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91.
The present work concerns with the investigation of the interior transmission problem, which is naturally associated to the
inverse elastic scattering problem of determining the support of an isotropic homogeneous penetrable body from a knowledge
of the time harmonic incident plane waves and the far-field patterns of the corresponding scattered wave-fields. Our approach
combines a boundary integral formulation of the problem and a compact perturbation argument to establish the discreteness
of the set of transmission eigenvalues and the well-posedness of the interior transmission problem under the most general
assumptions on the elastic parameters of the underlying media.
相似文献
92.
Kordatos Konstantinos Prato Maurizio Menna Enzo Scorrano Gianfranco Maggini Michele 《Journal of Sol-Gel Science and Technology》2001,22(3):237-244
We report on the synthesis of fullerene derivatives containing a trialkoxysilane moiety that exhibit enhanced solubility in solvents commonly used for sol-gel processing. These derivatives have been successfully embedded in glassy bulk samples and thin films that show very promising optical limiting properties. 相似文献
93.
Konstantinos G. Gatos Lszl Szzdi Bla Puknszky Jzsef Karger‐Kocsis 《Macromolecular rapid communications》2005,26(11):915-919
Summary: The effect of peroxide vulcanization on organoclay dispersion in hydrogenated nitrile rubber (HNBR)/organo‐montmorillonite (organo‐MMT) nanocomposites was investigated. Three types of organoclays were tested, one containing a primary amine and two bearing quaternary intercalants. In contrast to sulfur vulcanization, which in combination with primary amine intercalants produced a confined/deintercalated clay structure, the peroxide curing yielded well‐ordered intercalated nanocomposites. The tensile mechanical performance and oxygen permeability of the HNBR nanocomposites were determined.
94.
95.
The design and development of large-scale software projects is a complex endeavor, often facing problems like cost and schedule overruns as well as low quality. Over the last years the management of software development projects has been recognized as the cornerstone point of seeking improvement and solutions. Simulation modeling of the software project process is gaining interest among academics and practitioners, as a method to tackle the complex questions with which relevant enterprises are confronted. It offers support on several issues, such as defining software product development strategies, decision-making regarding process improvement and training, in a time span ranging from a short portion of the life cycle to long term product evolution, with organization-wide implications. The aim of this work is to implement a model simulating a core part of a software project process, enabling the estimation of several project development details such as delivery times and quality metrics. The purpose of the model is to assist project managers in control and monitoring, but also in identifying the best planning alternatives. The model scope covers a portion of the life cycle of an incremental software development venture. 相似文献
96.
A new mechanism for the evolution of primordial magnetic fields is described and analysed. The field evolution is followed from the time of its creation until the epoch of structure and galaxy formation. The mechanism takes into account the turbulent behaviour of the early universe plasma, whose properties determine strongly the evolution of the field configuration. A number of other related issues such as the case of an electroweak plasma are also considered. Finally, as an example, the mechanism is applied to specific models. 相似文献
97.
Graphene‐Based Inverted Planar Perovskite Solar Cells: Advancements,Fundamental Challenges,and Prospects 下载免费PDF全文
Dr. Konstantinos Petridis George Kakavelakis Dr. Minas M. Stylianakis Prof. Emmanuel Kymakis 《化学:亚洲杂志》2018,13(3):240-249
Metal halide based perovskite solar cells (PSCs) are considered among the most promising photovoltaic technologies, and already present certified efficiencies that surpass 22 %. The high performance and low fabrication cost make this technology competitive with that of state‐of‐the‐art thin‐film photovoltaics. However, PSCs present some striking disadvantages that hinder their commercialization, including short operational lifetimes, high toxicity, and hysteresis effects, which lower both the performance and long‐term stability of the devices. Herein, work conducted within the last two years is summarized with regard to addressing the challenges of low‐temperature‐processed planar inverted PSCs composed of graphene‐based materials. In addition, critical challenges and the prospects of this field are discussed and some prospects for future research directions are proposed. 相似文献
98.
Konstantinos D. Demadis 《Journal of solid state chemistry》2004,177(12):4768-4776
Aminomethylene phosphonates are important scale inhibitors applied in diverse areas of technology. This study adds to the existing body of information on this subject and reports the crystal and molecular structures of tetrasodium 2-hydroxyethylamino-bis(methylene-phosphonate) decahydrate ([Na4(HOCH2CH2N(CH2PO3)2)]·10H2O, 1). The crystal structure of 1 could be described as two-dimensional polymeric layered structure hydrogen bonded into a 3D supramolecular polymeric network. The structure of the tetraanion consists of a “three-arm” backbone stemming from the N atom. Two “arms” are deprotonated methylene phosphonate (-CH2PO32−) moieties and the third is a hydroxyethyl (-CH2CH2OH) moiety. One Na cation forms an intramolecular complex with two oxygens from separate phosphonate groups, a hydroxyl oxygen, the nitrogen and two lattice water molecules. The position of this Na cation points to a possible coordination site for Ca in a proposed Ca-HEABMP complex (HEABMP=2-hydroxyethylamino-bis(methylene-phosphonate). 相似文献
99.
Konstantinos F. Mavreas Dionysios D. Neofytos Evangelia D. Chrysina Alessandro Venturini Thanasis Gimisis 《Molecules (Basel, Switzerland)》2020,25(22)
Dysregulation of glycogen phosphorylase, an enzyme involved in glucose homeostasis, may lead to a number of pathological states such as type 2 diabetes and cancer, making it an important molecular target for the development of new forms of pharmaceutical intervention. Based on our previous work on the design and synthesis of 4-arylamino-1-(β-d-glucopyranosyl)pyrimidin-2-ones, which inhibit the activity of glycogen phosphorylase by binding at its catalytic site, we report herein a general synthesis of 2-substituted-5-(β-d-glucopyranosyl)pyrimidin-4-ones, a related class of metabolically stable, C-glucosyl-based, analogues. The synthetic development consists of a metallated heterocycle, produced from 5-bromo-2-methylthiouracil, in addition to protected d-gluconolactone, followed by organosilane reduction. The methylthio handle allowed derivatization through hydrolysis, ammonolysis and arylamine substitution, and the new compounds were found to be potent (μM) inhibitors of rabbit muscle glycogen phosphorylase. The results were interpreted with the help of density functional theory calculations and conformational analysis and were compared with previous findings. 相似文献
100.
Stavrakis S Koutsoupakis K Pinakoulaki E Urbani A Saraste M Varotsis C 《Journal of the American Chemical Society》2002,124(15):3814-3815
Time-resolved step-scan Fourier infrared spectroscopy has been used to study the CO-bound cbb(3)-type cytochrome c oxidase from Pseudomonas stutzeri at room temperature. We observe a single band in the FTIR spectrum at 1956 cm(-1) (beta-form). The time-resolved data indicate that upon photolysis, CO is transferred from heme b(3) (nu(CO) = 1956 cm(-1)) to CuB (nu(CO) = 2064 cm(-1)). The decay of the 2065 cm(-1) peak (t(1/2) = 120 +/- 16 ms) and the development of the 1956 cm(-1) peak (t(1/2) = 144 +/- 8 ms ) suggest that formation of the Fe-CO complex is concurrent with the decay of the CuB-CO complex. The intensity ratio of the Fe-CO/CuB-CO (2.15) remains constant for all data points, and thus we conclude that no fraction of CO escapes the binuclear center at 293 K. 相似文献