Slope anomaly in the vapour pressure curve of Hg
The investigation of normally-metallic fluids at reduced densities has created considerable experimental and theoretical interest. Hensel1 has presented evidence for transitions, related to electronic properties, in both the liquid and vapour phases of Hg, and predicted that these would affect the liquid–vapour transition. We present here evidence that the vapour pressure curve of Hg, p(T), has an unusual and probably unique form in that the In p against 1/T plot showed a sharp change of slope at temperature T = T′ = 1,361 K and saturated liquid density ρL = 10.7 g cm−3. The latter is about the density at which Hensel1 deduced that the electronic mean free path equalled the mean interatomic spacing, and which he took to be associated with the electronic-property related transition in the liquid phase.
Unusual Thermodynamic and Electrical Properties of Metallic Solutions Near the Critical Point of the Almost Pure Solvent
The paper presents experimental results of the electrical conductivity σ, the equation of state data and different related properties such as excess volumes of mixing VEx and partial molar volumes VIn for dilute amalgams of In as a function of pressure p. temperature T and composition XIn to 2700 bar, 1900 K and 2.85 at-% In, respectively. Particular attention is given to the behaviour of these properties in the metal-nonmetal transition range and close to the critical point of pure Hg. It is found that the divergence of the compressibility χT of pure Hg at the critical point is reflected in the behaviour of VEx, VIn and in the concentration dependence of the conductivity. The limiting values of the negative partial molar volume VIn and of for infinitely dilute solutions become extremely large as the critical point of pure Hg is approached. — An attempt is made to separate the different effects of temperature, volume and concentration and to analyze the data in terms of existing models for the electrical transport in expanded Hg and the critical behaviour of fluid dilute solutions.
Three New C19-Diterpenoid Alkaloids from Delphinium Bonvalotii
Three new lycoctonine-type C19-diterpenoid alkaloids, bonvalotidine A, bonvalotidine B, and bonvalotidine C, along with sixteen known alkaloids, were isolated from the roots of Delphinium bonvalotii Franch. Their structures were established by spectral analysis and chemical methods.