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11.
12.
(Fe,Co)–Zr,Hf)–Cu–B (HITPERM-type) alloys with variable Hf, Zr and Co content were isothermally crystallised at 500–650 °C for 1 h, and the optimum nanocrystallisation temperature was selected on the basis of the minimum coercive field at room temperature. The quasistatic hysteresis loops were measured at temperature from 20 to 650 °C. Subsequently, the optimally annealed alloys were subjected to long-term annealing at 500, 550 and 600 °C. Working temperature of 600°C is too high for the investigated alloys to maintain stable magnetic properties. Temperature of 550 or 500 °C permits the material to be magnetically stable for a long period. The magnetic hysteresis loops recorded for the nanocrystalline alloys, where Fe:Co ratio is close to 1 and refractory metals content is 7 at.%, prove that coercive field increases slightly with temperature, but remains in the range of 20–40 A/m (depending on the alloy composition) from 20 to 550 °C. This proves that the investigated alloys, after optimisation of chemical composition, may be suitable for high temperature use. 相似文献
13.
Ferenc Sztaricskai Gyula Batta Zoltan Dinya Istvan F. Pelyvas Pal Herczegh Tamas E. Gunda Istvan Koczka 《Chemistry of Heterocyclic Compounds》1998,34(11):1296-1307
Starting from 3,5-dimethylisoxazole the carboxylic acids I and V, the amino acids VIII (L-) and IX (D-), and the ureido acids X (L-) and XI (D-) were prepared, which were used for the synthesis of the new cephalosporins XVIIb, XXa-c (L-), and XXIb (D-). Thein vitro antibacterial activity of these semi-synthetic antibiotics was studied. The resorption of XVIIb was investigated in mice.Research Group for Antibiotics of the Hungarian Academy of Sciences, H-4010 Debrecen, P.O. Box 70, Hungary. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1524–1535, November, 1998. 相似文献
14.
Conflict resolution methodology is discussed with fuzzified Pareto frontier. Four solution concepts, namely, the Nash solution, the generalized Nash solution, the Kalai-Smorodinsky concept, and a solution method based on a special bargaining process are examined. The solutions are also fuzzy, the corresponding payoff values are fuzzy numbers, the membership functions of which are determined. Three particular cases are considered in the paper. Linear, quadratic, and general nonlinear Pareto frontiers with known shape are examined. 相似文献
15.
16.
Zusammenfassung Die Jodidoxydation durch Cu(II) wird in Anwesenheit von Ammoniak, Natriumtartrat, citrat oder -oxalat infolge Komplexbildung verhindert. Daher kann man z. B. Quecksüber(II) in Anwesenheit der genannten Komplexbildner mit Kaliumjodid maskieren und Kupfer(II) durch direkte Titration mit ÄDTA gegen Murexid, Brenzcatechinviolett, Chromazurol S, PAN oder PAR als Indikator bestimmen.
Masking with potassium iodide in direct titrations of copper(II) with ethylenediamine tetraacetic acid
Summary The formation of a complex prevents the iodide oxidation by Cu(II) in the presence of ammonia, sodium tartrate, citrate, or oxalate. Hence mercury(II) for instance, can be masked against potassium iodide in the presence of these complex formers, and Cu(II) can be determined by direct titration with EDTA in the presence of murexide, pyrocatechol violet, chromazurol, PAN or PAR as indicator.相似文献
17.
The present state of a long term program is reviewed. It was started to elaborate a remote controlled automated radiochemical
processing system for the neutron activation analysis of biological materials. The system is based on wet ashing of the sample,
followed by reactive desorption of some volatile components. The distillation residue is passed through a series of columns
filled with selective ion screening materials to remove the matrix activity. The solution is thus “stripped” from the interfering
radioions, and it is processed to single-elements through group separations using ion-exchange chromatographic techniques.
Some special problems concerning this system are treated. (a) General aspects of the construction of a (semi)automated radiochemical
processing system are discussed; (b) Comparison is made between various technical realizations of the same basic concept;
(c) Some problems concerning the “reconstruction” of an already published processing system are outlined. 相似文献
18.
Tuoto C. V. Regina A. Nagy J. B. Nastro A. 《Journal of Thermal Analysis and Calorimetry》1998,54(3):891-899
DSC, TG and quadrupole mass spectrometer data concerning methylquinuclidinium iodide (MeQ1), dried precursor gel, and crystalline
levyne-type zeolite are discussed together with the thermal degradation of MeQ1 mixed with single inorganic components of
the gel.
It is shown that MeQ+ions play a role in the organization of the gel structure.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
20.
Crystal orbital calculations on cis- and trans-polyacethylene chains indicate two kinds of geometry changes on charge transfer. (1) increase (decrease) of the CC bond lenght and CCC bond angles in the trans conformer taking up (losing) electrons, and a tendency towards bond-length equalization on electron uptake and loss for both conformers. 相似文献