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1.
Wojakowska A. Krzyżak E. Wojakowski A. 《Journal of Thermal Analysis and Calorimetry》2001,65(2):491-495
The phase diagram for the RbBr–CuBr system has been determined. In the system two intermediate compounds are formed: RbCu2Br3, melting congruently at 537 K and Rb3CuBr4, melting incongruently at 544 K. The coordinates of the two eutectic points are: 501 K, 54 mole% CuBr and 522 K, 74 mole%
CuBr.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
A. Wojakowska 《Journal of Thermal Analysis and Calorimetry》1989,35(7):2433-2439
The phase diagram of the SnI2-CuI system was determined by the method of thermal analysis. No intermediates were found. It is suggested that limiting solid solutions of SnI2 in-CuI,-CuI and-CuI, respectively, are formed. The eutectic point parameters (32.7 mol% CuI, 270.4 ±0.1 °C) and those of two invariant points (64.0 mol% CuI, 385.3 ±0.5 °C and 61.5 mol% CuI, 366.6±0.2 °C), corresponding to the equilibria+liquid and+liquid , respectively, were determined.Mittels Thermoanalyse wurde das Phasendiagramm SnI2-CuI bestimmt. Es konnten keine Intermediäre gefunden werden. Es scheint, daß Grenzmischkristalle von Shl2 und-CuI,-CuI,-CuI gebildet werden. Es wurden ein Eutektikum (32,7 mol% CuI, 270,4 ± 0,1 °C) und zwei den Gleichgewichten+Flüssigkeit und+Flüssigkeit entsprechende invariante Punkte (64,0 mol% CuI, 385,3±0,5 °C und 61,5 mol% CuI, 366,6±0,2 °C) gefunden. SnI2-CuI, . , , -CuI,-CuI Cul. (32,7 % CuI, 270,4±0,1°) (64,0 % Cul, 385,3 ±0,5° 61,5 % CuI, 366,6±0,2°), + + .
The present work was carried out within the framework of contract CPBP 01.15. 相似文献
The present work was carried out within the framework of contract CPBP 01.15. 相似文献
3.
Agata Górniak Alina Wojakowska Bożena Karolewicz Janusz Pluta 《Journal of Thermal Analysis and Calorimetry》2011,104(3):1195-1200
Enhancement of the dissolution rate of poorly soluble compounds through the formation of drug–drug eutectics was investigated
using fenofibrate and acetylsalicylic acid. Solid–liquid equilibria in the system under study were investigated by differential
scanning calorimetry (DSC). The phase diagram for the whole range of compositions was constructed. In addition, existence
of a metastable polymorph of fenofibrate has been confirmed. The investigation has revealed that acetylsalicylic acid and
fenofibrate form a simple eutectic mixture containing 0.958 mol fraction of fenofibrate at the eutectic point. Dissolution
rate improvement of fenofibrate correlated with the phase diagram. The amount of fenofibrate released from the solid dispersions
that contained fenofibrate as the eutectic mixture with acetylsalicylic acid was at least threefold higher compared to untreated
fenofibrate. 相似文献
4.
Alina Wojakowska E. Krzyżak Stanisława Plińska 《Journal of Thermal Analysis and Calorimetry》2007,88(2):525-530
Melting
and high temperature solid-state transitions in CoCl2
and CoBr2 are widely discussed. On the basis of DSC
and conductometric measurements it was found that melting process of CoCl2
is preceded by a solid-state transition appearing about 20 K below the melting
point of CoCl2. Due to deconvolution of the thermograms,
the enthalpy of fusion and that of solid-state transition were found to be
36.4 and 9.6 kJ mol–1, respectively. Melting
points of CoCl2 and CoBr2 were
established to be 999.0 and 949.7 K, respectively. Hitherto unknown enthalpy
of fusion of CoBr2 was determined to be 27.2 kJ mol–1.
A solid-state transition in CoBr2 at 650 K has been
confirmed. 相似文献
5.
A. Wojakowska 《Journal of Thermal Analysis and Calorimetry》1996,46(2):369-376
Phase diagrams for the series of CuY-MIY and CuY-MIIY systems (whereM
I=Li, Na, K, Rb, Cs, Tl,M
II=Zn, Cd, Hg, Sn, Pb andY=Cl, Br, I) were compared. Changes and trends accompanying the increase of charge of the second cation were discussed. 相似文献
6.
A. Wojakowska 《Journal of Thermal Analysis and Calorimetry》1989,35(1):91-97
The phase diagram of the SnBr2-CuBr system was determined by the method of thermal analysis. One intermediate compound, CuSn5Br11, melting congruently at 218.7 °C, was found. 相似文献
7.
Commonly used methods for protein extraction from plant leaves, such as extraction with phenol or a combination of trichloroacetic acid and acetone, were ineffective for four tested cultivars of poplar. Moreover, multiple protocols for 2DE of the extracted proteins gave different results when protein profiles of relatively closely related plants were compared. Given that polycyclic compounds strongly hinder 2DE, we analyzed the impact of polyphenols and polysaccharides present in the plant tissues used for protein extraction, on the quality of 2DE protein profiles. Analysis of content of polyphenols and polysaccharides in leaves of poplar cultivars showed that even small differences in concentrations of analyzed metabolites accompany large differences between poplar cultivars when considering the susceptibility of samples to protein extraction for 2DE. High‐quality 2DE results were correlated with decreased amounts of polyphenols. Additional analysis using MS/MS suggested that only levels of total phenolics affected the results of 2DE. Soluble total nonstructural carbohydrates also had a negative effect, but the level of starch was not important. Finally, we present an optimized method for extraction of proteins from poplar leaves, which enables reliable comparative analysis of four different poplar cultivars, that is, “Eridano,” “Villafranca,” “NE‐42,” and “Luisa Avanzo,” which have not yet been used for the proteomic studies. 相似文献
8.
Anna Wojakowska Juliusz Perkowski Tomasz Góral Maciej Stobiecki 《Journal of mass spectrometry : JMS》2013,48(3):329-339
The aim of this study was to present integrated mass spectrometric methods for the structural characterization and identification of flavonoid glycoconjugates. During the liquid chromatography/mass spectrometry analyses, TriVersa NanoMate chip‐based system with nanoelectrospray ionization and fraction collection was combined to a quadrupole time‐of‐flight mass spectrometer. In the extract samples prepared from green leaves of wheat plantlets, 41 flavonoid derivatives were recognized. Part of the target natural products had the full structure being characterized after the registration of mass spectra, where m/z values for protonated [M + H]+ and deprotonated molecules [M ? H]? were annotated. MS2 and pseudo‐MS3 experiments were performed for [M + H]+ or [M ? H]? and aglycone ions (Y0+/?‐type), respectively. It should be underlined that pseudo‐MS3 mass spectra were registered for aglycone product ions in the mass spectra of O‐glycosides present in the extract samples. In many cases, only tentative structural identification of aglycones was possible, mainly because of the presence of numerous C‐monoglycoside or C‐diglycoside in the samples. Acylation of the sugar moiety and/or methylation of the aglycone in the flavonoid glycosides under study was observed. The existence of isobaric and/or isomeric compounds was demonstrated in the extract studied. The collision‐induced dissociation mass spectra registered for C,O‐diglycosides and C,C‐diglycosides did not permit to draw complete structural conclusions about the compounds studied. For the investigated class of natural products, unambiguous classification of sugar moieties linked to the aglycones from the recorded mass spectra was not possible. Registration of the positive and negative ion mass spectra did not lead to the precise conclusion about the glycosylation position at C‐6 or C‐8, and O‐4′ or O‐7 atoms. It was possible, on the basis of the collected MS2 spectra, to differentiate between O‐glycosides and C‐glycosides present in the samples analyzed. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
9.
Alina Wojakowska Agata Górniak A. Wojakowski Stanisława Plińska 《Journal of Thermal Analysis and Calorimetry》2004,77(1):41-47
Phase equilibria in the systems zinc chloride - silver chloride and zinc bromide - silver bromide were investigated by differential
scanning calorimetry, electric conductivity measurements and X-ray diffraction methods. No intermediate compounds were found.
Solubility of components in the solid-state is negligible. Both systems are of the eutectic type. The eutectic temperatures
in the ZnCl2-AgCl system and in the ZnBr2-AgBr system are 504 K and 551 K, respectively, and the compositions of the eutectic point are 53.5 mol% AgCl and 59.4 mol%
AgBr, respectively.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.