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21.
Galvanic cells of the type (C+Cl2)(NaCl(s))(MCl2(s))(C+Cl2) give e. m. f. 's above 280°, which are due to the formation of ternary chlorides NanMCln+2. By the change in slope of continuously measured e.m.f.vs. T curves, the temperatures of solid-state reactions in systems NaCl-MCl2 can be found. This method was applied for the systems of NaCl with NiCl2, CoCl2 and CdCl2, and for KCl-NiCl2. With the exception of the system NaCl-NiCl2, all phase diagrams must be corrected.
This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie. 相似文献
Zusammenfassung Mit galvanischen Zellen des Typs (C+Cl2)/NaCl(s)/MCl2(s)/(C+Cl2) lassen sich oberhalb 280° EMK's messen, die auf der Bildung ternärer Chloride NanMCln+2 beruhen. Durch die Änderung der Steigung kontinuierlich gemessener EMK- gegen T-Kurven lassen sich in Systemen NaCl/MCl2 die Temperaturen von Festkörperreaktionen nachweisen. Diese Methode wurde auf die Systeme des NaCl mit NiCl2, CoCl2 und CdCl2 sowie auf das System KCl-NiCl2 angewendet. Alle Phasendiagramme, mit Ausnahme des Systems NaCl-NiCl2, mußten auf Grund dieser Messungen revidiert werden.
(C+Cl2)/NaCl./MCl2./(C +Cl2) 280 °C . . , NanMCln+2. . . , NaCl-MCl2. NaCl NiCl2, CoCl2, CdCl2 KCl-NiCl2. NaCl-NiCl2,ce .
This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie. 相似文献
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The systems RbBr/SrBr2 and RbBr/BaBr2 were reinvestigated by DTA and X-ray-crystallography. Additionally to the known compounds RbSrBr3, RbSr2Br5 and RbBa2Br5, the phases Rb2.23Sr0.885Br4 and Rb2.13 Ba0.935Br4 were found, which are structural related to the Th3 P4 — type. By EMF-measurements the thermodynamic functions G, H and S were determined for all compounds.
This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie. 相似文献
Zusammenfassung Die Systeme RbBr/SrBr2 und RbBr/BaBr2 wurden mittels DTA und Röntgenaufnahmen an Kristallpulvern neu untersucht. Zusätzlich zu den schon bekannten Verbindungen RbSrBr3, RbSr2Br5 und RbBa2Br5 wurden die Phasen Rb2,23Sr0,885Br4 und Rb2,13Ba0,935Br4, die sich strukturell vom Th3P4-Typ ableiten lassen, neu gefunden. Für alle Verbindungen wurden durch EMK-Messungen in galvanischen Feststoffzellen die thermodynamischen Funktionen G, H und S bestimmt.
RbBr/SrBr RbBBr/BaBr2. RbSrBr3, Rbsr2Br5 RbBa2Br5, Rb2,23Sr0,885Br4 Rb2,I3Ba0,935Br4, Th3P4. $ G, H S.
This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie. 相似文献
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Jií Davídek Miloslava Neméthová Josef Seifert 《Fresenius' Journal of Analytical Chemistry》1977,287(4-5):286-287
Summary An indirect polarographic method for the determination of phosmet was elaborated. It is based on the fact that N-hydroxymethylphthalimide formed by the reaction of phosmet with sulphuric acid is polarographically active and exhibits a behaviour during electrolysis at a Hg dropping-electrode similar to that of phthalimide. The method has been applied to the determination of phosmet in apples. The sensitivity is 0.1 ppm.
Indirekte polarographische Bestimmung von Phosmet O,O-Dimethyl-S-(phthalimidomethyl)dithiophosphat
Zusammenfassung Das Verfahren beruht darauf, daß N-Hydroxymethylphthalimid, das bei der Reaktion von Phosmet mit Schwefelsäure gebildet wird, polarographisch aktiv ist und sich bei der Elektrolyse mit der Quecksilber-Tropfelektrode ähnlich wie Phthalimid verhält. Die Methode wurde zur Bestimmung von Phosmet in Äpfeln angewandt. Die Empfindlichkeit beträgt 0,1 ppm.相似文献
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For many permanent cell lines the transition from a growing (P) to a resting (R) state is reversibly controlled by growth factors present in serum. This P-to-R transition was studied in a neuronal cell line (B104) with respect to the action of serum, dibutyryl cyclic AMP (DBcAMP), gangliosides, and a glioma cell-produced growth factor GGF. In this cell system gangliosides seem to act as differentiation and survival factors. The kinetics of uptake of radioactively labeled gangliosides and survival experiments both support the idea of the stable incorporation of exogenously added gangliosides into the cells. Based on the experimental evidence a new model of cell development is proposed. Thus in addition to the R or Go state, which in this cell system is rather unstable and probably regulated by cyclic nucleotides, we postulate a differentiated D state, which is controlled by gangliosides and which is characterized by its stability (survival time). This D compartment seems to be closer to the in vivo differentiated neuron than does the R or P state. tthe possible mechanisms for the action of gangliosides are discussed. 相似文献
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Edith Chow Burkhard Raguse Karl‐H. Müller Lech Wieczorek Avi Bendavid James S. Cooper Lee J. Hubble Melissa S. Webster 《Electroanalysis》2013,25(10):2313-2320
The porosity of 1‐hexanethiol‐functionalised gold nanoparticle films was assessed and utilised as chemiresistor sensors. Electrochemical capacitance measurements showed that the accessibility of electrolytes of different ionic strengths into the pores depended on the thickness of the electric double layer formed. A large variation in capacitance was measured in 0.01–1000 mM NaClO4, implying a wide pore size distribution. The change in morphology of the nanoparticle films upon storage in air, water and ethanol for two weeks was investigated. There was a significant decrease in the electrochemical capacitance at high electrolyte concentrations for the ethanol‐stored films compared to the freshly‐prepared films suggesting a decrease in the number of small pores of radii in the range of 0.3–3 nm. This was further supported by optical topographical measurements where a decrease in the thickness of ethanol‐stored films was observed relative to the freshly‐prepared films. The porous nature of the nanoparticle films was found to have an effect on the chemical sensing behaviour. When used as chemiresistor sensors, for the detection of heptane in water, the ethanol‐stored films provided larger resistance changes and longer response times. This suggests that the more densely packed ethanol‐stored films provided more sites that enabled film swelling, and that diffusion of the analyte occurred through the narrower water‐filled pores. This demonstrates the effect of different storage conditions on film morphology and subsequently sensor response. 相似文献
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