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101.
Dragan Manasijevi? Duško Mini? Iwao Katayama Desimir Petkovi? 《Journal of Physics and Chemistry of Solids》2009,70(9):1267-1273
Binary thermodynamic data, successfully used for phase diagram calculations of binary systems Bi-Ga, Bi-Sn, and Ga-Sn, were used for prediction of phase equilibria in ternary Bi-Ga-Sn system. The thermodynamic functions, such as enthalpy of formation and activity, were calculated using the Redlich-Kister-Muggianu model and compared with experimental data reported in the literature. The liquidus surface, invariant equilibria and three vertical sections with molar ratio Ga:Sn=1, Bi:Sn=1 and Bi:Ga=1 of the Bi-Ga-Sn ternary system were calculated by the CALPHAD method. Alloys, situated along three calculated vertical sections, were investigated by Differential Scanning Calorimetry (DSC). The experimentally determined phase transition temperatures were compared with calculation results and good mutual agreement was noticed. 相似文献
102.
Klavdija Kutnar Urban Borštnik Dragan Marušič Dušanka Janežič 《Journal of mathematical chemistry》2009,45(2):372-385
A class of interconnection networks for efficient parallel MD simulations based on hamiltonian cubic symmetric graphs is presented.
The cubic symmetric graphs have many desirable properties as interconnection networks since they have a low degree and are
vertex- and edge-transitive. We present a method for scheduling collective communication routines that are used in parallel
MD and are based on the property that the graphs in question have a Hamilton cycle, that is, a cycle going through all vertices
of the graph. Analyzing these communication routines shows that hamiltonian cubic symmetric graphs of small diameter are good
candidates for a topology that gives rise to an interconnection network with excellent properties, allowing faster communication
and thus speeding up parallel MD simulation. 相似文献
103.
Ecaterina Stela Dragan Ionel Adrian Dinu Marcela Mihai 《Colloids and surfaces. A, Physicochemical and engineering aspects》2009,348(1-3):282-288
The interaction between strong polycations, which possess the ammonium quaternary centers attached to an acrylic macromolecular chain derived from poly(N,N-dimethylaminoethyl methacrylate) (polycations Qx), and divalent counterions was investigated by viscometry and turbidimetry. Conformational changes of polycations were influenced by the polycation charge density, counterion nature (SO42− or S2O82−) and concentration. The morphology of the polycation layers deposited onto silicon wafers has been studied by tapping mode atomic force microscopy, a strong influence of the polycation and ammonium persulfate concentration on the surface topography being observed. The optimum flocculation concentration of polycation decreased and the flocculation window increased in the presence of S2O82−, in the destabilization of kaolin model dispersion. Removal of Congo Red from aqueous solution by the complex system formed between polycations and divalent counterions was also investigated. The behavior of polycations Qx in separation processes was compared with that of one polycation containing 95 mol% N,N-dimethyl-2-hydroxypropyleneammonium chloride units in the backbone (PCA5). 相似文献
104.
Ecaterina Stela Dragan Maria Valentina Dinu Andrzej W. Trochimczuk 《European Polymer Journal》2009,45(7):2119-114
Cu(II), Co(II) and Ni(II) complexes of chelating resins (CR) bearing iminodiacetate (IDA) ligands were prepared. The CR-metal complexes were characterized by FT-IR spectroscopy, X-ray diffraction (XRD), thermal behavior (TG and DTG) under nitrogen atmosphere, and electron paramagnetic resonance (EPR). FT-IR spectra of the CR-metal complexes showed the characteristic bands of CR were still present but red-shifted after the metal complexation, and new bands assigned to Me-N bonds were observed. Thermal behavior of the metal-CR complexes supported the metal complexation, metal complexation leading to the decrease of the thermal stability of the CR, the lowest thermal stability being found when the highest amount of Cu(II) was loaded. Based on the EPR results and the thermal behavior of Cu(II)-CR complexes, the scheme for the complexation of Cu(II) on the CR was suggested. 相似文献
105.
Said A. Farha Al-Said Reda Hassanien Jennifer Hannant Miguel A. Galindo Stela Pruneanu Andrew R. Pike Andrew Houlton Benjamin R. Horrocks 《Electrochemistry communications》2009,11(3):550-553
Ag nanowires and nanoparticles have been formed on hybrid λ-DNA/conducting polymer templates. The strong, but non-covalent, interaction of the conducting polymer with the double helix allowed us to incorporate chemical functionalities (alkynyl) into the DNA/conducting polymer strands by synthesis of functional monomers. Oxidative polymerisation of alkynyl-thienylpyrrole in the presence of λ-DNA produced conductive nanowires bearing alkyne groups; we show, using a combination of AFM, cAFM and EFM phase measurements that the alkyne functionality strong influences the subsequent templating reaction of Tollens’ reagent to produce uniform conductive nanowires comprised of many connected Ag clusters. 相似文献
106.
Dragan Juki 《Journal of Approximation Theory》2009,156(2):212-222
For the given data (wi,xi,yi), i=1,…,M, we consider the problem of existence of the best discrete approximation in lp norm (1≤p<∞) by reciprocals of real polynomials. For this problem, the existence of best approximations is not always guaranteed. In this paper, we give a condition on data which is necessary and sufficient for the existence of the best approximation in lp norm. This condition is theoretical in nature. We apply it to obtain several other existence theorems very useful in practice. Some illustrative examples are also included. 相似文献
107.
108.
Ecaterina C. Niculescu Cristina Stan Gabriela Tiriba Cristina Truşcǎ 《The European Physical Journal B - Condensed Matter and Complex Systems》2017,90(5):100
The electronic properties and optical characteristics – absorption coefficient, refractive index and group index – in an impurity doped pseudo-harmonic quantum disc subjected to an applied magnetic field are investigated. Numerical calculations are performed using the exact diagonalization technique and the compact density-matrix formalism. It is found that the chosen structure could be switched between a lambda-type and a ladder-type configuration by a proper tailoring of the magnetic field strength. Furthermore, the absorption profile and the associated slow light frequency range can be controlled not only by varying the control field amplitude and its detuning but also by changing the impurity position and the magnetic field strength. 相似文献
109.
Magdalena Stevanović Igor Savanović Vuk Uskoković Srečo D. Škapin Ines Bračko Uroš Jovanović Dragan Uskoković 《Colloid and polymer science》2012,290(3):221-231
A simple and green chemical method has been developed to synthesize stable bare and capped silver nanoparticles based on the
reduction of silver ions by glucose and capping by poly(α,γ,l-glutamic acid) (PGA). The use of ammonia during synthesis was avoided. PGA has had a dual role in the synthesis and was used
as a capping agent to make the silver nanoparticle more biocompatible and to protect the nanoparticles from agglomerating
in the liquid medium. The synthesized PGA-capped silver nanoparticles in the size range 5–45 nm were stable over long periods
of time, without signs of precipitation. Morphological examination has shown that the silver nanoparticles had a nearly spherical,
multiply twinned structure. The effects of the reaction temperature and the reaction time during the synthesis were investigated
too. The biocompatibility of the PGA-capped silver nanoparticles is discussed in terms of in vitro toxicity with human intestinal
Caco-2 cells. The samples were characterized by UV–Visible spectroscopy, field emission scanning electron microscopy, transmission
electron microscopy, and zeta potential measurements. 相似文献
110.
This paper presents an experimental characterization of two sources of calcium carbonate, limestone and calcium carbonate precipitate (CCP) used in wet flue gas desulphurization processes. Characterization of the two carbonate sources was carried out by chemical analysis, IR spectra, thermal behavior, particle size distribution for CCP, BET surface area and absorption capacity of SO2 in calcium carbonate suspensions. The absorption temperature, suspension concentration and carbonate grain size were found to be the most influential parameters in the absorption capacity measurements. 相似文献