RESUMO
The vibrational spectra of H3 +Ar2,3 and D3 +Ar2,3 are investigated in the 2000 cm-1 to 4500 cm-1 region through a combination of mass-selected infrared laser photodissociation spectroscopy and computational work including the effects of anharmonicity. In the reduced symmetry of the di-argon complex, vibrational activity is detected in the regions of both the symmetric and antisymmetric hydrogen stretching modes of H3 +. The tri-argon complex restores the D3h symmetry of the H3 + ion, with a concomitant reduction in the vibrational activity that is limited to the region of the antisymmetric stretch. Throughout these spectra, additional bands are detected beyond those predicted with harmonic vibrational theory. Anharmonic theory is able to reproduce some of the additional bands, with varying degrees of success.
RESUMO
Near-infrared spectroscopy measurements are presented for protonated water clusters, H+(H2O) n, in the size range of n = 1-8. Clusters are produced in a pulsed-discharge supersonic expansion, mass selected, and studied with infrared laser photodissociation spectroscopy in the regions of 3600-4550 and 4850-7350 cm-1. Although there is some variation with cluster size, the main features of these spectra are a broad absorption near 5300 cm-1, a sharp doublet near 7200 cm-1, as well as a structured absorption near 4100 cm-1 for n ≥ 2. The vibrational patterns measured for the hydronium, Zundel, and Eigen ions are compared to those predicted by different forms of anharmonic theory. Second-order vibrational perturbation theory (VPT2) and a local mode treatment of the OH stretches both capture key aspects of the spectra but suffer understandable deficiencies in the quantitative description of band positions and intensities.
RESUMO
Ion-molecule complexes of the form H+Arn are produced in pulsed-discharge supersonic expansions containing hydrogen and argon. These ions are analyzed and mass-selected in a reflectron spectrometer and studied with infrared laser photodissociation spectroscopy. Infrared spectra for the n = 3-7 complexes are characterized by a series of strong bands in the 900-2200 cm-1 region. Computational studies at the MP2/aug-cc-pVTZ level examine the structures, binding energies, and infrared spectra for these systems. The core ion responsible for the infrared bands is the proton-bound argon dimer, Ar-H+-Ar, which is progressively solvated by the excess argon. Anharmonic vibrational theory is able to reproduce the vibrational structure, identifying it as arising from the asymmetric proton stretch in combination with multiple quanta of the symmetric argon stretch. Successive addition of argon shifts the proton vibration to lower frequencies, as the charge is delocalized over more ligands. The Ar-H+-Ar core ion has a first solvation sphere of five argons.
RESUMO
An analytical Bayesian inversion of the JET interferometry line integrated densities into density profiles and associated uncertainty information, is demonstrated. These are used, with a detailed model of plasma polarimetry, to predict the rotation and ellipticity for the JET polarimeter. This includes the lateral channels, for over 45,000 time points over 1313 JET pulses. Good agreement with measured values is shown for a number of channels. For the remaining channels, the requirement of a more detailed model of the diagnostic is demonstrated. A commonly used approximation for the Cotton-Mouton effect on the lateral channels is also evaluated.
RESUMO
OBJECTIVES: To identify the core skills required of dental graduates, and to identify if and when these skills had been acquired. DESIGN: Postal questionnaire containing a stimulus list of clinical, technical and professional skills. SUBJECTS AND SETTING: General Dental Practitioners (GDPs) registered as vocational trainers, Vocational Dental Practitioners (VDPs) starting their vocational training (VT) year and VDPs ending their VT year in the NHS Trent Region of England. METHOD: The list of skills on the questionnaire was formulated following discussion with a group of 4 clinical academics and 5 GDPs working in the University of Sheffield School of Clinical Dentistry. The questionnaire was sent to the total population of GDPs and VDPs, and responses were requested on an anonymous basis. The purpose mirrored that of a previous survey undertaken in the University of Sheffield Medical School to identify core skills (1), initially in this present survey, defined as skills required by the majority of GDPs (> 50%) and/or used by VDPs (> 50%) in their VT year. RESULTS: 45 of the skills were identified by GDPs as those they expected of the new graduate. All these core skills had been acquired by > 50% of VDPs commencing their VT year with 32 of the skills acquired by > 75% of that group. Of the group ending their VT year, 90% and above had acquired the majority of these skills. At the time of graduation > 50% of VDPs had acquired 10 skills not expected by GDPs. At the end of the VT year, 6 of these unexpected skills had been acquired by > 75% of VDPs. CONCLUSIONS: The survey enabled us to audit the skills required at the end of the undergraduate course and provided the basis for monitoring skills development in undergraduate dental students.
Assuntos
Competência Clínica , Currículo , Educação em Odontologia , Odontologia Geral/educação , Inglaterra , Humanos , Mentores , PreceptoriaRESUMO
A social worker's Home Inquiry was conducted for 75 schizophrenic males as soon as possible after hospitalization. A standard set of items based on this inquiry was scored in terms of nine factors. These Home Inquiry factor scores were found to have modest but statistically significant correlations with specific symptom ratings conducted two years after admission. In the present sample, an interpersonally uncomfortable childhood home and low premorbid self-esteem have untoward implications for the remission of symptoms.
