Direct observation of two protons in the decay of 54Zn

The two protons emitted in the decay of 54Zn have been individually observed for the first time in a time projection chamber. The total decay energy and the half-life measured in this work agree with the results obtained in a previous experiment. Angular and energy correlations between the two protons are determined and compared to theoretical distributions of a three-body model. Within the shell model framework, the relative decay probabilities show a strong contribution of the p2 configuration for the two-proton emission. After 45Fe, the present result on 54Zn constitutes only the second case of a direct observation of the ground state two-proton decay of a long-lived isotope.     

Properties of epoxy polymers cured with polyoxypropylene diamine

The results of investigations of epoxy polymers cured with polyoxypropylene diamine D-230 depending on the molecular weight of epoxide oligomer, the content of the curing agent, active diluents, and plasticizers are presented. It is shown that epoxy polymers cured with polyoxypropylene diamine are characterized by a rather high complex of physicomechanical and adhesion properties.     

Modification of epoxy polymers with epoxy thiirane derivative of benzimidazolone-2

An epoxy thiirane derivative of benzimidazolone-2 was synthesized. An addition of epoxy thiirane derivative of denzimidazolone-2 to epoxy rubber and epoxy composites was shown to increase their thermal stability, elasticity modulus, and cohesion and adhesion strengths, especially at higher test temperatures. The effect depends on the concentration of additive, hardening temperature, type of rubber, and other factors.     

Solution of two-dimensional problems of the statics of flexible shallow shells by spline approximation

S. P. Timoshenko Institute of Mechanics, National Academy of Sciences of the Ukraine, Kiev. Translated from Prikladnaya Mekhanika, Vol. 31, No. 4, pp. 10–16, April, 1995.     

Solution of problems of the statics of shallow shells and plates with hinged and rigidly-fastened opposing edges

Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Kiev University. Translated from Prikladnaya Mekhanika, Vol. 26, No. 1, pp. 30–38, January, 1990.     

Frequency mixing in a bistable system in the presence of noise

The dynamics of a bistable system resulting from the action of several periodic perturbations and noise is studied. The response of the system at combination harmonics and the changes in the response caused by high-frequency modulation and a constant field that removes the degeneracy in the bistable system are calculated. The mixing of harmonics is investigated experimentally in an iron garnet thin film. It is shown that the higher harmonics exhibit behavior characteristic of stochastic resonance and that the form and symmetry of the dependence of harmonics on the constant field removing the degeneracy can be used to determine the characteristics of a bistable system with respect to its response to external periodic modulation. Zh. éksp. Teor. Fiz. 112, 628–642 (August 1997)     

Reply to comment on "Negative refractive index in artificial metamaterials"

The claims of the preceding Comment [Opt. Lett. 32, 1510 (2007)] are discussed. It is shown that Kildishev misread the previously presented method [Opt. Lett. 31, 2483 (2006)] for determining optical constants of nanostructured films. Reasons for a disagreement of the simulations presented in the Comment are also discussed.