Wrocław University of Technology

About: Wrocław University of Technology is a education organization based out in Wrocław, Poland. It is known for research contribution in the topics: Laser & Fuzzy logic. The organization has 13115 authors who have published 31279 publications receiving 338694 citations.

On differences between hydrogen bonding and improper blue-shifting hydrogen bonding.

Abstract: Twenty two hydrogen-bonded and improper blue-shifting hydrogen-bonded complexes were studied by means of the HF, MP2 and B3LYP methods using the 6-31G(d,p) and 6—311++G(d,p) basis sets. In contrast to the standard H bonding, the origin of the improper blue-shifting H bonding is still not fully understood. Contrary to a frequently presented idea, the electric field of the proton acceptor cannot solely explain the different behavior of the H-bonded and improper blue-shifting H-bonded complexes. Compression of the hydrogen bond due to different attractive forces—dispersion or electrostatics—makes an important contribution as well. The symmetry-adapted perturbation theory (SAPT) has been utilized to decompose the total interaction energy into physically meaningful contributions. In the red-shifting complexes, the induction energy is mostly larger than the dispersion energy while, in the case of blue-shifting complexes, the situation is opposite. Dispersion as an attractive force increases the blue shift in the blue-shifting complexes as it compresses the H bond and, therefore, it increases the Pauli repulsion. On the other hand, dispersion in the red-shifting complexes increases their red shift.

Fractional Lévy stable motion can model subdiffusive dynamics.

Abstract: We show in this paper that the sample time average mean-squared displacement MSD of the fractional Levy -stable motion behaves very differently from the corresponding ensemble average second moment. While the ensemble average MSD diverges for 2, the sample MSD may exhibit either subdiffusion, normal diffusion, or superdiffusion. Thus, H-self-similar Levy stable processes can model either a subdiffusive, diffusive or superdiffusive dynamics in the sense of sample MSD. We show that the character of the process is controlled by a sign of the memory parameter d =H �1 /. We also introduce a sample p-variation dynamics test which allows to distinguish between two models of subdiffusive dynamics. Finally, we illustrate a subdiffusive behavior of the fractional Levy stable motion on biological data describing the motion of individual fluorescently labeled mRNA molecules inside live E. coli cells, but it may concern many other fields of contemporary experimental physics. DOI: 10.1103/PhysRevE.82.021130

Bicriterion Single Machine Scheduling with Resource Dependent Processing Times

Abstract: A bicriterion problem of scheduling jobs on a single machine is studied. The processing time of each job is a linear decreasing function of the amount of a common discrete resource allocated to the job. A solution is specified by a sequence of the jobs and a resource allocation. The quality of a solution is measured by two criteria, F1 and F2. The first criterion is the maximal or total (weighted) resource consumption, and the second criterion is a regular scheduling criterion depending on the job completion times. Both criteria have to be minimized. General schemes for the construction of the Pareto set and the Pareto set $\epsilon$-approximation are presented. Computational complexities of problems to minimize F1 subject to F_2\le K$ and to minimize F2 subject to $F_1\le K$, where K is any number, are studied for various functions F1 and F2. Algorithms for solving these problems and for the construction of the Pareto set and the Pareto set $\epsilon$-approximation for the corresponding bicriterion problems are presented.

Effects of Si-rich oxide layer stoichiometry on the structural and optical properties of Si QD/SiO2 multilayer films.

Abstract: The effects of the stoichiometry of the Si-rich oxide (SRO) layer, O/Si ratio, on the structural and optical properties of SRO/SiO2 multilayer films were investigated in this work. SRO/SiO2 multilayer films with different O/Si ratios were grown by a co-sputtering technique, and Si quantum dots (QDs) were formed with post-deposition annealing. By transmission electron microscopy (TEM) and glancing incidence x-ray diffraction (GIXRD), it was found that the Si QD size decreases with increases in O/Si ratio. The photoluminescence (PL) spectrum varies with the O/Si ratio in band position, shape and intensity. In addition, it was observed that the absorption edge blue-shifts with increases in the O/Si ratio. The change in the absorption edge is consistent with strengthening quantum confinement effects in Si QDs, as indicated by TEM and GIXRD. The optical properties were also investigated by 2D photoluminescence excitation (2D-PLE) and lifetime measurements. The origin of emission and absorption is discussed based on the absorption, PL, 2D-PLE and decay time measurements.