Meson-meson potentials from lattice QCD and inverse scattering

Potentials between light-light and heavy-light mesons are computed from meson-meson Green’s functions in the framework of quenched lattice QCD with Kogut-Susskind fermions. Comparisons with a full QCD simulation and a simulation using an O(a ²) tree-level and tadpole improved gauge action show that dynamic quarks and lattice discretization errors have no drastic influence. Calculations from inverse scattering theory propose a similar shape for $K\bar K$ potentials, whereas a good qualitative agreement with ππ potentials could not be obtained.     

Interaction of monovalent cationic drugs with montmorillonite

The aim of this study was to compare the adsorption of various organic drugs and a well-studied surfactant. The organic drugs used were promethazine chloride [10-(2-dimethylammonium) propylfenothiazine chloride] and buformin hydrochloride (1-butylbiguanidine chloride). The surfactant was benzalkonium chloride (N-tridecyl-N-benzyl-N,N-dimethylammonium chloride). Different amounts of drug solutions were added to montmorillonite suspensions, either separately (simple system) or in combination (competitive system) under the same conditions, and the organocomplexes formed were investigated. The organic molecule with the short alkyl chain adsorbed to yield monolayer coverage, whereas the aromatic molecule and the surfactant formed a pseudotrimolecular arrangement. In the competitive system, the larger organic molecules (having the same charge) displaced the smaller one from the interlayer space. The intercalation of molecules in the interlayer space was investigated by X-ray diffraction measurements. Received: 30 November 2000 Revised: 20 December 2001 Accepted: 26 October 2001     

An external theorem on divisors of a number

Main result: Let ? be a collection of divisors of N = pe11?penn (e1 = minei for all i? {1,…, n}) such that if any two numbers in ? are coprime then their common multiple is N and maximal with respect to this condition, i.e. there is no other collection satisfying this condition which properly contains ?. We prove that ? consists of at least $\text{e}{}_1\text{П}{}^{\mathrm{n}}{}_{\mathrm{i\; =\; 2}}\text{(e}{}_{\mathrm{i}}\text{+ 1)?(e}{}_1\text{? 2)}$ elements.     

Electronic spectra of the organic charge transfer salts TTT-In

Electronic spectra of TTT—I_n both in solution and in the solid state were measured between 8000 and 40,000 cm^-1. The highly conducting phase TTT—I_1.5 is assigned as (TTT^oTTT⁺) (T₃)^-. A phase TTT—I_2.7 is obtained and its possible electronic structure discussed. Conductivity results on both phases are presented.     

Interchain interactions and phase transition in NMeQn(TCNQ)2

A sharp non-reversible phase transition is found in the charge transfer salt NMeQn (TCNQ)₂. It is argued that solvent molecules between the chains are responsible for this phase transition, in that, when present they destroy the interchain coupling and lead to effectively decoupled chains in the material. The magnetic and electric properties of both phases are discussed.     

Analytic second derivatives for general coupled-cluster and configuration-interaction models

Analytic second derivatives of energy for general coupled-cluster (CC) and configuration-interaction (CI) methods have been implemented using string-based many-body algorithms. Wave functions truncated at an arbitrary excitation level are considered. The presented method is applied to the calculation of CC and CI harmonic frequencies and nuclear magnetic resonance chemical shifts up to the full CI level for some selected systems. The present benchmarks underline the importance of higher excitations in high-accuracy calculations.     

Investigating the Time Dependent Behavior of Thermoplastic Polymers under Tensile Load

The relationship between the results of the tensile and the stress relaxation tests of polypropylene specimens were analyzed and an attempt was made to find a way to estimate the former from the latter based on the measurements and the theory of linear viscoelasticity. The mechanical response of real polymers are basically of nonlinear character, therefore their behavior patterns do not meet the idealized (linear) ones. Experiments were performed on poly(propylene) (PP) as a test material and the stress relaxation behavior, as well as the linear elastic and linear viscoelastic approximation of the tensile load-time curve were analyzed. To demonstrate the applicability of our idea and to perform the numerical calculations we have chosen a flexible function with three parameters to realize the nonlinear behavior.     

Improved interval methods for solving circle packing problems in the unit square

Journal of Global Optimization - In this work computer-assisted optimality proofs are given for the problems of finding the densest packings of 31, 32, and 33 non-overlapping equal circles in a...     

A Double‐Clicking Bis‐Azide Fluorogenic Dye for Bioorthogonal Self‐Labeling Peptide Tags

Herein, we give the very first example for the development of a fluorogenic molecular probe that combines the two‐point binding specificity of biarsenical‐based dyes with the robustness of bioorthogonal click‐chemistry. This proof‐of‐principle study reports on the synthesis and fluorogenic characterization of a new, double‐quenched, bis‐azide fluorogenic probe suitable for bioorthogonal two‐point tagging of small peptide tags by double strain‐promoted azide–alkyne cycloaddition. The presented probe exhibits remarkable increase in fluorescence intensity when reacted with bis‐cyclooctynylated peptide sequences, which could also serve as possible self‐labeling small peptide tag motifs.     

An Algebraic Version of Haag’s Theorem

Under natural conditions (such as split property and geometric modular action of wedge algebras) it is shown that the unitary equivalence class of the net of local (von Neumann) algebras in the vacuum sector associated to double cones with bases on a fixed space-like hyperplane completely determines an algebraic QFT model. More precisely, if for two models there is a unitary connecting all of these algebras, then — without assuming that this unitary also connects their respective vacuum states or spacetime symmetry representations — it follows that the two models are equivalent. This result might be viewed as an algebraic version of the celebrated theorem of Rudolf Haag about problems regarding the so-called “interaction-picture” in QFT. Original motivation of the author for finding such an algebraic version came from conformal chiral QFT. Both the chiral case as well as a related conjecture about standard half-sided modular inclusions will be also discussed.