Space charge and thermal depolarization currents in PZT thin films

Space-charge effects in PZT thin films obtained by rf cathode sputtering were studied. There is evidence that space charge forms in the ferroelectric phase during dielectric aging. Charge accumulation and disappearance were investigated by the method of thermally stimulated depolarization currents. Current peaks due to preliminary poling by a dc electric field and dielectric aging were determined. Effects that can be attributed to the rearrangement of point defects with the production of defect complexes, such as dimers, were observed for the first time. The activation energies for trap depletion (0.98 eV) and defect complex breakdown (1.20 eV) were found.     

Quantum space-times in the year 2002

We review certain emergent notions on the nature of space-time from noncommutative geometry and their radical implications. These ideas of space-time are suggested from developments in fuzzy physics, string theory, and deformation quantization. The review focuses on the ideas coming from fuzzy physics. We find models of quantum space-time like fuzzy S ⁴ on which states cannot be localized, but which fluctuate into other manifolds like CP³. New uncertainty principles concerning such lack of localizability on quantum space-times are formulated. Such investigations show the possibility of formulating and answering questions like the probability of finding a point of a quantum manifold in a state localized on another one. Additional striking possibilities indicated by these developments is the (generic) failure of CPT theorem and the conventional spin-statistics connection. They even suggest that Planck’s ‘constant’ may not be a constant, but an operator which does not commute with all observables. All these novel possibilities arise within the rules of conventional quantum physics, and with no serious input from gravity physics.     

Synthesis and properties of an aminocarboxylic polyampholyte based on polyacrylonitrile fiber

Aminocarboxylic fibrous polyampholytes containing up to 2.5 mg-equiv g^?1 weakly acidic groups and up to 2.9 mg-equiv g^?1 weakly basic groups were prepared from Nitron commercial polyacrylonitrile fiber by its treatment with mixed aqueous solutions of diethylenetriamine and sodium silicate. The acid-base properties of the polyampholyte were studied.     

Cross-sections of large-angle hadron production in proton- and pion-nucleus interactions I: beryllium nuclei and beam momenta of +8.9 GeV/c and −8.0 GeV/c

We report on double-differential inclusive cross-sections of the production of secondary protons, deuterons, and charged pions and kaons, in the interactions with a 5% λ _abs thick stationary beryllium target, of a +8.9 GeV/c proton and pion beam, and a −8.0 GeV/c pion beam. Results are given for secondary particles with production angles 20^○<θ<125^○. On leave of absence at Ecole Polytechnique Fédérale, Lausanne, Switzerland.     

A convenient synthesis of substituted 3-bromotetrahydrofurans from homoallylic alcohols

Substituted 3-bromotetrahydrofurans were prepared from homoallylic alcohols via bromination and cyclization in methanol in the presence of potassium carbonate.     

Thermal decomposition of 2,6-di-tert-butyl-p-benzoquinone diazide in solutions of olefins with the formation of spirodienones

Conclusions A new method suitable for the preparative synthesis of spirodienones has been developed which is based on the thermal decomposition of 2,6-di-tert-butyl-p-benzoquinone diazide in solution in olefins and their functional derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 558–563, March, 1968.The authors express their gratitude to N. M. Émanuél' for constant interest in the work during its performance.