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1.
Standstill Electric Charge Generates Magnetostatic Field under Born-Infeld Electrodynamics 总被引:1,自引:1,他引:0
S. O. Vellozo J. A. Helayël Neto A. W. Smith L. P. G. De Assis 《International Journal of Theoretical Physics》2008,47(11):2934-2944
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. 相似文献
2.
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 相似文献
3.
4.
G. Czajkowski 《Il Nuovo Cimento D》1987,9(12):1545-1549
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. 相似文献
5.
Local electric field and configuration of CO molecules adsorbed on a nanostructured surface with nanocones 下载免费PDF全文
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. 相似文献
6.
X. Ni G. V. Naik A. V. Kildishev Y. Barnakov A. Boltasseva V. M. Shalaev 《Applied physics. B, Lasers and optics》2011,103(3):553-558
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. 相似文献
7.
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) 相似文献
8.
G. F. Cerofolini 《Il Nuovo Cimento D》1983,2(3):763-772
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.
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.相似文献
9.
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. 相似文献
10.
Mark E. Perel''man Galina M. Rubinstein Vitali A. Tatartchenko 《Physics letters. A》2008,372(22):4100-4103
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. 相似文献
11.
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. 相似文献
12.
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.
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.相似文献
13.
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.
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.相似文献
14.
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 相似文献
15.
16.
J. Gregor I. Jakubova J. Senk 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(2):329-334
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. 相似文献
17.
X.-M. Wang H.-P. Zheng C.-J. Li 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,52(2):255-263
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. 相似文献
18.
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 相似文献
19.
K. A. Nikiforov N. V. Egorov Che-Chou Shen 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2009,3(5):833-839
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. 相似文献
20.
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. 相似文献