The large and uneven grain size of anhydrous magnesium carbonate (MgCO_(3)) seriously restricts its application ranges and performances. In this study, we proposed a controllable and cost-effective strategy to synthes...
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The large and uneven grain size of anhydrous magnesium carbonate (MgCO_(3)) seriously restricts its application ranges and performances. In this study, we proposed a controllable and cost-effective strategy to synthesize uniform small-sized MgCO_(3) from Mg^(2+) concentrated seawater brine in the absence of crystal modifiers. In this process, solid NaOH was directly added to Mg^(2+) concentrated seawater brine to completely and rapidly convert Mg^(2+) to magnesium hydroxide (Mg(OH)_(2)) nanoparticles. These nanoparticles are redispersed in water to form the colloidal system, where Mg(OH)_(2) nanoparticles hydrothermally reacts with urea to obtain uniform small-sized MgCO_(3) particles. The influence of reaction temperature, reaction time, and the molar ratio of magnesium ions to urea on the synthesis of MgCO_(3) is systematically investigated. In the highly-dispersed and stable colloidal system, Mg(OH)2 nanoparticles could exert an effective and sustained retarding effect on the hydrolysis rate of urea by attracting free water, resulting in the controllable release of NH_(4)^(+), CO_(3)^(2−), and Mg^(2+). This study presents a simple route to realize the controllable synthesis of uniform small-sized MgCO_(3) particles, and demonstrates the feasibility of using MgCO_(3) as an ideal filler for enhancing the performance of polymers as well as an ideal precursor for high-purity MgO production.
Aiming at the problems of complex process and high cost in the production of potassium bromide at present,the solubility data and the phase diagram of the quaternary system KBr-MgBr_(2)-K_(2)SO_(4)-MgSO_(4)-H_(2)O at ...
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Aiming at the problems of complex process and high cost in the production of potassium bromide at present,the solubility data and the phase diagram of the quaternary system KBr-MgBr_(2)-K_(2)SO_(4)-MgSO_(4)-H_(2)O at 298.15 K were studied using the isothermal dissolution equilibrium *** results showed that there are eight invariant points,sixteen univariant curves,and nine crystallization regions in the phase diagram which is complex and contains two double salts(K_(2)SO_(4)·MgSO_(4)·6H_(2)O and KBr·MgBr_(2)·6H_(2)O)and a metastable phase(MgSO_(4)·5H_(2)O).On the basis of the Pitzer model and HW model,the solubilities of the quaternary system were calculated,with which the corresponding phase diagram was *** comparison,the evaluated phase diagram is in accordance with the measured *** analysis,the phase diagrams of the quaternary system at(298.15 and 323.15)K were combined to put forward a process to separate KBr from the system by evaporation and crystallization,which realized the full circulation of the mother solution.
The design and operation of radial flow adsorber are crucial in large-scale industrial oxygen production,which necessitate accurate prediction of gas-solid transfer *** this work,a developed Computational Fluid Dynami...
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The design and operation of radial flow adsorber are crucial in large-scale industrial oxygen production,which necessitate accurate prediction of gas-solid transfer *** this work,a developed Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)model combined with the adsorption model is *** developed CFD-DEM model is validated by comparing simulated results with experimental data and empirical ***,the effect of particle packing structure and particle shapes on the dynamic adsorption process are analyzed in *** results reveal the mechanism of particle packing structure affecting axial velocity distribution,showing that uneven distribution of resistance on the outer flow channel side leads to uneven axial velocity distribution in the *** to cylindrical adsorbents,the use of spherical adsorbents results in a more uniform axial velocity distribution,consequently reducing bed pressure *** study holds significant potential for optimizing gas distribution and improving separation efficiency in future industrial applications.
Multiphase microstructure significantly increases the strength,usually at the expense of flangeability because of lacking microstructure *** further improve the strength-flangeability of multiphase steel,the microstru...
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Multiphase microstructure significantly increases the strength,usually at the expense of flangeability because of lacking microstructure *** further improve the strength-flangeability of multiphase steel,the microstructural homogeneity was advanced by adjusting the hard martensite/austenite(M/A)*** strength-flangeability was measured via uniaxial tensile tests and hole expansion *** microstructures were characterized using a scanning electron microscope equipped with an electron backscatter diffraction detector and a transmission electron *** tests were supplementally used to quantitatively reveal the microstructural homogeneity of the *** show that the adjusted multiphase steel achieves an excellent ultimate tensile strength(~800 MPa)and flangeability(~135%hole expansion ratio).A promising homogeneous multiphase microstructure was obtained by controlling undercooled austenite transformed at about 600℃.This microstructure consists of soft polygonal ferrite,blocky bainitic ferrite,and hard M/A *** volume fraction of M/A islands is around 5%,and the average size is less than l *** nanoindentation analysis indicated that the participation of M/A islands impressively influenced the microstructural *** strain partition and better mechanical compatibility were present in the adjusted multiphase steel since the plasticity initiation started late,which resulted in a positive ***,avoiding M/A islands distributed in the chain along the rolling direction on the matrix hindered the possibility of voids coalescing into cracks and stabilized the flanging performance.
Carbonyl small molecule compounds hold great potential as cathode materials for alkali-ion batteries（AIBs） due to their environmental friendliness, structural designability, and high theoretical capacity. However, i...
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Carbonyl small molecule compounds hold great potential as cathode materials for alkali-ion batteries（AIBs） due to their environmental friendliness, structural designability, and high theoretical capacity. However, it's practical application is hindered by intrinsic drawbacks, such as low electrical conductivity and high solubility in organic electrolytes. Additionally, most carbonyl small molecule cathodes can't be charged first in half-cells due to the absence of detachable Li+/Na+/K+ions, diminishing their appeal when assembled into full cells with alkali-free anodes. This review provides a detailed overview of carbonyl-contained small molecule cathode materials centered around oxygen, including their charge storage mechanisms, solutions to overcome their drawbacks, and the latest research advancements in AIBs. This review also summarizes the electrochemical performance of carbonyl small molecules as cathodes that have been assembled in batteries. Finally, the review outlines the prospects and directions for future research on carbonyl small molecule cathodes. It is hoped that this review will offer meaningful guidance for the development of carbonyl small-molecule cathode materials in AIBs.
Flue gas and coal bed methane are two important sources of greenhouse *** swing adsorption process has a wide range of application in the field of gas separation,and the selection of adsorbent is *** this regard,in or...
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Flue gas and coal bed methane are two important sources of greenhouse *** swing adsorption process has a wide range of application in the field of gas separation,and the selection of adsorbent is *** this regard,in order to assess the better adsorbent for separating CO_(2) from flue gas and CH_(4) from coal bed methane,adsorption isotherms of CO_(2),CH_(4) and N_(2) on activated carbon and carbon molecular sieve are measured at 303.15,318.15 and 333.15 K,and up to 250 *** experimental data fit better with Langmuir 2 compared to Langmuir 3 and Langmuir-Freundlich models,and Clausius-Clapeyron equation was used to calculate the isosteric *** the order of the adsorbed amount and the adsorption heat on the two adsorbents are CO_(2)>CH_(4)>N_(2).The adsorption kinetics are calculated by the pseudo-first kinetic model,and the order of adsorption rates on activated carbon is N_(2)-CH_(4)>CO_(2),while on carbon molecular sieve,it is CO_(2)-N_(2)>CH_(4).It is shown that relative molecular mass and adsorption heat are the primary effect on kinetics for activated carbon,while kinetic diameter is the main resistance factor for carbon molecular ***,the adsorption selectivity of CH_(4)/N_(2) and CO_(2)/N_(2) were estimated with the ideal adsorption solution theory,and carbon molecular sieve performed best at 318.15 K for both CO_(2) and CH_(4) *** study suggested that activated carbon is a better choice for separating flue gas and carbon molecular sieve can be a strong candidate for separating coal bed methane.
The poor surface conditions and osseointegration capacity of 3D printed Ti6Al4V implants(3DPT)sig-nificantly influence their performance as orthopedic and dental *** this work,we creatively introduce a one-step femtos...
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The poor surface conditions and osseointegration capacity of 3D printed Ti6Al4V implants(3DPT)sig-nificantly influence their performance as orthopedic and dental *** this work,we creatively introduce a one-step femtosecond laser treatment to improve the surface conditions and *** surface characterization,mechanical properties,corrosion resistance,and biological responses were *** results found that femtosecond laser eliminated defects like embedded powders and superficial cracks while forming the nano cones-like structures surface on 3DPT,leading to enhanced osseointegration,anti-corrosion,and anti-fatigue *** dynamics simulations revealed the ablation removal mechanism and the formation of nano cone-like *** findings were fur-ther supported by the in vivo studies,showing that the FS-treated implants had superior bone-implant contact and ***,the one-step femtosecond laser method is regarded as a promising surface modification method for improving the functional performance of Ti-based orthopedic implants.
The infrared conformal window is one of the most critical components in *** windows with high performance bring low aberrations,high aerodynamic performance,reliability in extreme working environments,and added value ...
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The infrared conformal window is one of the most critical components in *** windows with high performance bring low aberrations,high aerodynamic performance,reliability in extreme working environments,and added value for *** the past decades,remarkable advances have been achieved in manufacturing technologies for conformal windows,where the machining accuracy approaches the nanometer level,and the surface form becomes more *** advances are critical to aircraft development,and these manufacturing technologies also have significant reference values for other directions of the ultra-precision machining *** this review,the infrared materials suitable for manufacturing conformal windows are introduced and compared with insights into their *** remarkable advances and concrete work accomplished by researchers are *** challenges in manufacturing conformal windows that should be faced in the future are discussed.
In this paper,a multi-objective optimization strategy for a volute mixed flow pump is implemented based on inverse design *** controllable velocity moment(CVM)design parameters are defined based on the impeller outlet...
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In this paper,a multi-objective optimization strategy for a volute mixed flow pump is implemented based on inverse design *** controllable velocity moment(CVM)design parameters are defined based on the impeller outlet velocity moment and its partial derivative in the streamline direction,and flow control is further realized by directly adjusting the velocity moment distribution inside the *** significance order of the effect of the CVM parameters on the efficiency and NPHSc at the best operation points is first investigated,and the elliptical basis function(EBF)approximation model and MOPS optimization algorithm are combined to carry out multi-objective *** with the baseline model,an improvement in the efficiency and head at the best operation points of 0.48%,1.07 m is obtained for the optimal model,with a widened and efficient operation range,and NPHSc is reduced from 4.545 m-4.235 m,with a slowed cavitation *** proposed CVM method effectively realizes flow control under multiple conditions,optimizing the pressure distribution on the blade pressure side and suppressing the reverse jet in the cavity closure area.
Two-dimensional MXenes have great potential for gas sensing applications due to their distinct electronic structure and unique surface ***,low sensitivity and poor selectivity to target gas at room temperature are maj...
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Two-dimensional MXenes have great potential for gas sensing applications due to their distinct electronic structure and unique surface ***,low sensitivity and poor selectivity to target gas at room temperature are major shortcomings of MXene *** this study,PdCl_(2) was used to decorate Pd single atoms(PdSA)on Ti_(3)C_(2) nanosheet(Ti_(3)C_(2)/PdSA).The Pd^(2+)was directly reduced(in-situ)into a PdSA due to abundant Ti vacancies and the inherent reducing ability of Ti_(3)C_(2) *** Ti_(3)C_(2)/PdSA sensor exhibited the highest response of 0.289 to 1 ppm NO_(2),which is 28.9 and 7.8 times higher over pristine Ti_(3)C_(2) and Pd nanoparticles(Pdnano)-decorated on Ti_(3)C_(2)(Ti_(3)C_(2)/Pdnano),***,the Ti_(3)C_(2)/PdSA sensor possessed an ultralow detection limit(10 ppb)and excellent selectivity towards NO_(2).The enhanced gas sensing mechanism of Ti_(3)C_(2)/PdSA was investigated in detail through the activation energy calculation,in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS),and density functional theory(DFT)*** rich active sites,chemical sensitization effect,and NO_(2) adsorption enhancement resulting from the Pd single atoms in Ti_(3)C_(2)/PdSA significantly boosted sensing *** work can provide new insights and guidelines for fabricating highly effective NO_(2) sensors operated at room temperature.
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