过硫酸盐活化方式与氧化降解有机物效能及其在污染场地修复中的应用

过氧单硫酸盐（PMS）及过二硫酸盐（PDS）在工业污染场地修复中应用广泛，通过活化作用能够产生氧化性更强的·\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\text{-}}自由基，从而更好地氧化降解有机污染物。本文比较了几种典型活化方式，包括紫外（UV）、碱、过渡金属、热以及含碳物质，并分析了它们的优缺点及适用条件；讨论了过硫酸盐活化机理及动力学过程；分析了无机阴离子（Cl^-、\mathrm{H}\mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{\text{-}}\text{/}\mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{\mathrm{2}\text{-}}、\mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{\text{-}}、\mathrm{N}{\mathrm{O}}_{\mathrm{2}}^{\text{-}}、\mathrm{H}\mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}\text{-}}、{\mathrm{H}}_{\mathrm{2}}\mathrm{P}{\mathrm{O}}_{\mathrm{4}}^{\text{-}}）与·\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\text{-}}自由基相互作用及其对有机污染物氧化降解的影响；针对活化过硫酸盐在工业污染场地修复领域的应用，对过硫酸盐活化方法的发展趋势进行了展望。理论研究和实践表明，过硫酸盐不同活化方式为工业污染场地修复提供了多样选择，多种活化方式协同作用将是过硫酸盐高效活化氧化降解有机污染物的发展方向。由于Cl^-、\mathrm{H}\mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{\text{-}}\text{/}\mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{\mathrm{2}\text{-}}抢夺·\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\text{-}}的能力较强，认为这些无机盐与有机物复合的污染场地或土壤采用PDS修复需格外谨慎选择活化方法。     

Numerical and sensitivity analysis of MHD bioconvective slip flow of nanomaterial with binary chemical reaction and Newtonian heating

The impact of Stefan blowing on the MHD bioconvective slip flow of a nanofluid towards a sheet is explored using numerical and statistical tools. The governing partial differential equations are nondimensionalized and converted to similarity equations using apposite transformations. These transformed equations are solved using the Runge–Kutta–Fehlberg method with the shooting technique. Graphical visualizations are used to scrutinize the effect of the controlling parameters on the flow profiles, skin friction coefficient, local Nusselt, and Sherwood number. Moreover, the sensitivities of the reduced Sherwood and Nusselt number to the input variables of interest are explored by adopting the response surface methodology. The outcomes of the limiting cases are emphatically in corroboration with the outcomes from preceding research. It is found that the heat transfer rate has a positive sensitivity towards the haphazard motion of the nanoparticles and a negative sensitivity towards the thermomigration. The thermal field is enhanced by the Stefan blowing aspect. Moreover, the fluid velocity can be controlled by the applied magnetic field.     

A theoretical study of the ability of 2D monolayer Au (111) to activate gas molecules

The adsorption and activation of gas molecules are investigated substantially in solid-gas heterogeneous catalysis. Here we investigated the interaction between gas molecules and unique two-dimensional monolayer Au (111) structure using density functional theory. It is found that CO₂, H₂O, N₂ and CH₄ molecules are weakly adsorbed on the surface with the adsorption energies between ?0.150 and ?0.250 eV due to van der Waals interaction. While CO, NO, NO₂, and NH₃ molecules are adsorbed more stably with the adsorption energies between ?0.300 and ?0.470 eV. Especially, the bond length of CO is stretched by 0.038 Å and the bond angle of NO₂ is obviously enlarged by 10.460°. The activation originates from the rearrangement of molecule orbitals and the orbitals hybridization between the partial orbitals of gas molecules and Au-5d orbitals. The fundamental analyses of adsorption mechanism and electronic properties may provide guidance for the applications of two-dimensional monolayer metal catalysis.PACSnumbers 73.22.-f, 73.61.-r     

胡萝卜丁中维生素C在热风辅助射频干燥过程中降解的动力学模型

目的研究热风辅助射频(hot air-assisted radio frequency,HA-RF)干燥过程中维生素C随温度变化的降解动力学模型。方法在6.5 cm极板间距和60℃热风系统条件下进行HA-RF干燥,重点研究胡萝卜丁中维生素C在干燥过程中的降解动力学,包括脱氢抗坏血酸(dehydroascorbic acid,DHAA)和抗坏血酸(ascorbic acid,AA)。总维生素C含量采用2,4-硝基苯肼分光光度法测定,AA采用2,6-二氯吲哚酚滴定法测定。结果HA-RF干燥过程中维生素C的降解规律符合一级可逆模型,其降解活化能为40.54 kJ/mol。DHAA活化能为35.83 kJ/mol,表明DHAA的稳定性低于AA。结论本研究使用的干燥温度为62.5~77.5℃,较高的干燥温度下维生素C降解速率较高,较低处理温度下的降解过程具有更好的模型适应度(R2>0.98)。     

Electrochemical activation construction of LaCo1-x-yNixFeyO3 promoted by optimized lattice Ni doping toward water oxidation

Iron sites with high intrinsic activity for oxygen evolution reaction (OER) can effectively enhanced the performance of perovskite oxide as electrocatalyst for water electrolysis. However, doping of iron in perovskite LaCoO₃ remains a challenge owing the strong Co–O bond and robust structure of LaCoO₃. Herein, the lattice doping of Ni in LaCoO₃ has been adopted to promote the interaction between iron ions and Co site in LaCoO₃. Firstly, molten salt of Ni(NO₃)₂ provides free-moving Ni ions to substitute Co sites in the lattice of LaCoO₃ forming LaCo_1-xNi_xO₃ at the optimized Ni doping condition. Then, iron ions can easily be absorbed to LaCo_1-xNi_xO₃ due to the strong interaction between Ni and Fe by electrochemical activation at room temperature. The prepared LaCo_1-x-yNi_xFe_yO₃ nanoparticles keep the coarse surface for maximizing the exposure of active sites. The high-valence Co and oxygen vacancy from LaCo_1-x-yNi_xFe_yO₃ contribute to the better intrinsic activity for OER, demonstrating the overpotential of ?₁₀ of approximately 315 mV and good stability. The strategy of by introducing the lattice doping of other metal ion can realize the facile and effective construction of iron doped perovskite oxide for water oxidation.     

Investigation of flow parameters of Reiner–Philippoff nanofluid flow with higher-order slip properties,activation energy,and bioconvection by artificial neural networks

In this study, the flow parameters of Reiner–Philippoff nanofluid flow with high-order slip properties, activation energy, and bioconvection have been analyzed using artificial neural networks (ANNs). Local Nusselt number (LNN), local Sherwood number (LSN), and motile density number (MDN) are considered as flow parameters. Numerical values have been obtained by numerical methods using flow equations. To estimate the flow parameters, three different ANN models have been designed. The Levenberg–Marquardt training algorithm is used in multilayer perceptron network models with 10 neurons in the hidden layers. In all, 70% of the data set has been used for training the models, 15% for validation, and 15% for testing. The performance analysis of the network models has been made by calculating the determined performance parameters. The R values for the LNN, LSN, and MDN parameters have been calculated as 0.99261, 0.98769, and 0.99102, respectively, and the average deviation values are −0.65%, 0.06%, and −0.11%, respectively. The attained outcomes showed that the ANNs can predict the LNN, LSN, and MDN, which are the flow parameters of the Reiner–Philippoff nanofluid flow, with high accuracy.     

微波辅助孵育法富集麦胚多肽的工艺优化

目的 麦胚孵育过程中蛋白酶将蛋白质水解成肽和氨基酸，多肽具有明确的生理活性和营养调节作用。本研究以麦胚为试验原料，采用微波辅助预处理的方法，研究孵育的温度、时间、pH及料液比4种因素对孵育后的蛋白酶活力及多肽含量的影响。 方法 通过单因素和响应曲面试验进行工艺条件优化。 结果 与未进行微波辅助预处理的样品相比，微波辅助处理（600 W, 10 s）能显著提高孵育后样品中的蛋白酶酶活力（约9.4倍）和肽含量（约3.1倍）。经过微波辅助处理后，孵育温度为51.5℃、pH为4.0、时间为6.33 h、料液比为1:7时，蛋白酶活力达最高为3826.24 U/g；孵育温度为45.0 ℃、pH为4.8、时间为8 h、料液比为1:7时，肽含量达最高为262.63 mg/g。 结论 微波辅助处理能有效的激活麦胚孵育液中的内源性蛋白酶活性，促进蛋白水解反应，显著提高孵育后的肽含量。该研究结果为麦胚多肽的制备新工艺开发提供了研究基础。     

Preparation of composite cathode material by using the extracted lead (Pb) of waste lead acid battery for LT-SOFC

The extraction of Pb from the waste lead acid batteries offers the conservation of energy resources and reduction of pollution load in the environment. The recycling of waste lead acid batteries than discarding by conventional methods is the best way. In the present studies, for LT-SOFC, three composite cathode materials (Pb_0.1Fe_0.4Co_0.5O_4-δ, Pb_0.2Fe_0.3Co_0.5O_4-δ and Pb_0.3Fe_0.2Co_0.5O_4-δ) were produced by extracting Pb from the waste lead acid batteries, cobalt nitrate [Co(NO₃)₃.6H₂O] and iron nitrate [Fe(NO₃)₃.9H₂O] using standard solid state reaction method. Thermal stability, morphological and structural characteristics were studied by TGA, SEM and XRD analyses. FTIR spectra were used to investigate the types of metal oxide bonding in the prepared ceramic composite cathode materials. Fuel cell testing and DC four probes were used to investigate electrochemical properties. The measurement of average crystalline size of the composites was found to be in the range of 12–37 nm.Scanning electron microscopy (SEM) images showed that composite materials are porous and suitable to diffuse the gases. The maximum conductivities of 1.6 Scm^?1, 2.05 Scm^?1 and 2.6 Scm^?1 have been obtained for Pb_0.1Fe_0.4Co_0.5O_4-δ, Pb_0.2Fe_0.3Co_0.5O_4-δ and Pb_0.3Fe_0.2Co_0.5O_4-δ, respectively. At 600 °C, the high OCV (0.95V) and the maximum power density (439 mW/cm²) have been achieved using hydrogen as the fuel. Lower value of activation energy (0.36ev) of Pb_0.3Fe_0.2Co_0.5O_4-δ confirms that it is the efficient material to convert electrochemically hydrogen fuel into valuable electricity.     

Entropy generation minimization on electromagnetohydrodynamic radiative Casson nanofluid flow over a melting Riga plate

Minimizing entropy generation is a technique that helps improve the effectiveness of real processes by studying the associated irreversibility of system performance of nanofluid. This study examines the entropy generation analysis of electromagnetohydrodynamic radiative Casson flow induced by a stretching Riga plate in a non-Darcian porous medium under the influence of internal energy change, Arrhenius activation energy, chemical reaction, and melting heat transfer. The thermophysical features of the fluid are assumed constant in most of the literature. However, this current research bridges this gap by considering viscosity, conductivity, and diffusivity as temperature-dependent variables. Also, the exponential decaying Grinberg term is used as a resistive force in this investigation due to the electromagnetic properties of the Riga plate in the momentum conservation equation. Some suitable dimensionless variables are introduced to remodel the transport equations into unitless ones and then solved numerically by employing Galerkin Weighted Residual Method. Analyses reveal that the Casson parameter declines the fluid velocity, while the existence of the melting parameter has the opposite effect. Also, this article includes some future recommendations.