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Matilda Vojnović Ana J. Šetrajčić-Tomić Siniša M. Vučenović Jovan P. Šetrajčić 《Optical and Quantum Electronics》2018,50(4):198
Recent research in nano-optical engineering and in nanomedicine as well, seeks for methods of construction of various types of nano-markers, nano-carriers, and ways to deliver drugs to the exactly determined regions of body. In this process it is important to find methods of recognition of certain types of molecules. It is obvious that optical recognition would be the easiest and the most effective way to do it. Our research presents a model of a molecular ultrathin crystalline film and generated exciton system inside it and corresponding methodology of analysis of their optical characteristics. Properties of these spatially very restricted structures are very sensitive to their surrounding surfaces. Using the two-time Green’s functions adapted for crystalline structures with symmetry breaking, and graphical-numerical software, we have calculated the energy spectra and possible exciton states. We have shown that the appearance and the presence of localized states on the surfaces and in the boundary layers of the film depend on the thickness of the film and the film surroundings, presented through the perturbation of parameters on surfaces. Optical properties in these structures demonstrate discrete and very selective resonant absorption spectra, depending on the perturbation on their surfaces. 相似文献
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Jinlong Cheng Matilda Fone Vijay N. Reddy Kenneth B. Schwartz Howard P. Fisher Bernhard Wunderlich 《Journal of Polymer Science.Polymer Physics》1994,32(16):2683-2693
The observation of chain conformation and mobility in polyethylene by solid-state 13C magic angle spinning (MAS) nuclear magnetic resonance (NMR) permits unambiguous identification and quantitative analysis of an intermediate phase. The carbon-carbon bonds in the intermediate phase adopt, on the average, an all-trans conformation and are more mobile than in the crystalline state (room temperature rate of reorientation ≈ 107 Hz). Comparisons of crystallinities by differential scanning calorimetry, wide-angle x-ray diffraction, and NMR support the high orientation of the intermediate phase and suggest a lower heat of fusion than for the crystals. Results from 13C spin-lattice relaxation and 1H spin diffusion show that the mass fractions are ≈ 20% and the domain sizes ≈ 36 Å. Both change with crystallization and annealing conditions. © 1994 John Wiley & Sons, Inc. 相似文献
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Salomonsson ML Bondesson U Hedeland M 《Rapid communications in mass spectrometry : RCM》2008,22(17):2685-2697
For the first time chemical derivatization of isomeric drug glucuronides with 1,2-dimethylimidazole-4-sulfonyl chloride (DMISC) has been successfully applied as a tool for determining the site of conjugation. This provides a way to differentiate between glucuronide isomers containing aliphatic and phenolic hydroxyl groups. The analyses were performed with liquid chromatography/electrospray ion trap mass spectrometry (LC/ESI-MSn). DMISC has previously been shown to react selectively with phenols in estrogens, thus improving sensitivity in ESI-MS. The model compounds selected for this study were commercially available standards of formoterol, morphine, morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G). Formoterol glucuronides were produced with an enzymatic method in house. Both formoterol and morphine possess one phenolic and one aliphatic hydroxyl group where glucuronidation could take place. The product ion mass spectra of the native morphine glucuronides were indistinguishable due to the initial neutral loss of monodehydrated glucuronic acid (176 u). However, a significant difference between the isomers was observed with DMISC derivatization, as only the form with a free phenol, M6G, gave a detectable reaction product. Formoterol formed two detectable glucuronide isomers in the enzymatic reaction. Their respective sites of conjugation could not be directly determined from the product ion spectra. Reaction with DMISC, however, gave a detectable product with only one of the isomers. Based on previous experience of the preferred DMISC reactions with phenols, and interpretation of the fragmentation pattern of the derivative, it was concluded that the reactive isomer had a free phenol, and was thus conjugated on the aliphatic chain. 相似文献
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Energy dispersive X-ray spectroscopy and scanning electron microscopy were used to analyse nickel on anodic aluminium surfaces
after stripping the anodic aluminium oxide. The metal was electroplated at the bottom of the pores of anodised aluminium during
electrolytic colouring in solutions without (Watts) and with (citrate) complexing agents, respectively. A relation between
the anodic-cathodic processes, changes of the structure and composition of the coating in dependence on the used solution
were studied. A morphology study performed after stripping the anodic aluminium oxide revealed the crucial influence of the
anodic process/cycle and the complexing agent on the nickel structure on the aluminium surface. Off-time of half-way rectified
current influenced the nickel deposition in the pores of anodic alumina negatively. 相似文献
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The microstructure, electronic structure and chemical bonding of chromium carbide thin films with different carbon contents have been investigated with high-resolution transmission electron microscopy, electron energy loss spectroscopy and soft x-ray absorption-emission spectroscopies. Most of the films can be described as amorphous nanocomposites with non-crystalline CrC(x) in an amorphous carbon matrix. At high carbon contents, graphene-like structures are formed in the amorphous carbon matrix. At 47 at.% carbon content, randomly oriented nanocrystallites are formed creating a complex microstructure of three components. The soft x-ray absorption-emission study shows additional peak structures exhibiting non-octahedral coordination and bonding. 相似文献
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Ern E. Kiss Matilda M. Lazic Goran C. Boskovic 《Reaction Kinetics and Catalysis Letters》2004,83(2):221-227
Catalytic wet peroxide oxidation of phenol over AlFe-pillared montmorillonites, with different iron contents, was carried
out at room temperature, in a glass batch reactor, under constant airflow and halogen lamp light. At lower concentration (0.5
mg phenol/100 cm3 water) a phenol conversion of 100% was achieved independently of the iron content in pillared clay catalyst. However, at
higher phenol concentration (5.0 mg phenol/100 cm3 water) retardation of the catalyst activity was observed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Jinlong Cheng Matilda Fone Yigang Fu Wei Chen 《Journal of Thermal Analysis and Calorimetry》1996,47(3):673-683
Solid-state13C nuclear magnetic resonance (13C NMR) methods have been applied to study a gel-spun ultra-high molecular-mass polyethylene fiber. The mass fractions of the crystalline (orthorhombic and monoclinic), intermediate, and amorphous phases have been determined at temperatures between 296 and 413 K. The mobility of the polymer chains in the crystalline and the intermediate phases have been measured within the same temperature range, 296–413 K. Discussions on the chain conformation and the rate of motion are carried out based on the13C chemical shift and spin-lattice relaxation time, respectively.Dedicated to Professor Bernhard Wunderlich on the occasion of his 65th birthday 相似文献
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Frank W. Mercer Matilda M. Fone Martin T. McKenzie 《Journal of polymer science. Part A, Polymer chemistry》1997,35(3):521-526
The new monomer 2,2-bis[4-(4-{4-fluorobenzoyl}-1-naphthoxy)phenyl]hexafluoropropane ( 2 ) was synthesized in a two-step reaction sequence. 2,2-his[4-(1-naphthoxy)phenyl]-hexafluoropropane ( 1 ) was prepared using the Ullmann ether synthesis reaction of 4,4-(hex-afluoroisopropylidiene)diphenol with 1-bromonaphthalene. Friedel-Crafts acylation of 1 with 4-fluorobenzoyl chloride in methylene chloride containing dimethylsulfone selectively afforded 2 in 82% yield. The polycondensation of 2 with various bisphenols in DMAc in the presence of an excess of potassium carbonate as a condensation reagent was carried out at 165°C to quantitatively afford the corresponding fluorinated poly(aryl ether ketone)s containing 1,4-naphthalene moieties. Thermal analysis of the polymers showed them to have Tgs ranging from 194 to 230°C and to be thermally stable in air up with initial weight losses at about 500°C. In addition, these novel polymers exhibited excellent solubility in organic solvents including NMP, DMAc, and chloroform. © 1997 John Wiley & Sons, Inc. 相似文献
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Matilda Zemanová 《Chemical Papers》2009,63(5):574-578
Corrosion resistance of zinc coatings was investigated in an accelerated corrosion test in a condensation chamber. Zinc was
electrodeposited from alkaline and acidic electrolytes using direct current (DC) or pulse current (PC). The zinc coating was
subsequently protected against corrosion with a chrome (III) layer. Morphology and structure of the coatings was investigated
using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction analysis (XRD)
before and after the corrosion test. Corrosion resistance of alkaline zinc coatings electrodeposited with DC and PC under
test conditions was found to be comparable. The corrosion resistance of zinc coatings deposited from acidic electrolytes by
PC was lower in comparison with corrosion resistance of zinc coatings deposited using DC.
Presented at the 8th Conference on Solid State Chemistry, Bratislava, Slovakia, 6–11 July 2008. 相似文献