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Pavel?Bro?Email author Jir?í?Bur?ík Zdeňka?Stará 《Monatshefte für Chemie / Chemical Monthly》2005,136(11):1915-1920
Summary. Multicomponent Ni-base alloys exhibit good mechanical properties even at elevated temperatures and they are widely used for
industrial production of exertion-resistive parts of engines. These properties are mainly determined by the coexistence of
a disordered γ matrix with a face centred cubic lattice and cuboidal domains of its ordered γ′ structure. Therefore it is
useful to study phase equilibria in Ni-base systems, namely in the regions involving both mentioned phases. One of the conclusions
of our recent work on Ni–Al–Cr–W system was a necessity of modification of selected thermodynamic parameters of the ternary
Ni–Al–W subsystem in order to achieve a better agreement of our experimental observations with theoretical modelling. This
involves new measurements of the microstructure of selected samples of the Ni–Al–W system at 900°C and the comparison of the
results with existing literature data in order to confirm our conclusions on higher order system investigated before. It is
a first step on the way to an assessment of the Ni–Al–W system, which has not been done before. 相似文献
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J. Brož A. Bergstein S. Krupička J. Vintera K. Závěta 《Czechoslovak Journal of Physics》1957,7(1):66-77
Zusammenfassung Proben von Mangan-Zinkferrit mit Manganüberschuss wurden in verschiedenen Atmosphären und bei verschiedenen Temperaturen hergestellt. Es wurden einige magnetische Eigenschaften studiert und ihr Zusammenhang mit der Struktur und chemischen Zusammensetzung der Proben verfolgt. 相似文献
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The influence of the oxygen content on the saturation magnetic moment and the Curie temperature was studied experimentally on non-stoichiometric manganese ferrites having a varying excess of manganese. Taking into consideration the results of studying the electrical conductivity and magnetic relaxation effects, a model was elaborated for the distribution of ions in these ferrites, which starts out from the distribution of ions in stoichiometric manganese ferrite. The experimental results obtained by us and those of other authors confirm the justification of this model.
In conclusion the authors thank members of their technological department for preparing the samples and M. Mikulá for carefully carrying out the chemical analyses. 相似文献
II. Mn1+xFe2-xO4+y
. , . .
In conclusion the authors thank members of their technological department for preparing the samples and M. Mikulá for carefully carrying out the chemical analyses. 相似文献
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In the last few years, the need to determine peroxide-based explosives in solid samples and air samples has resulted in the
development of a series of new analytical methods for triacetonetriperoxide (TATP, acetone peroxide) and hexamethylenetriperoxidediamine
(HMTD). In this review, after a short introduction describing the state of the art in the field, these new analytical methods
are critically discussed. Particular emphasis is placed on spectroscopic and mass spectrometric methods as well as on chromatographic
techniques with selective detection schemes. The potential of these methods to analyse unknown solid samples that might contain
one or more of the explosives and to analyse peroxide-based explosives in air is evaluated. 相似文献
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Proton-detected scalar coupling based assignment strategies in MAS solid-state NMR spectroscopy applied to perdeuterated proteins 总被引:1,自引:0,他引:1
Assignment of proteins in MAS (magic angle spinning) solid-state NMR relies so far on correlations among heteronuclei. This strategy is based on well dispersed resonances in the 15N dimension. In many complex cases like membrane proteins or amyloid fibrils, an additional frequency dimension is desirable in order to spread the amide resonances. We show here that proton detected HNCO, HNCA, and HNCACB type experiments can successfully be implemented in the solid-state. Coherences are sufficiently long lived to allow pulse schemes of a duration greater than 70 ms before incrementation of the first indirect dimension. The achieved resolution is comparable to the resolution obtained in solution-state NMR experiments. We demonstrate the experiments using a triply labeled sample of the SH3 domain of chicken α-spectrin, which was re-crystallized in H2O/D2O using a ratio of 1/9. We employ paramagnetic relaxation enhancement (PRE) using EDTA chelated CuII to enable rapid data acquisition. 相似文献