Light scattering method is the most commonly used method for on-line measurement of ultralow particulate matter mass concentration. However, when the particle characteristics change, the effectiveness of the empirical...
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Lead or lead-alloy cooled fast reactors (LFRs) have been proved to be the most promising Generation IV reactors with high performance in neutronics, thermal hydraulics and security features. Small forced circulation m...
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Sodium ion batteries have a huge potential for large-scale energy storage for the low cost and abundance of sodium resources. In this work, a novel structure of ultrafine polycrystalline TiO2 nanofibers is prepared on...
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Sodium ion batteries have a huge potential for large-scale energy storage for the low cost and abundance of sodium resources. In this work, a novel structure of ultrafine polycrystalline TiO2 nanofibers is prepared on nickel foam/carbon cloth by a simple vapor deposition method. The as-prepared TiO2 nanofibers show excellent performance when used as anodes for sodium-ion batteries. Specifically, the TiO2 nanofibers@nickel foam electrode delivers a high reversible capacity of 263.2 m Ahg^-1 at 0.2 C and maintains a considerable capacity of 144.2 m Ahg^-1 at 10 C. The TiO2 nanofibers@carbon cloth electrode also shows excellent high-rate capability, sustaining a capacity of 148 m Ahg^-1 after 20 0 0 cycles at 10 C. It is believed that the novel nanofibrous structure increases the contact area with the electrolyte and greatly shortens the sodium ion diffusion distance, and meanwhile, the polycrystalline nature of nanofibers exposes more intercalation sites for sodium storage. Furthermore, the density functional theory calculations exhibit strong ionic interactions between the exposed TiO2(101) facets and sodium ions, leading to a preferable sodiation/desodiation process. The unique structural features endow the TiO2 nanofibers electrodes great advantages in rapid sodium storage with an outstanding high-rate capability.
To enhance knowledge about efficiency improvement and reactor optimization in supercritical water gasification,an experimental system was designed to study the pressure and temperature distribution of subcritical and ...
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To enhance knowledge about efficiency improvement and reactor optimization in supercritical water gasification,an experimental system was designed to study the pressure and temperature distribution of subcritical and supercritical water in a channel,representing a simplified continuous *** pressure drop and temperature distribution along and perpendicular to the forced flow are studied by the measure points inserted inside the test *** results show that the pressure drop in the test section is linearly negatively correlated with the average enthalpy of the inlet and outlet,eventually reaching negative values(-0.177 MPa)at high average enthalpy(2300 kJ kg^(-1)).Temperature and specific enthalpy along the flow direction match theoretical estimates,except near the pseudocritical *** subcritical cases,horizontal temperature differences are positively correlated with enthalpy differences and mass flow rates but remain nearly constant in supercritical ***,with fluid temperature rising from the pseudocritical point,the horizontal temperature difference first increases,then decreases,and reaching a peak of 4.29 K at a fluid temperature of 664 *** of the obtained data reveals that the negative correlation and values of the pressure drop are caused by fluid volume ***,fluid volume expansion,near-wall natural convection,and turbulent forced flow fluctuations contribute to horizontal temperature non-uniformity.
The high temperature gas-cooled reactor (HTR) is an advanced reactor with the characteristics of Generation IV nuclear energy system which has attracted wide attention due to the excellent performances of inherent saf...
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In recent years,small-size,low-weight aerospace propulsion systems have developed rapidly for space exploration,on-orbit scientific instruments and extra space missions,while additional electron emission devices are c...
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In recent years,small-size,low-weight aerospace propulsion systems have developed rapidly for space exploration,on-orbit scientific instruments and extra space missions,while additional electron emission devices are commonly required in those propulsion *** nanotube(CNT)based field emission cathodes exhibit extraordinary field emission properties and are regarded to be an ideal alternative of conventional thermionic or hollow *** this study,the authors give an overview of present status of researches on CNT-based electron emission cathodes for utilising as neutralisers or electron sources particularly in space electric propulsion systems,the theory and characteristics of CNT are also ***,challenges,problems and possible solutions before actual applications of CNT in a space mission are discussed accordingly.
The characteristics of R134a boiling heat transfer in a vertically helically coiled tube are studied. The experimental parameters are as follows: the heat flux is 10∼60 kW•m-2, the mass flux is 195∼400 kg•m-2 •s-1, ...
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The hydraulic performance of lead-bismuth eutectic (LBE) pump is of great importance for the safety aspects concerning lead-alloy cooled fast reactors (LFRs). To investigate the effect of different rotation speed on t...
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Nanocapillaries are essential for a wide range of applications, from enhanced oil recovery to the study of fluid dynamics at the nanoscale. This study examines the dynamics of miscible flow in planar nanochannels unde...
Nanocapillaries are essential for a wide range of applications, from enhanced oil recovery to the study of fluid dynamics at the nanoscale. This study examines the dynamics of miscible flow in planar nanochannels under pressure-driven Poiseuille flow conditions. We conducted extensive molecular dynamics (MD) simulations to investigate the microscopic mechanisms governing solute displacement and dispersion within nanoscale confinement. As a representative case, we focused on CO2 dispersion in oil (n-decane) across various channel materials, estimating average velocity, slip lengths, and diffusion coefficients. Our findings reveal significant differences in slip lengths between various channel materials, with graphene exhibiting a slip length over an order of magnitude higher than others. We estimated the slip length of oil on graphene to be 4.5 nm, an order of magnitude smaller than that of water on graphene, whereas for MoS2 and silica, it was smaller than 1 nm. From MD simulations, we found that the diffusion coefficient increases nonlinearly with channel height and applied pressure, ranging from [4–20]×10−9m2/s for the studied conditions. Taylor analysis was used to qualitatively interpret these findings. This study enhances the understanding of the slippage dynamics and diffusion processes in nanoconfined space, particularly focusing on CO-oil systems. These findings provide insights that may be applicable to other solute-solvent systems, offering a new approach for extending theories to different two-phase flow and multiphaseflow systems.
Lithium extraction is a great challenge from the high magnesium content salt solution. In this work, an integrated polyamide tight ultrafiltration (UF) and nanofiltration (NF) membranes are systematically investigated...
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