Zeitschrift für Naturforschung. A, A journal of physical sciences 

About: Zeitschrift für Naturforschung. A, A journal of physical sciences is an academic journal. The journal publishes majorly in the area(s): Crystal structure & X-ray crystallography. Over the lifetime, 317 publications have been published receiving 2077 citations.

Fractals, Multifractals, and Thermodynamics: An Introductory Review

Abstract: The basic concept of fractals and multifractals are introduced for pedagogical purposes, and the present status is reviewed. The emphasis is put on illustrative examples with simple mathematical structures rather than on numerical methods or experimental techniques. As a general characterization of fractals and multifractals a thermodynamical formalism is introduced, establishing a connection between fractal properties and the statistical mechanics of spin chains.

Construction of Differential Equations from Experimental Data

Abstract: A new algorithm to determine the number of degrees of freedom of dynamic systems is presented. To obtain a concise description of an observed chaotic time sequence, an approximation of the flow in a state space representation by series is shown to be useful.

Molecular Dynamics and X-Ray Diffraction Study of Aqueous Beryllium (II) Chloride Solutions

Abstract: A structural investigation of a 1.1 molal BeCl2 aqueous solution has been performed by a molecular dynamics simulation together with X-ray diffraction studies of 1.1 and 5.3 molal BeCl2 aqueous solutions at pH =1. A central force model in combination with an improved intramolecular three-body potential was used for water. The ion-water and ion-ion potentials were derived from ab initio calculations. The structure function obtained from the simulation is in satisfactory agreement with that from X-ray diffraction. The MD simulation of the 1.1 molal solution shows that the hydration shell o f Be2+ consists of six water molecules occupying octahedral sites around a central Be2+. The X-ray scattering data of the 5.3 molal solution indicate that Be2+ has only four water molecules in the first hydration shell. The average coordination number of Cl- is found to be about seven in the 1.1 molal solution from both X-ray diffraction and MD simulation, but Cl- is surrounded on the average by 3.4 water molecules in the 5.3 molal solution. The influence of the small divalent Be2+ on the geometry of its nearest neighbour water molecules is compared with the results of previous simulations of 1.1 molal MgCl2 and CaCl2 solutions.

An Improved Modified Extended tanh-Function Method

Abstract: In this paper we further improve the modified extended tanh-function method to obtain new exact solutions for nonlinear partial differential equations. Numerical applications of the proposed method are verified by solving the improved Boussinesq equation and the system of variant Boussinesq equations. The new exact solutions for these equations include Jacobi elliptic doubly periodic type, Weierstrass elliptic doubly periodic type, triangular type and solitary wave solutions.

Anachelin, the siderophore of the cyanobacterium Anabaena cylindrica CCAP 1403/2A

Abstract: A catecholate siderophore - anachelin - has been isolated from the cyanobacterium Anabaena cylindrica CCAP 1403/2A. The central part of the siderophore is a tripeptide consisting of L-Thr, D-Ser and L-Ser. Its C-terminus is linked amidically to a 1,1-dimethyl-3-amino-1,2,3,4-tetrahydro-7,8-dihydroxyquinolinium system and its N-terminus to 6-amino-3,5,7-trihydroxyheptanoic acid. The 7-hydroxyl group of the latter is esterified with salicylic acid whose carboxyl group is condensed with the 6-amino group to an oxazoline ring. Anachelin is the first genuine siderophore of a cyanobacterium whose structure has been elucidated.