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71.
72.

Iron phosphate-silicate glasses from P2O5–SiO2–K2O–MgO–CaO–Fe2O3 system were subjected to the thermal and spectroscopic studies in order to gain information about their structure and thermal behavior in the range of glass transition effect. Research includes results obtained via DSC, MIR and DRIFT spectroscopy. Designated values of glass transition temperature and specific heat change slightly increases with Fe2O3 incorporation. Spectra collected during thermal treatment of glasses containing 2 and 30 mol% Fe2O3 exhibited various changes. Fe2O3 addition affected the glass structure by its reinforcement and led to its preservation during thermal treatment. The connection between density, molar volume, oxygen packing density and the chemical composition’s alteration were also established because of the direct dependence of physical properties and the structure. Obtained results supported thermal and spectroscopic studies. Conducted research is considered as a contribution to the knowledge about the family of iron phosphate glasses, which are known from their interesting properties and widely used applications.

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73.
In the presented paper the use of a novel environmentally friendly aminopolycarboxylate chelating agent trisodium salt of methylglycinediacetic acid (MGDA) to inactivate various metal ions by complex formation in microporous anion exchangers and sorbents was tested. MGDA is a new generation of chelator, undergoing biodegradation.  相似文献   
74.
The synthesis and binding abilities of peptides containing β-amino acids towards Cu(II) ions are presented. The peptides studied were: Ala-βAsp-Ser-Gly and Arg-Lys-βAsp-Val-Tyr. Potentiometric titrations were carried out to establish the stoichiometry of the resulting metal-ligand complexes. The copper(II) coordination mode of the complexes was investigated by performing detailed spectroscopic analyses (UV–Vis, CD) in strict correlation with potentiometric measurements. The results obtained on the β-peptides studied allowed the characterization of the influence of this structural modification on the coordination abilities of the peptides. Moreover, the role of the α-Asp position in the peptide chain was also described.  相似文献   
75.
Journal of Radioanalytical and Nuclear Chemistry - The activity concentration of a 177Lu solution was measured by the Laboratory of Radioactivity Standards in the Radioisotope Centre POLATOM. The...  相似文献   
76.
A green and sensitive thin-film solid-phase microextraction method based on deep eutectic solvent was developed that enables simultaneous isolation, preconcentration, and determination of parabens in surface waters. Six new deep eutectic solvents were synthesized and used directly to prepare thin-film coatings on a stainless steel mesh support. Among the compounds obtained, the highest efficiency in the extraction of parabens was found for a material consisting of trihexyltetradecylphosphonium chloride and n-docosanol in a molar ratio of 1:2. For the proposed method, parameters affecting the extraction efficiency of parabens, such as the coating material, the desorption solvent, the volume of the sample, the pH of the sample, the extraction and desorption time, and the salting-out effect, were optimized. Under optimal conditions, the proposed method allowed us to achieve good precision between 3.6 and 6.5% and recovery ranging from 68.1 to 91.4%. The limits of detection range from 0.018 to 0.055 ng/mL.  相似文献   
77.
Pyridine-2,5-dicarboxylic acid, known as isocinchomeric acid is one of six isomers containing two carboxylic groups. Light lanthanide (III) complexes with pyridine-2,5-dicarboxylic acid with general formula Ln2L3·nH2O, where n = 8, 9, were obtained. Their thermal and spectroscopic properties were studied. Sodium salt was obtained as Na2L·H2O. Hydrated complexes of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) and Gd(III) are stable to 313–333 K, whereas Na2L·H2O is stable to about 333 K. Dehydration process for all compounds runs in one stage, next they decompose into appropriate lanthanide oxalates, oxocarbonates carbonates and finally to metal oxides. Bands of νCOOH vibrations at 1736 and 1728 cm−1 disappear on complex spectra and νas and νs of COO groups appear thus indicating that complexation process took place.  相似文献   
78.
1-Hydroxyphosphonate 1 in the presence of triethylamine in acetonitrile solution undergoes irreversible rearrangement to phosphate 2 and reversible retro-phospho-aldol (retro-Abramov) reaction. The X-ray structures for 1 and 2 revealed that the phosphonate-phosphate rearrangement occurs with retention of configuration at the phosphorus atom.  相似文献   
79.
Let IR be a non-trivial interval, s:I→(0,) be a function, and let φ,ψ be real continuous strictly monotonic functions defined on I. We consider the equation
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80.
In the present paper we describe a specialization of prinjective Ringel-Hall algebra to 1, for prinjective modules over incidence algebras of posets of finite prinjective type, by generators and relations. This gives us a generalisation of Serre relations for semisimple Lie algebras. Connections of prinjective Ringel-Hall algebras with classical Lie algebras are also discussed.  相似文献   
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