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The title compounds contain groups (amine, amide, imine, carboxylic acid) that are capable of forming intramolecular hydrogen bonds involving a six-membered ring. In compounds where the two interacting functional groups are imine and carboxylic acid, the imine is protonated to give a zwitterion; where the two groups are imine and amide, the amide remains intact and forms a hydrogen bond to the imine nitrogen. The former is confirmed by the iminium 15N signal, which shows the coupling of 1J(15N,1H) -85 to -86.8 Hz and 3J(1H,1H) 3.7-4.2 Hz between the iminium proton and the methine proton of a cyclopropyl substituent on the iminium nitrogen. Hydrogen bonding of the amide is confirmed by its high 1H chemical shift and by coupling of the amide hydrogen to (amide) nitrogen [(1J(15N,1H) -84.7 to -90.7 Hz)] and to ortho carbons of a phenyl substituent. Data obtained from N,N-dimethylanthranilic acid show 15N-1H coupling of (-)8.2 Hz at 223 K (increasing to (-)5.3 Hz at 243 K) consistent with the presence of a N... H-O hydrogen bond. 相似文献
85.
We investigate the connection between sub-Planck structure in the Wigner function and the output fidelity of continuous-variable teleportation protocols. When the teleporting parties share a two-mode squeezed state as an entangled resource, high fidelity in the output state requires a squeezing large enough that the smallest sub-Planck structures in an input pure state are teleported faithfully. We formulate this relationship, which leads to an explicit relation between the fine-scale structure in the Wigner function and large-scale extent of the Wigner function, and we treat specific examples, including coherent, number, and random states and states produced by chaotic dynamics. We generalize the pure-state results to teleportation of mixed states. 相似文献
86.
Quantum discord and the power of one qubit 总被引:1,自引:0,他引:1
We use quantum discord to characterize the correlations present in the model called deterministic quantum computation with one quantum bit (DQC1), introduced by Knill and Laflamme [Phys. Rev. Lett. 81, 5672 (1998)10.1103/PhysRevLett.81.5672]. The model involves a collection of qubits in the completely mixed state coupled to a single control qubit that has nonzero purity. The initial state, operations, and measurements in the model all point to a natural bipartite split between the control qubit and the mixed ones. Although there is no entanglement between these two parts, we show that the quantum discord across this split is nonzero for typical instances of the DQC1 ciruit. Nonzero values of discord indicate the presence of nonclassical correlations. We propose quantum discord as figure of merit for characterizing the resources present in this computational model. 相似文献
87.
Mallika Somayajulu-Ni?u Jagdeep K Sandhu Jerome Cohen Marianna Sikorska TS Sridhar Anca Matei Henryk Borowy-Borowski Siyaram Pandey 《BMC neuroscience》2009,10(1):88
Background
Parkinson's disease, for which currently there is no cure, develops as a result of progressive loss of dopamine neurons in the brain; thus, identification of any potential therapeutic intervention for disease management is of a great importance. 相似文献88.
Carlton J. Maxson 《Discrete Mathematics》1974,10(1):133-144
For an arbitrary set X, if denotes the collection of finite subsets of X, then is called the finite subset algebra of X (which we also denote by . Because of the many natural occurrences of finite subset algebras, the intent of this paper is to initiate an investigation of the semigroup, End , of endomorphisms of .Several representations of End are obtained and these representations are in turn used to obtain information about the structure of End . In particular, the Green relations are characterized; for finite X, the maximal subgroups of End are found and the number of idempotents is given. As a side result, an abstract characterization of a certain semigroup of (0,1)-matrices is obtained. 相似文献
89.
In this paper we show that kinematic spaces with nontrivial dilatations are commutative. 相似文献
90.