Hydrogen-enriched natural gas offers a promising alternative for reducing greenhouse gas emissions. This study investigates pollutant emissions during hydrogen-methane co-combustion in a double-layer porous burner, fo...
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Accurately tailoring microstructures, especially grain size, during thermomechanical processing is crucial for achieving the desired strength-ductility synergy of wrought magnesium alloys. This study establishes a mul...
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Accurately tailoring microstructures, especially grain size, during thermomechanical processing is crucial for achieving the desired strength-ductility synergy of wrought magnesium alloys. This study establishes a multilevel cellular automaton (CA) model to predict the microstructure evolution of wrought magnesium alloys undergoing both dynamic recrystallization (DRX) and dynamic precipitation (DP), surpassing the capabilities of traditional DRX models. Multiple physical metallurgical mechanisms, including variations in dislocation with work hardening (WH) and dynamic recovery (DRV), DRX, DP, and solute diffusion, are integrated and interconnected by their mutual effects. To facilitate the CA modeling, a novel local pinning model is proposed to reflect the uneven retardation of a precipitate to grain boundary migration and the virtual intersections of precipitates and grain boundaries based on their distribution, and its rationality is verified by simulations for grain coarsening. Considering the substantial difference in grain size and precipitate size, a multilevel cellular space is constructed, with a coarse parent cellular space for DRX and a sub-cellular space discretized from parent cells for DP, to balance computational efficiency and accuracy. The simulation successfully captures the microstructure evolution with multiscale characteristics, specifically the refinement of grains from hundreds of micros to a few micros through DRX, aided by dynamically precipitated second-phase particles in the submicron (hundreds of nanometers) range. The high degree of agreement between simulated and experimental results in terms of kinetics for microstructure evolution and microstructure after deformation at various temperatures and strain rates attests to the sound rationality and strong predictive capability of the established multilevel CA model. A comparison between the simulated results of the traditional CA model exclusively for DRX and those obtained from the multile
Kelvin-Helmholtz (K-H) instability theory is extensively used to predict the transition from stratified flow to slug flow. This study developed a one-dimensional (1-D) model based on K-H theory and considering the var...
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Objective The Monte Carlo (MC) method has become a cornerstone for simulation of light propagation in biological tissues, particularly for applications in laser therapy and medical imaging. However, traditional voxel-...
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Objective The Monte Carlo (MC) method has become a cornerstone for simulation of light propagation in biological tissues, particularly for applications in laser therapy and medical imaging. However, traditional voxel-based Monte Carlo (VMC) methods often exhibit significant errors when dealing with complex curved surfaces due to the inherent limitations of structured grid discretization. By contrast, tetrahedron-based Monte Carlo (TMC) methods, based on unstructured meshes, offer better adaptability to complex geometries but incur higher computational cost. This study aims to address the trade-off between computational efficiency and accuracy in light propagation simulations by proposing a novel correction method to improve the performance of VMC in handling curved interfaces with large refractive index differences. The objective is to enhance the accuracy of VMC while maintaining its computational efficiency, making it more viable for practical biomedical applications, such as laser treatment and optical diagnosis. Methods This study compares the performance of VMC and TMC in light propagation simulations under different refractive index conditions. We propose a coordinate transformation-based correction method to reduce the errors in VMC caused by the inaccurate handling of reflection and refraction at curved interfaces. The simulations were carried out on a multi-layer skin tissue model with varying refractive index conditions;the laser light was directed at blood vessels embedded within the dermis. The correction method involves transforming the photon direction vector in a way that accounts for the curvature of the interface, thereby improving the accuracy of light photon interactions at the tissue boundaries. Simulations were conducted using MATLAB, and the results were validated through experimental cases, such as diabetic retinopathy laser treatment. The computational setup included an Intel i7-9700K processor and an NVIDIA GTX 3080 graphics card (GPU). Resu
Wireless charging technology for electric vehicles (EVs) encounters critical technical challenges, particularly in terms of misalignment tolerance and interoperability. To address these issues, this paper proposes a w...
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The deposition behavior of aerosols due to diffusiophoresis directly influences the migration and deposition of radioactive materials following an accident. This is critical in analyzing source term migration and the ...
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In this work, the interactions between the two components of CO2/N-2 mixtures adsorbed by metal-organic framework-5 (MOF-5) are investigated using the molecular dynamics (MD) method. It is found that CO2 absorption am...
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In this work, the interactions between the two components of CO2/N-2 mixtures adsorbed by metal-organic framework-5 (MOF-5) are investigated using the molecular dynamics (MD) method. It is found that CO2 absorption amount in the partial pressure of 0.01 similar to 0.10 MPa decreases linearly with the increase of N-2 partial pressure, while that of N-2 is basically unaffected by CO2 until the CO2 partial pressure reaches the critical point of 0.95 MPa, and N-2 adsorbed amount decreases after the CO2 partial pressure is larger than the critical point. The diffusion constants for both CO2 and N-2 decrease with increasing partial pressure of the other component. The adsorption energies of CO2 and N-2 on the MOF in case of single-component and mixed adsorption are calculated using the density functional theory (DFT) method, and the gas-MOF interactions are visualized. The effect of N-2 on the adsorption energy of CO2 is found to be greater than that of CO2 on N-2. The interactions between components in the non-equilibrium processes such as gas breakthrough are also studied. N-2 breaks through before CO2 in general because of the larger diffusion constant. When the partial pressure of CO2 is much higher than that of N-2, CO2 breaks through before N-2, and the percent composition of N-2 in the breakthrough gases increases first and then decreases. We have studied the adsorption of gas mixtures on MOF from a new perspective of inter-component interactions and found that CO2 and N-2 interact with each other in interesting patterns.
Comprehensive Mission Spectrum(CMS)of an aero-engine can reflect the usage characteristics of the *** can provide load input for engine life prediction and accelerated mission *** this paper,a novel compilation method...
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Comprehensive Mission Spectrum(CMS)of an aero-engine can reflect the usage characteristics of the *** can provide load input for engine life prediction and accelerated mission *** this paper,a novel compilation method of CMS of aero-engine maneuvering load based on mission segment is ***,the use-related Typical Mission Segment(TMS)of maneuvering load is divided and identified according to spectral ***,the mathematical model of different kinds of TMS are established based on stochastic process ***,the CMS of maneuvering load is compiled based on *** proposed method can accurately quantify the compilation of *** compiled CMS shows good agreement with the original load *** to damage consistency inspection,the compiled CMS is consistent with the damage caused by the original load spectrum in terms of low cycle fatigue.
Gel polymer electrolytes(GPEs)effectively combine the advantages of high ionic conductivity and re-duce the risk of leakage associated with *** this study,a chemically cross-linked gel polymer electrolyte was prepared...
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Gel polymer electrolytes(GPEs)effectively combine the advantages of high ionic conductivity and re-duce the risk of leakage associated with *** this study,a chemically cross-linked gel polymer electrolyte was prepared by in-situ polymerization using polymethyl methacrylate(PMMA)as a matrix and neopentyl glycol diacrylate(NPGDA)as cross-linking *** cross-linked structure of the GPE was preliminarily investigated,as well as the influence of the degree of cross-linking on its phys-ical *** GPE exhibited a superior conductivity of 1.391 mS cm^(-1) at 25℃.Herein,the Li|GPE|LiNi_(0.8) Co_(0.1) Mn_(0.1) O_(2) cell has an excellent capacity retention rate of 80.7%after 150 cycles at 0.5 C in addition to a high discharge specific capacity of 203 mAh g^(-1).The structure of the cathode ma-terial is shielded from the production of byproducts during the charging and discharging of lithium-ion batteries by the cross-linked PMMA GPE.
In the evaporation and crystallization process for treating high salt wastewater, spraying part of the concentrate or crystallized miscellaneous salts into the coal-fired boiler hearth for combustion not only helps to...
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In the evaporation and crystallization process for treating high salt wastewater, spraying part of the concentrate or crystallized miscellaneous salts into the coal-fired boiler hearth for combustion not only helps to reduce the cost of treating the concentrate and crystallized miscellaneous salts, but also effectively decomposes the toxic and hazardous substances contained therein with the help of high temperatures in the hearth. However, the sodium in the salt may affect the coal ash fusibility, causing the boiler's fouling and slagging problems. Ash samples were prepared regarding the sodium salt ratio of a large coal mine in the Longdong area, China. The effects of multiple sodium salts co-loading on the ash fusibility and mineral evolution behavior of the ash samples were investigated, and the mechanism of the effects of multiple sodium salts co-loading on the fusibility of the ash was revealed, confirming the feasibility of adopting this new incineration process in this region. The results showed that SiO2 can react with other minerals such as K2O, Al2O3, and Na2O, to form the low-temperature fusion substances, nepheline (KNa3(AlSiO4)4), sodium nepheline (NaAlSiO4), and potassium feldspar (KAlSi3O8). The characteristic temperatures of both Coal 1 and Coal 2 ash samples decrease significantly when the sodium salt loading content increases from 0 % to 5 %, and the DT showed the most significant decrease. The DTs of Coal 1 and Coal 2 ash samples at 5 % sodium salt loading were 1205 degrees C and 1222 degrees C, which was 65 degrees C and 64 degrees C lower than that of the no-sodium loaded condition, respectively. In addition, the initial temperature of more than 50 % liquid slag material formation Coal 1 ash samples decreased from 1322 degrees C to 1079 degrees C as the sodium salt loading increased from 0 % to 5 %, since sodium salt loading can promote the generation of low fusion point substances (NaAlSiO4 and CaMgSi2O6) and adhesive substances. According to t
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