Thomas-Fermi theory is an approximate method, which is widely used to describe the properties of matter at various hierarchical levels （atomic nucleus, atom, molecule, solid, etc.）. Special development is achieved u...Thomas-Fermi theory is an approximate method, which is widely used to describe the properties of matter at various hierarchical levels （atomic nucleus, atom, molecule, solid, etc.）. Special development is achieved using Thomas-Fermi theory to the theory of extreme states of matter appearing under high pressures, high temperatures or strong external fields. Relevant sections of physics and related sciences （astrophysics, quantum chemistry, a number of applied sciences） determine the scope of Thomas-Fermi theory. Popularity Thomas-Fermi theory is related to its relative simplicity, clarity and versatility. The latter means that result of the calculation by Thomas-Fermi theory applies immediately to all chemical elements： the transition from element to element is as simple scale transformation. These features make it highly convenient tool for qualitative and, in many cases, quantitative analysis.展开更多
Thomas-Fermi theory is an approximate method, which is widely used to describe the properties of matter at various hierarchical levels (atomic nucleus, atom, molecule, solid, etc.). Special development is achieved usi...Thomas-Fermi theory is an approximate method, which is widely used to describe the properties of matter at various hierarchical levels (atomic nucleus, atom, molecule, solid, etc.). Special development is achieved using Thomas-Fermi theory to the theory of extreme states of matter appearing under high pressures, high temperatures or strong external fields. Relevant sections of physics and related sciences (astrophysics, quantum chemistry, a number of applied sciences) determine the scope of Thomas-Fermi theory. Popularity Thomas-Fermi theory is related to its relative simplicity, clarity and versatility. The latter means that the result of the calculation by Thomas-Fermi theory applies immediately to all chemical elements: the transition from element to element is as simple scale transformation. These features make it to be a highly convenient tool for qualitative and, in many cases, and quantitative analysis.展开更多
Understanding the degradation behavior of azo dyes in photocatalytic wastewater treatment is of fundamental and practical importance for their application in textile-processing and other coloration industries. In this...Understanding the degradation behavior of azo dyes in photocatalytic wastewater treatment is of fundamental and practical importance for their application in textile-processing and other coloration industries. In this study, quantum chemistry, as density functional theory, was used to elucidate different degradation pathways of azo pyridone dyes in a hydroxyl radical(HO ·)-initiated photocatalytic system. A series of substituted azo pyridone dyes were synthesized by changing the substituent group in the para position of the benzene moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The effect of dye molecular structure on the photocatalytic degradation reaction mechanism was analyzed and quantification of substituent effects on the thermodynamic and kinetics parameters was performed. Potential energy surface analysis revealed the most susceptible reaction site for the HO ·attack. The calculated reaction barriers are found to be strongly affected by the nature of substituent group with a good correlation using Hammett σp constants and experimentally determined reaction rates. The stability of pre-reaction complexes and transition state complexes were analyzed applying the distortion-interaction model. The increased stability of the transition state complexes with the distancing from the substituent group has been established.展开更多
文摘Thomas-Fermi theory is an approximate method, which is widely used to describe the properties of matter at various hierarchical levels （atomic nucleus, atom, molecule, solid, etc.）. Special development is achieved using Thomas-Fermi theory to the theory of extreme states of matter appearing under high pressures, high temperatures or strong external fields. Relevant sections of physics and related sciences （astrophysics, quantum chemistry, a number of applied sciences） determine the scope of Thomas-Fermi theory. Popularity Thomas-Fermi theory is related to its relative simplicity, clarity and versatility. The latter means that result of the calculation by Thomas-Fermi theory applies immediately to all chemical elements： the transition from element to element is as simple scale transformation. These features make it highly convenient tool for qualitative and, in many cases, quantitative analysis.
文摘Thomas-Fermi theory is an approximate method, which is widely used to describe the properties of matter at various hierarchical levels (atomic nucleus, atom, molecule, solid, etc.). Special development is achieved using Thomas-Fermi theory to the theory of extreme states of matter appearing under high pressures, high temperatures or strong external fields. Relevant sections of physics and related sciences (astrophysics, quantum chemistry, a number of applied sciences) determine the scope of Thomas-Fermi theory. Popularity Thomas-Fermi theory is related to its relative simplicity, clarity and versatility. The latter means that the result of the calculation by Thomas-Fermi theory applies immediately to all chemical elements: the transition from element to element is as simple scale transformation. These features make it to be a highly convenient tool for qualitative and, in many cases, and quantitative analysis.
基金supported by the Ministry of Education,Science and Technological Development of the Republic of Serbia and the Slove-nian Research Agency (research core funding No. P2-0152)。
文摘Understanding the degradation behavior of azo dyes in photocatalytic wastewater treatment is of fundamental and practical importance for their application in textile-processing and other coloration industries. In this study, quantum chemistry, as density functional theory, was used to elucidate different degradation pathways of azo pyridone dyes in a hydroxyl radical(HO ·)-initiated photocatalytic system. A series of substituted azo pyridone dyes were synthesized by changing the substituent group in the para position of the benzene moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The effect of dye molecular structure on the photocatalytic degradation reaction mechanism was analyzed and quantification of substituent effects on the thermodynamic and kinetics parameters was performed. Potential energy surface analysis revealed the most susceptible reaction site for the HO ·attack. The calculated reaction barriers are found to be strongly affected by the nature of substituent group with a good correlation using Hammett σp constants and experimentally determined reaction rates. The stability of pre-reaction complexes and transition state complexes were analyzed applying the distortion-interaction model. The increased stability of the transition state complexes with the distancing from the substituent group has been established.
