Abstract: A method is disclosed for injecting water into a multistage axial compressor of a gas turbine. With low equipment cost, a significant power enhancement can be achieved, even under changing boundary conditions, by water being injected at a plurality of points along the axial compressor, and by the injected water mass flow being controlled at the individual injection points in accordance with ambient conditions and operating parameters of the gas turbine in such a way that an evened-out loading in the individual stages of the axial compressor can be created.

Abstract: Compounds of the formula I ##STR1## in which R is a C.sub.1 - to C.sub.22 -alkyl radical,A.sup.1 and A.sup.2 are hydrogen or methyl or,A.sup.1 is hydrogen and A.sup.2 is the nitro group, andB is the cyano group, the nitro group or an electron-attracting organic group having a double bond which is in conjugation with the thieno?3,2-b!thiophene ring system,have a high dipole moment and a high polarizability and are suitable for purposes of nonlinear optics. If R in the formula I is a C.sub.12 - to C.sub.22 -alkyl radical, monomolecular layers can be applied to a substrate by the Langmuir-Blodgett method. The resulting layer elements are suitable, inter alia, as waveguides.

Abstract: Materials of the formula I: ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 in each case independently of one another can be identical or different and are a hydrogen atom, halogen atom, hydroxyl group, nitro group, cyano group or monovalent, optionally substituted organic radical; R.sub.4 is a hydrogen atom, halogen atom, nitro group, cyano group or monovalent, optionally substituted organic radical; and R.sub.5 can be identical or different and is a halogen atom, hydroxyl group, nitro group, cyano group or monovalent, optionally substituted organic radical.

Abstract: Substituted thieno[3,2-b]thiophenes, processes for their preparation and their useCompounds of the formula I ##STR1## in which R is a C.sub.1 - to C.sub.22 -alkyl radical,A.sup.1 and A.sup.2 are hydrogen or methyl orA.sup.1 is hydrogen and A.sup.2 is the nitro group, andB is the cyano group, the nitro group or an electron-attracting organic group having a double bond which is in conjugation with the thieno[3,2-b]thiophene ring system,have a high dipole moment and a high polarizability and are suitable for purposes of nonlinear optics. If R in the formula I is a C.sub.12 - to C.sub.22 -alkyl radical, monomolecular layers can be applied to a substrate by the Langmuir-Blodgett method. The resulting layer elements are suitable, inter alia, as waveguides.