Ionic partition equilibrium in charged membrane immersed in solution of single electrolyte with monovalence or multi-valence is systematically investigated and several expressions are established for determination of ...Ionic partition equilibrium in charged membrane immersed in solution of single electrolyte with monovalence or multi-valence is systematically investigated and several expressions are established for determination of partition coefficients. On this basis, the effects of the ratio of membrane charge density to bulk electrolyte solution concentration, the charge sign and valence of electrolyte ions and the type of membrane on the partition equilibrium were analyzed and simulated within chosen parameters. It is revealed that ion partition is not related solely with the respective concentrations but also definitely with the concentration ratio of fixed group to bulk solution in addition to the charge sign and the valence. For a counterion, the partition coefficient increases with this ratio and the valence; while for a coion, the partition coefficient decreases with this ratio and the valence. The theoretical calculations were compared with the experimental data and a good agreement was observed.展开更多
The effect of strain and drawing temperature on the evolution of microstructure and fiber textures of aluminum wiresdrawn at room temperature and cryogenic temperature was investigated by TEM and EBSD observations.The...The effect of strain and drawing temperature on the evolution of microstructure and fiber textures of aluminum wiresdrawn at room temperature and cryogenic temperature was investigated by TEM and EBSD observations.The results show that lowangle boundaries frequency increases and high angle boundaries frequency decreases with strain increasing when the strain is low.Athigh strain,most of grain and dislocation boundaries are parallel to the drawn direction and low angle boundaries frequencydecreases and high angle boundaries frequency increases with strain increasing.The decrease of deformation temperature leads tomicrostructure finer and low angle boundaries frequency increasing.Texture analysis indicates that volume fraction of complextexture component decreases with strain increasing and a mixture of?111?and?100?fiber texture forms at high strain.?111?is stableat low strains but?100?becomes stable at high strain.The decrease of temperature can enhance the stability of?111?orientation athigh strain.展开更多
Four achiral Cu(Ⅱ)-coordinated Schiff bases complexes containing aromatic structures were synthesized and their supramolecular assemblies at the air/water interface were investigated.All the compounds could be spread...Four achiral Cu(Ⅱ)-coordinated Schiff bases complexes containing aromatic structures were synthesized and their supramolecular assemblies at the air/water interface were investigated.All the compounds could be spread on water surface although they have no alkyl chains.The Schiff base complex molecules with naphthyl groups tended to form J-aggregate in the Langmuir-Blodgett(LB) films transferred from water surface.By investigation of atomic force microscopy,a multilayer film or three-dimensional structures were observed.It was interesting to note that the LB films of achiral compound Cu-NA with naphthyl segment and without methyl groups transferred from water surface showed chirality.The supramolecular chirality in the present LB films was suggested to be due to a cooperative stereoregular-stacking of the functional groups in a helical sense.This research work provides a helpful clue for regulating the nanostructures and supramolecular chiral assembly in organized films.展开更多
文摘重非水相液体(Dense Non-Aqueous Phase Liquid,DNAPL)与水相的界面面积是影响DNAPL在地下水中溶解速率的关键参数。通过设计二维砂箱实验,运用界面分配示踪法测定DNAPL残余饱和态下的界面面积。为量化分析保守示踪剂Br^-的存在对实验结果的影响,共进行两组实验,Br^-和界面分配示踪剂的注入方式分别为依次注入和同时注入。结果表明:(1)两组实验测定的固液相分配系数K_d值分别为0.079 m L/g和0.142 m L/g,表明Br^-的存在增大了介质对界面分配示踪剂的吸附作用;(2)两组实验测定的单位体积多孔介质中界面面积值分别为215 cm^2和237 cm^2,表明Br^-的存在增大了DNAPL与水相交界面对界面分配示踪剂的吸附作用;(3)在本实验范围内(Br^-浓度C_(Br)≤200mg/L),K_d值与Br^-浓度呈良好的线性关系(K_d=0.00032C_(Br)+0.0798),可用于对砂介质的K_d值进行估算和验证。
基金Supported by the National Natural Science Foundation of China (No. 29976040), the Natural Science Foundation of Anhui Province(No. 99045431) and the Foundation of Environments and Resources of USTC (2000).
文摘Ionic partition equilibrium in charged membrane immersed in solution of single electrolyte with monovalence or multi-valence is systematically investigated and several expressions are established for determination of partition coefficients. On this basis, the effects of the ratio of membrane charge density to bulk electrolyte solution concentration, the charge sign and valence of electrolyte ions and the type of membrane on the partition equilibrium were analyzed and simulated within chosen parameters. It is revealed that ion partition is not related solely with the respective concentrations but also definitely with the concentration ratio of fixed group to bulk solution in addition to the charge sign and the valence. For a counterion, the partition coefficient increases with this ratio and the valence; while for a coion, the partition coefficient decreases with this ratio and the valence. The theoretical calculations were compared with the experimental data and a good agreement was observed.
基金Projects(51471123,51171135)supported by the National Natural Science Foundation of ChinaProjects(2012K07-08,2013KJXX-61)supported by the Natural Science Foundation of Shaanxi Province,ChinaProject(2013JC14)supported by the Industrialization Program of Shaanxi Province,China
文摘The effect of strain and drawing temperature on the evolution of microstructure and fiber textures of aluminum wiresdrawn at room temperature and cryogenic temperature was investigated by TEM and EBSD observations.The results show that lowangle boundaries frequency increases and high angle boundaries frequency decreases with strain increasing when the strain is low.Athigh strain,most of grain and dislocation boundaries are parallel to the drawn direction and low angle boundaries frequencydecreases and high angle boundaries frequency increases with strain increasing.The decrease of deformation temperature leads tomicrostructure finer and low angle boundaries frequency increasing.Texture analysis indicates that volume fraction of complextexture component decreases with strain increasing and a mixture of?111?and?100?fiber texture forms at high strain.?111?is stableat low strains but?100?becomes stable at high strain.The decrease of temperature can enhance the stability of?111?orientation athigh strain.
基金supported by the National Natural Science Foundation of China (Grant Nos. 20903078,21207112)the Natural Science Foundation of Hebei Province (Grant No. B2012203060)+4 种基金the China Postdoctoral Science Foundation (Grant Nos. 2011M500540,2012M510770)the Support Program for Hundred Excellent Innovation Talents from Universities and Colleges of Hebei Province (Grant No. CPRC020)the Science Foundation for the Excellent Youth Scholars from Universities and Colleges of Hebei Province (Grant No. Y2011113)the Scientific Research Foundation for Returned Overseas Chinese Scholars of Hebei Province (Grant No.2011052)the Open Foundation of State Key Laboratory of Solid Lubrication (Grant No. 1002)
文摘Four achiral Cu(Ⅱ)-coordinated Schiff bases complexes containing aromatic structures were synthesized and their supramolecular assemblies at the air/water interface were investigated.All the compounds could be spread on water surface although they have no alkyl chains.The Schiff base complex molecules with naphthyl groups tended to form J-aggregate in the Langmuir-Blodgett(LB) films transferred from water surface.By investigation of atomic force microscopy,a multilayer film or three-dimensional structures were observed.It was interesting to note that the LB films of achiral compound Cu-NA with naphthyl segment and without methyl groups transferred from water surface showed chirality.The supramolecular chirality in the present LB films was suggested to be due to a cooperative stereoregular-stacking of the functional groups in a helical sense.This research work provides a helpful clue for regulating the nanostructures and supramolecular chiral assembly in organized films.
