A unification of the Voigt functions

This paper aims to present a simple unification of the Voigt functions K(x,y) and L(x,y) through Fourier and Mellin transforms resulting in connections with the error functions, the parabolic cylinder functions and, ultimately, the Whittaker functions. Analogues of related functions are highlighted. The Voigt integrals will follow as natural consequences for analytical evaluations and uses.     

On the life and work of Cyrus Derman

This article provides a brief biographical synopsis of the life of Cyrus Derman and a comprehensive summary of his research. Professor Cyrus Derman was known among his friends as Cy.     

Resonance transition 795-nm rubidium laser using He buffer gas

We report a demonstration of a 795-nm rubidium optical resonance transition laser using a buffer gas consisting of pure ³He. This follows our recent demonstration of a hydrocarbon-free 795-nm rubidium resonance laser which used naturally-occurring He as the buffer gas. Using He gas that is isotopically enriched with ³He yields enhanced mixing of the Rb fine-structure levels. This enables efficient lasing at reduced He buffer gas pressure, improved thermal management in high average power Rb lasers and enhanced power scaling potential of such systems.     

Priming and sentence context support listening to noise-vocoded speech by younger and older adults

Older adults are known to benefit from supportive context in order to compensate for age-related reductions in perceptual and cognitive processing, including when comprehending spoken language in adverse listening conditions. In the present study, we examine how younger and older adults benefit from two types of contextual support, predictability from sentence context and priming, when identifying target words in noise-vocoded sentences. In the first part of the experiment, benefit from context based on primarily semantic knowledge was evaluated by comparing the accuracy of identification of sentence-final target words that were either highly predictable or not predictable from the sentence context. In the second part of the experiment, benefit from priming was evaluated by comparing the accuracy of identification of target words when noise-vocoded sentences were either primed or not by the presentation of the sentence context without noise vocoding and with the target word replaced with white noise. Younger and older adults benefited from each type of supportive context, with the most benefit realized when both types were combined. Supportive context reduced the number of noise-vocoded bands needed for 50% word identification more for older adults than their younger counterparts.     

Crystal and molecular structure of 3,3-diphenyl-3-phosphoniabicyclo[3.2.1]oct-6-ene bromide monohydrate

The title compound crystallizes in the monoclinic space groupP2₁/n,a=13.429(3),b=18.248(6),c=14.497(4)Å,=90.61(2)°,Z=8, with two independent molecules in the asymmetric unit. The structure was solved by heavy-atom methods, and refined to a finalR value of 0.040. The phosphoranium ring adopts a chair conformation which is substantially flattened at the phosphorus end. The ring conformation and torsion angles are compared with similar compounds.     

Nature of "hydrogen bond" in the diborane-benzene complex: covalent, electrostatic, or dispersive?

Motivated by the recent discovery of unusual "hydrogen bonding"-like interaction between a borane system and benzene molecules in a molecular crystal, we carried out quantum mechanical calculations on a model complex, diborane-benzene cluster. The aim is to understand the nature of this unique interaction, which is expected to play an essential role in this novel class of molecular crystals. As analyzed in the present study, the interaction between diborane and benzene is special in the following aspects: (1) this interaction is mostly dispersive; (2) the observed pseudodirectionality with one of the diborane bridge hydrogen directed toward the benzene centroid minimizes the van der Waals contact; and (3) in the "hydrogen bond" map, this interaction is located in a unique region, which is presently populated by a few known molecular complexes with very different chemical characteristics. It is anticipated that the results from the present analysis will provide meaningful guidance for molecular engineering with diborane-benzene as a building block and for stabilization of this and possible other hydrogen bonds by dispersive contributions.