Electro- and magneto-optical measurements of electric field strength in magnetic colloids based on liquid dielectrics

The distribution of the electric field strength in liquid dielectrics containing colloidal magnetite particles was investigated based on the data of electro- and magneto-optical experiments. It is shown that the field distribution between plane-parallel electrodes is nonuniform. The dependences of the field enhancement in the near-electrode region on the temperature and average field strength in the cell are determined. The parameters of the near-electrode space charge are calculated based on the data of optical experiments.     

Passage of beta particles through dielectrics in presence of an electric field

The effect of an electric field on the passage of thallium-204 beta particles through polymethyl methacrylate, polystyrene, polyethylene terephthalate (Lavsan), and polyethylene targets was investigated. The number of transmitted beta particles and their angular and energy distributions were determined. The transmission curves were obtained with a SBT-7 counter. The angular distribution was investigated in a specially designed scattering chamber, and the energy distribution was determined with a scintillation beta spectrometer incorporating the USD-1 and AI-100 instruments. It was found that the relative change in the number of transmitted beta particles depends on the size of the entrance solid angle, depends linearly on the potential difference applied to the dielectric, and is practically independent of the dielectric material if its thickness is expressed in mass units. It was also found that the relative change in angular distribution up to 60° with potential differences of not more than 10 kV is independent of the scattering angle. The energy distribution is not only shifted on the energy scale, but its shape is also altered. The results are attributed to the effect of the electric field on both the energy of the particles and the direction of their momentum. A simple method of calculating the effect of the field on the number of transmitted beta particles is proposed. The results of calculation agree with the experimental data.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 16, No. 9, pp. 113–118, September, 1973.     

Effect of an electric field on the limits of liquid stability

When electric fields are applied to metastable liquids, the energy barrier for nucleation of the vapor phase will increase. Reported observations of field-induced nucleation should not be used to infer stability limits of bulk liquids.     

On the contactless effect of an electric field on liquid systems

An effect of an electric field on the evaporation of polar and nonpolar liquids (water and a hydrocarbon, respectively) is established. The effect is stronger in the former case.     

Influence of electric field on photoluminescence of lanthanide-doped nematic liquid crystal

Highly resolved luminescence and luminescence excitation spectra of recently synthesized LnL₃bpy complexes, where Ln=Eu³⁺, Tb³⁺, bpy=2,2′- bipyridyne and L=phosphoroazo derivative of β-diketone: CCl₃C(O)NP(O)(OCH₃)₂, in solid state and dissolved in nematic liquid crystal 6CHBT [4-(isothiocyanatophenyl)-1-(trans-4-hexyl)cyclohexane] were measured. The photoluminescence intensity of the complexes dissolved in 6CHBT was found to exhibit a strong dependence on the electric field. The mechanism of the effect and reason of its asymmetry with respect to the sign of electric field are discussed in the paper. Luminescence decay time in various environments and experimental quantum yields of the luminescence of these compounds in CDCl₃ and CHCl₃ solutions were measured.     

Surface flow of liquid in an electric field

An analytic solution is proposed for a model problem which demonstrates the occurrence of a surface flow of weakly conducting liquid in an electric field which was previously observed experimentally by the author. Zh. Tekh. Fiz. 69, 127–128 (June 1999)     

Effect of an external electric field on liquid crystalline polymers

The effect of an external electric field on the order parameter and on the isotropic-anisotropic phase transition temperature for semi-flexible liquid crystalline polymers is studied by a mean-field approximation. For the polymers whose electric dipole moments are parallel to the chain backbone, the critical transition temperature T_c is extensively changed by gDT ∼ ∥E∥², where E is the external electric field.     

Influence of additional electric field on the birefringence of a nematic liquid crystal

Influence of the longitudinal voltage applied along the semiconductor substrate of a planar-oriented liquid crystal cell on the birefringence of a nematic liquid crystal (NLC) was investigated. It is shown that for a fixed magnitude of the transverse field the application of a longitudinal voltage creates an additional possibility to control the electro-optically induced phase incursion of the radiation passing through NLC. Dependence of the phase incursion on the control voltages is obtained. The results of simulation of the longitudinal voltage effect on the NLC reorientation are described. The obtained results can be used in development and designing of NLC phase modulators.     

Emergence of an electric field in finely disperse dielectrics during their interaction with hydrogen

The interaction of hydrogen molecules with the surface of the particles of a finely disperse dielectric CsNO₃, KMnO₄, or Pb(NO₃)₂ was found to be accompanied by the emergence of an electric field in the powder layer. This effect is independent of the material of the identical metal electrodes (Pt, Au, Hf, Mo, Pb, Al) and is determined by the decay into hydrogen Н⁺ ions and the electrons of the chemisorbed Н₂ molecules.     

Influence of an electric field on the magnetoabsorption in a field of resonant laser radiation

The frequency dependence of the coefficient of interband magnetoabsorption of a weak electromagnetic wave propagating in a constant electric field and in a field of resonant laser radiation at a frequency equal to the cyclotron frequency (infrared magnetic resonance) is calculated. The specific features observed in interband absorption of the electromagnetic wave in a uniform electric field are considered for the case in which the frequency of laser radiation is equal to the confinement frequency in a parabolic quantum well (infrared quantum-well resonance).     

Local field in liquid dielectrics: A two-parameter mean field approach

In the molecular field approximation, one derives an expression of the static dielectric constant of an isotropic liquid involving renormalized expressions of the molecular dipole and polarizability. The long-range moderate attractive forces are treated as a perturbation of the short-range intense repulsions, so that two parameters λ and η describe the short-range correlations and the long-range order, respectively. On the condition of a superposition hypothesis, the model is compared in its hard-sphere limit (λ=0, η=1) with the available experimental data about a series of organic liquids and with Onsager's continuum approach.     

Influence of an electric field on the capillary analogue of the dead-water effect

It is shown that the capillary analogue of the dead-water effect strongly depends on an external electrostatic field: in the presence of the field, the number of nonlinear resonance situations increases sharply. The field increases the wave amplitudes and excites both degenerate and secondary combination resonances, which are not observed without the field.     

Influence of an AC electric field on He II film transfer

The helium film transfer rates were found to be reduced considerably under ac field, the phenomenon being controllable and reproducible. The proposed explanation of the phenomenon observed is based on the excitation of He II film thickness oscillations.     

落球半径对测量粘度的影响

用实验和图解方法研究了落球法测粘度实验中落球半径对粘度测量的影响，给出了落球速度、运动距离与半径的关系，讨论了有限边界对速度的影响。     

Effect of an electric field on the surface tension of a liquid at low temperatures

An external electric field changes the dispersion law of waves on the surface of a liquid. Besides the usual capillary term (∝k ³, k is the wave number) and gravitational term (∝k), a term quadratic in the wave vector appears in the expression for the square of the frequency in a homogeneous field. These excitations are associated with the variation of the coefficient of surface tension of the liquid at low temperatures. In the case of a large field tangent to the surface, the correction is proportional to T ^8/3, unlike the T ^7/3 correction in the absence of a field. Zh. éksp. Teor. Fiz. 111, 1369–1372 (April 1997)