Search results for "spectrum"

Symmetry patterns in the (N, Delta) spectrum

2007

We revise the role played by symmetry in the study of the low-lying baryon spectrum and comment on the difficulties when trying to generalize the symmetry pattern to higher energy states. We show that for the $(N,\Delta)$ part such a generalization is plausible allowing the identification of spectral regularities and the prediction of until now non-identified resonances.

The electronic spectrum of pyrrole

1999

The electronic spectrum of pyrrole has been investigated by performing calculations using a hierarchy of coupled-cluster models consisting of CCS, CC2, CCSD, and CC3. Basis-set effects have been investigated by carrying out calculations using correlation-consistent basis sets augmented with functions especially designed for the description of Rydberg states. Oscillator strengths, excited state dipole moments, and second moments of the electronic charge distributions have been used to characterize the electronic transitions and final states. Structures and vibrational frequencies have been calculated for a few selected states, and the importance of distinguishing between vertical and adiabat…

Coordination in a multi-cell multi-antenna multi-user W-CDMA system: a beamforming approach

2008

The problem of designing joint power control and optimal beamforming (JPCOB) algorithms for the downlink of a coordinated multi-cell WCDMA system is considered throughout this paper. In this case, the JPCOB design is formulated as the problem of minimizing the total transmitted power in the coordinated multi-cell system, subject to a certain quality of service requirement for each user. In this paper, the performance of two JPCOB algorithms based on different beamforming approaches is compared over the coordinated multi-cell system. The first one, obtains local beamformers by means of the well-known virtual uplink-downlink duality. In contrast, the second algorithm implements multi-base bea…

Behavioral phenotype and autism spectrum disorders in Cornelia de Lange syndrome

2015

Cornelia de Lange syndrome (CdLS) is a congenital disorder characterized by distinctive facial features, growth retardation, limb abnormalities, intellectual disability, and behavioral problems. Cornelia de Lange syndrome is associated with abnormalities on chromosomes 5, 10 and X. Heterozygous point mutations in three genes (<em>NIPBL</em>, <em>SMC3</em> and <em>SMC1A</em>), are responsible for approximately 50-60% of CdLS cases. CdLS is characterized by autistic features, notably excessive repetitive behaviors and expressive language deficits. The prevalence of autism spectrum disorder (ASD) symptomatology is comparatively high in CdLS. However, the pro…

Theoretical Analysis of the Electronic Spectra of Benzaldehyde

2001

The electronic spectrum of benzaldehyde has been studied by using multiconfigurational second-order perturbation theory through the multistate extension (MS-CASPT2). The nπ* 11A‘ ‘ state, placed ve...

Studies in organic mass spectrometry.VIII. The electron impact mass spectra of 2,4-substituted-3-diazo-5-phenylpyrroles

1990

The electron impact mass spectra (75 eV) of the β-diazopyrroles always show the molecular ions and undergo as the main fragmentation process the elimination of nitrogen followed by ring opening reactions leading to benzonitrile either as neutral or charged species. The peaks at 26 amu below the molecular ions, which are a general feature of these spectra, are due to the presence of the corresponding pyrroles which are formed by reductive reactions during the vaporization process of the samples.

Theoretical absorption and emission spectra of 1H- and 2H-benzotriazole

2003

Excitation energies, dipole moments, and transition properties for the lowest-lying 1(π, π*) and 1(n, π*) electronic states of two benzotriazole tautomers have been studied at the complete active space (CAS) SCF and multiconfigurational second-order perturbation (CASPT2) levels. With these results, the UV absorption spectra of 1H- and 2H-benzotriazole were first described individually, and then they were considered simultaneously in order to better understand the experimental, observed spectrum of benzotriazole. Aspects of the fluorescence of the compound have been also analyzed. The spectrum of benzotriazole is finally related to those of other azo-compounds.

Synthesis and photovoltaic performance of the porphyrin based sensitizers with 2H-[1,2,3]triazolo[4,5-c]pyridine and benzotriazole as auxiliary accep…

2017

Abstract Two novel zinc porphyrin dyes containing either benzotriazole or 2 H -[1,2,3]triazolo[4,5- c ]pyridine as auxiliary acceptors, respectively, were synthesized for dye-sensitized solar cells. These two auxiliary acceptors were firstly applied into porphyrin based dyes. The photophysical and electrochemical properties of the dyes were investigated. These two dyes show the whole visible light absorption when they are adsorbed on the TiO 2 film, which means that they are promising sensitizers for dye-sensitized solar cells. The absorption intensity of the triazolopyridine containing dye is higher than that of the benzotriazole containing dye, resulting in a better light harvesting. Thus…

Elektronenstoß-induzierte massenspektrometrische Fragmentierung von 2,2′-Bisindolylmethoxy- und Trisindolyl-methanen

1986

Preparation of dopaminergic N-alkyl-benzyltetrahydroisoquinolines using a 'one-pot' procedure in acid medium.

2000

The preparation of N-methyl-BTHIQ (4) from N-phenylethyl-phenacetamide (1) by cyclization, reduction and N-alkylation in acid medium has been achieved in good yield in a 'one-pot' procedure. Acylation of imine (2) intermediate afforded the Z and E stereoselectivity in the enamide formation. 6-Hydroxy-BTHIQ (7) shows selectivity for D2 dopamine receptors, while its N-methylated homologue (8) displays higher affinities for both D1 and D2 receptor types, with an unexpected increase in D1 dopamine receptor affinity.