The development of deep learning has inspired some new methods to solve the 3D reconstruction problem for Tomographic Particle Image Velocimetry (Tomo-PIV). However, the supervised learning method requires a large num...
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The development of deep learning has inspired some new methods to solve the 3D reconstruction problem for Tomographic Particle Image Velocimetry (Tomo-PIV). However, the supervised learning method requires a large number of data with ground truth as training information, which is very difficult to gather from experiments. Although synthetic datasets can be used as alternatives, they are still not exactly the same with the real-world experimental data. In this paper, an Unsupervised Reconstruction Technique based on U-net (UnRTU) is proposed to reconstruct volume particle distribution explicitly. Instead of using ground truth data, a projection function is used as an unsupervised loss function for network training to reconstruct particle distribution. The UnRTU was compared with some traditional algebraic reconstruction algorithms and supervised learning method using synthetic data under different particle density and noise level. The results indicate that UnRTU outperforms these traditional approaches in both reconstruction quality and noise robustness, and is comparable to the supervised learning methods AI-PR. For experimental tests, particles dispersed in cured epoxy resin are moved by an electric rail with a certain speed to obtain the ground truth data of particle velocity. Compared with other algorithms, the reconstructed particle distribution by UnRTU has the best reconstruction fidelity. And the accuracy of the 3D velocity field estimated by UnRTU is 12.9% higher than that from the traditional MLOS-MART algorithm. It demonstrates significant potential and advantages for UnRTU in 3D reconstruction of particle distribution. Finally, UnRTU was successfully applied to the high-speed planar cascade airflow field, demonstrating its applicability for measuring complex fluid flow fields at higher particle density.
Crystallographic defects in noble metal nanocrystals are recognized as highly active catalytic sites,significantly enhancing activities in many important *** their importance,synthesizing noble metal nanocrystals with...
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Crystallographic defects in noble metal nanocrystals are recognized as highly active catalytic sites,significantly enhancing activities in many important *** their importance,synthesizing noble metal nanocrystals with a high density of defects poses a considerable synthetic ***,we present a novel lattice mismatch-induced formation mechanism to create high-density defects in noble metal *** approach takes advantage of lattice mismatch to enable nonepitaxial nucleation and growth of a noble metal on a foreign metal substrate,forming abundant noble metal crystallites with random lattice orientations not dictated by the substrate *** these crystallites grow extensively,they merge,forming numerous grain boundaries and yielding defect-rich noble metal ***-rich alloy nanocrystals can also be synthesized through a subsequent vacancy-diffusion alloying *** take defective PdCu alloy nanocages as an example and demonstrate the effectiveness of crystallographic defects in enhancing catalytic performance of noble metal *** nanocages exhibit superior activity in the electrocatalytic formic acid oxidation reaction,which is 1.6 times greater than their defect-free *** strategy offers a new avenue for creating defect-rich noble metal nanocrystals as highly efficient catalysts for a wide array of catalytic applications.
Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater ***,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coupled with th...
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Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater ***,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coupled with the dispersion of magnetic Fe_(3)O_(4)/FeS(Fe/S)nanoparticles,was synthesized by simple impregnation precursor,followed by *** prepared Fe/S-biochar catalyst demonstrated outstanding phenol degradation efficiency across a wide pH range,with 98%of which eliminated even under neutral conditions(pH 7.0).The high catalytic activity was due to the multilevel porous structure of pollenderived biochar provided enough active sites and allowed for better electron transfer,then increases oxidation ability to promote the ***,the acid microenvironment formed by SO_(4)^(2-)group from Fe/S composite extended the pH range for Fenton reaction,and S^(2-)facilitated the conversion of≡Fe^(3+)to≡Fe^(2+),resulting in remarkable degradation ***,biochar can effectively promote cycling stability by limiting Fe *** work may provide a general strategy for designing 3D framework biochar-based Fe/S catalysts with excellent performance for heterogeneous Fenton reactions.
Carbon dioxide(CO_(2))is one of the main factors contributing to the greenhouse *** dependence on fossil fuels has led to increasing levels of carbon dioxide in the atmosphere every *** it is far from enough to solve ...
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Carbon dioxide(CO_(2))is one of the main factors contributing to the greenhouse *** dependence on fossil fuels has led to increasing levels of carbon dioxide in the atmosphere every *** it is far from enough to solve the climate problem by reducing the consumption of fossil fuels to cut down carbon dioxide *** recent years,a series of researches on Carbon Capture,Utilization and Storage(CCUS)have been carried out in various countries around the ***_(2) is a nontoxic,tasteless and stable gas at normal ***,when it reaches supercritical state after rising temperature and pressure,it has the characteristics of low viscosity,high diffusivity and high density,and is widely used in green,pollution-free and efficient development *** of these unique properties,supercritical carbon dioxide(sCO_(2))has attracted more and more attention from ***_(2) has been widely used in many aspects by virtue of its high solubility and easy *** from previous reviews which only introduced the application of sCO_(2) property,this paper introduces the current research status of the application of the thermodynamic property of carbon dioxide in extraction,dyeing,pharmaceutical,power generation,heat transfer and exploitation of unconventional oil and gas,and mainly analyzes each application in detail from the aspects of working mechanism and improving working ***,the research direction and problems needed to be solved for the application of CO_(2) thermal physics are proposed,which pave the way for other new applications.
Air Brayton cycle obtains the significant advantages of high efficiency, compact structure, easy medium requirement and so on, which is one of the most suitable choices for the mobile nuclear power conversion system. ...
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In the combined system of lead cooled fast reactor (LFR) and supercritical carbon dioxide (S-CO2) Brayton cycle, the intermediate heat exchanger plays a key role in the whole power system. However, the existing heat e...
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作者:
Bin WANGBei ANXiaoqian LIShaohua SHENSchool of Physics
Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter(Ministry of Education)Key Laboratory of Shaanxi for Advanced Materials and Mesoscopic PhysicsXi’an Jiaotong UniversityXi’an 710049China International Research Center for Renewable Energy
State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049China
It has been widely reported that,for faceted nanocrystals,the two adjacent facets with different band levels contribute to promoted charge separation,and provide active sites for photocatalytic reduction and oxidation...
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It has been widely reported that,for faceted nanocrystals,the two adjacent facets with different band levels contribute to promoted charge separation,and provide active sites for photocatalytic reduction and oxidation reaction,*** such cases,only one family of facets can be used for photocatalytic hydrogen ***,by using SrTiO_(3)nanocrystals enclosed by{023}and{001}facets as a model photocatalyst,this paper proposed a strategy to achieve the full-facets-utilization of the nanocrystals for photocatalytic hydrogen via chemically depositing Pt nanoparticles on all *** photo-deposition experiment of CdS provided direct evidence to demonstrate that the{023}facets which were responsible for photooxidation reaction can be function-reversed for photocatalytic hydrogen evolution after depositing Pt nanoparticles,together with the{001}***,the full-facets-utilization led to a much-improved activity for photocatalytic hydrogen,in contrast to those SrTiO_(3)nanocrystals with only{001}facets deposited by Pt nanoparticles via a photo-deposition method.
In the concept of Fluoride-Salt-cooled high-Temperature Advanced Reactor (FuSTAR), the Printed Circuit Heat Exchanger (PCHE) is mainly considered in its supercritical carbon dioxide (S–CO2) Brayton cycle secondary lo...
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The main pump blades of lead cooled fast reactor have complex mechanical characteristics, and there are complex fluid-structure coupling problems in the structural analysis of the impeller. In this paper, CFX software...
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