Temperature Dependent Characteristics

At lower temperatures (T < T,), a exhibits a temperature dependence characteristic of a small activation energy (= 0.03 eV) for excitation of charge carriers from stationary trap sites It is reasonable to suspect that small polarons tend to be trapped at impurity centers at low temperature. 

Chemical dynamics at low temperatures is connected with elementary reactions that surmount potential energy barriers separating reactants from products in the absence of thermal activation. The first experimental evidence of this type of reactions was obtained in the early 1970s in studies of solid-state conversion of free radicals. These investigations clearly demonstrated that there is a sufficiently sharp transition from Arrhenius-like exponential temperature dependence, characteristic of thermal activation, to much weaker power-like temperature dependence down to the low-temperature limit of the rate constant. 

The thermal conductivity of the three samples within their glass states from T = 2 K up to 7 is shown in Fig. 2. The data shown there exhibits a temperature dependence characteristic of most amorphous solids. The thermal conductivity increases with temperature with a maximum rate below 4 K. A... 

Details of optical thermometers for measuring each temperature-dependent characteristic will be described as follows. 

In the MFN model the flow resistances and pressure sources are dependent on heat flow or temperature. Discretization has to be made so that over an individual discrete section the temperature-dependent characteristics can be expressed by lumped values with sufficient accuracy. Pipes, which can be taken as isothermal and have a constant cross-section can be modeled as a single flow resistance. 

The temperature-dependent characteristics result essentially in the following curves (in fact, each group of plastics is characterized by large numbers of different curves), see Fig. 2. 

T temperature dependence characteristic of phonon scattering dominated by Umklapp processes in crystalline solids... 

Transport in conducting polyaniline / nylon blends is observed to be independent on the composition, dopant anion, host matrix and structure of the conducting phase. The microscopic transport in all salt networks remains unchanged by the dilution of the salt in the nylon matrix. The conductivity follows a temperature dependence characteristic of generalized variable r e hopping mechanism with % = -1/4. The slope of the temperature dependence increases with dilution, indicating increased disorder in the polyaniline salt. 

Figure 2 Temperature dependent characteristic parameters ofP(S-b-B) during an upward and downward temperature scan, inverse of the normalized scattering peak maximum, I o/l (i o is the peak intensity at the transition), maximum position, q, and peak width, Aq, as obtained from fits of a Lorentz function to the q dependent scattering intensity. The solid lines are guides to the eyes. The data point in brackets represents the peak intensity of the sample directly q/ter the preparation. The dotted line indicates the position of the microphase separation temperature Tmst-...

Extensions of the WLF equation to include a parameter with Arrheniuslike temperature dependence, characteristic of chemical structure, have been developed in several different ways., 92-94 essentially equivalent to the form... 

In fact, the electrical properties have many time and temperature dependent characteristics in common with the mechanical properties. The significant measure of the charging and polarisation (dielectric) behaviour of a polymer insulator is its permittivity. This can be thought of as a parallel to mechanical compliance where the stress is replaced by the electric field or voltage, and the strain by the charge movement or polarisation. Then the equivalent to mechanical loss is electrical conductance loss or dissipation. 

Usually, the above equations hold fine in restricted pressure ranges, say for p Pm (with pj and p two temperature-dependent characteristic pressures depending on the considered adsorption system) for the Temkin and Toth isotherm, pi is allowed to vanish. 

For a full specification of a glass transition, besides the specific changes of the measured temperature-dependent characteristics of a polymer, must be stated both the cooling and heating rate (respective the... 

In the insulating regime, when the resistivity follows the activated temperature dependence characteristic of variable range hopping (VRH), In p (7o/T) the reduced activation energy becomes... 

Nose, N., A. Sugiyama, I. Okada, N. Nagaoka, and A. Ametani. 1998. Transistor model including temperature dependent characteristic for EMTP. National convention record, lEEJ 709. 

Sun et al. [173] later investigated the mechanism of SE in the same MQW samples. They observed SE induced by both exciton-exdton scattering and EHP recombination. The exciton-based recombination mechanism of SE was studied further by measuring the temperature dependence of the SE peak position. It was observed that the exdton-exciton band has the same temperature dependence characteristics as that of a ZnO single layer, supporting the notion that this emission in ZnO/MgZnO MQWs is indeed due to exdton-exdton scattering. In addition, the measurements at... 

Table 5. Temperature Dependence Characteristics of the Barrierless Discharge of a Hydrogen Ion at a Mercury Cathode...

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