The potential—pH diagrams of the Cr-H2O system at temperatures of 298, 323, 373 and 423 K were established through thermodynamic calculation with coupling of experimental results. The potential—pH diagram at 298 K a...The potential—pH diagrams of the Cr-H2O system at temperatures of 298, 323, 373 and 423 K were established through thermodynamic calculation with coupling of experimental results. The potential—pH diagram at 298 K agrees well with the previously reported results. Based on the potential—pH diagrams of the Cr-H2O and Fe-H2O systems, IR spectra and XRD pattern, the existence forms of iron in the potassium chromate were analyzed, and the methods of iron removal were investigated. The results show that the existence forms of iron in the potassium chromate are potassium ferrate. These results are instructive and helpful to the hydrometallurgical processing of chromite ore.展开更多
For aqueous interfacial reactions involving H+and OH-, the interfacial pH varies dynamically during the reaction process, which is a key factor determining the reaction performance. Herein, the kinetic relevance betwe...For aqueous interfacial reactions involving H+and OH-, the interfacial pH varies dynamically during the reaction process, which is a key factor determining the reaction performance. Herein, the kinetic relevance between the interfacial pH and reaction rate is deciphered owing to the success in establishing the transport equations of H+/OH- in unbuffered solutions, and is charted as a current(j)–pH diagram in the form of an electrochemical response. The as-described j–pH interplay is experimentally verified by the oxygen reduction and hydrogen evolution reactions. This diagram serves to form a panoramic graphic view of pH function working on the interfacial reactions in conjunction with the Pourbaix’s potential–pH diagram, and particularly enables a kinetic understanding of the transport effect of H+and OH-on the reaction rate and valuable instruction toward associated pH control and buffering manipulation.展开更多
Aqueous E pH Diagram is an essential tool for analyzing hydrometallurgical and corrosion processes. Due to the requirements for environmental protection and energy saving in recent years, waste water processing a...Aqueous E pH Diagram is an essential tool for analyzing hydrometallurgical and corrosion processes. Due to the requirements for environmental protection and energy saving in recent years, waste water processing and hydrometallurgical process of concentrate have been greatly developed. The construction of E pH diagrams has turned to multi component systems. However, there are some limits in plotting such diagrams. There is only one diagram for one multi component system, which can not reflect the truth of the aqueous reaction. In the paper, a new computation method is proposed to construct E pH diagrams. Component activity term is used to determine the boundary of stable areas. For the multi component systems, different atom ratios of elements have been taken into account. M S H 2O system is chosen to study since it is of importance in metallurgical solution. Compared with conventional methods, the algorithm is simple and conforms to real conditions.展开更多
Fluorinated smectic liquid crystals each with a biphenyl benzoate rigid core are investigated. Molecular structures of the studied compounds have difference only in fluorine position and the length of the carbon chain...Fluorinated smectic liquid crystals each with a biphenyl benzoate rigid core are investigated. Molecular structures of the studied compounds have difference only in fluorine position and the length of the carbon chain. Dielectric relaxation study and electro-optical measurements are carried out with the classical SSFLC geometry. The field-induced phase transitions are studied and the（E,T） phase diagram is established.展开更多
基金Project(2007CB613501) supported by the National Basic Research Program of ChinaProject(2006BAC02A05) supported by the National Science and Technology Pillar Program of ChinaProject(50904058) supported by the National Natural Science Foundation of China
文摘The potential—pH diagrams of the Cr-H2O system at temperatures of 298, 323, 373 and 423 K were established through thermodynamic calculation with coupling of experimental results. The potential—pH diagram at 298 K agrees well with the previously reported results. Based on the potential—pH diagrams of the Cr-H2O and Fe-H2O systems, IR spectra and XRD pattern, the existence forms of iron in the potassium chromate were analyzed, and the methods of iron removal were investigated. The results show that the existence forms of iron in the potassium chromate are potassium ferrate. These results are instructive and helpful to the hydrometallurgical processing of chromite ore.
基金the National Natural Science Foundation of China(51525805,51727812,51808526)。
文摘For aqueous interfacial reactions involving H+and OH-, the interfacial pH varies dynamically during the reaction process, which is a key factor determining the reaction performance. Herein, the kinetic relevance between the interfacial pH and reaction rate is deciphered owing to the success in establishing the transport equations of H+/OH- in unbuffered solutions, and is charted as a current(j)–pH diagram in the form of an electrochemical response. The as-described j–pH interplay is experimentally verified by the oxygen reduction and hydrogen evolution reactions. This diagram serves to form a panoramic graphic view of pH function working on the interfacial reactions in conjunction with the Pourbaix’s potential–pH diagram, and particularly enables a kinetic understanding of the transport effect of H+and OH-on the reaction rate and valuable instruction toward associated pH control and buffering manipulation.
文摘Aqueous E pH Diagram is an essential tool for analyzing hydrometallurgical and corrosion processes. Due to the requirements for environmental protection and energy saving in recent years, waste water processing and hydrometallurgical process of concentrate have been greatly developed. The construction of E pH diagrams has turned to multi component systems. However, there are some limits in plotting such diagrams. There is only one diagram for one multi component system, which can not reflect the truth of the aqueous reaction. In the paper, a new computation method is proposed to construct E pH diagrams. Component activity term is used to determine the boundary of stable areas. For the multi component systems, different atom ratios of elements have been taken into account. M S H 2O system is chosen to study since it is of importance in metallurgical solution. Compared with conventional methods, the algorithm is simple and conforms to real conditions.
文摘Fluorinated smectic liquid crystals each with a biphenyl benzoate rigid core are investigated. Molecular structures of the studied compounds have difference only in fluorine position and the length of the carbon chain. Dielectric relaxation study and electro-optical measurements are carried out with the classical SSFLC geometry. The field-induced phase transitions are studied and the（E,T） phase diagram is established.
