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A combined experimental and theoretical study is presented of fluctuations observed by field ion microscopy in the catalytic reaction of water production on a rhodium tip. A stochastic approach is developed to provide a comprehensive understanding of the different phenomena observed in the experiment, including burst noise manifesting itself in a bistability regime, noisy oscillations, and nanopatterns with a cross-like oxidized zone separating the surface into four quadrants centered on the {111} facets. The study is based on a stochastic model numerically simulating the processes of adsorption, desorption, reaction, and transport. The surface diffusion of hydrogen is described as a percolation process dominated by large clusters corresponding to the four quadrants. The model reproduces the observed phenomena in the ranges of temperature, pressures, and electric field of the experiment. [ABSTRACT FROM AUTHOR]

We report a theoretical study of stochastic processes modeling the growth of first-order Markov copolymers, as well as the reversed reaction of depolymerization. These processes are ruled by kinetic equations describing both the attachment and detachment of monomers. Exact solutions are obtained for these kinetic equations in the steady regimes of multicomponent copolymerization and depolymerization. Thermodynamic equilibrium is identified as the state at which the growth velocity is vanishing on average and where detailed balance is satisfied. Away from equilibrium, the analytical expression of the thermodynamic entropy production is deduced in terms of the Shannon disorder per monomer in the copolymer sequence. The Mayo-Lewis equation is recovered in the fully irreversible growth regime. The theory also applies to Bernoullian chains in the case where the attachment and detachment rates only depend on the reacting monomer. [ABSTRACT FROM AUTHOR]

We report a study of the oxidation of CO on a gold nanotip in the presence of high electrostatic fields. With the binding energies obtained using density functional theory as a function of the electric field, a simple field-dependent kinetic model based on the Langmuir-Hinshelwood mechanism is set up. We show that the dissociative adsorption of oxygen on gold happens only below a negative critical value of the electric field while the binding of CO on gold is enhanced for positive values. We explain the propagation of a wave observed in field ion microscopy experiments and predict that the oxidation of CO occurs on negatively charged gold clusters. [ABSTRACT FROM AUTHOR]

The Onsager and higher-order reciprocity relations are derived from a fluctuation theorem for nonequilibrium reactions ruled by the chemical master equation. The fluctuation theorem is obtained for the generating function of the macroscopic fluxes between chemiostats maintaining the system in a nonequilibrium steady state. The macroscopic affinities associated with the fluxes are identified by graph theory. The Yamamoto-Zwanzig formulas for the reaction constants are also derived from the fluctuation theorem. [ABSTRACT FROM AUTHOR]

Examines the general form of the slippage to be applied to the initial conditions of the Redfield master equation for a slow open quantum subsystem. Non-Markovian dynamics of the subsystem; Preservation of possitivity by the Redfield equation after the slippage superoperator has been applied to the initial density matrix of the subsystem; Reduction of the Redfield equation to the Lindblad equation.

Studies a non-Markovian stochastic Schrodinger equation corresponding to the Redfield master equation. Description of the dynamics of a slow subsystem coupled to a thermal bath; Simulation of the time evolution of the quantum wave functions.

Investigates the time-dependent intramolecular vibrational dynamics of acetylene with the vibrogram method. Fundamental operators of vibrational motion; Effective Hamiltonian obtained; Constants of motion; Vibrational energy levels and vibrogram; Staircase functions; Classical dynamics of acetylene; Classical effective Hamiltonian and dynamics.

Reports on a study of intramolecular vibrational dynamics (IVD) after an ultrashort excitation. Dynamical quantities and different time scales of IVD; Expression of the time signal in the semiclassical approximation in terms of the classical periodic orbits; Properties which determine the amplitudes of the semiclassical recurrences.

We report a study of the effect of rotation on the activated complex of direct ultrafast dissociation processes. The dissociative potential energy surface is supposed to have a single unstable equilibrium point of saddle type. The vibration–rotation molecular Hamiltonian is expanded around the saddle equilibrium point by the Van Vleck perturbative method of contact transformations. In this way, we obtain the effect of vibration–rotation coupling on the complex energies of the scattering resonances of the activated complex. We show that rotation may induce either a stabilization or a destabilization depending on the values of the imaginary vibration–rotation coupling constants αFν between rotation and the unstable motion along the vibrational normal mode of dissociation. Explicit formulas are given for these constants and their order of magnitude is evaluated for typical molecules. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The dynamics of the molecular transition state, in a reaction or photodissociation process, may be analyzed by semiclassical methods. We investigate the classical dynamics of the transition state in the dissociation HgI2 (X 1Σ+g)→hνHgI(X 2Σ+)+I, and apply the semiclassical quantization methods based on periodic-orbit theory. A series of resonances is characterized in a low-energy regime, where the classical dynamics is regular, and at high energies, after a transition to chaos has occurred. In a complementary fashion, we analyze the quantum-mechanical propagation of wave packets. The spectrum which is derived from the quantum-mechanical autocorrelation function is compared with the semiclassical results. [ABSTRACT FROM AUTHOR]

Objectives Viruses are recognized as important agents of gastroenteritis outbreaks in institutions caring for dependent people. We aimed to define norovirus (NoV) and rotavirus (RV) immunochromatographic tests (ICT) and reverse transcription-polymerase chain reaction (RT-PCR) used in gastroenteritis investigations. Methods Fourteen sites were monitored from 2010 to 2015, with 360 laboratory investigations. Twenty-two outbreaks and 44 sporadic case patients were investigated with ICTs (114 NoVs and 80 RVs) and RT-PCRs (114 NoVs and 52 RVs). Results ICTs were useful during outbreaks (identification of NoVs and RVs in respectively 76.5% and 75.0% of episodes) despite the NoV sensitivity limit (55.1%) and the four RV false positive results observed for 10 samples. Given the NoV ICT performance and the observed variations of the NoV and RV prevalence (between 20.0% and 5.0%), ICTs are not appropriate to identify sporadic gastroenteritis case patients. Positive predictive values < 60.0% were observed when the prevalence of RV and NoV was low (< 5.0%). NoV and RV RT-PCR indications are sporadic gastroenteritis case patients, negative NoV and RV ICT during outbreaks, control of positive RV ICT in cases of suspected NoV and RV co-circulation, patients with long symptom duration, and NoV genogroup and genotype identifications (infection control and epidemiological surveillance). Inclusion of patients with specific clinical symptoms is recommended irrespective of the technique. Conclusion On the basis of the ICT limits identified in this work, RT-PCR development seems essential to improve viral gastroenteritis investigations in institutions caring for dependent people. [ABSTRACT FROM AUTHOR]

We derive a set of isometric fluctuation relations, which constrain the order parameter fluctuations in finite-size systems at equilibrium and in the presence of a broken symmetry. These relations are exact and should apply generally to many condensed-matter physics systems. Here, we establish these relations for magnetic systems and nematic liquid crystals in a symmetry-breaking external Held, and we illustrate them on the Curie-Weiss and the XY models. Our relations also have implications for spontaneous symmetry breaking, which are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Outbreaks of acute respiratory infections (ARI) are common in institutions for elderly people. We had for objective to investigate clusters of cases (lower respiratory tract infection and influenza-like illness [LRTI/ILI]) in order to improve and validate alert strategies in these institutions. Methodology: Prospective surveillance for LRTI/ILI was implemented in 11 institutions in Alsace, over five years. Clinical criteria were used to identify infected residents and clusters. Nasopharyngeal swabs were collected and rapid tests (Immunoassay) were performed to identify the influenza virus. Results: The three week periods were analyzed if three cases or more were recorded during the first week. This analysis demonstrated an important risk of epidemic when this number of cases was reached in healthcare units. The influenza virus (10 clusters) and respiratory syncytial virus ([RSV], two clusters) were identified. Conclusion: The authors confirmed and emphasized the importance of adequate surveillance for clusters of respiratory tract infection cases. Early identification of an outbreak (three cases) is an important point to prevent transmission, especially during epidemic periods and if a virus is identified in the unit or institution. [Copyright &y& Elsevier]

The effects of external torque on the F1-ATPase rotary molecular motor are studied from the viewpoint of recent advances in stochastic thermodynamics. This motor is modeled in terms of discrete-state and continuous-state stochastic processes. The dependence of the discrete-state description on external torque and friction is obtained by fitting its transition rates to a continuous-angle model based on Newtonian mechanics with Langevin fluctuating forces and reproducing experimental data on this motor. In this approach, the continuous-angle model is coarse-grained into discrete states separated by both mechanical and chemical transitions. The resulting discrete-state model allows us to identify the regime of tight chemomechanical coupling of the F1 motor and to infer that its chemical and mechanical efficiencies may reach values close to the thermodynamically allowed maxima near the stalling torque. We also show that, under physiological conditions, the F1 motor is functioning in a highly-nonlinear-response regime, providing a rotation rate a million times faster than would be possible in the linear-response regime of nonequilibrium thermodynamics. Furthermore, the counting statistics of fluctuations can be obtained in the tight-coupling regime thanks to the discrete-state stochastic process and we demonstrate that the so-called fluctuation theorem provides a useful method for measuring the thermodynamic forces driving the motor out of equilibrium. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: Objective: Outbreaks of acute respiratory infections (ARI) are common in institutions for elderly people. The objective of our study was the assessment of immunoassay rapid test used for influenza diagnosis in institutions for elderly people. Methodology: Prospective surveillance for ARI was conducted in 11 institutions in Alsace over a four-year period. Clinical case definitions are used to identify the infected residents. For the identification of influenza virus, nasopharyngeal swabs are obtained and rapid tests (immunoassay) are performed. Results: Influenza virus was identified with immunoassay rapid test. Then, prophylaxis according to the Conseil supérieur d’hygiène publique de France guidelines was implemented. Nevertheless, the use of the rapid test was not frequent in the individual institution and the information recorded at the Grog Géronto-Alsace level could be use to inform the institutions when it is important to perform these rapid tests. Conclusion: Ours findings show the value of the rapid test used in the influenza surveillance and how the networks could help to improve their uses. [Copyright &y& Elsevier]

Abstract: The oxidation of nanosized rhodium facets is investigated in the presence of a high external electric field with field ion microscopy experiments (FIM). Corresponding density functional theory (DFT) calculations were done on Rh(001), Rh(011) and Rh(111). A cross-like granular structure is obtained with FIM when the electric field is increased from 11 to 12.3V/nm, which strongly indicates that the field promotes the oxidation of the tip. The DFT calculations confirm this scenario with a corresponding reduction of the activation barrier for oxygen incorporation into the surface of an oxide layer. [Copyright &y& Elsevier]

Abstract: We report a theoretical study of the -ATPase molecular rotary motor experimentally studied by R. Yasuda, H. Noji, M. Yoshida, K. Kinosita Jr., H. Itoh [Nature 410 (2001) 898]. The motor is modeled as a stochastic process for the angle of its shaft and the chemical state of its catalytic sites. The stochastic process is ruled by six coupled Fokker–Planck equations for the biased diffusion of the angle and the random jumps between the chemical states. The model reproduces the experimental observations that the motor proceeds by substeps and the rotation rate saturates at high concentrations of adenosine triphosphate or at low values of the friction coefficient. Moreover, predictions are made about the dependence of the rotation rate on temperature, and about the behavior of the motor under the effect of an external torque, especially, in the regime of synthesis of adenosine triphosphate. [Copyright &y& Elsevier]

We study the transport property of diffusion in a finite translationally invariant quantum subsystem described by a tight-binding Hamiltonian with a single energy band. The subsystem interacts with its environment by a coupling expressed in terms of correlation functions which are delta-correlated in space and time. For weak coupling, the time evolution of the subsystem density matrix is ruled by a quantum master equation of Lindblad type. Thanks to the invariance under spatial translations, we can apply the Bloch theorem to the subsystem density matrix and exactly diagonalize the time evolution superoperator to obtain the complete spectrum of its eigenvalues, which fully describe the relaxation to equilibrium. Above a critical coupling which is inversely proportional to the size of the subsystem, the spectrum at given wave number contains an isolated eigenvalue describing diffusion. The other eigenvalues rule the decay of the populations and quantum coherences with decay rates which are proportional to the intensity of the environmental noise. An analytical expression is obtained for the dispersion relation of diffusion. The diffusion coefficient is proportional to the square of the width of the energy band and inversely proportional to the intensity of the environmental noise because diffusion results from the perturbation of quantum tunneling by the environmental fluctuations in this model. Diffusion disappears below the critical coupling [ABSTRACT FROM AUTHOR]

Two-dimensional random Lorentz gases with absorbing traps are considered in which a moving point particle undergoes elastic collisions on hard disks and annihilates when reaching a trap. In systems of finite spatial extension, the asymptotic decay of the survival probability is exponential and characterized by an escape rate γ, which can be related to the average positive Lyapunov exponent and to the dimension of the fractal repeller of the system. For infinite systems, the survival probability obeys a stretched exponential law of the form P(c,t)∼exp(−Ct1/2). The transition between the two regimes is studied and we show that, for a given trap density, the non-integer dimension of the fractal repeller increases with the system size to finally reach the integer dimension of the phase space. Nevertheless, the repeller remains fractal. We determine the special scaling properties of this fractal. [Copyright &y& Elsevier]

For a piecewise linear version of the periodic map with anomalous diffusion, the evolution of statistical averages of a class of observables with respect to piecewise constant initial densities is investigated and generalized eigenfunctions of the Frobenius–Perron (FP) operator are explicitly derived. The evolution of the averages is controlled by real eigenvalues as well as continuous spectra terminating at the unit circle. Appropriate scaling limits are shown to give a normal diffusion if the reduced map is in the stationary regime with normal fluctuations, a Le´vy flight if the reduced map is in the stationary regime with Le´vy-type fluctuations and a transport of ballistic type if the reduced map is in the non-stationary regime. [Copyright &y& Elsevier]

For a piecewise linear version of the periodic map with anomalous diffusion, the evolution of statistical averages of a class of observables with respect to piecewise constant initial densities is investigated and generalized eigenfunctions of the Frobenius–Perron (FP) operator are explicitly derived. The evolution of the averages is controlled by real eigenvalues as well as continuous spectra terminating at the unit circle. Appropriate scaling limits are shown to give a normal diffusion if the reduced map is in the stationary regime with normal fluctuations, a Le´vy flight if the reduced map is in the stationary regime with Le´vy-type fluctuations and a transport of ballistic type if the reduced map is in the non-stationary regime. [Copyright &y& Elsevier]

We show that simple diffusive systems, such as the Lorentz gas and multibaker maps, are perfectly compatible with the laws of irreversible thermodynamics, despite the fact that the moving particles, or their equivalents, in these models do not interact with each other, and that the dynamics takes place in low-dimensional phase spaces. The interaction of moving particles with scatterers provides the dynamical mechanism responsible for an approach to equilibrium, under appropriate conditions. This analysis provides a refutation of the criticisms expressed recently by Cohen and Rondoni (Physica A 306 (2002) 117). [Copyright &y& Elsevier]

In chaotic reaction–diffusion systems with two degrees of freedom, the modes governing the exponential relaxation to the thermodynamic equilibrium present a fractal structure which can be characterized by a Hausdorff dimension. For long wavelength modes, this dimension is related to the Lyapunov exponent and to a reactive diffusion coefficient. This relationship is tested numerically on a reactive multibaker model and on a two-dimensional periodic reactive Lorentz gas. The agreement with the theory is excellent. [Copyright &y& Elsevier]

Reports on experimental evidence for microscopic chaos. The observation of erratic or random time evolution by many macroscopic dynamical phenomena, such as hydro-dynamics and oscillatory chemical reactions; What chaotic behavior of a system is characterized by; What positive Lyapunov exponents indicate.

Studies the consequences of deterministic chaos for diffusion-controlled reaction. Diffusive-reactive deterministic multibaker and a parameter-dependent variation; Construction of the diffusive and reactive modes of the models as eigenstates of the Frobenius-Perron operator; Dispersion relations of diffusion and reaction.

Reports the results of a periodic orbit quantization of classically chaotic billiards beyond Gutzwiller approximation in terms of asymptotic series in powers of the Planck constant. Scattering resonances for two-dimensional billiards; Classically chaotic scattering of a wave on three disks.

A correction to the article "Fluctuation theorem and Onsager reciprocity relations," that was published in the 2004 issue is presented.

The authors propose a new method, the Helfand-moment method, to compute the shear viscosity by equilibrium molecular dynamics in periodic systems. In this method, the shear viscosity is written as an Einstein-type relation in terms of the variance of the so-called Helfand moment. This quantity is modified in order to satisfy systems with periodic boundary conditions usually considered in molecular dynamics. They calculate the shear viscosity in the Lennard-Jones fluid near the triple point thanks to this new technique. They show that the results of the Helfand-moment method are in excellent agreement with the results of the standard Green-Kubo method. [ABSTRACT FROM AUTHOR]

The thermal conductivity is calculated with the Helfand-moment method in the Lennard-Jones fluid near the triple point. The Helfand moment of thermal conductivity is here derived for molecular dynamics with periodic boundary conditions. Thermal conductivity is given by a generalized Einstein relation with this Helfand moment. The authors compute thermal conductivity by this new method and compare it with their own values obtained by the standard Green-Kubo method. The agreement is excellent. [ABSTRACT FROM AUTHOR]

We report a study of the adsorption and reaction of CO on a gold nanotip in high electrostatic fields. Field ion microscopy is used to investigate the emergence of a Au-carbonyl wave that is made visible with oxygen as the imaging gas. We set up a simple kinetic model that reproduces the adsorption wave and confirms that the presence of oxygen merely serves as an imaging gas and does not lead to field-induced oxidation of CO. [ABSTRACT FROM AUTHOR]

We report a study of the influence of molecular fluctuations on a limit-cycle model of circadian rhythms based on the regulatory network of a gene involved in a biochemical clock. The molecular fluctuations may become important because of the low number of molecules involved in such genetic regulatory networks at the subcellular level. The molecular fluctuations are described by a birth-and-death stochastic process ruled by the chemical master equation of Nicolis and co-workers and simulated by Gillespie's algorithm. The robustness of the oscillations is characterized, in particular, by the probability distribution of the first-return times and the autocorrelation functions of the noisy oscillations. The half-life of the autocorrelation functions is studied as a function of the size of the system which controls the magnitude of the molecular fluctuations and of the degree of cooperativity of some reaction steps of the biochemical clock. The role of the attractivity of the limit cycle is also discussed. [ABSTRACT FROM AUTHOR]

Molecular spectra have traditionally been interpreted in the frequency domain and more recently in the time domain. For simple absorption and emission spectra these are the Fourier transform of one another. In this paper we illustrate that it can be useful to examine spectra in a compromise representation which balances uncertainties in time and energy. In this paper we give the basic ideas and several examples which reveal dynamical effects hidden in either energy or time representations. The resulting ‘‘vibrogram’’ is available from experimental spectra or theoretical calculations. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Highlights a graduate school and workshop on chaos and irreversibility organized at the Bolyai College of the Eotvos University in Budapest, Hungary in 1997. Papers written by invited speakers to the workshop, published in the June 1998 issue of the journal 'American Institute of Physics'; Views that opposed or complemented each other.

Provides an analysis of the stoichometry of a thin iron oxide layer based on Kerr spectum which is compared to an analysis based on Verwey transition. Results and discussion; Significance of subsequent model calculations; Importance of spectral variations in magneto-optic-Kerr effect experiments.

Abstract: Objective: Outbreaks of respiratory tract infections are common in institutions for elderly people. The objective of our study was the implementation of a network including 11 institutions to determine the frequency of such outbreaks. Using the collected data, criteria and alert levels are defined to assess the level of respiratory tract infections and develop appropriate interventions. Methodology: Prospective surveillance for respiratory tract infection was conducted in 11 institutions in Alsace for 2 years. Clinical definitions were used to identify the infected residents. For the identification of influenza virus, nasopharyngeal samples using swabs were obtained and rapid tests (immunoassay) were performed. Results: During the surveillance, outbreaks were identified in institutions. The same observations occurred in all institutions at the same time. Alert levels were defined in order to characterize the outbreak period and to improve detection and control of outbreaks of respiratory tract infections. Conclusion: Ours findings show the importance of an adequate surveillance and networks improve the impact of such measures. [Copyright &y& Elsevier]

The effect of ultrafast diffusion is studied on reaction-diffusion processes in heterogeneous media, as encountered in catalysis and field emission microscopy. The reaction-diffusion equations describe adsorption, desorption, and reaction processes for two adspecies, for instance, on a paraboloidal heterogeneous surface in the presence of an external electric field. Using multiscale analysis, we show that the fast adspecies rapidly reaches a quasiequilibrium spatial distribution, characterized by a nonequilibrium chemical potential of the fast adspecies. An ordinary differential equation is derived for the time evolution of the nonequilibrium chemical potential. Numerical simulations are performed under different conditions, which confirm the convergence of the dynamics for finite diffusion toward the ultrafast diffusion limit predicted by our multiscale analysis. The numerical simulations also demonstrate that electric fields may induce important diffusive currents on heterogeneous surfaces under the conditions of field emission microscopy. [ABSTRACT FROM AUTHOR]

Abstract: The present paper overviews our recent experimental and theoretical results concerning the catalytic properties of nanosized rhodium and platinum facets in the presence of an external electric field. We first show that field ion microcopy (FIM) experiments along with corresponding density functional theory (DFT) calculations strongly indicate that a positive field value promotes the oxidation of a rhodium field emitter tip. We also demonstrate that the catalytic oscillatory nanopatterns, as observed when H2 and O2 are exposed on a rhodium field emitter tip, find their origin in the different catalytic properties of all the nanofacets that are simultaneously exposed at the tip’s surface. In the case of platinum field emitter tips, the dependence of dissociation barrier of NO on the external electric field is examined with DFT and compared to experimental results. Corresponding calculations on Pt are done for the (NO)2 dimer. [Copyright &y& Elsevier]

A calculated exhaustive set of vibrational state energies in 12 C 2 H 2 , 13 C 2 H 2 and 12 C 2 D 2 has been used to analyse the evolution of the integrated number of states with increasing vibrational energy N(E) up to 15 000 cm -1 , 12 000 cm -1 and 10 000 cm -1 in each isotopomer, respectively. The regular contribution to N(E) was modelled analytically and numerical parameters were fitted. The other expected contribution to N(E) , which is of oscillatory nature, was quantified and is discussed using energy- and time-dependent theories. Related periods of oscillation and temporal recurrences are interpreted consistently in terms of the constant of the motion N r = 5 v 1 +3 v 2 +5 v 3 + v 4 + v 5 and of an average vibrational quantum. More pragmatically, the vibrational dynamics appear to be dominated by the bending vibrations, i.e., by the slowest oscillators. [ABSTRACT FROM AUTHOR]

We studied the interplay between Ag decoration of a stepped Pt(355) surface and CO adsorption by in situ high-resolution x-ray photoelectron spectroscopy. Varying amounts of Ag deposited at 300 K initially lead to a row-by-row growth starting from the lower Pt step edges. Such decoration of the step sites results in a change in the CO adsorption behavior. An apparent blocking of step sites for low CO coverages is attributed to a change in the electronic structure, resulting in a C 1s binding energy of CO at step sites being equal to that for CO at terrace on-top sites in the presence of Ag. Higher CO coverages induce the formation of embedded Ag clusters within the upper terraces, thus freeing up a part of the original Pt step sites for CO adsorption, as was derived by a comparison to density functional theory calculations in the corresponding surface models. [ABSTRACT FROM AUTHOR]

We have studied oxygen interaction with Au crystals (field emitter tips) using time-resolved atom-probe) field desorption mass spectrometry. The results demonstrate no adsorption to take place on clean Au facets under chosen conditions of pressures (p<10-4 mbar) and temperatures (T=300-350 K). Steady electric fields of 6 V/nm do not allow dissociating the oxygen molecule. The measured O2+ intensities rather reflect ionization of O2 molecules at critical distances above the Au tip surface. Certain amounts of Au-O2 complex ions can be found at the onset of Au field evaporation. Calculations by density functional theory (DFT) show weak oxygen end-on interaction with Au10 clusters (ΔE=0.023 eV) and comparatively stronger interaction with Au1/Au(100) model surfaces (ΔE=0.25 eV). No binding is found on {210} facets. Including positive electric fields in the DFT calculations leads to an increase of the activation energy for oxygen dissociation thus providing an explanation for the absence of atomic oxygen ions from the field desorption mass spectra. [ABSTRACT FROM AUTHOR]

A correction to the article "Interaction between silver nanowires and CO on a stepped platinum surface" that was published online in the November 4, 2009 issue is presented.