Inductivism and Parmenidean epistemology: Kyburg’s way

cording to Henry Kyburg, all extralogical and extramathematical propositions accepted as evidence and all propositions accepted inductively on the basis of such evidence are uncertain. There is a possibility of error. Consequently, neither the corpus of inductively accepted statements nor the corpus of statements accepted as evidence can serve as a standard for serious possibility in the sense I have deployed since the 1970s. The standard for serious possibility remains an unchanging Parmenidean standard. In contrast to other Parmenidean epistemologists that eschew inductive acceptances Kyburg insists that the corpus of evidence and of inductively accepted statements is subject to critical review and change; but the changes have no bearing on the standard for serious possibility.have always agreed with Henry’s emphasis on a distinction between acceptance as evidence and inductive acceptance. But I have insisted that the corpus of evidence or state of full belief is a standard for serious possibility and that the standard is subject to modification.burg does think of acceptance as evidence and inductive acceptance as modal notions and has recently used the expression “serious possibility” in this connection. But when Kyburg and Teng speak of “risky knowledge”, they are speaking of claims that might be false in the sense of serious possibility that they seem to be suggesting is immune to change and seems to correlate with serious possibility as I have used it since the 1970s. So acceptance (both inductive and evidential) are modal notions subject to change but are not to be confused with the notion of serious possibility of error or riskiness.     

Palladium-catalyzed oxidative homocoupling of potassium alkenyltrifluoroborates: synthesis of symmetrical 1,3-dienes

Herein, we describe a convenient method for the synthesis of symmetrical 1,3-dienes employing an oxidative palladium-catalyzed homocoupling of potassium alkenyltrifluoroborates providing products in good yields relative to existing methodologies. This is the first report of a cross-dimerization of potassium alkenyltrifluoroborates.     

Streckenkomplexe auf Flächen

Ohne Zusammenfassung     

Integrable Nonlinear Equations for Water Waves in Straits of Varying Depth and Width

A considerable amount of information is currently available on the creation and propagation of large solitary waves in marine straits. In order to be able to analyze such data we develop a theoretical model, extending previous one-dimensional models to the case of straits with varying width and depth, and nonvanishing vorticity. Starting from the Euler equations for a three-dimensional homogeneous incompressible inviscid fluid, we derive, in the quasi-one-dimensional long-wave and shallow-water approximation, a generalized KadomtsevPetviashvili (GKP) equation, together with its appropriate boundary conditions. In general, the coefficients of this equation depend on the form of the bottom and on the vorticity; the sides of the straits figure only in the boundary conditions. Under certain restrictions on the vorticity and the geometry of the straits we reduce the GKP equation to one of several completely integrable partial differential equations, in order to study the evolution of solitons which originate in the straits.     

Redox Potential and Crystal Chemistry of Hexanuclear Cluster Compounds

Most of TM₆-cluster compounds (TM = transition metal) are soluble in polar solvents, in which the cluster units commonly remain intact, preserving the same atomic arrangement as in solids. Consequently, the redox potential is often used to characterize structural and electronic features of respective solids. Although a high lability and variety of ligands allow for tuning of redox potential and of the related spectroscopic properties in wide ranges, the mechanism of this tuning is still unclear. Crystal chemistry approach was applied for the first time to clarify this mechanism. It was shown that there are two factors affecting redox potential of a given metal couple: Lever’s electrochemical parameters of the ligands and the effective ionic charge of TM, which in cluster compounds differs effectively from the formal value due to the bond strains around TM atoms. Calculations of the effective ionic charge of TMs were performed in the framework of bond valence model, which relates the valence of a bond to its length by simple Pauling relationship. It was also shown that due to the bond strains the charge depends mainly on the atomic size of the inner ligands.