Correlation between mechanical and electrical properties on conductive SiC-fibre reinforced composites

Electrical and mechanical properties of ceramic composites are investigated to develop “smart materials” and establish a fracture prediction technique. The “smart materials” are based on silicon carbide fibre-reinforced composites. The SiC-fibres were checked to determine the changes in mechanical and electrical properties during the composites’ production. Samples were produced for the determination of the mechanical strength with in situ detection of the degree of damage by recording the electrical resistance.     

Distinguishable equivalent particles with symmetrized wave functions

The quantum formalism ofdistinguishable, yetequivalent particles (with symmetric or antisymmetric wave functions) is here worked out. The result is an entirely explicit formulation of the way in which classical mechanics emerges from quantum mechanics for such particles. Distinguishability is achieved at the cost of dynamical precision; the two are, in fact, complementary.Research sponsored in part by the Air Force Office of Scientific Research, Office of Aerospace Research, United States Air Force, under AFOSR Grant No. 557–67.     

Experimental evidence for spin diffusion of four-spin correlation functions in a one-dimensional heisenberg magnet

The EPR magic angle linewidth and dynamic shift have been measured as a function of frequency in TMMC. Both the linewidth and the shift vary with frequency as $\text{ω}{}^{\mathrm{<mtext>?</mtext><mtext>1</mtext><mtext>2</mtext>}}$. These results support strongly the one-dimensional behaviour of the relaxation dynamics of this compound. The results are in good agreement with a recent calculation.