Polycyclic aromatic hydrocarbons (PAH) are a prominent substance class with variety of applications in molecular materials science. Their electronic properties crucially depend on the bond topology ways that often highly non-intuitive. Here, we study, using density functional theory, triplet states four biphenylene-derived PAHs finding dramatically different excitation energies for closely rela...

Aquest article analitza i desenvolupa les implicacions tributàries de dos conceptes emergents dels últims mesos: el metavers els NFT. Pel que fa al metavers, s’analitza la tributació quatre negocis digitals es poden donar seu si, com publicitat digital, comerç electrònic, compravenda dades d’usuari d’objectes a través NFT, tot plegat lliga amb concepte jurídic nexe o punt connexió. D’altra band...

Fibonacenes (zig-zag unbranched catacondensed benzenoid hydrocarbons) are a class of polycyclic conjugated systems whose molecular graphs possess remarkable properties, often related with the Fibonacci numbers. This article is a review of the chemical graph theory of fibonacenes, with emphasis on their Kekulé–structure–related and Clar–structure–related properties. ————————————————— ∗Supported ...

We define the anti-forcing number of a perfect matching M of a graph G as the minimal number of edges of Gwhose deletion results in a subgraph with a unique perfect matching M , denoted by af (G,M). The anti-forcing number of a graph proposed by Vukičević and Trinajstić in Kekulé structures of molecular graphs is in fact the minimum anti-forcing number of perfect matchings. For plane bipartite ...

Strains of Entamoeba histolytica which were isolated from symptomatic patients and which possess a characteristic pathogenic isoenzyme pattern (zymodeme) have extrachromosomal circular DNA molecules containing RNA genes and clusters of tandemly reiterated PvuI elements. The nucleotide sequence of comparable reiterated BamHI elements present in amebae with nonpathogenic zymodemes differs from th...

Authors Jerome O Klein, MD Stephen Pelton, MD Section Editors Sheldon L Kaplan, MD Ellen M Friedman, MD Deputy Editor Mary M Torchia, MD Disclosures: Jerome O Klein, MD Consultant/Advisory Boards: GlaxoSmithKline [Vaccines (Pneumococcal)]; Cubist [Antibiotic for Clostridium difficile (Fidaxomicin)]. Stephen Pelton, MD Grant/Research/Clinical Trial Support: Pfizer [pneumococcal disease surveilla...

I will first explain the issue of social influence and illustrate the importance of evidence and trust relation between agents. Then I will introduce a new logic language that can be used to reason about an agents belief formation and dynamical change, due to evidences provided by other agents in the society. Some interesting features of social structure can be represented eventually as a updat...

The paper presents some approximation methods for the Boltz-mann equation. In the rst part fully implicit discretization techniques for the spatially homogeneous Boltzmann equation are investigated. The implicit equation is solved using an iteration process. It is shown that the iteration converges to the correct solution for the moments of the distribution function as long as the mass conserva...