At a temperature of 100 K, CH5N2+·I- (I), crystallizes in the monoclinic space group P21/c. The formamidinium cation adopts a planar symmetrical structure [the r.m.s. deviation is 0.002 Å, and the C-N bond lengths are 1.301 (7) and 1.309 (8) Å]. The iodide anion does not lie within the cation plane, but deviates from it by 0.643 (10) Å. The cation and anion of I form a tight ionic pair by a str...

Berry’s phase carries physical information coded as topological and geometrical objects that can be directly verified in measurements. In some cases the situation can be reduced to an irrational phase shift, that can be usually obtained by an iterative process. Take the Berry phase as the geometric object and let the iterative process be a non-linear phase-locked feedback mechanism defined by s...

A comparison is made of two different approaches to the description of phase transitions in the A2BX4 structure (space group D4&, I4/mmm) due to rigid octahedral tiltings. The lower-symmetry subgroups due to coupling of the K»f (X2) and E&2~ (P4) representations (6 tilts) to other tilting modes are listed. All observed transitions in the A2BX4 structure are of the octahedral tilting types. Thes...

We examine a model of non-self-avoiding, uctuating surfaces as a candidate continuum string theory of surfaces in three dimensions. This model describes Dynamically Triangulated Random Surfaces embedded in three dimensions with an extrinsic curvature dependent action. We analyze, using Monte Carlo simulations, the dramatic crossover behaviour of several observables which characterize the geomet...

It is shown that the Galilean invariant structure of geometric phase in nonrelativistic quantum mechanics corresponds to the difference between geometric phases for two paths in ray space with common initial and final points.

Landau-type theories describe the observed behaviour of phase transitions in ferroelastic and co-elastic minerals and materials with a high degree of accuracy. In this review, the derivation of the Landau potential G=1/2AthetaS [coth(thetaS/T)-coth(thetaS/TC)]Q2 + 1/4BQ4 + ... is derived as a solution of the general phi4 model. The coupling between the order parameter and spontaneous strain of ...

this paper provides an overview on obtaining low-carbon ultra-fine grained dual-phase steels through rapid intercritical annealing of cold-rolled sheet as improved materials for automotive applications. a laboratory processing route was designed that involves cold-rolling of a tempered martensite structure followed by a second tempering step to produce a fine grained aggregate of ferrite and ca...

in this research, cellulose-silk composites production in liquid phase was studied. in this respect,bmimcl ionic liquid was synthesized in the laboratory and was used for dissolution purpose. afterdissolution of the biopolymers and mixing them in the liquid phase, obtained suspension was spread ina petri dish. then, the composite gel was washed with running methanol to remove the il, cellulosea...

thermal conformational changes in human serum albumin (hsa) in present with a 10 mm phosphate buffer, at ph=7 have been investigated via circular dichroism (cd) and uv spectroscopic methods. the results indicate that temperature in a range of 25oc to 55oc could induce a reversible conformational change in the structure of hsa. the hsa phase transition corresponds to the physiological and pathol...

The dynamical scaling hypothesis for the structure factor, S (q) , in depletion-driven colloidal phase separation is studied by carrying out Brownian dynamics simulations. A true dynamical scaling is observed for shallow quenches into the two-phase coexistence region. In such a quench, compact clusters nucleate and grow with time and there is only one characteristic length scale in the system a...