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The rick order parameter of Spin Density Wavesallows for an unusual object of a complex topological nature:"Chimeras" composed by a half-integer dislocation combined witha semi-vortex of the staggered magnetization. They becomeene...
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The rick order parameter of Spin Density Wavesallows for an unusual object of a complex topological nature:"Chimeras" composed by a half-integer dislocation combined witha semi-vortex of the staggered magnetization. They becomeenergetically favorable due to enhanced Coulomb interactions.Their generation changes the NBN frequency.
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A partitioning scheme for the molecular cubic polarizability #gamma# in terms of local atomic contributions is further developed and applied to long organic conjugated molecules. We discuss, in chemically-oriented terms, the origi...
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A partitioning scheme for the molecular cubic polarizability #gamma# in terms of local atomic contributions is further developed and applied to long organic conjugated molecules. We discuss, in chemically-oriented terms, the origin of the high nonresonant cubic response in polyenes and its enhancement upon push-pull substitution due to the mutual influence, of the donor/acceptor substituents and the conjugated bridge. Extremely large #gamma# values are predicted for specifically built compounds.
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This paper is part of a study of the frictional dynamics of a confined solid lubricant film - modelled as a ID chain of interacting particles confined between two ideally incommensurate substrates, one of which is driven relative ...
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This paper is part of a study of the frictional dynamics of a confined solid lubricant film - modelled as a ID chain of interacting particles confined between two ideally incommensurate substrates, one of which is driven relative to the other through an attache!! spring moving at constant velocity. This model system is characterized by three inherent length scales; depending on the precise choice of incommensurability among them it displays a strikingly different tribological behavior. Contrary to two length-scale systems such as the standard Frenkel-Kontorova (FK) model, for large chain stiffness one finds that here the most favorable (lowest friction) sliding regime is achieved by chain-substrate incommensurabilities belonging to the class of non-quadratic irrational numbers (e.g., the spiral mean). The well-known golden-mean (quadratic) incommensurability which slides best in the standard FK model shows instead higher kinetic friction values. The underlying reason lies in the pinning properties of the lattice of solitons formed by the chain with the substrate having the closest periodicity, with the other slider.
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We present a partitioning scheme for the molecular third-order polarizability gamma, in terms of local atomic contributions. These contributions allow a pictorial representation of gamma in real space and its easy evaluation for l...
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We present a partitioning scheme for the molecular third-order polarizability gamma, in terms of local atomic contributions. These contributions allow a pictorial representation of gamma in real space and its easy evaluation for long conjugated molecules. A good insight is obtained into the origin of the sign and value of the static gamma in unsubstituted and push-pull polyenes and cyanines. [References: 4]
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Methods are developed to describe catalytic reactions on multi-facetted surfaces in high electric fields in the conditions of field emission microscopy. These methods are applied to the hydrogen-oxygen-rhodium system for which a m...
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Methods are developed to describe catalytic reactions on multi-facetted surfaces in high electric fields in the conditions of field emission microscopy. These methods are applied to the hydrogen-oxygen-rhodium system for which a mean-field kinetic model is established. This model is shown to reproduce not only the nonequilibrium regimes of bistability and oscillations and their nanopatterns, but also the temperature-programmed desorption spectra of hydrogen and oxygen on rhodium, as well as the equilibrium phase diagram of oxygen on rhodium with the transition to the trilayer surface oxide ORhO. The dependence of the kinetic constants on the surface orientation of the facets is taken into account by expanding them in kubic harmonics suitable for the fcc rhodium crystal. The electric field modifies the gas pressure as well as the activation energies of the different kinetic processes. The tip of the field emission microscope is shown to behave as a nanoreactor.
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Nonlinear quantum phonon excitations are studied in 1D lattice models for both effective nonlinear phonon and coupled electron-phonon systems. Multi-phonon bound states exist which are eigenstates of the system Hamiltonian, and wh...
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Nonlinear quantum phonon excitations are studied in 1D lattice models for both effective nonlinear phonon and coupled electron-phonon systems. Multi-phonon bound states exist which are eigenstates of the system Hamiltonian, and which are natural counterparts of breather solutions of classical nonlinear systems. These quantum breather states form particle-like bands and are characterized by a finite coherence length. Due to their structure and dynamics, quantum breathers have specific experimentally observable responses in many correlation functions. In the pure phonon model, the dynamic structure factor is found to have significant intensity for the breather states, with a corresponding quenching of the neighboring bands of multi-phonon extended states. In the coupled electron-phonon model, IR and optical absorption spectra for breathers are reported. [References: 12]
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The change in the liquid meniscus at the surface of a specimen (rectangular or cylindrical) being lifted from water and immersed into it is considered. An equation for the meniscus surface is given, and the boundary conditions of ...
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The change in the liquid meniscus at the surface of a specimen (rectangular or cylindrical) being lifted from water and immersed into it is considered. An equation for the meniscus surface is given, and the boundary conditions of its existence are determined. The solution of this equation describes the shape of the meniscus at all stages of its displacement from the vertical surface of a specimen to its upper and lower planes. The solution agrees with the data of observations. Dependences of the profile area and volume of a meniscus on its height have been obtained. The relationship between the meniscus parameters at the instant of its collapse and the contact angle is given. The meniscus parameters for a standard cylindrical specimen have been estimated. A typical curve of the change in the meniscus weight depending on its height is given. It can be employed for assessing the contact angle on a rough surface of a specimen.
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Si(110) surface morphology evolution under normal-incident Ar+ ion sputtering has been studied as a function of Si temperature with the ion energy of 1.5keV and the ion flux 20 mu A/cm(2). During temperature rising from room tempe...
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Si(110) surface morphology evolution under normal-incident Ar+ ion sputtering has been studied as a function of Si temperature with the ion energy of 1.5keV and the ion flux 20 mu A/cm(2). During temperature rising from room temperature to 800 degrees C, Si(110) surface morphology changes from a dim dot/hole pattern to a distinct dot one, meanwhile the surface roughness increases steadily. The usually-accepted Bradley-Harper model fails to explain these data. By taking into account the Ehrlich-Schwoebel effect in the nanostructuring process, a simulation work was conducted based on a continuum dynamic model, which reproduces the experimental results.
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We outline a theory of coexisting elastic and plasticdeformations in sliding Charge Density Waves. They occur in thecourse of the conversion from the normal current at the contact tothe collective one in the bulk. Several mechanis...
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We outline a theory of coexisting elastic and plasticdeformations in sliding Charge Density Waves. They occur in thecourse of the conversion from the normal current at the contact tothe collective one in the bulk. Several mechanisms of phase slipsvia creation and proliferation of dislocations are compared. Wepresent a modeling which helps to interpret space-resolved studiesin recent [1] and earlier [2] X-ray experiments, in multi-contact [3]and optical [4] studies.
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A study is made by means of Monte Carlo (MC) simulations of the kinetics of random sequential adsorption (RSA) of dimers and linear and bent trimers on some geometrically disordered substrates. The MC data are explained by a semie...
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A study is made by means of Monte Carlo (MC) simulations of the kinetics of random sequential adsorption (RSA) of dimers and linear and bent trimers on some geometrically disordered substrates. The MC data are explained by a semiempirical equation whose parameters interpret the jamming fraction of the process and some geometric characteristics of the systems studied.
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