The geometries, stabilities, and electronic properties of FSin （n=1～12） clusters are systematically investigated by using first-principles calculations based on the hybrid density-functional theory at the B3LYP/6-3...The geometries, stabilities, and electronic properties of FSin （n=1～12） clusters are systematically investigated by using first-principles calculations based on the hybrid density-functional theory at the B3LYP/6-311G level. The geometries are found to undergo a structural change from two-dimensional to three-dimensional structure when the cluster size n equals 3. On the basis of the obtained lowest-energy geometries, the size dependencies of cluster properties, such as averaged binding energy, fragmentation energy, second-order energy difference, HOMO–LUMO （highest occupied molecular orbital–lowest unoccupied molecular orbital） gap and chemical hardness, are discussed. In addition, natural population analysis indicates that the F atom in the most stable FSin cluster is recorded as being negative and the charges always transfer from Si atoms to the F atom in the FSin clusters.展开更多
A new algorithm for fault superimposed quantity(FSIQ)is presented and analyzed.The network equations are built up by combining fault superimposed networks(FSIN)with the boundary conditions of FSIQ at the fault point a...A new algorithm for fault superimposed quantity(FSIQ)is presented and analyzed.The network equations are built up by combining fault superimposed networks(FSIN)with the boundary conditions of FSIQ at the fault point and are solved with the Newton iterative method.The algorithm has clear physical meaning and does not require an intermediate procedure to derive FSIQ.The algorithm is implemented by computer programming,and the results of calculations show that the algorithm is fast and accurate.The method can be used not only to calculate FSIQ in the complex power systems with simple or multiple faults,but also to analyze and evaluate the performance of the protective relays and automatic devices based on FSIQ.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304167 and 51374132)the Postdoctoral Science Foundation of China(Grant No.20110491317)+1 种基金the Young Core Instructor Foundation of Henan Province,China(Grant No.2012GGJS-152)the Natural Science Foundation of Henan Province,China(Grant Nos.132300410209 and 132300410290)
文摘The geometries, stabilities, and electronic properties of FSin （n=1～12） clusters are systematically investigated by using first-principles calculations based on the hybrid density-functional theory at the B3LYP/6-311G level. The geometries are found to undergo a structural change from two-dimensional to three-dimensional structure when the cluster size n equals 3. On the basis of the obtained lowest-energy geometries, the size dependencies of cluster properties, such as averaged binding energy, fragmentation energy, second-order energy difference, HOMO–LUMO （highest occupied molecular orbital–lowest unoccupied molecular orbital） gap and chemical hardness, are discussed. In addition, natural population analysis indicates that the F atom in the most stable FSin cluster is recorded as being negative and the charges always transfer from Si atoms to the F atom in the FSin clusters.
基金study was supported by the National Natural Science Foundation of China (No.50077011).
文摘A new algorithm for fault superimposed quantity(FSIQ)is presented and analyzed.The network equations are built up by combining fault superimposed networks(FSIN)with the boundary conditions of FSIQ at the fault point and are solved with the Newton iterative method.The algorithm has clear physical meaning and does not require an intermediate procedure to derive FSIQ.The algorithm is implemented by computer programming,and the results of calculations show that the algorithm is fast and accurate.The method can be used not only to calculate FSIQ in the complex power systems with simple or multiple faults,but also to analyze and evaluate the performance of the protective relays and automatic devices based on FSIQ.
