic circuit, including the magnetic conducting ring, magnetic conducting sidewall, magnetic conducting body, and coil, were used as inputs, and the axial magnetic induction intensity, uniformity of axial magnetic induction intensity, and coil loss on the Giant Magnetostrictive Material (GMM) rod were used as outputs to establish a back propagation (BP) neural network model. This model delineated the nonlinear relationship between structural parameters and performance parameters. Then, the BP-NSGA-II algorithm was applied to perform multi-objective optimization on the actuator's structural parameters, resulting in a set of Pareto optimal non-dominated solutions, from which a set of optimal solutions was obtained using the entropy weight method. Finally, simulation analysis of this optimal solution was conducted, indicating that under a 5 A power supply excitation, the maximum axial magnetic induction intensity on the optimized GMM rod increased from 0.87 T to 1.12 T; the uniformity of axial magnetic induction intensity improved from 93.1% to 96.5%; and the coil loss decreased from 7.79 × 104 W/m3 to 4.97 × 104 W/m3. Based on the optimization results, a prototype actuator was produced, and the test results of the prototype's output characteristics proved the feasibility of this optimization design method. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The cutterhead is one of the core components of the shield machine, and reasonable cutterhead structural design is the foundation for safe and efficient excavation. In order to quickly and efficiently establish the finite element model of the cutterhead and then analyze its mechanical properties, a parameterized modeling method based on the ANSYS parametric design language (APDL) command flow was adopted to establish a digital model of a certain type of composite shield machine cutterhead. By applying the ultimate thrust and torque to the cutterhead, the stress and deformation distributions were obtained through a finite element analysis, and the positions where experience maximum stress and displacement were identified. In doing so, the strength and stiffness conditions were validated as well. In addition, a parameterized modeling based optimization method for cutterheads was established by incorporating with the overall mass of the cutterhead as the optimization objective and the strength and stiffness of as constraints, and the corresponding optimization process was proposed. The optimization parameters of the cutterhead were determined through parameter sensitivity analysis, and the influence of relevant parameters on the strength and stiffness of the cutterhead was explored. The key parameters of the composite shield machine cutterhead studied were optimized. After optimization, the maximum stress of the cutterhead, the maximum deformation and the total weight were reduced by 12%, 20%, and 119 kg, respectively. As a result, the proposed optimization method based on parameterized modeling can improve the strength and stiffness of the cutterhead while reducing the quality of the cutterhead. The research results can shed light on the optimization of multi-objective cutterhead structure. [ABSTRACT FROM AUTHOR]

An optimization design was carried out based on a back propagation (BP) neural network and a genetic algorithm (GA) to improve the stiffness and accuracy of the self-developed MGK6030 five-axis tool grinding machine. First, finite element analysis was carried out on the whole grinding machine based on ANSYS Workbench, and the key parts were found to be the grinding wheel headstock, B axle box body, and column. Sensitivity analysis was carried out after the model parameterization, and ten parameters, which affect the quality, maximum deformation, and first-order mode, were obtained. These parameters were used as input variables. A total of 235 sets of sample data were obtained by using the optimal overall performance of the grinder for the target (large first-order natural frequency, small deformation, and mass). The BP neural network was then used to fit the nonlinear coupling relationship between the input and the output. Thereafter, the optimization function of the GA was used to perform multi-objective optimization in the specified range. Finally, the parameters are verified by software simulation and prototype test. Results showed that the maximum deformation of the optimized machine tool is reduced by 21%, and the first four order natural frequencies are increased by 6.36%, 9%, 6.4%, and 2.84%. The positioning accuracies of the linear axis and rotary axis are increased by 22% and 21%, respectively, which demonstrates the effectiveness of the optimization scheme and provides theoretical and technical support for similar optimization problems. [ABSTRACT FROM AUTHOR]

Additive manufacturing has emerged as a promising technique in energy device research, owing to its ability to fabricate programmable geometries. Nevertheless, it remains a significant challenge to prepare three-dimensional electrode structures with finely resolved features. Herein, we propose a vat photopolymerization (VP) 3D printing process for Nickel Oxide-Yttria Stabilized Zirconia (NiO-YSZ) anode structure of solid oxide fuel cell (SOFC). A photosensitive NiO-YSZ slurry was prepared with appropriate curing properties, low viscosity, and stability. Optimal debinding processes, determined through thermo-gravimetric analysis, were employed to prevent green part cracking and deformation. Microstructural analysis demonstrated a uniform and finely distributed pore structure in the anode. Remarkably, cells featuring the VP-printed NiO-YSZ anode demonstrated notable performance with peak power densities of 239 mW·cm−2, 364 mW·cm−2, and 536 mW·cm−2 at 750 °C, 800 °C, and 850 °C, respectively. This novel method opens avenues for enhancing the performance of SOFCs through the optimization of anode structure. [ABSTRACT FROM AUTHOR]

The cylinder mass affects the ball mill's operation and economy. To reduce the mass of the current cylinder, this paper utilized a response surface optimization module and a multi-objective genetic algorithm to optimize the cylinder structure. First, the optimal parts of the cylinder were determined by static analysis. Subsequently, the mathematical model was established with the goal of achieving structural lightweight. Then, the size of the cylinder was optimized based on the response surface optimization module and multi-objective genetic algorithm. Finally, the static analysis and modal analysis results before and after optimization were compared to verify the stress and resonance of the structure, and the optimization effect was evaluated. The optimized cylinder had a mass reduction of 15.624 % without compromising the strength and deformation. The optimization design can save materials and costs, and provide a theoretical reference for the lightweight research of the ball mill's cylinder. [ABSTRACT FROM AUTHOR]

Compartment dryers for fruits and vegetables involve problems including dead zones and nonuniform drying. To address these problems, experimental and numerical analyses are carried out in this study using an airflow control equation and the k-omega SST model to optimize the structural parameters of the drying section in the compartment dryer. The dryer was numerically simulated using Fluent software, and the dryer structural parameters (i.e., numbers of hot-air inlets and outlets, aperture size, and tilt angle) were optimized using response surface analysis. Subsequently, the airflow distribution within the dryer was determined by using Fluent software; the temperature nonuniformity coefficient (Mt), the velocity nonuniformity coefficient (Mv), the temperature deviation ratio (Et), and the velocity deviation ratio (Ev) served as evaluation metrics for airflow uniformity in the dryer. The results revealed that Mt, Mv, Et, and Ev decreased by 25.47%, 30.49%, 28.41%, and 14.74%, respectively, enhancing the airflow uniformity in the dryer. [ABSTRACT FROM AUTHOR]

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Engineers pay more and more attention to the economic benefits of foundation pit engineering. At present, the optimal design of the foundation pit supporting structure mainly focuses on strength and functional design, and there is no mature theoretical design method for deformation control. In this paper, a method for calculating the overall deformation of a foundation pit supporting structure based on the principle of minimum potential energy is proposed. Based on this method, the optimal design of the foundation pit of Guangzhou Baiyun District Comprehensive Transportation Hub Metro Station is realized. The deformation calculation results and optimization design scheme are validated by finite element numerical simulation and field monitoring data. The results show that the proposed theoretical algorithm predicts the pile deformation curves better than the finite element method, suggesting the proposed theoretical method is reasonable and the optimization scheme of the retaining pile is feasible. In the optimized design, the deformation of the foundation pit retaining pile is controlled by its push-back effect. The proposed deformation calculation method can realize the overall deformation calculation of the foundation pit supporting structure. [ABSTRACT FROM AUTHOR]

This paper designs a kind of air suspension mechanical-vibration-reduction wheel for mining engineering vehicles; the research work on topology analysis and the structural optimization of the inner and outer rims are carried out with this wheel as the research object. Using Workbench finite-element analysis software, taking the results of static analysis and modal analysis of the two as constraints, a variety of structural improvement styles are obtained through a topology analysis method and compared and verified, and a more reasonable improvement result is selected and assembled into a whole wheel for final analysis and verification. The results show that the optimization results of the wheel still meet the design's load-bearing requirements, and the weight is lighter; the topology analysis results are ideal. [ABSTRACT FROM AUTHOR]

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To address the problem of undesirable prediction accuracy of a deep echo state network caused by redundant structures in the reservoirs, a pruning algorithm for the deep echo state network based on detrended multiple cross-correlation was proposed. Firstly, according to the detrended covariance function and the detrended variance function, the detrended cross-correlation coefficient between each two neurons in the selected reservoirs in turn was calculated, and the detrended cross-correlation matrix was constructed. Based on this matrix, the detrended multiple cross-correlation between a selected neuron and all remaining neurons in this reservoir could be evaluated. Subsequently, the connections from the highly correlated neurons in each reservoir to the output layer were pruned sequentially, thus removing redundant components in the network. Finally, the network after pruning was retrained by least squares regression to obtain the optimal deep echo state network topology. Simulation results showed that the prediction accuracy and memory capacity of the deep echo state network optimized by the proposed algorithm on Mackey-Glass time series were improved by 89. 80% and 30. 93%, respectively, and on Call time series by 14.34% and 0.10%, respectively. [ABSTRACT FROM AUTHOR]

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This paper develops a conformal architected materials design method based on implicit modeling, which enables functional gradient modulation. This method utilizes the mapping relationship between conformal hexahedral element and the cubic bounding box of architected material to construct the signed distance field. To enhance strength and stiffness of the structure, this study integrates the relative density distribution obtained from topology optimization to regulate the density of conformal architected materials through density mapping. Compared to traditional methods, the proposed method not only reduces the damage of the boundary structure caused by cutting, achieving a mutual match between the architected materials and curved geometry, but also retains the ability to control the distribution of relative density. The numerical analysis and experimental results demonstrate that conformal gradient architected materials exhibit better structural strength and stiffness compared to array-generated gradient architected materials, which indicates that the proposed method has potential applications in lightweight design.

Bistable curved shells have become a promising low-cost application in energy absorption fields owing to recent advances in material and technology. Significant research has been conducted to improve their energy absorption effect through forward prediction and single-objective optimization. However, these approaches may not fully explore their functional potential. In this study, we propose a multi-objective optimization framework based on the principle of main objective optimization that combines neural networks and genetic algorithms. The energy absorption effect and backward snapping force of the bistable curved shell are improved synchronously. Meanwhile, a reverse design algorithm is developed to generate the preset load-displacement curve, which further expands the application of machine learning methods in the field of multi-objective optimization. The combination of machine learning and multi-objective optimization is highly effective for building meta-structures with specific performance requirements and has potential applications in solving complex optimization tasks in various fields.

The possibilities of combining known techniques for optimizing the securities portfolio (SP) structure were studied. A method was introduced that enables the simultaneous use of both passive and active approaches to managing the SP structure. The combined application of these methods is based on techniques for SP diversification and searching for an SP structure that mirrors the SP structure of an index fund. The objective function was modified in order to optimize the SP structure according to the traditional “return–risk” approach. The proposed objective function, along with the security risk, describes the degree to which the desired distribution of SP shares coincides with the distribution generated using an index fund. It was established that the main properties of optimal SPs obtained with the “return–risk” approach also occur in the case under consideration.