The studies of laser damage resistance o silica glass and.fluoride crystals (MgF2, OaF2 and LIE), perrormed at the wavelengths of excimer lasers Ar (193nrn), KrF (248nm), and. XeF (353rim) with the pulse duration SOns have given the following set of data:-the dependence o1 the bulk damage threshold on irradiated spot size , ranging in value from 6 to I 20OtLm;-temperature dependence of laser damage resistance;-the influence o metal admixtures on damage threshold; -the influence o ionizing radiation on damage resistance;-the coefficients of nonlinear absorption; -frequency dependence o the bulk damage threshold for silica glass in UV region.

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The evolution of the structures, that developed in cellulose hydrate films from a rayon after coagulation in the precipitating bath from organic solvent, water and sulfuric acid in presence of inorganic salt has been investigated. The specific features of structure formation at coagulation and cellulose hydrate film extension have been found. It was shown that there is a high diversity of supermolecular structures, whose morphology depends on the precipitation conditions and preliminary orientation. The films structure characteristics correspond to its strength properties. An increase in salt concentration resulted in a films with a more homogeneous, tensile strength structures and small sizes of spherulites. The films of high resistance is formed, in a precipitation bath of organic solvent, because of the realization of the liquid crystalline phase in the coagulation process.

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