Interaction of quantum system Sa described by the generalised × eigenvalue equation A|s=EsSa|s (s=1,...,) with quantum system Sb described by the generalised n×n eigenvalue equation B|i=iSb|i (i=1,...,n) is considered. With the system Sa is associated -dimensional space Xa and with the system Sb is associated an n-dimensional space Xnb that is orthogonal to Xa. Combined system S is described by the generalised (+n)×(+n) eigenvalue equation [A+B+V]|k=k[Sa+Sb+P]|k (k=1,...,n+) where operators V and P represent interaction between those two systems. All operators are Hermitian, while operators Sa,Sb and S=Sa+Sb+P are, in addition, positive definite. It is shown that each eigenvalue ki of the combined system is the eigenvalue of the × eigenvalue equation
. Operator
in this equation is expressed in terms of the eigenvalues i of the system Sb and in terms of matrix elements s|V|i and s|P|i where vectors |s form a base in Xa. Eigenstate |ka of this equation is the projection of the eigenstate |k of the combined system on the space Xa. Projection |kb of |k on the space Xnb is given by |kb=(kSb–B)–1(V–kP})|ka where (kSb–B)–1 is inverse of (kSb–B) in Xnb. Hence, if the solution to the system Sb is known, one can obtain all eigenvalues ki} and all the corresponding eigenstates |k of the combined system as a solution of the above × eigenvalue equation that refers to the system Sa alone. Slightly more complicated expressions are obtained for the eigenvalues ki} and the corresponding eigenstates, provided such eigenvalues and eigenstates exist. 相似文献
The photochemistry of some members of the two series of γ-phenyl substituted acyclic β, γ-unsaturated ketones 1 and 2 upon direct irradiation with γ 310nm has been investigated, viz 1c–1h and 2b+2c.The alkyl substituted (E)-5-phenyl-4-penten-2-ones 1c–1h yield the corresponding 1,3-acyl shift products and (Z)-isomers, and 1g and 1h in addition two decarbonylated products. 2b only yields the (Z)-isomer and some benzaldehyde, but 2c yields the 1,3-acyl shift product, the ODPM product, three hydrocarbons formed by disproportionation of the allyl radical, and some benzaldehyde. The β-phenyl β, γ-UK 3a proved to be photostable. The 1,3-acyl shift products of 1c–1h result mainly from the singlet excited state in a cage radical process. The exclusive formation of the (E)-configuration of the 1,3-acyl shift product is explained in terms of conformational preference of the intermediate allyl radical. It is proposed that the formation of the (Z)-isomer proceeds from 1T(π -π*) which is populated according to . Evidence is presented which supports the proposed mechanism.The β,γ-UK 2b containing a benzoyl moiety leads to a higher degree of (E)-(Z) isomerization than the corresponding 1d which has an acetyl moiety.The triplet energies of (E)- and (Z)-1h are 56 and ca 70 kcal/mol respectively. 相似文献
The molecular structure of COBr2 has been determined as follows by an analysis of electron diffraction intensity: rg(CO) = 1.178 ± 0.009 Å, rg(C-Br) = 1.923 ± 0.005 Å and θ°α(Br-C-Br) = 112.3 ± 0.4°. The uncertainties represent estimated limits of error. The observed systematic trends in the bond lengths and bond angles in carbonyl and thiocarbonyl halides are discussed. 相似文献
AbstractFive new α-tetralone glycosides, juglanbiosides A-E (1–5), together with an α-tetralone derivative (15) and nine known 1,4-naphthoquinones (6–14) were isolated from the 95% EtOH extract of green walnut husks of Juglans mandshurica Maxim. Their structures were elucidated by comprehensive spectroscopic methods (1H, 13C NMR, DEPT, HSQC, HMBC, CD, HR-ESI-MS). In vitro cytotoxicities of all the isolated compounds were evaluated against BGC-823, HCT-15 and K562 cancer cell lines. 相似文献
This note is concerned with a novel inequality condition for the existence of ground states of partial difference systems. Our result is potentially applicable to the estimation of eigenvalues of the loaded strings and nets. 相似文献