Extended defects in CdZnTe crystals: Effects on device performance

We explored some unique defects in a batch of cadmium zinc telluride (CdZnTe) crystals, along with dislocations and Te-rich decorated features, revealed by chemical etching. We extensively investigated these distinctive imperfections in the crystals to identify their origin, dimensions, and distribution in the bulk material. We estimated that these features ranged from 50 to 500 μm in diameter, and their depth was about ∼300 μm. The density of these features ranged between 2×10² and 1×10³ per cm³. We elaborated a model of them and projected their effect on charge collection and spectral response. In addition, we fabricated detectors with these defective crystals and acquired fine details of charge-transport phenomena over the detectors’ volume using a high-spatial resolution (25 μm) X-ray response mapping technique. We related the results to better understand the defects and their influence on the charge-transport properties of the devices. The role of the defects was identified by correlating their signatures with the findings from our theoretical model and our experimental data.     

Absolute exponential stability criteria for a class of nonlinear time-delay systems

This paper is concerned with the problem of absolute exponential stability analysis for a class of continuous-time systems with sector-bounded nonlinearities and interval time-varying delays. Absolute exponential stability criteria, which depend not only on the delay range but also on the decay rate, are derived by using a novel Lyapunov functional. These criteria are expressed in the form of linear matrix inequalities (LMIs) and they can easily be checked. By solving these LMIs, estimates of the exponential decay rate and decay coefficient are obtained. A numerical example is provided to demonstrate the effectiveness of the proposed method.     

Mori dream spaces

We explore the circle of ideas connecting finite generation of the Cox ring, Mori dream spaces and invariant theory.     

Thermochemistry of Binding of Lead(II) and Cadmium(II) by Saccharides in Aqueous Solution

Solution calorimetry was used to determine enthalpies and stability constants for binding of lead(II) or cadmium(II) by galacturonic acid and several monosaccharides in aqueous solution. New values for enthalpies of solution in water are reported for galacturonic acid and maltose monohydrate. The interaction of water solvent with the reactants is the largest factor in the binding process.     

On the local behavior of certain homeomorphisms. II

In the previous paper by the authors, it is shown that a sense-preserving homeomorphism, absolutely continuous on lines (ACL), under certain integral conditions on the complex dilation is conformal at a point. This result includes the Teichmüller-Wittich-Belinski theorem. In the present paper, it is shown that under weakened conditions the local behavior of such a homeomorphism is similar to that of a quasiconformal mapping. Bibliography: 2 titles.Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 237, 1997, pp. 11–20.Dedicated to the 90th anniversary of G. M. Goluzin's birth.     

Riemann-Roch-Grothendieck and torsion for foliations

In this article we prove a Riemann-Roch-Grothendieck theorem for the characteristic classes of a flat vector bundle over a foliation whose graph is Hausdorff. We assume that the strong foliation Novikov-Shubin invariants of the flat bundle are greater than three times the codimension of the foliation. Using transgression, we define a torsion form which in the odd acyclic case determines a Haefliger cohomology class which only depends on the foliation and the flat bundle. We construct examples where this torsion class is highly non-trivial.