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It is shown that it is sufficient to solve a single first order differential equation to determine exact Bianchi type V imperfect fluid solutions of Einstein's field equations. Two exact solutions are presented in this paper. One of these two solutions corresponds to the case when the anisotropic pressure tensor is proportional to the shear tensor. This proportionality, it is shown, is a necessary but not a sufficient condition for the absence of heat flow in a Bianchi type V universe. It is also observed that the presence of heat flow necessarily introduces anisotropy in a Bianchi type V universe. 相似文献
105.
Dipak Ghosh Argha Deb Swarup Ranjan Sahoo Kanchan Kumar Patra Prabir Kumar Haldar Jayita Ghosh 《Czechoslovak Journal of Physics》2002,52(6):789-794
An analysis of data of target fragments of 28Si-AgBr (at 14.5 AGeV) reveals the existence of emission asymmetry in the azimuthal plane, which is found to depend on the number of target fragments. The comparison with the data of 32S-AgBr (at 200 AGeV) and 16O-AgBr (at 60 AGeV) interactions indicates that emission asymmetry depends on the projectile mass and energy. 相似文献
106.
Akhilesh K. Arora R. Kesavamoorthy A.K. Sood G. Venkatraraman R. Krishnaswamy Debendranath Sahoo 《Journal of Physics and Chemistry of Solids》1984,45(1):69-77
The formation and dissolution behaviour of precipitates in NaCl : Pb2+ single crystals is studied by light scattering and ultramicroscopy. Measurements of Rayleigh ratio together with ultramicroscopic observations during isochronal annealing indicate the presence of two types of precipitates in as-grown crystals. Isochronal annealing after suitable thermal and thermomechanical treatments shows that precipitates of first type (I) which form and dissolve at lower temperatures, are due to homogeneous nucleation. Precipitates of the second category (II) which form and dissolve at higher temperatures are aligned along crystallographic directions and have their origin in stress-assisted processes. Isothermal annealing has been used to study the dissolution kinetics of the precipitated fraction, and it is found that the kinetics is of first order. The enthalpy of solution is determined from a study of the temperature dependence of the kinetic rate constant, in conjunction with available information on the migration energy of Pb2+ in NaCl. The enthalpy so deduced is in good agreement with the value as usually obtained from the concentration dependence of the dissolution temperature. 相似文献
107.
A direct method of solution is presented for singular integral equations of the first kind, involving the combination of a logarithmic and a Cauchy type singularity. Two typical cases are considered, in one of which the range of integration is a single finite interval and, in the other, the range of integration is a union of disjoint finite intervals. More such general equations associated with a finite number (greater than two) of finite, disjoint, intervals can also be handled by the technique employed here. 相似文献
108.
Stability of the generalized quadratic and quartic type functional equation in non-Archimedean fuzzy normed spaces 下载免费PDF全文
In this paper, we prove some stability results concerning the generalized quadratic and quartic type functional equation in the context of non-Archimedean fuzzy normed spaces in the spirit of Hyers-Ulam-Rassias. As applications, we establish some results of approximately generalized quadratic and quartic type mapping in non-Archimedean normed spaces. Also, we show that the assumption of the non-Archimedean absolute value of $2$ is less than $1$ cannot be omitted in our corollaries. The results improve and extend some recent results. 相似文献
109.
The electric quadrupole moment for the 4d(2)D(5/2) state of (88)Sr(+); one of the most important candidates for an optical clock, has been calculated using the relativistic coupled-cluster theory. This is the first application of this theory to determine atomic electric quadrupole moments. The result of the calculation is presented and the important many-body contributions are highlighted. The calculated electric quadrupole moment is (2.94 +/- 0.07)ea(2)(0), where a(o) is the Bohr radius and the electronic charge while the measured value is (2.6 +/- 0.3) ea(2)(0). This is so far the most accurate determination of the electric quadrupole moment for the above mentioned state. We have also calculated the electric quadrupole moments for the metastable 4d(2)D(3/2) state of 88(Sr(+) and for the 3d(2)D(3/2.5/2) and 5d(2)D(3/2.5/2) states of (43)Ca(+) and (138)Ba(+), respectively. 相似文献
110.
Two extensive homologous series of H-shaped symmetrical dimers were synthesized and their thermotropic properties studied by differential scanning calorimetry and on a hot-stage of a polarizing microscope. These compounds consist of two mesogenic units of azoester interconnected through flexible spacers (n?=?4) resulting in the structure of ‘H-shaped’ dimeric compounds. The difference between the two series is in the structure of terminal substituents (–CH3 for series I and –OCH3 for series II) attached on the azoester mesogens at one terminus. All these compounds were found to be smectogenic. The effect of different terminal substituents on mesomorphism is discussed. The trans-azobenzene groups of the H-shaped dimeric compounds display a high-intensity π–π* transition at about 365?nm and a low-intensity π–π* transition at around 460?nm, therefore, photochromism can be achieved by the introduction of the azo linkage to the H-shaped dimeric compounds. 相似文献