Lithium-gas batteries(LGBs)have garnered significant attention due to their impressive high-energy densities and unique gas conversion ***,the practical application of LGBs faces substantial challenges,including slugg...
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Lithium-gas batteries(LGBs)have garnered significant attention due to their impressive high-energy densities and unique gas conversion ***,the practical application of LGBs faces substantial challenges,including sluggish gas conversion kinetics inducing in low-rate performance and high overpotential,along with limited electrochemical reversibility leading to poor cycle *** imperative task is to develop gas electrodes with remarkable catalytic activity,abundant active sites,and exceptional electrochemical ***,a versatile and well-established technique for fabricating fibrous nanomaterials,has been extensively explored in LGB *** this work,we emphasize the critical structure-property for ideal gas electrodes and summarize the advancement of employing electrospun nanofibers(NFs)for performance enhancement in *** elucidating the fundamental principles of LGBs and the electrospinning technique,we focus on the systematic design of electrospun NF-based gas electrodes regarding optimal structural fabrication,catalyst handling and activation,and catalytic site optimization,as well as considerations for large-scale *** demonstrated principles and regulations for electrode design are expected to inspire broad applications in catalyst-based energy applications.
2-D numerical simulations on the nitrogen expansion flow with spontaneous condensation in a nozzle were conducted based on the equilibrium model and the non-equilibrium model respectively. In the equilibrium model, th...
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ISBN:
(纸本)9782362150128
2-D numerical simulations on the nitrogen expansion flow with spontaneous condensation in a nozzle were conducted based on the equilibrium model and the non-equilibrium model respectively. In the equilibrium model, the mass transfer between the liquid and vapor is determined by the saturation enthalpies of the liquid and vapor phases. The pressure distribution of the nozzle could be influenced slightly by the condensation process. In the non-equilibrium model, the classical nucleation model is used for the droplets formation. The flow is heated by the latent heat and consequently the decrease of pressure and the increase of Mach number are delayed. Meanwhile, due to the requirement of a certain supercooling level, the condensation onset point is pushed away from the nozzle inlet, and the nozzle outlet wetness fraction becomes smaller. Then, the influence of the nozzle inlet temperature and inlet pressure on gas supercooling, nucleation rate and wetness are analyzed.
The solar chimney power plant (SCPP) is dominated by the solar radiation, and therefore its discontinuous operation is an unavoidable problem. In this paper, low temperature geothermal energy is introduced into the SC...
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The solar chimney power plant (SCPP) is dominated by the solar radiation, and therefore its discontinuous operation is an unavoidable problem. In this paper, low temperature geothermal energy is introduced into the SCPP for overcoming this problem. Based on a developed mathematical model, theoretical analyses are carried out to investigate the performance of the geothermal-solar chimney power plant (GSCPP) with main dimensions the same as the Manzanares prototype in Spain. It is found that the GSCPP can attractively run in the full geothermal mode to deliver power continuously, which could solve the problem of the SCPP's running without sunlight in a long time, including at night. In addition, the introducing of geothermal energy into the SCPP can highly improve its power capacity.
Self-passivation in aqueous solution and sluggish surface reaction kinetics significantly limit the photoelectrochemical(PEC)performances of silicon-based ***,a WO_(3) thin layer is deposited on the p-Si substrate by ...
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Self-passivation in aqueous solution and sluggish surface reaction kinetics significantly limit the photoelectrochemical(PEC)performances of silicon-based ***,a WO_(3) thin layer is deposited on the p-Si substrate by pulsed laser deposition(PLD),acting as a photocathode for PEC hydrogen *** to bare p-Si,the single-junctional p-Si/WO_(3) photoelectrodes exhibit excellent and stable PEC performances with significantly increased cathodic photocurrent density and exceptional anodic shift in onset potential for water *** is revealed that the WO_(3) layer could reduce the charge transfer resistance across the electrode/electrolyte interface by eliminating the effect of Fermi level pinning on the surface of *** importantly,by varying the oxygen pressures during PLD,the collaborative modulation of W–O bond covalency and WO6 octahedral structure symmetry contributes to the promoted charge carrier transport and ***,a large band bending at the p-Si/WO_(3) junction,induced by the optimized O vacancy contents in WO_(3),could provide a photovoltage as high as~500 mV to efficiently drive charge transfer to overcome the water reduction ***,by manipulating W–O local atomic structures in the deposited WO_(3) layer,a great improvement in PEC performance could be achieved over the singlejunctional p-Si/WO_(3) photocathodes for solar hydrogen generation.
One of the most important components of solar thermal power system is the solar central receiver, which performance is in direct relation to the efficiency of the whole power generation system. The calculation of inte...
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The purpose of this work is to investigate the effect of ethanol blending into methylcyclohexane during the ignition at low temperatures. The ignition delay times of the binary fuels with ethanol blending ratio varied...
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Plastic has caused serious"white pollution"to the environment,and the highly inert characteristics of plastic bring a major challenge for *** fluids have unique physical properties and have been widely used ...
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Plastic has caused serious"white pollution"to the environment,and the highly inert characteristics of plastic bring a major challenge for *** fluids have unique physical properties and have been widely used in various *** this work,supercritical CO_(2)(Sc-CO_(2))with mild conditions was selected and assisted by NaOH/HCl solution to degrade polystyrene(PS)plastic,and the reaction model was designed using response surface methodology(RSM).It was found that,regardless of the types of assistance solutions,the factors affecting PS degradation efficiencies were reaction temperature,reaction time,and NaOH/HCl *** the temperature of 400℃,time of 120 min,and base/acid concentration of 5%(in weight),0.15 g PS produced 126.88/116.99±5 mL of gases with 74.18/62.78±5 mL of H2,and consumed 81.2/71.5±5 mL of CO_(2).Sc-CO_(2)created a homogeneous environment,which made PS highly dispersed and uniformly heated,thus promoting the degradation of ***,Sc-CO_(2)also reacted with the degradation products to produce new CO and more CH_(4)and C_(2)H_(x)(x=4,6).Adding NaOH/HCl solution not only improved the solubility of PS in Sc-CO_(2),but also provided a base/acid environment that reduced the activation energy of the reaction,and effectively improved the degradation efficiencies of *** short,degrading PS in Sc-CO_(2)is feasible,and better results are obtained with the assistance of base/acid solution,which can provide a reference for the disposal of waste plastics in the future.
Porous cryptomelane-type octahedral molecular sieve(OMS-2)with mixed Mn valence and abundant lattice oxygen species has attracted much attention in volatile organic compounds(VOC)catalytic ***,complete conversion of a...
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Porous cryptomelane-type octahedral molecular sieve(OMS-2)with mixed Mn valence and abundant lattice oxygen species has attracted much attention in volatile organic compounds(VOC)catalytic ***,complete conversion of arene over OMS-2 catalysts at relatively low temperature is still a challenge due to its limited crystal structure and inferior ***,a series of PdCe/OMS-2 catalysts with different Pd/Ce molar ratios was fabricated by a facile impregnation method and the physicochemical properties of which were extensively characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HR-TEM),B runauer-Emmett-Teller(BET)method,X-ray fluorescence(XRF),X-ray photoelectron spectroscopy(XPS),temperature programmed reduction of H2(H2-TPR),Raman,In situ diffused reflectance infrared Fourier transform spectra(DRIFTS),and density functional theory(DFT)*** show that the total conversion of toluene can be achieved at 207℃ over PdCe2 with apparent activation energy as low as 62.6 kJ/*** strong synergistic effect between Pd and Ce remarkably boosts the catalytic activity of OMS-2,attributed to the abundant Mn^(3+)-O bands and active surface oxygen *** results reveal that oxygen vacancy can be formed over PdCe2 much easily than that of Pd/OMS-2 and Ce/OMS-2 with the oxygen vacancy formation energy of2.42,2.83 and 2.68 eV,*** increasing the Pd content cannot promote the catalytic activity although PdO is a critical active center in toluene *** vacancy attributed to the integrative effect of Pd,Ce and Mn species plays a promine nt role over prepared catalysts in toluene activation *** findings reported in this work showed new insights into the designing of highly efficient OMS-2catalysts for VOC deep oxidation by tuning oxygen vacancy concentration.
A set of solar photovoltaic and thermal combined (PV/T) system is installed and tested in the present study. The PV/T system is designed and constructed by integrating coiled-channel flat-plate collectors with polycry...
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A set of solar photovoltaic and thermal combined (PV/T) system is installed and tested in the present study. The PV/T system is designed and constructed by integrating coiled-channel flat-plate collectors with polycrystalline silicon PV modules. The linear Fresnel lens acts as the concentrator. Three systems, i.e. the non-cooling PV system, the non-concentrating PV/T system and the concentrating PV/T system, are tested and analyzed. Experimental results show that a high thermal and electrical combined efficiency, over 65%, is achieved by the PV/T system. Water in the flat plate can significantly decrease the PV module temperature and improve the electricity-conversion efficiency. Comparing with the non-concentrating PV/T system, the concentrating PV/T system can increase the total utilization of solar energy.
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