コロイド分散系やペーストなど、いわゆる「やわらかいガラス」において観測される、普遍的な非線形レオロジーを記述する微視的理論の紹介と、新しいレオロジー実験の提案を行う。%Many soft glassy materials such as dense colloidal suspensions, pastes, and particle gels show an universal nonlinear viscoelasticity with increasing oscillatory-strain amplitude. It has been known for long time that, for fixed frequencies, the storage modulus G'(ω) decreases monoton-ically as the strain amplitude 7 increases whereas the loss modulus G"(ω) has a distinct peak around γ ≈ 1 followed by decrease at larger strains. This ubiquitous behavior can be understood by noticing that the characteristic relaxation time of many glassy systems are extremely sensitive to the strain rates. Under shear flow, the structural relaxation time is roughly given by τ~(-1) = τ_0~(-1) + γ, where γ is the strain rate and τ_0 is the relaxation time without shear[l].
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