Complete solutions of a family of quartic Thue and index form equations

Continuing the recent work of the second author, we prove that the diophantine equation

for has exactly 12 solutions except when , when it has 16 solutions. If denotes one of the zeros of , then for we also find all with .

     

The effects of temperature and pressure on the lifetime of benzophenone emission

The variation in the lifetime of flash-excited gaseous benzophenone with pressure and temperature indicates that (1) self-quenching is a relatively inefficient process for the long-lived emission, k_sq = 9 × 10⁵ M^?1 s^?1 (estimated from solution data) at 25°C and 1.2 × 10⁷ M^?1 s^?1 at 170°C and (2) the lifetime decreases with increasing temperature as a result of photochemical and photophysical decay pathways which have significant activation energies. The importance of diffusion to the walls on lifetime measurements is discussed.     

Toward understanding the ionization of biomarkers from micrometer particles by bio-aerosol mass spectrometry

The appearance of informative signals in the mass spectra of laser-ablated bio-aerosol particles depends on the effective ionization probabilities (EIP) of individual components during the laser ionization process. This study investigates how bio-aerosol chemical composition governs the EIP values of specific components and the overall features of the spectra from the bio-aerosol mass spectrometry (BAMS). EIP values were determined for a series of amino acid, dipicolinic acid, and peptide aerosol particles to determine what chemical features aid in ionization. The spectra of individual amino acids and dipicolinic acid, as well as mixtures, were examined for extent of fragmentation and the presence of molecular ion dimers, which are indicative of ionization conditions. Standard mixtures yielded information with respect to the significance of secondary ion plume reactions on observed spectra. A greater understanding of how these parameters affect EIP and spectra characteristics of bio-aerosols will aid in the intelligent selection of viable future biomarkers for the identification of bio-terrorism agents.     

Recherches sur la structure électronique de composés soufrés (méthode L.C.A.O. améliorée)

Improved L.C.A.O. method primitively built for conjugated molecules holding only atoms of second row in the periodic classification is extended to molecules holding atoms of the third row. The application is done for thiophen, thioketones, SO₂ and SO₃. d orbitals are not introduced in this study. Discussion about results shows that d orbitals must be introduced when the sulphur atom is strongly positively charged like in sulphur oxides.     

Anil-Synthese. 19. Mitteilung. Über die Herstellung von Stilbenyl-Derivaten des Isoxazols

Preparation of Stilbenyl Derivatives of Isoxazoles Schiff's bases derived from 3- and 5-(p-formylphenyl)-phenylisoxazoles and o- or p-chloroaniline are reacted with various p-tolyl substituted aromatic heterocycles in the presence of dimethylformamide and potassium hydroxide or potassium t-but-oxide to yield the corresponding heterocyclic substituted stilbenes (‘Anil synthesis’). 5-[4-(Chlorphenylimino-methyl)phenyl]-phenylisoxazoles react less readily than the corresponding 3-isomers.