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2篇 您的检索式:作者名="Jingyun Weng"
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1Recent advances of pharmaceutical crystallization theories显示文摘As a technology of separation and purification,crystallization plays a vital role in diverse industries such as inorganic salt,pharmaceutical,and food industries,which has a huge impact on purity,crystal polymorph,crystal morphology,and particle size distribution of final products.In the past few decades,with the rapid advancement of experimental approaches and molecular simulation methods,considerable advances in the interpretation of crystallization mechanisms have been obtained,promoting the investigation and understanding of crystallization theories greatly.In this review,the advances of pharmaceutical crystallization theories in recent years from the perspectives of nucleation and crystal growth are summarized and discussed.Two thermodynamic models that are helpful in the study of the crystallization mechanisms will be introduced.In this section,the perturbed-chain statistical associating fluid theory(PC-SAFT)and a chemical-potential-gradient model will be introduced,which have been successfully applied in pharmaceutical solubility prediction,the research of dissolution mechanism as well as dissolution kinetics analysis.These two models are expected to be applied to the study of pharmaceutical crystallization process and mechanism.Furthermore,molecular simulation based on the interaction between particles can provide structural information,thermodynamics,and dynamics properties of complex systems at the molecular level,like intermolecular interaction and surface adsorption energies.Application and some shortcomings of molecular simulation,especially molecular dynamics simulation,in the field of pharmaceutical crystallization will be expounded.Jingyun Weng Yiping Huang Dule Hao Yuanhui Ji 2020Chinese Journal of Chemical Engineering2020,28,4:5
2Effect of manganese and/or ceria loading on V_2O_5-MoO_3/TiO_2 NH_3 selective catalytic reduction catalyst显示文摘The effect of manganese and/or ceria loading of V2 O5-MoO3/TiO2 catalysts was investigated for selective catalytic reduction(SCR) of NOx by NH3.The manganese and/or ceria loaded V2 O5-MoO3/TiO2 catalysts we re prepared by the wetness impregnation method.The physicochemical characteristics of the catalysts were thoroughly characterized.The catalytic performance of 1.5 wt% V2 O5-3 wt% MoO3/TiO2(V1.5 Mo3/Ti) is greatly enhanced by addition of 2.5 wt% MnOx and 3.0 wt% CeO2(V1.5 Mo3 Mn2.5 Ce3/Ti) below450℃.Compared with the V1.5 Mo3/Ti catalyst with NOx conversion of 75% at 275 ℃,V1.5 Mo3 Mn2.5 Ce3/Ti exhibits higher NOx conversion of 84% with good resistance to SO2 and H2 O at a gas hourly space velocity value of 150000 h-1.The active manganese,cerium,molybdenum,and vanadium oxide species are highly dispersed on the catalyst surface and some synergistic effects exist among these species.Addition of MnOx significantly enhances the redox ability of the cerium,vanadium,and molybdenum species.Addition of Ce increases the acidity of the catalyst.More active oxygen species,including surface chemisorbed oxygen,form with addition of Mn and/or Ce.Because of the synergistic effects,appropriate proportions of manganese in different valence states exist in the catalysts.In summary,the good redox ability and the strong acidity contribute to the high NH3-SCR activity and N2 selectivity of the V1.5 Mo3 Mn2.5 Ce3/Ti catalyst in a wide temperature range.And the V1.5 Mo3 Mn2.5 Ce3/Ti catalyst shows good resistance to H2 O and SO2 in long-time catalytic testing,which can be ascribed to the highly sulfated species adsorbed on the catalyst.Daojun Zhang Ziran Ma Baodong Wang Tao Zhu Duan Weng Xiaodong Wu Jingyun Chen Hongyan Wang Ge Li Jiali Zhou 2020Journal of Rare Earths2020,38,7:1
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