The distributed multi-energy systems place emphasis on the complementary and local application of heterogeneous energy sources, and power to methanol process can be coupled, reducing carbon emissions while increasing ...
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Machine learning combined with density functional theory(DFT)enables rapid exploration of catalyst descriptors space such as adsorption energy,facilitating rapid and effective catalyst ***,there is still a lack of mod...
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Machine learning combined with density functional theory(DFT)enables rapid exploration of catalyst descriptors space such as adsorption energy,facilitating rapid and effective catalyst ***,there is still a lack of models for predicting adsorption energies on oxides,due to the complexity of elemental species and the ambiguous coordination *** work proposes an active learning workflow(LeNN)founded on local electronic transfer features(e)and the principle of coordinate rotation *** accurately characterizing the electron transfer to adsorption site atoms and their surrounding geometric structures,LeNN mitigates abrupt feature changes due to different element types and clarifies coordination *** a result,it enables the prediction of^(*)H adsorption energy on binary oxide surfaces with a mean absolute error(MAE)below 0.18 ***,we incorporate local coverage(θ_(l))and leverage neutral network ensemble to establish an active learning workflow,attaining a prediction MAE below 0.2 eV for 5419 multi-^(*)H adsorption *** findings validate the universality and capability of the proposed features in predicting^(*)H adsorption energy on binary oxide surfaces.
Producing chemical fuels from sunlight enables a sustainable way for energy *** various solar fuel generation approaches,photocatalytic CO_(2) reduction has the advantages of simple structure,mild reaction condition,d...
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Producing chemical fuels from sunlight enables a sustainable way for energy *** various solar fuel generation approaches,photocatalytic CO_(2) reduction has the advantages of simple structure,mild reaction condition,directly reducing carbon emissions,***,most of the current photocatalytic systems can only absorb the UV-visible spectrum of solar ***,finding a way to utilize infrared light in the photocatalytic system has attracted more and more ***,a Z-scheme In_(2)S_(3)-TiO_(2) was constructed for CO_(2) reduction under concentrated natural *** infrared light was used to create a high-temperature environment for photocatalytic *** evolution rates of H2,CO,and C2H5OH reached 262.2,73.9,and 27.56μmol・h^(-1)・g^(-1),respectively,with an overall solar to fuels efficiency of 0.002%.This work provides a composite photocatalyst towards the utilization of full solar light spectrum,and could promote the research on photocatalytic CO_(2) reduction.
Synthesizing ring structure aviation fuels from biomass-derived platform molecules is challenging,especially for bridged ring structure aviation fuels which are typically achieved from fossil-derived ***,we report the...
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Synthesizing ring structure aviation fuels from biomass-derived platform molecules is challenging,especially for bridged ring structure aviation fuels which are typically achieved from fossil-derived ***,we report the synthesis of a series of ring structure biofuels in two steps by a combination of a solvent-free Michael-cyclization reaction and a hydrodeoxygenation(HDO)reaction from lignocellulosederived 5,5-dimethyl-1,*** biofuels are obtained with high overall yields up to 90%,which exhibit high densities of 0.81 g cm^(-3)-0.88 g cm^(-3)and high volumetric neat heat of combustion(VNHOC)values of 36.0 MJ L^(-1)-38.6 MJ L^(-1).More importantly,bridged-ring structure hydrocarbons can also be achieved in two steps by a combination of a Robinson annulation reaction and an HDO reaction to afford the final products at high overall yields up to 90%.The bridged-ring structure products have comparable high densities and high VNHOC values to the best artificial fuel JP-10(0.94 g cm^(-3)and 39.6 MJ L^(-1)).The results demonstrate a promising way for the synthesis of high-density aviation fuels with different fuel properties at high yields.
When the boiler load varies, the operational parameters in the water wall will change, this process is called as dynamic process. Dynamic process presents unique flow and heat transfer phenomena within the water wall....
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The catalyst layer(CL)is the core component in determining the electrical-thermal-water performance and cost of proton exchange membrane fuel cell(PEMFC).Systemic analysis and rapid prediction tools are required to im...
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The catalyst layer(CL)is the core component in determining the electrical-thermal-water performance and cost of proton exchange membrane fuel cell(PEMFC).Systemic analysis and rapid prediction tools are required to improve the design efficiency of *** this study,a 3D multi-phase model integrated with the multi-level agglomerate model for CL is developed to describe the heat and mass transfer processes inside ***,a research framework combining the response surface method(RSM)and artificial neural network(ANN)model is proposed to conduct a quantitative analysis,and further a rapid and accurate *** the help of this research framework,the effects of CL composition on the electrical-thermal-water performance of PEMFC are *** results show that the mass of platinum,the mass of carbon,and the volume fraction of dry ionomer has a significant impact on the electrical-thermal-water *** the selected points,the sensitivity of the decision variables is ranked:volume fraction of dry ionomer>mass of platinum>mass of carbon>agglomerate *** particular,the sensitivity of the volume fraction of dry ionomer is over 50%at these ***,the comparison results show that the ANN model could implement a more rapid and accurate prediction than the RSM model based on the same sample *** in-depth study is beneficial to provide feasible guidance for high-performance CL design.
Internal components play a crucial role in the synthesis of organic silicon monomer in gas-solid fluidized bed reactors (FBRs). Finger-tube (F-tube) and U-tube components are commonly utilized to control the temperatu...
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Internal components play a crucial role in the synthesis of organic silicon monomer in gas-solid fluidized bed reactors (FBRs). Finger-tube (F-tube) and U-tube components are commonly utilized to control the temperature and ensure its homogeneity in FBRs, thereby guaranteeing a high selectivity of the target product. The main objective of this work is to better understand the influence of F-tube and U-tube on the hydrodynamics in FBRs. Computational fluid dynamics (CFD) combined with the particle image velocimetry (PIV) technique were employed to explore the flow characteristics. The numerical data were validated against the particle velocity using an image processing technique. The results revealed that the F-tube increases the bed voidage by 3.2% and reduces the pressure drop by 13.0%. While the U-tube increases the bed voidage by 2.1% and reduces the pressure drop by 11.2%. These internals improve fluidization by ensuring even particle distribution and enhancing intra-particle circulation compared to reactors without internals.
In slag tapping furnaces, char particles undergo a series of complex structural evolution before and after being captured by the liquid slag layer. The evolution results affect the carbon conversion rate and are affec...
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In slag tapping furnaces, char particles undergo a series of complex structural evolution before and after being captured by the liquid slag layer. The evolution results affect the carbon conversion rate and are affected by temperature fluctuations, especially in the ash melting temperature zone. Experimental study on structure evolution of bituminous char prepared at around ash melting temperature was carried out on a fixed bed. The morphology, specific surface area and mineral chemical composition were measured at different temperatures. Experimental results show that the number density and the size of ash droplets exuded on the char surface increased significantly with the increasing temperature. The ash specific surface area from gasification was slightly greater than that from combustion. The residual content of chloride in the char become 1% and the contents of Fe, K, Mg and Na decrease significantly during the pyrolysis process across the ash melting temperature zone. The diffraction intensity of oldhamite increase which indicates the reaction of carbon substrate with minerals during the evolution;the diffraction intensity of quartz dramatically decreases for the reason of anorthite generation. The ignition and burnout temperatures of char were found to increase and the combustion stability decreased with the increasing pyrolysis temperature.
Switching between wet and dry states occurs frequently when the ultra-supercritical coal-fired power plant operates between 15% and 30% rated load. How to keep wet-state operation stable and switching between wet and ...
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In order to address the issues of global energy crisis and environmental pollutions, renewable energies are being rapidly developed. However, solar energy and wind energy are intermittent, and energy storage should be...
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