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2006 IEEE Nuclear science Symposium, Medical Imaging Conference and 15th International Workshop on Room-Temperature Semiconductor X- and Gamma-Ray Detectors, Special Focus Workshops, NSS/MIC/RTSD

作者： Grybos, P. Maj, P. Szczygiel, R. Ramello, L. Idzik, M. Swientek, K. Stobiecki, T. Faculty of Electrical Engineering Automatics Computer Science and Electronics Department of Measurement and Instrumentation AGH University of Science and Technology Al. Mickiewicza 30 30-059 Cracow Poland Dip. Scienze e Tecnologie Avanzate Universita del Piemonte Orientale INFN Alessandria Italy Faculty of Physics and Applied Computer Science AGH University of Science and Technology Al. Mickiewicza 30 30-059 Cracow Poland Faculty of Electrical Engineering Automatics Computer Science and Electronics Department of Electronics AGH University of Science and Technology Al. Mickiewicza 30 30-059 Cracow Poland

ISBN: (纸本)1424405610

We present the development of a 64 channel readout ASIC called DEDIX for high count rate position-sensitive measurements using semiconductor detectors. The ASIC is designed in 0.35 μm CMOS process and its total area is 3400×5000 μm2. The DEDIX has a binary readout architecture. Each channel is built of a charge sensitive amplifier (CSA) with a pole-zero cancellation circuit, a shaper, two independent discriminators and two independent 20-bit counters. The size of the input device in CSA has been optimized for a detector capacitance in the range of 1-3 pF per strip. An equivalent noise charge of 110 el rms has been achieved for a total detector capacitance of 1 pF at the shaper peaking time of 160 ns. Internal correction DAC implemented in each channel independently ensures the low spread of effective threshold of discriminators at 0.4 mV on one sigma level. The mean gain in the multichannel ASIC is 54 μV/el, with a good uniformity from channel to channel (sd/mean = 0.8%). Low noise performance and high rate capability have been demonstrated by the measurement up to and above 1 MHz of average rate of input signals. © 2006 IEEE.

关键词： Imaging systems

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Perpendicular Magnetic Anisotropy Induced by Tetragonal Distortion of FeCo Alloy Films Grown on Pd(001)

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Physical Review Letters 2006年第25期96卷 257205-257205页

作者： Aimo Winkelmann Marek Przybylski Feng Luo Yisheng Shi Jochen Barthel Max-Planck Institut für Mikrostrukturphysik Weinberg 2 D-06120 Halle (Saale) Germany Solid State Physics Department Faculty of Physics and Applied Computer Science AGH University of Science and Technology Mickiewicza 30 30-059 Krakow Poland

We grew tetragonally distorted FexCo1−x alloy films on Pd(001). Theoretical first-principles calculations for such films predicted a high saturation magnetization and a high uniaxial magnetic anisotropy energy for specific values of the lattice distortion c/a and the alloy composition x. The magnetic anisotropy was investigated using the magneto-optical Kerr effect. An out-of-plane easy axis of magnetization was observed for Fe0.5Co0.5 films in the thickness range of 4 to 14 monolayers. The magnetic anisotropy energy induced by the tetragonal distortion is estimated to be almost 2 orders of magnitude larger than the value for bulk FeCo alloys. Using LEED Kikuchi patterns, a change of the easy axis of magnetization can be related to a decrease of the tetragonal distortion with thickness.

关键词： Iron alloys

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Medullary thyroid carcinoma: Multivariate analysis of prognostic factors influencing survival

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Clinical and Translational Oncology 2006年第6期8卷 435-443页

作者： Callejo, Isabel Peixoto Brito, José Américo Zagalo, Carlos Manuel Santos, Jorge Rosa Department of Head and Neck Surgery Portuguese Institute of Cancer 1750-401 Lisboa Rua Herminio Monteiro 3-5o A Portugal Department of Mathematics. Physics and Computer Science Faculty of Engineering and Applied Science Ryerson University Toronto ON Canada Department of Head and Neck Sullgery 1750-401 Lisboa Rua Herminio Monteiro 3-5o A Portugal

Background: Medullary thyroid carcinoma (MTC) is a rare development of thyroid cancer with a no negligible mortality rate. Our aim was to determine factors that predict outcome in patients with MTC. Methods: We reviewed the records of all patients with MTC (n=56) who underwent treatment at our institution between January 1990 and December 2000. Univariate and multivariate analysis of clinicopathologic predictors of MTC outcome were performed to identify subsets of patients with different probabilities in terms of overall survival, local recurrence, and distant metastases. Results: Multivariate analysis demonstrated that a statistically significant decrease in overall survival is associated with T4b tumours (p=0.06), the presence of distant metastases at the time of presentation (p=0.033), lymphatic invasion (p=0.099), and postoperative treatment (p=0.045). Conclusions: The analysis of survival curves of patients with MTC shows that the occurrence of locoregional and distant metastases occurs preferentially within the first 5 years, which identifies this as a crucial period for follow-up. In this series of patients with MTC, the tumours classified as T4b, metastases at presentation, the presence of lymphovascular invasion, and postoperative treatment were the most important prognostic features. At present, there is no available beneficial adjuvant therapy. However, as the development of molecular therapy progresses, it should be tested in clinical trials with the purpose of achievement of novel targeted therapies for selected MTC patients with risk factors. © FESEO 2006.

关键词： Lymphovascular invasion Medullary thyroid carcinoma RET Risk factors RTK Survival analysis

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Directed Evolutionary Programming: Towards an Improved Performance of Evolutionary Programming

Directed Evolutionary Programming: Towards an Improved Perfo...

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Congress on Evolutionary Computation

作者： A.-R. Hedar M. Fukushima Department of Computer Science Faculty of Computer and Information Sciences Assiut University Egypt Department of Applied Mathematics and Physics Graduate School of Informatics Kyoto University Kyoto Japan

Evolutionary programming (EP) is one of the main classes of evolutionary algorithms (EAs). Improving existing EAs is necessary in order to achieve better results and overcome their costly computational complexity. In this paper, we present a new version of EP called Directed Evolutionary Programming (DEP) in which more directing strategies with learned termination criteria are invoked to overcome some drawbacks of EP. In DEP, the mutated children are given the chance to improve themselves with the guidance of their parents. The search process in DEP is supported by diversification and intensification schemes in order to keep the diversity, achieve faster convergence and equip the search with an automatic termination criteria. The computational experiments show that DEP is efficient and cheaper than some well-known versions of EP.

关键词： Genetic programming Convergence Evolutionary computation Search methods Mathematics physics Informatics computer science Computational complexity Computational intelligence

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Sequence-structure-function relation characterized in silico

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In Silico Biology 2006年第6期6卷 589-600页

作者： Brylinskia, Michal Kochanczyk, Marek Konieczny, Leszek Roterman, Irena Department of Bioinformatics and Telemedicine Collegium Medicum Jagiellonian University 31-501 Krakow Kopernika 17 Poland Faculty of Chemistry Jagiellonian University 30-060 Krakow Ingardena 3 Poland Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University 30-059 Krakow Reymonta 4 Poland Department of Biochemistry Collegium Medicum Jagiellonian University 31-034 Krakow Kopernika 7 Poland

Methods for biological function recognition in silico appeared to be useful also for identifying characteristics of structure-to-function relations. The introduction of a three-dimensional Gauss function was assumed to represent the hydrophobic core in a protein molecule. The discrepancy between idealized "fuzzy oil-drop" and the observed one in real proteins appeared to be localized in the ligation site or in the area of biological function related part of protein molecule. The examples of proteins presented in this paper reveal that the structure-function relation can be evaluated and characterized also using the profile of the difference in value between idealized and real hydrophobicity distribution along the polypeptide chain. The specificity of particular polypeptide chain fragments in respect to their biological function and their specific participation in active site creation is discussed in this paper. The scale allowing comparison of different proteins in respect to their ligand-binding sites characteristics is introduced. © 2006 IOS Press. All rights reserved.

关键词： Active site Biological function Hydrophobicity Proteins of unknown biological function

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Functionalized carbazole AZO dyes for nonlinear optical application

Functionalized carbazole AZO dyes for nonlinear optical appl...

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8th International Conference on Laser and Fiber-Optical Networks Modeling, LFNM 2006

作者： Sahraoui, B. Czaplicki, R. Kajzar, F. Nizioll, Jacek Bednarz, Monika Laboratoire POMA UMR CNRS 6136 Universite d'Angers 2 Boulevard Lavoisier 49045 Angers Cedex France Faculty of Physics and Applied Computer Science AGH- University of Science and Technology al. Mickiewicza 30 30-059 Krakow Poland Department of Polymer Science and Technology Cracow University of Technology ul. Warszawska 24 31-155 Krakow Poland

ISBN: (纸本)1424402336

Nonlinear optics has been the subject of intensive research, because of its wide applications in field of photonics, nanophotonics and optoelectronics such as optical signal processing, broadband optical communications, integrated optics, optical sensing, optical poling, optical limiting, optical computing etc. Optical materials, with large coefficients of TPA and nonlinear refraction, are of prime importance in nonlinear optical applications Recently the carbazole azo dyes have attracted much attention because they are forming a spacious group of products which shows a wide range of colours and shades. These compounds are of significant importance for chemistry and technological applications particularly for optoelectronics applications. They are mostly obtained by the coupling reaction of diazonium salts and amines or phenols. We show that such compounds could be suitable candidate and promising materials for nonlinear optical application. In this talk third nonlinear optical properties using DFWM and THG will be discussed. Additionally in this talk illustration of new system for optical recording and erasing of holograms under weak laser illumination will be discussed. © 2006 IEEE.

关键词： Dyes

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Broken one-particle symmetry in few-electron coupled quantum dots

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Physical Review B 2006年第7期73卷 075422-075422页

作者： T. Chwiej S. Bednarek B. Szafran J. Adamowski F. M. Peeters Faculty of Physics and Applied Computer Science AGH University of Science and Technology PL-30059 Kraków Poland Departement Fysica Universiteit Antwerpen (UA/CGB) Groenenborgerlaan 171 B-2020 Antwerpen Belgium

Few-electron systems confined in vertically coupled quantum dots are studied by exact methods and through the local spin density approximation (LSDA). Special attention is paid to the recovering of the one-particle symmetry properties in the LSDA. It is shown that—in spite of accurate energy estimates—the LSDA does not reproduce the one-particle parity and the relative probability of finding a definite number of electrons in the different quantum dots. This symmetry breaking appears for certain electron configurations and intermediate thickness of the interdot barrier and is a direct result of electron-electron correlation. We discuss the effect of correlation on the symmetry properties of the few-electron wave function and determine the limits of the applicability of the LSDA for coupled quantum dots.

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Topology-dependent interface contribution to magneto-optical response from ultrathin Co films grown on the (001), (110), and (111) surfaces of Pd

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Physical Review B 2006年第8期73卷 085413-085413页

作者： M. Przybylski L. Yan J. Żukrowski M. Nyvlt Y. Shi A. Winkelmann J. Barthel M. Waśniowska J. Kirschner Max-Planck-Institut für Mikrostrukturphysik Weinberg 2 06120 Halle Germany Solid State Physics Department Faculty of Physics and Applied Computer Science AGH University of Science and Technology Mickiewicza 30 30-059 Krakow Poland Faculty of Mathematics and Physics Institute of Physics Charles University Ke Karlovu 5 12116 Praha 2 Czech Republic

We have grown ultrathin epitaxial Co films on three low-index surfaces of Pd. Their magnetic properties studied by the magneto-optical Kerr effect are correlated with the surface morphology analyzed by scanning tunneling microscopy. A perpendicular magnetic anisotropy in the films appeared after exposure to residual gas atmosphere at low temperature, after coverage with an Au overlayer or after annealing at 370K and above. For one- and two-monolayer-thick films the hysteresis loops are reversed with respect to those of thicker Co films. This is due the negative polar Kerr rotation contribution from the Co∕Pd interface dominating over the positive polar Kerr rotation contribution from the noninterface part of the Co film. Reversed loops are not seen when the Co films grow in a three-dimensional mode. This indicates a clear correspondence between the mode of growth and the magneto-optical response. Near the film thickness where the Kerr rotation changes sign a remarkable temperature behavior is observed which is discussed as a superposition of two different magneto-optical contributions. The results qualitatively agree with the available ab initio band-structure calculations for the Co∕Pd multilayer structures with variable thickness of the Co layers.

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Magnetisation and electron spin resonance of the colossal magnetoresistive la0.67Ca0.33Mn1-xFexO3

Magnetisation and electron spin resonance of the colossal ma...

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作者： ZajĄc, T. Folcik, L. Chmist, J. Kolodziejczyk, A. Drulis, H. Krop, K. Gritzner, G. Faculty of Physics and Applied Computer Science AGH University of Science and Technology 30-059 Cracow Poland Institute of Low Temperature and Structure Research Polish Academy of Sciences 50-950 Wroclaw Poland Institut für Chemische Technologie Anorganischer Stoffe Johannes Kepler Universität A-4040 Linz Austria

We report magnetisation and electron spin resonance (ESR) measurements on the colossal magnetoresistive manganites Lao0.67Ca 0.33Mn1-xFexO3, with x = 0, 0.01, 0.03, 0.06, 0.10, and 0.15, in the vicinity of their magnetic (TC) and metal-insulator (TMI) transition temperatures. Above T C, the resonance lines with g 2 are caused by ferromagnetic metallic clusters exhibiting a double exchange interaction between Mn 3+-Mn4+ ions. The lines were observed with cooling far below both TC and TMI, and were fitted by the Dysonian line-shape. The temperature dependences of the line-widths exhibited a minimum value at Tmin 1.25TC, followed by an increase with further cooling toward TC. The anomalous behaviour of the line-width below Tmin is due to the appearance of a ferromagnetic metallic phase within the paramagnetic matrix. The role of phase segregation, in which the compounds are phase-separated into a mixture of ferromagnetic and paramagnetic regions, is discussed.

关键词： Colossal magnetoresistance

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Dependence of the vortex structure in quantum dots on the range of the inter-electron interaction

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Physical Review B 2006年第7期73卷 075315-075315页

作者： T. Stopa B. Szafran M. B. Tavernier F. M. Peeters Departement Fysica Universiteit Antwerpen Groenenborgerlaan 171 B-2020 Antwerpen Belgium Faculty of Physics and Applied Computer Science AGH University of Science and Technology al. Mickiewicza 30 30-059 Kraków Poland

The internal structure of a composite fermion is investigated for a two-dimensional parabolic quantum dot containing three electrons. A Yukawa screened Coulomb interaction is assumed, which allows us to discuss the evolution of the electron-vortex correlations from the Coulomb interaction limit to the contact potential limit. The vortex structure approaches the Laughlin limit nonmonotonically through the formation of intermediate composite fermions in which a flip of the spatial orientation of the vortices with respect to the position of the electrons is observed. Only when we limit ourselves to the lowest Landau level (LLL) approximation the flip appears through the formation of an intermediate giant vortex at specific values of the screening length. Beyond the LLL approximation antivortices appear in the internal structure of the intermediate composite fermions which prevent the nucleation of giant vortices. We also studied the system of five electrons and show that the mechanism of the flip of the vortex orientation found for three-electron system is reproduced for higher number of electrons.

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