Uniaxial stress effects and excited states for multiple bound excitons

The theoretical model for multiple bound excitons (MBE) recently introduced by Dean et al¹ is used to discuss uniaxial stress effects in silicon. The fine structures observed in MBE spectra for SiC and Si are qualitatively strikingly similar. However, the interpretation of the strongest features in terms of a specific model for excited states suggested by Kirczenow² and Thewalt³ is not valid for SiC.     

Erschöpftheit und Invarianz beim Vergleich von Experimenten

Summary Let E be the collection of all experiments (in the sense of LeCam) with the same index set. Using the notion of -informativity a binary relation is introduced in E, which turns out to be equivalent with various other relations of comparison studied previously. For a certain subclass of E a characterization of -informativity via randomisation kernels yields the equivalence to Blackwell's sufficiency and in the case of contraction experiments also to sufficiency in the sense of Halmos and Savage. Furthermore the concept of translation invariance is generalized to large subclasses of E. In the case of invariance the characterizing kernels can also be chosen invariant. Applications of the theory to allocation and testing problems as well as to Shannon- and Fisher-informativity illuminate the general set up. The special case of experiments with only a finite index set appears strongly related to the study of orderings in the set of all positive Radon measures on compact convex subsets of certain topological vector spaces.

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Die vorliegende Arbeit wurde von der Naturwissenschaftlichen Fakultät der Friedrich-Alexander-Universität Erlangen-Nürnberg im SS 1968 als Habilitationsschrift angenommen.     

The Lorentz process converges to a random flight process

The Lorentz process is the stochastic process defined by a particle moving, according to Newton's law of motion, through static scatterers distributed according to some probability measure in space. We consider the Boltzmann-Grad limit: The density of scatterers increases to infinity and at the same time the diameter of the scatterers decreases to zero in such a way that the mean free path of the particle is kept constant. We show that the Lorentz process converges in the weak*-topology of regular Borel measures on the paths space to some stochastic process. The limit process is Markovian if and only if the rescaled density of scatterers converges in probability to its mean. In that case the limit process is a (spatially inhomogeneous) random flight process.On leave of absence of Fachbereich Physik der Universität München. Work supported by a DFG fellowship     

PHOTOSENSITIZATION OF INORGANIC SOLIDS*

Abstract— Experimental facts on the phenomenon of photosensitization of inorganic solids are summarized and the different mechanisms—especially electron transfer mechanisms—are discussed. It is shown that the concept of a macropotential difference formed between dye and inorganic solid in the dark, which separates electron-hole pairs generated by illumination, can answer a series of questions on the mechanism of spectral sensitization.     

A facile synthesis of α-chloroboronic esters via the base induced reaction of α,α-dichloromethyl methyl ether with hindered borinic esters

Treatment of hindered borinic esters, R₂ BOR′; with an equimolar quantity of α,α-dichloromethyl methyl ether and lithium triethylcarboxide yields the α-chloroboronic esters, R₂ CHClB(OCH₃)OR′, in excellent yields. In cases where the steric requirements of R are not sufficient, the steric requirements of R′ can be increased to achieve the synthesis.