Indium(I) trifluoromethanesulfonate and other soluble salts for univalent indium chemistry

Herein we report the synthesis, structure and preliminary reactivity studies of a series of unusually soluble indium(i) salts that are improved alternatives to indium(i) halide reagents.     

Second-harmonic generation in resonant waveguide gratings incorporating ionic self-assembled monolayer polymer films

Experimental results on resonantly excited second-harmonic generation (SHG) in a periodic ionically self-assembled monolayer (ISAM) film are reported. A double-layer guided-mode resonance filter (GMRF) structure is coated with 40 bilayers of pyrlium-based chi(2) ISAM thin film and excited with the fundamental of a Nd:YAG laser. Enhanced second-harmonic conversion in the ISAM film is achieved because of the local field enhancement associated with the fundamental resonating leaky mode. This method of SHG is particularly promising, as the ISAM films under investigation exhibit anomalous dispersion that may be applied for phase matching to improve nonlinear conversion efficiency.     

Atomic level control over surface species via a molecular precursor approach: isolated Cu(I) sites and Cu nanoparticles supported on mesoporous silica

A nonaqueous molecular precursor grafting approach was employed for the generation of well-defined surface structures featuring Cu on a mesoporous silica support. X-ray absorption measurements (XANES and EXAFS) were used to determine that [CuOSi(OtBu)3]4 provided 100% isolated Cu(I) sites upon grafting (without thermal treatment), whereas [CuOtBu]4 gave isolated species with most of the original Cu-O-Cu linkages intact, but in a more relaxed straight chain form. Upon heating under inert conditions, the vast majority of Cu in the materials from [CuOSi(OtBu)3]4 remained as isolated Cu(I) sites (up to 88% isolation), with significant stabilization provided from the -OSi(OtBu)3 ligands. In stark contrast, approximately 100% of the Cu in the materials generated from [CuOtBu]4 was readily reduced upon heating, forming isolated Cu metal particles with an average diameter of 0.7 nm.     

Multicriteria Analysis Represented by Artificial Intelligence Techniques

This paper presents a possible representation of multicriteria analysis by means of artificial intelligence techniques. The decision process activities characterized by the existence of formal and technical knowledge were identified and attention was focused on the area of multicriteria outranking methods. The knowledge characteristics suggested the use of artificial intelligence techniques, based on a conceptualization in which the domain of discourse is the set of the multicriteria methodology concepts used in the analysed area of activities, and the relational set is the union of the admissible relations among the concepts and the relations elicited from experience. The suitable AI techniques were tested by implementing a knowledge-based interface between the outranking methods and a user who was not very familiar with this approach.     

Mass-spectrometric study of 6-methyl-2-aryl-7-benzylindolizines

The mass-spectral behavior of 15 compounds from the 6-methyl-2-aryl-7-benzylindolizine series was investigated, and it was shown that the peculiarities of their dissociative ionization are due to the formation of stable resonance-stabilized ions that contain a quaternized nitrogen atom in the heteroring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1368–1373, October, 1981.     

Optical symmetry in liquid crystal displays

Some authors include in their articles polar plots showing the directional dependence of either transmission or contrast ratio of a liquid crystal display (LCD). In some cases those plots have a symmetry axis; here we explain when and why it occurs.