Standstill Electric Charge Generates Magnetostatic Field under Born-Infeld Electrodynamics

The Abelian Born-Infeld classical non-linear Electrodynamic has been used to investigate the electric and magnetostatic fields generated by a point-like electric charge at rest in an inertial frame. The results show a rich internal structure for the charge. Analytical solutions have also been found. Such fields configurations have been interpreted in terms of vacuum polarization and magnetic-like charges produced by the very high strengths of the electric field considered. Apparently non-linearity is responsible for the emergence of an anomalous magnetostatic field suggesting a possible connection to that created by a magnetic dipole composed of two magnetic charges with opposite signs. Consistently in situations where the Born-Infeld field strength parameter is free to become infinite, Maxwell’s regime takes over, the magnetic sector vanishes and the electric field assumes a Coulomb behavior with no trace of a magnetic component. The connection to other monopole solutions, like Dirac’s and ’tHooft’s Poliakov’s types are also discussed. Finally, some speculative remarks are presented in an attempt to explain such fields.     

金属纳米椭球结构表面的局域电场和吸附分子分布

过渡金属纳米结构表面吸附CO分子时会出现异常红外效应,这一现象可以用纳米结构表面吸附分子在外电场作用下产生局部凝聚从而相互作用能增加来解释.在前期研究的基础上,给出金属基底表面生长出的纳米颗粒为椭球状颗粒的理论计算结果.基于均匀外电场中金属纳米椭球颗粒按一定对称性排列的表面结构模型,用经典电磁学理论计算了纳米椭球颗粒表面附近的局域电场.在此基础上,将吸附的CO分子等效为偶极子,在考虑了偶极子与局域电场、偶极子之间以及偶极子与金属基底三种相互作用的情况下,用Monte-Carlo方法进行数值模拟,最后给出纳 关键词： 金属纳米结构表面 纳米椭球 吸附分子 局域电场     

金属纳米锥表面吸附分子分布的数值模拟

在均匀外电场中,将吸附在由过渡金属基底生长的纳米锥颗粒表面的CO分子等效为偶极子,在考虑偶极子与局域电场,偶极子之间色散力及偶极子与锥表面原子之间三种相互作用的情况下,给出各相互作用能的数学模型,并用Monte Carlo方法进行数值模拟,得到纳米锥颗粒表面吸附CO分子的空间分布构型.结果表明,在这些相互作用下,纳米锥表面吸附CO分子产生局部凝聚,且随着纳米锥角的变小,吸附在锥顶部的分子更加密集,导致吸附分子间相互作用更强,为解释纳米结构表面吸附体系的异常红外效应提供依据.     

Excitonic susceptibility of semiconducting crystals influenced by a uniform electric field

Summary The Stahl’s polariton equations for crystals, influenced by a uniform electric field, can be solved by means of an appropriate Green’s function. The Green’s function is calculated for the half-space geometry and the field directed along the z-axis. Using its asymptotic form a formula for the excitonic susceptibility is derived.     

Local electric field and configuration of CO molecules adsorbed on a nanostructured surface with nanocones

Based on the nanostructured surface model that the (platinum, Pt) nanocones grow out symmetrically from a plane substrate, the local electric field near the conical nanoparticle surface is computed and discussed. On the basis of these results, the adsorbed CO molecules are modelled as dipoles, and three kinds of interactions, i.e. interactions between dipoles and local electric field, between dipoles and dipoles, as well as between dipoles and nanostructured substrate, are taken into account. The spatial configuration of CO molecules adsorbed on the nanocone surface is then given by Monte-Carlo simulation. Our results show that the CO molecules adsorbed on the nanocone surface cause local agglomeration under the action of an external electric field, and this agglomeration becomes more compact with decreasing conical angle, which results in a stronger interaction among molecules. These results serve as a basis for explaining abnormal phenomena such as the abnormal infrared effect (AIRE), which was found when CO molecules were adsorbed on the nanostructured transition-metal surface.     

Effect of metallic and hyperbolic metamaterial surfaces on electric and magnetic dipole emission transitions

Spontaneous emission patterns of electric and magnetic dipoles on different metallic surfaces and a hyperbolic metamaterial (HMM) surface were simulated using the dyadic Green’s function technique. The theoretical approach was verified by experimental results obtained by measuring angular-dependent emission spectra of europium ions on top of different films. The results show the modified behavior of electric and magnetic dipoles on metallic and HMM surfaces. The results of numerical calculations agree well with experimental data.     

Increase in the hydraulic pressure in various zones of a two-fluid hydrophilic capillary due to nonuniformity of the external electric field

The phenomenon whereby the thickness of the water film next to the inner surface of a hydrophilic capillary filled with two fluids increases in the presence of an external static electric field is investigated. A hypothesis of the essential nature of the phenomenon is submitted, along with a corresponding equation for calculating numerically the thickness variations as a function of several parameters of the working system, including the strength of the external field. Experimental results are given. The results of theoretical calculations and the experimental data are shown to be in good agreement. The orientation of stationary dipoles of the molecules constituting highly polar liquids in an electric field is estimated. Zh. Tekh. Fiz. 68, 24–30 (August 1998)     

A paradigm for the biomedium

Summary A model for water in biosystems, based on the assumption that water is adsorbed on macromolecules, is discussed. This model succeeds in explaining the Na⁺/K⁺ ratio without invoking active transport.

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Riassunto Si propone un modello per l’acqua nei sistemi biologici basato sull’ipotesi che l’acqua si trovi adsorbita sulle macromolecole. Questo modello riesce a spiegare il rapporto Na⁺/K⁺ senza richiedere nessuna ipotesi supplementare di trasporto attivo.

     

Soaring interfaces, vortices and vortex systems inside the internal waves wake past the horizontally moving cylinder in a continuously stratified fluid

The flow pattern around a horizontal cylinder towed at constant velocity along isopycnic plane in a continuously stratified liquid is visualized by conventional techniques of “Vertical slit-Foucault’s knife”, “Maksoutov’s slit-thread” and “horizontal slit-regular grating”. Using sensitive high-resolution methods allows detail studying such component of stratified flow structures as soaring interfaces, singular soaring vortices and vortex systems, which arise directly inside the internal waves field past the cylinder. These flow elements having high level of vorticity are separated from the downstream wake by a strip of fluid without any small-scale inhomogeneities. Formation of singular vortex dipoles on leading edges of soaring interfaces is investigated in details in a wide range of flow parameters.     

Mechanisms of dendrites occurrence during crystallization: Features of the ice crystals formation

Dendrites formation in the course of crystallization presents very general phenomenon, which is analyzed in details via the example of ice crystals growth in deionized water. Neutral molecules of water on the surface are combined into the double electric layer (DEL) of oriented dipoles; its field reorients approaching dipoles with observable radio-emission in the range of 150 kHz. The predominant attraction of oriented dipoles to points of gradients of this field induces dendrites growth from them, e.g., formation of characteristic form of snowflakes at free movement of clusters through saturated vapor in atmosphere. The constant electric field strengthens DELs' field and the growth of dendrites. Described phenomena should appear at crystallization of various substances with dipole molecules, features of radio-emission can allow the monitoring of certain processes in atmosphere and in technological processes. Crystallization of particles without constant moments can be stimulated by DELs of another nature with attraction of virtual moments of particles to gradients of fields and corresponding dendrites formation.     

Reduction of the duration of pulses emitted by a thin-walled piezoceramic cylinder with the use of a correcting electric circuit

On the basis of an electric circuit’s analog of a thin-walled cylindrical piezoceramic transducer connected with an electric circuit, the shapes of the pulses emitted into water are calculated. The optimal circuit’s parameters that provide the minimal pulse’s duration are calculated for different values of the cylinder height and relative wall’s thickness. The possibility to considerably reduce the emitted pulse’s duration is demonstrated, and specific results of numerical calculations are presented.     

Optical spectroscopic study of the Cu(II) complexes with adenosine and adenine nucleotides

Summary Aqueous adenosine-copper and D-ribose copper solutions have been studied as functions ofpH, in thepH range from 3 to 12. Our approach is the study of the effect that the field of ligands produces on the opticald-d transitions of the copper ion. The results show that abovepH 6 the ribose moieties of adenosine bind to the copper ions forming two kinds of soluble 1∶1 complex, one prevailing atpH 9 and the other prevailing atpH 11.5.

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Riassunto La formazione dei complessi del rame con molecole di adenosina e con molecole di D-ribosio in soluzione acquosa è studiata, al variare delpH nell’intervallo da 3 a 12, analizzando l’effetto del campo legante sulle transizioni ottiche tra i livellid dello ione Cu(II). I risultati mostrano che, per valori dipH maggiori di 6, il gruppo ribosio dell’adenosina si lega agli ioni Cu(II) formando due distinti complessi, uno prevalente apH 9 e l’altro prevalente apH 11.5.

     

Effects ofpH on the chromophore orientation in purple membrane

Summary Suspensions of purple-membrane fragments from Halobacterium halobium were oriented by a static electric field with intensity up to 25V/cm in the range ofpH from 4 to 9. It was found that the orientation of the transient dipole moment of the retinal chromophore for what concerns the permanent dipole moment of the membrane fragment undergoes a transition from (60±1)° atpH 5 to (71±1)° atpH 6. Moreover, the permanent dipole moment of the membrane fragments of 1.8·10⁻²³ C·m found at thepH values from 4 to 7 reduces to 1.3·10⁻²³ C·m atpH higher than 7.

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Riassunto Sospensioni di frammenti di membrana purpurea del Halobacterium halobium apH fra 4 e 9 furono orientati da un campo elettrico statico d’intensità fino a 25 V/cm. Fu trovato che l’orientazione del momento di transizione di dipolo del cromoforo, il retinale, rispetto al momento di dipolo permanente dei frammenti di membrana subisce una variazione da (60±1)°apH 5 a (71±1)° apH 6. Inoltre, il momento di dipolo permanente dei frammenti di membrana di 1.8·10⁻²³C·m trovato nell’intervallo dipH da 4 a 7 si riduce a 1.3·10⁻²³C·m per valori dipH delle sospensioni maggiori di 7.

     

金属纳米结构表面吸附的CO分子在外电场中的相互作用

建立金属纳米颗粒在外电场中的排列结构模型，用经典理论分析纳米结构金属表面上吸附的CO分子在外电场中的相互作用能，包括有效偶极子间的相互作用和与局域电场的相互作用，并讨论和计算了纳米颗粒表面附近的局域电场. 用Monte-Carlo方法进行数值计算和模拟，具体给出纳米颗粒表面CO分子的分布和相互作用能，表明金属表面纳米结构使CO产生凝聚，并使分子相互作用能增加，为解释异常红外吸收效应提供依据. 关键词： 纳米结构金属 吸附分子 相互作用 局域电场     

细胞骨架微管中水的电偶极集体辐射

微管是细胞骨架中的重要组成部分和功能组件，其中充满了液体水.采用量子场论方法，对细胞骨架微管中水分子的电偶极子与电磁辐射场的相互作用进行了探讨,研究水分子系统的电偶极子集体电磁辐射的特性.此外，还讨论了微管中水分子系统与其周围热库的耦合. 关键词： 微管 水 电偶极子 电磁辐射 集体辐射 热库     

Radiation of electric arc burning in argon

Using real experimentally obtained integral values, the paper deals with modelling of electric arc stabilised by flowing gas. Attention is focused namely on approximate estimation of radiation coefficient of argon. A designed model of electric arc burning in argon of atmospheric pressure inside arc heater’s anode channel is described. The model makes it possible to compute axial and/or radial dependencies of some quantities of interest (temperature, velocity, electric field intensity, arc radius, etc.), and subsequently to judge energy exchange between the arc and its surroundings. Sets of model’s input data, including arc voltage, arc current, argon flow-rate, and flow-rates and temperatures of water cooling individual parts of the arc heater, have been measured during numerous experiments. In a studied case with relatively high argon flow-rate, radiation has been found to be prevailing mechanism of energy transfer from arc to anode channel walls. Based on this finding, techniques have been designed for simple approximate estimation of radiation coefficient of argon in a limited extent of temperatures. As an example, they have been tested on a particular set of measured and computed data. Argon radiation coefficient estimated in this way has been compared with the results of theoretical computations carried out by other authors. Considering simplifications used and differences between a real situation and an ideal theoretical model, agreement of the results is within satisfactory limits.     

The equivalent potential of water molecules for electronic structure of cysteine

In order to get more reliable electronic structure of protein in aqueous solution, it is necessary to construct a simple, easy-use equivalent potential of water molecules for protein's electronic structure calculation. The first-principles, all-electron, ab initio calculations have been performed to construct the equivalent potential of water molecules for the electronic structure of Cys. The process consists of three steps. First, the electronic structure of the cluster containing Cys and water molecules is calculated. Then, based on the structure, the electronic structure of Cys with the potential of water molecules is calculated using the self-consistent cluster-embedding method. Finally, the electronic structure of Cys with the potential of dipoles is calculated. The dipoles are adjusted so the electronic structure of Cys with the potential of dipoles is close to that of water molecules. The calculations show that the major effect of water molecules on Cys' electronic structure is lowering the occupied electronic states by about 0.032 Ry, and broadening energy gap by 16%. The effect of water molecules on the electronic structure of Cys can be simulated by dipoles potential.     

Brewster angle for anisotropic materials from the extinction theorem

We explore the physical origin of the Brewster angle in the external and internal reflections associated with an anisotropic material. We obtain the expressions of the reflected fields and the existence condition of the Brewster angle by using the extinction theorem. It is found that the Brewster angle will occur if the total contribution of the material’s electric and magnetic dipoles to the reflected field becomes zero. In internal reflection, the requirements on the material parameters ε and μ for the Brewster angle are the same as those in external reflection, and the Brewster angle is just the refraction angle in external reflection at the incidence of the external Brewster angle. The results of the present paper are applicable to dielectric and magnetic materials, including metamaterials. PACS 73.20.Mf; 78.20.Ci; 41.20.Jb; 42.25.Fx     

Water molecules migration at oil–paper interface under the coupling fields of electric and temperature: a molecular dynamics study

Moisture is an important factor affecting the insulation properties of transformers. Due to the limitations of macroscopic experimental methods, the diffusion of water at oil–paper interface cannot be accurately measured. Therefore, molecular dynamics method was used in this work to establish oil–paper layer model of 10⁵ atoms. Through jointly analysing the aggregation degree, diffusion coefficient, free volume as well as radial distribution function of water molecules, the diffusion mechanism of water molecules at oil–paper interface was studied. The results show that when the initial water content in paper was high, water molecules would accumulate at oil–paper interface to form the local high-water region during heating. The polarisation of the electric field strengthened the hydrogen bonding interaction between water molecules and increased the probability of occurrence of the high-water region. Meanwhile, electric field reduced the free volume and diffusion coefficient of water molecules and rendered its diffusion coefficient anisotropic. What’s more, when the electric field was combined with the temperature field, the electric field played a leading role in the diffusion of water molecules while the temperature field was less affected. Diffusion coefficients of water molecules at different temperatures from molecular dynamics simulations were well consistent with experimental results, which verified the rationality of the model.     

Surface reconstruction of a field electron emitter

The surface and emission images of a metal field’s electron cathode in the form of a tip are simulated. The surface structure is calculated in the thin-shell and broken-bond (local-environment) models for the perfect crystal lattice. The cathode shape and macroscopic electric field are represented by the sphere-on-cone model. The amplification of a local electric field is the adjustable parameter of the model. The method of determination of the emitter tip’s crystal faces based on the analysis of the surface atoms’ environment geometry is proposed. It is shown that it is enough to restrict the consideration of geometric environment by the fifth order of the nearest neighbors for the emitter radius of 100–1000 lattice parameters (31.6–316 nm for the tungsten). The crystallographic model of work function anisotropy in the broken-bond approach is used: the local work function’s value is set in accordance with Miller indices of the face containing this area. The model adequacy is corroborated by the comparison of current-voltage characteristics and emission images with the data of the natural experiment.