The present paper deals with the induced orientational order of the probe molecules dissolved in the uniaxially strained rubbers measured by using deuterium NMR. The distinctive dependence of the quadrupolar splitting...The present paper deals with the induced orientational order of the probe molecules dissolved in the uniaxially strained rubbers measured by using deuterium NMR. The distinctive dependence of the quadrupolar splitting on the swelling, elongation and crosslinking density was observed. The orientational order arising from the correlation between chain segments decreases with the increase of the numbers of both links between junctions and solvent molecules around segments.展开更多
The orientational order is an important concept of the materials composed of large molecules or clusters. Using high-resolution scanning tunneling microscopy, we have studied the orientational order of two kinds of ty...The orientational order is an important concept of the materials composed of large molecules or clusters. Using high-resolution scanning tunneling microscopy, we have studied the orientational order of two kinds of typical low-dimensional C60 lattices: two-dimensional molecules array and C60(111) multi-layer film surface. Due to the change of the crystal field, their orientational orders are distinctly different from those in bulk system, and some unique phenomena appear.展开更多
The influence of free surface and depolarizing field on structural phase transitions in thin ferroelectric films from an ordered state to a disordered one is investigated.The dependences of the order parameter on the ...The influence of free surface and depolarizing field on structural phase transitions in thin ferroelectric films from an ordered state to a disordered one is investigated.The dependences of the order parameter on the distance from the free film surface are calculated.It is shown that with the presence of the depolarizing field and in its absence,the effective thickness of the surface layer depends on the temperature.Nearby the phase transition point,the thickness increases indefinitely.Calculations considering depolarizing field showed that the phase transition points for the bulk ferroelectrics and the film under given boundary conditions coincide.Also shown that in the absence of depolarizing field with mixed boundary conditions,the film thickness does not affect the order parameter,and in presence of the field,this influence is observed.展开更多
基金Supported by the National Natural Science Foundation of China
文摘The present paper deals with the induced orientational order of the probe molecules dissolved in the uniaxially strained rubbers measured by using deuterium NMR. The distinctive dependence of the quadrupolar splitting on the swelling, elongation and crosslinking density was observed. The orientational order arising from the correlation between chain segments decreases with the increase of the numbers of both links between junctions and solvent molecules around segments.
文摘The orientational order is an important concept of the materials composed of large molecules or clusters. Using high-resolution scanning tunneling microscopy, we have studied the orientational order of two kinds of typical low-dimensional C60 lattices: two-dimensional molecules array and C60(111) multi-layer film surface. Due to the change of the crystal field, their orientational orders are distinctly different from those in bulk system, and some unique phenomena appear.
文摘The influence of free surface and depolarizing field on structural phase transitions in thin ferroelectric films from an ordered state to a disordered one is investigated.The dependences of the order parameter on the distance from the free film surface are calculated.It is shown that with the presence of the depolarizing field and in its absence,the effective thickness of the surface layer depends on the temperature.Nearby the phase transition point,the thickness increases indefinitely.Calculations considering depolarizing field showed that the phase transition points for the bulk ferroelectrics and the film under given boundary conditions coincide.Also shown that in the absence of depolarizing field with mixed boundary conditions,the film thickness does not affect the order parameter,and in presence of the field,this influence is observed.
