This article is concerned with the problem of robust dissipative filtering for continuous-time polytopic uncertain neutral systems. The main purpose is to obtain a stable and proper linear filter such that the filteri...This article is concerned with the problem of robust dissipative filtering for continuous-time polytopic uncertain neutral systems. The main purpose is to obtain a stable and proper linear filter such that the filtering error system is strictly dissipative. A new criterion for the dissipativity of neutral systems is first provided in terms of linear matrix inequalities （LMI）. Then, an LMI sufficient condition for the existence of a robust filter is established and a design procedure is proposed for this type of systems. Two numerical examples are given. One illustrates the less conservativeness of the proposed criterion; the other demonstrates the validity of the filtering design procedure.展开更多
The two-state mechanism of the reaction of Nb(NH2)3 with N2O on the singlet and triplet potential energy surfaces has been investigated at the B3LYP level.Crossing points between the potential energy surfaces have bee...The two-state mechanism of the reaction of Nb(NH2)3 with N2O on the singlet and triplet potential energy surfaces has been investigated at the B3LYP level.Crossing points between the potential energy surfaces have been located using different methods.Analysis of the strain model shows that the singlet state of the four-coordinate(N2O)Nb(NH2)3 complex with N2O bonded via terminal N atom coordination(12) is more stable in the initial stage of reaction,since the bending of the N2O fragment [Edef(N2O) = 86.1 kcal mol-1] results in an energy splitting of the doubly degenerate LUMO;the low-energy LUMO can now strongly couple with the occupied Nb-localized d orbitals,forming a back-bond and transferring charge(q = 0.82 e) from Nb(NH2)3 to the N2O ligand.Going from 32 to 12,the reacting system changes spin multiplicity near the MECP(minimal energy crossing point) region,which takes place with a spin crossing barrier of 9.6-10.0 kcal mol-1.Analysis of spin-orbit coupling(SOC) indicates that MECP will produce a significant SOC matrix element.The value of SOC is 111.52 cm-1,due to the electron shift between two perpendicular φ orbitals with the same rotation direction,and the magnitude of the spin-multi-plicity mixing increases in the small energy gap between high-and low-spin states,greatly enhancing the probability of intersystem crossing.The probabilities of single(P1 ISC) and double(P2 ISC) passes estimated at MECP(SOC = 111.52 cm-1) are approximately 1.17×10-2 and 2.32×10-2,respectively.展开更多
The potential energy surface crossings for 1,2-dithiete have been investigated using the complete active space self-consistent field (CASSCF) method and simple group theory. Using the full Pauli-Breit spin-orbit coupl...The potential energy surface crossings for 1,2-dithiete have been investigated using the complete active space self-consistent field (CASSCF) method and simple group theory. Using the full Pauli-Breit spin-orbit coupling (SOC) operator $$ (\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{H} _{SO} ) $$ which consists of the one-electron $$ (\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{H} _{SO1} ) $$ and two-electron $$ (\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{H} _{SO2} ) $$ terms, we estimate the strengths of the SOC (198.37 cm?1 when symmetry is imposed, and 211.35 cm?1 with no symmetry constraints), which plays an essential role in the spin transitions between different spin states. The calculations show that the photolysis of 1,3-dithiol-2-one leads to the formation of trans-dithioglyoxal (trans-MinS0) as a primary product which subsequently gives a secondary product identified as thiolthioketene. Our calculated results are in close agreement with the experimental observations.展开更多
基金supported by the Major Program of National Natural Science Foundation of China(60710002)the Program for Changjiang Scholars and Innovative Research Team in University.
文摘This article is concerned with the problem of robust dissipative filtering for continuous-time polytopic uncertain neutral systems. The main purpose is to obtain a stable and proper linear filter such that the filtering error system is strictly dissipative. A new criterion for the dissipativity of neutral systems is first provided in terms of linear matrix inequalities （LMI）. Then, an LMI sufficient condition for the existence of a robust filter is established and a design procedure is proposed for this type of systems. Two numerical examples are given. One illustrates the less conservativeness of the proposed criterion; the other demonstrates the validity of the filtering design procedure.
基金Tianshui Normal University for a grant from the "QingLan" Talent Engineering Fundsthe Key Project of Chinese Ministry of Education(211189) for support of this research
文摘The two-state mechanism of the reaction of Nb(NH2)3 with N2O on the singlet and triplet potential energy surfaces has been investigated at the B3LYP level.Crossing points between the potential energy surfaces have been located using different methods.Analysis of the strain model shows that the singlet state of the four-coordinate(N2O)Nb(NH2)3 complex with N2O bonded via terminal N atom coordination(12) is more stable in the initial stage of reaction,since the bending of the N2O fragment [Edef(N2O) = 86.1 kcal mol-1] results in an energy splitting of the doubly degenerate LUMO;the low-energy LUMO can now strongly couple with the occupied Nb-localized d orbitals,forming a back-bond and transferring charge(q = 0.82 e) from Nb(NH2)3 to the N2O ligand.Going from 32 to 12,the reacting system changes spin multiplicity near the MECP(minimal energy crossing point) region,which takes place with a spin crossing barrier of 9.6-10.0 kcal mol-1.Analysis of spin-orbit coupling(SOC) indicates that MECP will produce a significant SOC matrix element.The value of SOC is 111.52 cm-1,due to the electron shift between two perpendicular φ orbitals with the same rotation direction,and the magnitude of the spin-multi-plicity mixing increases in the small energy gap between high-and low-spin states,greatly enhancing the probability of intersystem crossing.The probabilities of single(P1 ISC) and double(P2 ISC) passes estimated at MECP(SOC = 111.52 cm-1) are approximately 1.17×10-2 and 2.32×10-2,respectively.
基金Supported by the "QingLan" Talent Engineering Funds by Tianshui Normal University
文摘The potential energy surface crossings for 1,2-dithiete have been investigated using the complete active space self-consistent field (CASSCF) method and simple group theory. Using the full Pauli-Breit spin-orbit coupling (SOC) operator $$ (\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{H} _{SO} ) $$ which consists of the one-electron $$ (\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{H} _{SO1} ) $$ and two-electron $$ (\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\frown}$}}{H} _{SO2} ) $$ terms, we estimate the strengths of the SOC (198.37 cm?1 when symmetry is imposed, and 211.35 cm?1 with no symmetry constraints), which plays an essential role in the spin transitions between different spin states. The calculations show that the photolysis of 1,3-dithiol-2-one leads to the formation of trans-dithioglyoxal (trans-MinS0) as a primary product which subsequently gives a secondary product identified as thiolthioketene. Our calculated results are in close agreement with the experimental observations.
