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31.
57Fe Mössbauer study of amorphous and nanocrystalline Fe73.5Nb3Cu1Si13.5B9 after neutron irradiation
57Fe Mössbauer spectroscopy is used to study neutron irradiation induced changes in the short-range order of Fe73.5Nb3Cu1Si13.5B9 alloy. The samples are investigated in both amorphous and nanocrystalline states. Neutron irradiation leads to an increase of the standard deviation of a hyperfine field distribution (HFD), implying rearrangement of the atoms towards disordering. Simultaneously, changes in the average value of the hyperfine field and a net magnetic moment position occur as a consequence of a spin reorientation, atom mixing and microscopic stress centres which are introduced by neutron irradiation. 相似文献
32.
K. Mészáros Szécsényi K. Tomor G. Pokol 《Journal of Thermal Analysis and Calorimetry》1994,41(1):125-134
The phase diagram for the AgNO3?KNO3 system has been determined using differential scanning calorimetry (DSC). Eutectic point has been found at 391 K andX Ag=0.580 mole fraction AgNO3. The DSC curves indicate the existence of an intermermediate compound (AgNO3·KNO3) in the KNO3-rich region of the phase diagram. This compound was identified in the solid phase by X-ray diffraction. The melting and the crystallization processes were followed with the aid of a hot stage microscope, too. 相似文献
33.
Eles J Kalaus G Greiner I Kajtár-Peredy M Szabó P Keserû GM Szabó L Szántay C 《The Journal of organic chemistry》2002,67(21):7255-7260
The first syntheses of the alkaloids (-)-mehranine (3), (+)-voaphylline/conoflorine (4), (+)-N(a)-methylvoaphylline/hecubine (5), and (-)-lochnericine (2) were achieved by stereoselective epoxidation starting from (-)-tabersonine (1), through intermediates with the aspidospermane and quebrachamine skeleton. 相似文献
34.
Zusammenfassung Es wurde die thermische Zersetzung dercis-undtrans-Isomeren des [PtAox
2Cl2] sowie des [PtAox
3Cl]Cl mit Hilfe derTG-undTD-Kurven im Falle des reinen Komplexes sowie im Falle einer Mischung mit Al2O3 (1:3) geklärt. Dietrans-Form ist stabiler als diecis-Form, die Zersetzung wird durch Al2O3 nicht beeinflu\t. [PtAox
3Cl]Cl wird infolge der Erhitzung in die stabileretrans-Form [PtAox
2Cl2] umgewandelt und verhält sich auch weiterhin wie diese.
Mit 4 Abbildung 相似文献
A contribution to the study of the compounds of Pt(II) with acetoxime
The thermal decomposition ofcis- andtrans-[PtAox 2Cl2] and of [PtAox 3Cl]Cl was studied by means ofTGA andTDA on pure substances as well as on mixtures with Al2O3 (1:3). Thetrans form is more stable then thecis form, the presence of Al2O3 has no influence on its decomposition. The [PtAox 3Cl]Cl is transformed by heating into the more stabletrans-isomer and its further behaviour is identical with that of thetrans isomer.
Mit 4 Abbildung 相似文献
35.
An enzyme-immunoassay for the detection of the mycotoxin zearalenone by use of yolk antibodies 总被引:1,自引:0,他引:1
H. Pichler R. Krska A. Székács M. Grasserbauer 《Fresenius' Journal of Analytical Chemistry》1998,362(1):176-177
The development of an enzyme-immunoassay (ELISA) for the detection of the Fusarium mycotoxin zearalenone (ZON) is described. In contrast to the common antibody isolation from mammal serum, chicken were immunized
in order to isolate specific antibodies from the egg yolk. Five weeks after the start of the immunization a titer of 1:76 000
resulted from three injections without any adverse effects for the animals. Utilizing the indirect competitive assay format
ZON could be detected in a concentration range between 10 and 200 μg/L.
Received: 3 January 1998 / Revised: 16 March 1998 / Accepted: 20 March 1998 相似文献
36.
I. Tóth L. Szabó M. Kajtár-Peredi E. Baitz-Gács L. Radics Cs. Szántay 《Tetrahedron》1978,34(14):2113-2122
Acyloxy-ketone rearrangement, proceeding by the action of base, has been observed in the case of ketone 2. By the reduction of ketones 2 and 3 with sodium boron hydride, new 10, 11-dimethoxy(depyrrolo)raunescine stereoisomers (5a–7a) have been prepared. Previously known alcohols with alloberban skeleton (12,13) have been similarly converted into tetracyclic raunescine stereoisomers (8a,9) by the oxido-reductive method. The stereochemistry of these compounds has been investigated by physical (1H NMR, IR) and by chemical methods. 相似文献
37.
Albert Lévai Gábor Tóth Áron Szőllősy Tibor Timár 《Monatshefte für Chemie / Chemical Monthly》1990,121(5):403-411
Summary Arylsulfonyloxy-2,2-dimethyl-2H-chromenes (26–35) have been synthesized by reduction of arylsulfonyloxy-2,2-dimethyl-4-chromanones (6–15) followed by dehydration.
Synthese von Benzopyranderviaten. 15. Mitt.: Darstellung von Arylsulfonyloxy-2,2-dimethyl-2H-chromenen
Zusammenfassung Reduktion von Arylsulfonyloxy-2,2-dimethyl-4-chromanonen (6–15) und anschließende Dehydratisierung liefert Arylsulfonyloxy-2,2-dimethyl-2H-chromene (26–35).相似文献
38.
Sz. Vass 《Chemical physics letters》1980,70(1):135-137
The small number of reagents solubilized in a micelle prohibits the use of conventional reaction kinetics. In order to describe the kinetics of the reaction A + B ? AB proceeding in a micellar phase, a stochastic model is evaluated. The deviation of these results from those obtained by conventional kinetics may be as high as 20%. 相似文献
39.
J. Orbán Sz. Halasi G. Papp Szilvia Barkó Beáta Bugyi 《Journal of Thermal Analysis and Calorimetry》2005,82(1):287-290
Summary The thermodynamic properties of the cardiac and skeletal a-actin isoforms were studied to characterize the molecular bases
of the functional differences between them with the method of differential scanning calorimetry (DSC). The thermal properties
of the actin filaments were described in the presence of calcium and magnesium ions as well. Based on the calculated free
energy changes the α-cardiac actin filaments appeared to be more stable in its physiologically more relevant, magnesium saturated
form. The magnesium saturated form of the α-cardiac actin filaments seemed to be more stable compared to the calcium saturated
form of it. The enthalpy and entropy changes could differentiate between the α-cardiac and α-skeletal actin isoforms and between
the calcium and magnesium saturated cardiac actin isoforms as well. Our results can demonstrate that the few differences between
the amino acid sequences of the α-actin isoforms have an influence on the thermal properties and maybe on the function of
these proteins as well. 相似文献
40.
Trávníček Zdeněk Machala Viktor Szüčová Lucie Maloň Michal Marek Jaromír 《Transition Metal Chemistry》2004,29(4):352-357
A series of new [NiX(S2P{O-c-Hex}2)(PPh3)](X = Cl–, Br–, I– and NCS–)(1)–(4) and [Ni(NCS)(S2P{OR}2)(PPh3)][R =n-Pr (5), i-Pr (6)] complexes has been synthesized and characterized by elemental analyses, f.i.r., i.r., u.v.–vis., 1H-, 13C{1H}- and 31P{1H}-n.m.r. spectra, magnetochemical and conductivity measurements. A single crystal X-ray analysis of [Ni(NCS)(S2P{O-n-Pr}2)(PPh3)](5) reveals the molecular structure of the complex and confirms a square-planar geometry around the central atom of nickel with the NCS anion coordinated via the nitrogen atom. 相似文献