bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical study of the He–HF+ complex. II. Rovibronic states from coupled diabatic potential energy surfaces
Authors: Dhont G. , Zeimen W. B. , Groenenboom G. C. , van der Avoird A.
Published: December 2003

The bound rovibronic levels of the He–HF+ complex were calculated for total angular momentum J=12, 32, 52, 72, and 92 with the use of ab initio diabatic intermolecular potentials presented in Paper I and the inclusion of spin–orbit coupling. The character of the rovibronic states was interpreted by a series of calculations with the intermolecular distance R fixed at values ranging from 1.5 to 8.5 Å and by analysis of the wave functions. In this analysis we used approximate angular momentum quantum numbers defined with respect to a dimer body-fixed (BF) frame with its z axis parallel to the intermolecular vector R and with respect to a molecule-fixed (MF) frame with its z axis parallel to the HF+ bond. The linear equilibrium geometry makes the He–HF+ complex a Renner–Teller system. We found both sets of quantum numbers, BF and MF, useful to understand the characteristics of the Renner–Teller effect in this system. In addition to the properties of a “normal” semirigid molecule Renner–Teller system it shows typical features caused by large-amplitude internal (bending) motion. We also present spectroscopic data: stretch and bend frequencies, spin–orbit splittings, parity splittings, and rotational constants.
Lie symmetry analysis and some new exact solutions of the Wu–Zhang equation
Authors: Ji Xiaoda , Chen Chunli , Zhang Jin E. , Li Yishen
Published: December 2003

The Lie symmetry analysis and the basic similarity reductions are performed for the Wu–Zhang equation, a 2+1 dimensional nonlinear dispersive wave equation. Some new exact solutions generated from the similarity transformation are provided. They demonstrate some new three-dimensional features of a single solitary wave and two interacting solitary waves.
Equation-of-motion spin-flip coupled-cluster model with single and double substitutions: Theory and application to cyclobutadiene
Authors: Levchenko Sergey V. , Krylov Anna I.
Published: December 2003

While the equation-of-motion coupled-cluster (EOM-CC) method is capable of describing certain multiconfigurational wave functions within a single-reference framework (e.g., open-shell type excited states, doublet radicals, etc.), it may fail in cases of more extensive degeneracy, e.g., bond breaking and polyradicals. This work presents an extension of the EOM-CC approach to these chemically important situations. In our approach, target multiconfigurational wave functions are described as spin-flipping excitations from the high-spin reference state. This enables a balanced treatment of nearly degenerate electronic configurations present in the target low-spin wave functions. The relations between the traditional spin-conserving EOM models and the EOM spin-flip method is discussed. The presentation of the formalism emphasizes the variational properties of the theory and shows that the killer condition is rigorously satisfied in single-reference EOM-CC theories. The capabilities and advantages of the new approach are demonstrated by its application to cyclobutadiene.
Many-body interaction in glycine–(water)3 complex using density functional theory method
Authors: Chaudhari Ajay , Sahu Prabhat K. , Lee Shyi-Long
Published: December 2003

Various configurations were investigated to find the most stable structures of glycine–(water)3 complex. Five different optimized conformers of glycine–(water)3 complex are obtained from density functional theory calculations using 6-311++G* basis set. Relaxation energy and many body interaction energies (two, three, and four body) are also calculated for these conformers. Out of the five conformers, the most stable conformer has the BSSE corrected total energy −513.917 967 7 Hartree and binding energy −27.28 Kcal/mol. It has been found that the relaxation energies, two body energies and three body energies have significant contribution to the total binding energy whereas four body energies are very small. The chemical hardness and chemical potential also confirmed the stability of the conformer having lowest total energy.
Analysis of hot D2O emission using spectroscopically determined potentials
Authors: Shirin Sergei V. , Zobov Nikolai F. , Polyansky Oleg L. , Tennyson Jonathan , Parekunnel Treana , Bernath Peter F.
Published: December 2003

Fourier transform emission spectra of D2O vapor were recorded at a temperature of 1500 °C in the wavenumber range 380–1880 cm−1. 15 346 lines were measured, of which the majority were identified as belonging to D2O. The spectrum was analyzed using variational nuclear motion calculations based on spectroscopically determined potential-energy surfaces. Initial assignments were made using a potential surface obtained by fitting a high accuracy ab initio potential. The new assignments were used to refine the potential surface, resulting in additional assignments. A total of 6400 D2O transitions were assigned and 2144 new D2O energy levels were obtained. Transitions involving the 4ν2 and 5ν2 bending states, with band origins of 4589.30 (±0.02) and 5679.6 (±0.1) cm−1, respectively, were assigned for the first time.
Magnetic reconnection with space and time varying reconnection rates in a compressible plasma
Authors: Semenov Vladimir S. , Heyn Martin F. , Ivanov Ivan B.
Published: December 2003

Fast magnetic reconnection of Petschek-type including moving shock waves and discontinuities in a compressible plasma is studied. Magnetic flux tubes of finite size are reconnected by a localized dissipative electric field pulse. This process generates nonlinear perturbations propagating along the initial current surface. The linear wave problem in the outer regions is solved analytically in terms of the reconnection induced sources which move in different directions and with different speeds along the surface. The time-coordinate representation of the solution is given in form of convolution integrals over the reconnection initializing electric field. As an example, reconnection of flux tubes in a sheared magnetic field geometry is analyzed.
Production of high-density hydrogen plasmas by helicon waves in a simple torus
Authors: Sakawa Y. , Ohshima M. , Ohta Y. , Shoji T.
Published: December 2003

High-density plasma production by helicon waves in a simple torus has been investigated. The measured plasma density np versus external magnetic field B0 peaks at a condition close to the lower-hybrid resonance in H2, D2, and He. Three density regions are observed in the variation of rf power Prf. In the low-density region, helicon waves are not excited and plasmas are produced by an antenna induction field. In the medium- and high-density (H) regions, helicon waves with the m=+1 azimuthal mode are excited and plasmas are produced by the waves. In H2 plasmas, the second-radial mode is dominant over the first-radial mode at Prf>10 kW in the H region. The measured kz−np relation (kz is the wave number parallel to B0) of helicon waves in the H region shows deviation from that of the m=+1 mode derived using the uniform-plasma assumption. The kz−np relation is calculated for various radial-np profiles; parabolic, modified-parabolic, and Gaussian profiles. The difference in the kz−np relation of the m=+1 mode between the uniform- and nonuniform-plasma models is explained by adding a vacuum region between a uniform plasma and the radial boundary.
Molecular dynamics study of the thermal and the density effects on the local and the large-scale motion of polymer melts: Scaling properties and dielectric relaxation
Authors: Barbieri A. , Campani E. , Capaccioli S. , Leporini D.
Published: December 2003

Results from a molecular dynamics simulation of a melt of unentangled polymers are presented. The translational motion, the large-scale and the local reorientation processes of the chains, as well as their relations with the so-called “normal” and “segmental” dielectric relaxation modes are thoroughly investigated in wide temperature and pressure ranges. The thermodynamic states are well fitted by the phenomenological Tait equation of state. A global time-temperature-pressure superposition principle of both the translational and the rotational dynamics is evidenced. The scaling is more robust than the usual Rouse model. The latter provides insight but accurate comparison with the simulation calls for modifications to account for both the local chain stiffness and the nonexponential relaxation. The study addresses the issue whether the temperature or the density is a dominant control parameter of the dynamics or the two quantities give rise to comparable effects. By examining the ratio |ατ|/αP between the isochronic and isobaric expansivities, one finds that the temperature is dominant when the dynamics is fast. If the relaxation slows down, the fluctuations of the free volume increase their role and become comparable to those of the thermal energy. Detectable cross-correlation between the “normal-mode” and the “segmental” dielectric relaxations is found and contrasted with the usual assumption of independent modes.
Radiative transition probabilities, lifetimes and dipole moments for the vibrational levels of the X 1Σ+ ground state of K8539Rb
Authors: Zemke Warren T. , Stwalley William C.
Published: December 2003

Using a potential energy curve (based primarily on the RKR potential of Amiot and Vergès [J. Chem. Phys. 112, 7068 (2000)]) and a dipole moment function (based primarily on ab initio calculations of Park et al. [Chem. Phys. 257, 135 (2000)]), we have calculated radiative transition probabilities (Einstein A coefficients), radiative lifetimes, and dipole moment expectation values involving all vibrational levels (for several rotational quantum numbers) of the X 1Σ+ ground state of K8539Rb. We observe that the radiative lifetimes of vibrationally excited levels, in particular, are ∼103–106 seconds, far too long to be significant in most ultracold experiments involving K8539Rb or its isotopomers. Comparison with other molecules (LiH and HF) suggests that simple scaling (A∼μ2ν3∼τ−1) will predict similarly long lifetimes for many other heteronuclear molecules, e.g., RbCs.
Quantitative spectroscopic and theoretical study of the optical absorption spectra of H2O, HOD, and D2O in the 125–145 nm region
Authors: Cheng Bing-Ming , Chung Chao-Yu , Bahou Mohammed , Lee Yuan-Pern , Lee L. C. , van Harrevelt Rob , van Hemert Marc C.
Published: December 2003

The room temperature absorption spectra of water and its isotopomers D2O and HOD have been determined in absolute cross section units in the 125 to 145 nm wavelength region using synchrotron radiation. The experimental results for these B̃ band spectra are compared with results from quantum mechanical calculations using accurate diabatic ab initio potentials. A Monte Carlo sampling over the initial rotational states of the molecules is applied in order to calculate the cross sections at a temperature of 300 K. The overall rotation of the water molecule is treated exactly. Both for the experimental and for the theoretical spectrum an analysis is made in terms of a component attributed to rapid direct dissociation processes and a component attributed to longer-lived resonances. The agreement between the results from experiment and theory is excellent for H2O and D2O. In the case of HOD in the results of theory two more resonances are found at low energy. It is demonstrated that the width of the resonances of 0.04 eV is the result of overlapping and somewhat narrower resonances in the spectra of molecules differing in rotational ground state.
Experimental and theoretical study of line mixing in NH3 spectra. II. Effect of the perturber in infrared parallel bands
Authors: Hadded S. , Thibault F. , Flaud P.-M. , Aroui H. , Hartmann J. M.
Published: December 2003

In a previous paper [J. Chem. Phys. 116, 7544 (2002) (Paper I)] a model, based on the energy corrected sudden approximation, was proposed for the construction of the line-mixing relaxation matrix. It was successfully tested by comparisons with measured infrared spectra of ammonia–helium mixtures. The present paper extends this preliminary study by considering mixtures of NH3 with H2 and Ar. Measurements have been made at room temperature in the regions of the ν2 and ν1 bands for pressures up to several hundred atmospheres. As in Paper I, the relaxation operator is constructed, within the impact approximation, using the ECS approximation. The data required are dynamical factors (which can be predicted from the NH3–X potential energy surface) and a scaling length (adjusted using line broadening data). Comparisons between measured and calculated absorptions demonstrate the quality of the model which satisfactory corrects for the large deviations with respect to the purely Lorentzian behavior. Line-mixing effects for NH3–Ar and NH3–H2 are qualitatively similar to those observed for NH3–He but quantitative differences exist, particularly when intra- and interbranch couplings are considered. Finally, the proposed model leads to very satisfactory results in the wings of both the purely rotational and ν2 bands of NH3 diluted in H2, opening promising perspectives for the remote sensing study of planetary atmospheres.
Dissociation of multiply ionized isocyanic acid through electron impact
Authors: Wang Pengqian , Vidal C. R. , Geith Janna , Klapötke Thomas M. , Fuß Werner
Published: December 2003

The dissociation of singly to triply ionized isocyanic acid (HNCO) has been investigated by two- and three-dimensional covariance mapping techniques through electron impact ionization at an electron energy of 200 eV. The absolute cross sections for the various dissociation channels of up to triply ionized HNCO have been measured. The HNCO dications dissociate mostly into ion pairs, while the HNCO trications dissociate mostly into ion triples, both through all the possible bond cleavages and charge allocations. Some major ion-pair dissociation channels of HNCO2+ are supposed to be sequential dissociation through initial charge separation. The metastable decay traces caused by HNCO2+→H++NCO+ and HNCO+→HCO++N have been observed on the covariance map.
Magnetic trapping caused by resonant perturbations in tokamaks with reversed magnetic shear
Authors: Roberto Marisa , da Silva Elton C. , Caldas Iberê L. , Viana Ricardo L.
Published: December 2003

Reversed magnetic shear configurations in tokamaks reduce substantially particle diffusivity and improve plasma confinement due to the formation of a transport barrier, as a result of magnetic field line reconnection and bifurcation. The latter are caused by the resonant perturbation of an ergodic limiter on a tokamak with reversed magnetic shear, which creates a region with chaotic field lines in the vicinity of the dimerized island chains. An analytically derived nontwist map for field lines is used to describe the formation of a transport barrier, manifested in the decrease of field line diffusion rate. This barrier appears due to the chaotic field line trapping near the reconnection layer that survives the bifurcation.
Inhomogeneous plasma parametric decay instability driven by frequency modulated pump
Authors: Arkhipenko V. I. , Pisarev V. A. , Simonchik L. V. , Gusakov E. Z. , Yakovlev B. O.
Published: December 2003

The inhomogeneous plasma parametric decay instability (PDI) is studied in the present paper both experimentally and theoretically for different types of pump wave frequency modulation. It is shown that the theory conclusion on weak sensitivity of inhomogeneous plasma PDI to the pump frequency modulation holds only for modulation faster than the decay wave transient time. In the case of slower modulation, both harmonic and stochastic, the PDI resonant enhancement may take place instead. The expression for amplification in the resonance is derived and several mechanisms of the singularity saturation are studied.
Structure and diffusion in amorphous aluminum silicate: A molecular dynamics computer simulation
Authors: Winkler Anke , Horbach Jürgen , Kob Walter , Binder Kurt
Published: December 2003

The amorphous aluminum silicate (Al2O3)2(SiO2) [AS2] is investigated by means of large scale molecular dynamics computer simulations. We consider fully equilibrated melts in the temperature range 6100 K⩾T⩾2300 K as well as glass configurations that were obtained from cooling runs from T=2300 to 300 K with a cooling rate of about 1012 K/s. Already at temperatures as high as 4000 K, most of the Al and Si atoms are fourfold coordinated by oxygen atoms. Thus, the structure of AS2 is that of a disordered tetrahedral network. The packing of AlO4 tetrahedra is very different from that of SiO4 tetrahedra in that Al is involved with a relatively high probability in small-membered rings and in triclusters in which an O atom is surrounded by four cations. We find as typical configurations two-membered rings with two Al atoms in which the shared O atoms form a tricluster. On larger length scales, the system shows a microphase separation in which the Al-rich network structure percolates through the SiO2 network. The latter structure gives rise to a prepeak in the static structure factor at a wave number q=0.5 Å−1. A comparison of experimental x-ray data with the results from the simulation shows good agreement for the structure function. The diffusion dynamics in AS2 is found to be much faster than in SiO2. We show that the self-diffusion constants for O and Al are very similar and that they are by a factor of 2–3 larger than the one for Si.
Generalized-ensemble simulations of the human parathyroid hormone fragment PTH(1-34)
Authors: Hansmann Ulrich H. E.
Published: December 2003

A generalized-ensemble technique, multicanonical sampling, is used to study the folding of a 34-residue human parathyroid hormone fragment. An all-atom model of the peptide is employed and the protein–solvent interactions are approximated by an implicit solvent. Our results demonstrate that generalized-ensemble simulations are well suited to sample low-energy structures of such large polypeptides. Configurations with a root-mean-square deviation to the crystal structure of less than 1 Å are found. Finally, we discuss limitations of our implicit solvent model.
Binary homogeneous nucleation in water–succinic acid and water–glutaric acid systems
Authors: Gaman Anca I. , Kulmala Markku , Vehkamäki Hanna , Napari Ismo , Mircea Mihaela , Facchini Maria C. , Laaksonen Ari
Published: December 2003

Binary homogeneous nucleation of water–succinic acid and water–glutaric acid systems have been investigated. The numerical approach was based on the classical nucleation theory. Usually, nucleation is discussed in terms of kinetics, but the thermodynamics involved is undoubtedly equally important. In this paper we studied the above mentioned binary systems giving a quantitative insight into the nucleation process and a detailed consideration of the thermodynamics involved. Both diacids in study are in solid state at room temperature. They behave in environment according to their liquid state properties because of the absence of crystalline lattice energies, and therefore their subcooled liquid state thermodynamics have to be considered. The lack of consistent thermodynamic data for pure organic components and their aqueous solutions represent a high source of uncertainty. However, the present simulations indicate that in atmospheric conditions these binary systems will not form new particles.
Vibrational coherence of I2 in solid Kr
Authors: Karavitis M. , Apkarian V. A.
Published: December 2003

Time-resolved coherent anti-Stokes Raman scattering, with a resolution of 20 fs, is used to prepare a broadband vibrational superposition on the ground electronic state of I2 isolated in solid Kr. The coherent evolution of a packet consisting of ν=1–6 is monitored for as many as 1000 periods, allowing a precise analysis of the material response and radiation coherence. The molecular vibrations are characterized by ωe=211.330(2) cm−1, ωexe=0.6523(6) cm−1, ωeye=2.9(1)×10−3 cm−1; the dephasing rates at 32 K range from 110 ps for ν=1 to 34 ps for ν=6, with ν dependence: γ(ν)=8.5×10−3+4.9×10−4ν2+2.1×10−6ν4 ps−1. The signal amplitude is also modulated at ωq=41.56(3) cm−1; which can be interpreted as coupling between the molecule and a local mode. The surprising implication is that this resonant local mode is decoupled from the lattice phonons, a finding that cannot be rationalized based on a normal-mode analysis.
Quantum study of the spin inversion
Authors: Moretti P. , Lantieri M. , Cianchi L.
Published: December 2003

Spin motion is studied by means of the direct use of the Schrödinger equation. The solution is found in terms of Lommel’s polynomials. An expression of the tunneling splitting is obtained, in good agreement with the results coming from other calculations.
Weakly dissipative plasma equilibria in Kerr geometry
Authors: Elsässer Klaus , Kot Yauhen
Published: December 2003

Axisymmetric neutral plasma equilibria of electrons and ions near black holes can be constructed from solutions of ideal multifluid equations; the solutions for the ions are obtained from a modified Grad–Shafranov code for the stream function. The density and the flux functions are determined self-consistently from the normalization of the Eulerian four-velocity and a simple dissipation model for the ions, respectively. Solutions with moderate or vanishing toroidal velocity exist, but the black hole receives matter only in nonequilibrium situations.
String theory extensions of Einstein–Maxwell fields: The stationary case
Authors: Herrera-Aguilar Alfredo , Kechkin Oleg V.
Published: December 2003

We present a new approach for generating solutions in heterotic string theory compactified down to three dimensions on a torus with d+n>2, where d and n stand for the number of compactified space–time dimensions and Abelian gauge fields, respectively. It is shown that in the case when d=2k+1, and n is arbitrary, one can apply a solution-generating procedure which consists of mapping seed solutions of the stationary Einstein theory with k Maxwell fields to the heterotic string realm by using pure field redefinitions. A novel feature of this method is that it is precisely the electromagnetic sector of the stationary electrovacuum that mainly gives rise to a nontrivial multidimensional metric. This approach leads to classes of solutions which are invariant with respect to the total group of three-dimensional charging symmetries of the heterotic string theory, i.e., to all finite transformations which generate charged solutions from neutral ones and preserve the asymptotics of the starting field configurations. As an application of the presented approach we generate a particular extension of the stationary Einstein–multi-Maxwell theory obtained on the basis of the Kerr–multi-Newman–NUT special class of solutions and establish the conditions under which the resulting multi-dimensional metric of the heterotic string theory is asymptotically flat.
Positive operator valued measures covariant with respect to an Abelian group
Authors: Cassinelli G. , De Vito E. , Toigo A.
Published: December 2003

Given a unitary representation U of an Abelian group G and a subgroup H, we characterize the positive operator valued measures based on the quotient group G/H and covariant with respect to U.
Diaceleric structures in magnetized plasmas
Authors: da Silveira F. E. M. , Galvão R. M. O.
Published: December 2003

The existence of novel confinement configurations in magnetized plasmas, coined diaceleric structures, is predicted. The conditions for these configurations to emerge are derived and shown to depend on the functional relation between the so-defined material flux fraction and central velocity pitch. The analysis is based upon the application of the coercive criterion, followed by the adjustment procedure, developed by other authors, to a variational method approach. A complete description of Lagrange multipliers and Beltrami eigenvalues in terms of strictly physical parameters is presented. The model recovers the diamagnetic and reversed field pinch structures, investigated by those authors, leading to a comprehensive classification of the relaxed states in magnetized plasmas.
Electron velocity distributions during beam–plasma interaction
Authors: Lu Q. M. , Wang S.
Published: December 2003

It is well known that low-frequency Alfvén waves can be excited due to an ion/ion instability when a tenuous ion beam streams through a background plasma along a magnetic field. In this article, using a one-dimensional particle-in-cell code, the consequence of this beam–plasma interaction process is investigated. Emphasis is placed on the nonlinear effects of enhanced Alfvén waves on beam electrons. In the simulation, the speed between the beam plasma and ambient plasma is considered to be 10 VA (where VA is the Alfvén speed), the ratio of beam–plasma density to background plasma density is nb/n0=0.006 (nb and n0 are the beam and total plasma densities). For the case βi=4×10−4 (βi being the ratio of kinetic pressure of the ions to magnetic pressure), the Alfvén waves begin to grow exponentially at about t=32 Ωi−1, and they saturate at about t=88 Ωi−1. The excited waves are nearly monochromatic, which satisfies the resonant condition, and the perpendicular velocity (the velocity component whose direction is perpendicular to the ambient magnetic field) distribution of the beam electrons peaks away from its origin with a maximum radius about 2.5 VA at the saturation stage. Then, the amplitude of the excited waves decreases and the higher-frequency waves are also excited. A quasi-equilibrium stage is reached at about t=100 Ωi−1, and the radius of the ring in the perpendicular velocity distribution is about 0.7 VA. For the case βi=0.04, the situation is similar except that the radius of the ring in the perpendicular velocity distribution of the beam electrons is smaller, and the ring almost disappears at the quasi-equilibrium stage. Another point is that both the beam and background electrons can be heated by the excited Alfvén waves. The heating effect is more significant for the beam electrons than the background electrons, and their final thermal speeds are anticorrelated with the parameter βi.
Wigner distributions and quantum mechanics on Lie groups: The case of the regular representation
Authors: Mukunda N. , Arvind  , Chaturvedi S. , Simon R.
Published: December 2003

We consider the problem of setting up the Wigner distribution for states of a quantum system whose configuration space is a Lie group. The basic properties of Wigner distributions in the familiar Cartesian case are systematically generalized to accommodate new features which arise when the configuration space changes from n-dimensional Euclidean space Rn to a Lie group G. The notion of canonical momentum is carefully analyzed, and the meanings of marginal probability distributions and their recovery from the Wigner distribution are clarified. For the case of compact G an explicit definition of the Wigner distribution is proposed, possessing all the required properties. Geodesic curves in G which help introduce a notion of the midpoint of two group elements play a central role in the construction.
The space of state vectors: A hyperfinite approach
Authors: Almeida J. , Teixeira J.
Published: December 2003

We present a version of the formalism of Dirac based on nonstandard analysis, allowing us to deal with state vectors and operators using the resources of finite-dimensional linear algebra. The space of state vectors is a nonstandard Hilbert space with hyperfinite dimension, which includes all square-integrable functions, together with vectors representing states of definite position or momentum. Every vector is normalizable, even when its norm is infinite. Observables are represented by Hermitian operators, which are always (hyper)bounded and defined on the whole space. The connection with the standard theory is established by postulating the existence of “hyper-observables” and nonstandard states. Each observable in the usual sense appears as a kind of standard-scale approximation of some hyper-observable. We show that the probabilistic predictions are consistent with those of the standard theory. Consistency extends to time evolution, in the sense that if an initial nonstandard state is “near-standard,” then the state after a finite time shall be infinitely near the standard state obtained through the Schrödinger equation.
Characterization of electrostatic turbulent fluxes in tokamak edge plasmas
Authors: Nishimura Y. , Coster D. , Scott B.
Published: December 2003

A parametrization is presented for the transport from electrostatic turbulence in tokamak edge plasmas. Employing a nonlinear drift wave turbulence simulation, transport coefficients are obtained as functions of a density gradient, temperature gradients, and an external E×B shear parameter. An external radial electric field, Er, is passed to the turbulence model as a background E×B shear flow which suppresses the radial flux together with the Reynolds stress induced electric fields. In a multidimensional parameter space, the transport coefficients exhibit a nonmonotonic dependence on the density and temperature gradients that is unique to the low to high confinement transition.
Confining turbulence in plasmas
Authors: Carbone Vincenzo , Lepreti Fabio , Veltri Pierluigi
Published: December 2003

The transport properties of electrostatic turbulence in plasmas are investigated by using test-particle simulations. In particular, the possibility of control of the transport in a given synthetic turbulent field, which evolves both in space and time, is explored. The fluctuations are built up taking into account observations of real turbulence in laboratory plasmas, that is, by allowing the field to contain structures lying on all dynamically interesting scales. It is shown that, inside a given region of space, the transport can be reduced when phases of the field are randomized, that is, when correlations of the field, which are responsible for the generation of structures, are annihilated. This means that a barrier for the transport can be achieved in a plasma even without actually suppressing turbulence. When the barrier is active, a flux of particles toward the center of the simulation box is present inside the region where the barrier has been located.
Fusion neutron and ion emission from deuterium and deuterated methane cluster plasmas
Authors: Madison K. W. , Patel P. K. , Price D. , Edens A. , Allen M. , Cowan T. E. , Zweiback J. , Ditmire T.
Published: December 2003

Experiments on the interaction of intense, ultrafast pulses with large van der Waals bonded clusters have shown that these clusters can explode with substantial kinetic energy and that the explosion of deuterium clusters can drive nuclear fusion reactions. Producing explosions in deuterated methane clusters with a 100 fs, 100 TW laser pulse, it is found that deuterium ions are accelerated to sufficiently high kinetic energy to drive deuterium nuclear fusion. From measurements of cluster size and ion energy via time of flight methods, it is found that these exploding deuterated methane clusters exhibit higher ion energies than explosions of comparably sized neat deuterium clusters, in accord with recent theoretical predictions. From measurements of the plume size and peak density, the relative contribution to the fusion yield from both beam target and intrafilament fusion is discussed.
Free field dynamics in the generalized AdS (super)space
Authors: Didenko V. E. , Vasiliev M. A.
Published: December 2003

Pure gauge representation for general vacuum background fields (Cartan forms) in the generalized AdS superspace identified with OSp(L,M) is found. This allows us to formulate dynamics of free massless fields in the generalized AdS space–time and to find their (generalized) conformal and higher spin field transformation laws. Generic solution of the field equations is also constructed explicitly. The results are obtained with the aid of the star product realization of ortosymplectic superalgebras.
Towards a general solution of the inhomogeneous Bloch equation
Authors: Kobayashi M.
Published: December 2003

A general form of solution of the inhomogeneous Bloch equation is given in terms of a solution of the homogeneous Bloch equation which is assumed to be known. The fundamental system of the homogeneous Bloch equation is derived from the method inherent to the Riccati equation to which the homogeneous Bloch equation reduces. The fundamental matrix is an orthogonal matrix.
Hopf structure of the Yangian Y(sln) in the Drinfel’d realization
Authors: Crampé N.
Published: December 2003

The Yangian of the Lie algebra sln is known to have different presentations, in particular the RTT realization and the Drinfel’d realization. Using the isomorphism between them, the explicit expressions of the comultiplication, the antipode and the counit in the Drinfel’d realization of the Yangian Y(sln) are given. As examples, the cases of Y(sl2) and Y(sl3) are worked out.
Simulations of global electrostatic microinstabilities in ASDEX Upgrade discharges
Authors: Bottino A. , Peeters A. G. , Sauter O. , Vaclavik J. , Villard L. ,   ASDEX Upgrade Team
Published: December 2003

Electrostatic microinstabilities in ion internal barrier (ITB) and H-mode discharges of the ASDEX Upgrade tokamak [O. Gruber, R. Arslanbekov, C. Atanasiu et al., Nucl. Fusion 41, 1369 (2001)] have been investigated with a full radius gyrokinetic code. The code models linear stability and includes the effect of an equilibrium radial electric field and trapped electrons. In order to simulate plasmas in experimental conditions [k⊥ρL∼O(1)], the long wavelength approximation in the quasineutrality equation has been replaced by a Padé expansion of the modified Bessel function. Results show that the E×B flow, induced by the radial electric field, changes the linear stability of the dominant ion temperature gradient modes. The electrostatic potential eddies are tilted by the sheared flow thus reducing the radial extent and the growth rate of modes. However, the finite value of the flow has a stabilizing effect too; the most unstable modes are shifted away from the unfavorable curvature region leading to lower linear growth rates. In addition to this at least two other mechanisms give an important contribution to the stabilization in the ITB region; the reverse shear profile itself and, to a lesser degree, the local value of the temperature ratio, τ=Te/Ti.
The effect of asymmetric gas puffing on toroidal flow in the edge of tokamak plasma
Authors: Singh Raghvendra , Rogister Andre , Kaw Predhiman
Published: December 2003

The neoclassical theory of toroidal plasma rotation in the presence of an asymmetric neutral gas source in the edge of tokamak is examined. The poloidal dependence of momentum damping and ion energy loss due to charge-exchange processes are included. It is shown that the toroidal flow velocity increases significantly if the gas is fueled from the inboard side of the tokamak; the radial electric field and its shear are modified accordingly. It is also shown that for a fixed gas-fueling rate, the asymmetric fueling has a smaller role in TEXTOR [G. Mank et al., Phys. Rev. Lett. 85, 2312 (2000)] than in COMPASS-D [M. Valovi et al., Plasma Phys. Controlled Fusion 44, A175 (2002)]. The role of asymmetric gas injection is therefore effectively stronger in COMPASS-D.
Schools' Pages
Authors: Robinson Crispin
Published: December 2003

Great Modern Masters: Duchamp

Mulberger, Richard What Makes a Raphael a Raphael?

Working with Modern Art

Apostolos‐Cappadona, D. Dictionary of Christian Art

A Calendar of Art Exhibitions 1997–8

The 20th Century Artbook

Williams, Hilary The Genius of Dürer: Video

The Bauhaus and Design Today: Slides

Hollingsworth, Mary Patronage in Sixteenth‐Century Italy
Feature Reviews
Authors: Lambirth Andrew , Lynton Norbert , Robinson Crispin , Barnes Robert , Wootton David
Published: December 2003

Peppiat, Michael Francis Bacon: anatomy of an enigma

Blü, A.; Drost, W.; Hargrove, J.; He´ran, E.; Ward‐Jackson, P. and Yarrington, A. The Colour of Sculpture 1840–1910

Borsook, E. and Superbi, Gioffredi F. (eds) Italian Altar Pieces 1250–1550

Tomkins, Calvin Duchamp: a biography

Knowlson, James Damned to Fame: the Life of Samuel Beckett

Cronin, Anthony Samuel Beckett: the last modernist
‘ ... something new ...’
Authors: Newman Geoffrey
Published: December 2003

Leighton, John and Thomson, Richard, Seurat and the Bathers

Smith, Paul, Seurat and the Avant‐Garde
Erudite, intelligent, revealing
Authors: Pollock Griselda
Published: December 2003

Steinberg, Leo, The Sexuality of Christ in Renaissance Art and in Modern Oblivion
Colourful Devotions
Authors: Canning Jonathan
Published: December 2003

Weick, Roger S, Painted Prayers: The Book of Hours in Medieval and Renaissance Art
Is Art History Linear?
Authors: Martin Jean
Published: December 2003

Sandler, Irving, Art of the Postmodern Era: From the Late 1960s to the Early 1990s
A Postmodernist Look at Futurism
Authors: Railing Patricia
Published: December 2003

Blum, Cinzia Sartini (Editor), Futurism and the Avant‐Garde
A Scholarly Source Book
Authors: Bracken Susan
Published: December 2003

Anthony Wells‐Cole Art and Decoration in Elizabethan and Jacobean England: The Influence of Continental Prints, 1558–1625
A Bumper Harvest
Authors: Wootton David
Published: December 2003

Stephen Bann Paul Delaroche. History Painted

Stephan Duffy Paul Delaroche 1797–1856. Paintings in the Wallace Collection
The Canon Photography Gallery at the V&A
Authors: Mack Michael
Published: December 2003

Mark Haworth‐Booth, Photography: An Independent Art, photographs from the Vicroria & Albert Museum 1839–1996
Geistliche Heimat: Germany’s Past and Present
Authors: Rowe Dorothy
Published: December 2003

Stephanie Barron and Wolf‐Dieter Dube (eds), German Expressionism: Art and Society 1909–1923

Eckhart Gillen (ed), German art from Beckmann to Richter: Images of a Divided Country
The Arts in Renaissance Ferrara
Authors: Neher Gabriele
Published: December 2003

Stephen Campbell, Cosmè Tura of Ferrara: Style, Politics and the Renaissance City, 1450–1495

Charles M Rosenberg, The Este Monuments and Urban Development in Renaissance Ferrara
A Book Bag on Chagall
Authors: Railing Patricia
Published: December 2003

Susan Compton, Alexandra Shatskikh and Monica Bohm‐Duchen Chagall: Love and the Stage

Roland Doschka (ed.) Marc Chagall: Origins and Paths

Jacob Ball‐Teshuva Chagall 1887–1985

Mikhail Guerman and Sylvie Forestier Marc Chagall — The Land of My Heart: Russia

Aleksander Kamensky Chagall: The Russian Year 1907–1922

Daniel Marchesseau Chagall: The Art of Dreams

Brigitta Höppler Marc Chagall: Life is a Dream
Rethinking Mr Hopper
Authors: Platt Susan
Published: December 2003

Gail Levin Edward Hopper, An Intimate Biography
Embodying History: portraits by Ingress
Authors: Wootton David
Published: December 2003

Books reviewed in this article:

Gary Tinterlow and Philip Conisbee (eds.) Portraits by Ingress: Image of an Epoch

Aileen Ribeiro Ingress in Fashion: Representations of Dress and Appearance in Ingres’s Images of Women
An artist’s artist
Authors: Keller Victoria
Published: December 2003

Book reviewed in this article:

Karen Wilkin Giorgio Morandi
Degas’ New World
Authors: Barnett Walda
Published: December 2003

Book reviewed in this article:

Jean Sutherland Boggs Degas and New Orleans: A French Impressionist in America
A Bookbag on Victorian Art
Authors: Somerville Rosa
Published: December 2003

Books reviewed in this article:

Christopher Wood Victorian Painting

Lionel Lambourne Victorian Painting

Edited by Helen Valentine Art in the Age of Queen Victoria: Treasures from the Royal Academy of Arts Permanent Collection

Lene Østermark‐Johansen Sweetness and Strength: The Reception of Michelangelo in Late Victorian England

Edited by Tim Barringer and Elizabeth Prettejohn Frederic Leighton: Abtiquity, Renaissance, Modernity

Christine Poulson The Quest for the Grail: Arthurian Legand in British Art 1840–1920

Terry Parker Golden Hours: The Paintings of Arthur J Elsley

Jan Marsh and Pamela Gerrish Nunn Pre‐Raphaelite Women Artists
An Artist ahead of his Times?
Authors: Freeman Julian
Published: December 2003

Book reviewed in this article:

Lee MacCormick Edwards Herkomer — A Victorian Artist
Regional Identity, Tradition and Modernity
Authors: Bechhoeffer William
Published: December 2003

Udo Kultermann Contemporary Architecture in the Arab States: Renaissance of a Region
Invented Landscapes
Authors: Bumpus Judith
Published: December 2003

Christopher S. Wood Albrecht Altdorfer and the Origins of Landscape
Surrealism: Transatlantic Views
Authors: Sawin Martika
Published: December 2003

Edward Weisberger (eds) Surrealism: Two Private Eyes. The Neshui Ertegun and Daniel Filipachi Collections
London
Authors: Glaves‐Smith John
Published: December 2003

Michel Remy Surrealism in Britain
Visions of Design: Bloomsbury After One Hundred Years
Authors: Bullen J. B.
Published: December 2003

Books reviewed in this article:

Ed by Christopher Green Art Made Modern: Roger Fry's Vision of Art

Ed by Richard Stone The Art of Bloomsbury

Mary Ann Caws and Sarah Bird Wright Bloomsbury and France: Art and Friends

Simon Watney The Art of Duncan Grant

Ed by Tony Bradshaw The Bloomsbury Artists: Prints and Book Design
Artists' Books
Authors: Peixoto Tania
Published: December 2003

Books Reviewed:

Hamish Fulton Rainbow Walking

Ian Hamilton Finlay, Ian Stephen, Graham Rich Green Waters

Alec Finlay (ed) Passport
Seeing Ruskin Whole
Authors: Wootton David
Published: December 2003

Books reviewed:

John Batchelor, John Ruskin. No Wealth but Life

James S Dearden, John Ruskin: A Life in Pictures

Robert Hewson, with Ian Warrell and Stephen Wildman, Ruskin, Turner and the Pre‐Raphaelites

Tim Hilton, John Ruskin. The Early Years

Tim Hilton, John Ruskin. The Later Years

Sarah Quill, Ruskin's Venice: The Stones Revisited

Ed by Toshio Watanabe, Ruskin in Japan 1840–1940: Nature for Art, Nature for Life

Michael Wheeler, Ruskin's God
Art, Philosophy and Comics
Authors: Brandl Mark Staff
Published: December 2003

Book reviewed in this article:

David Carrier The Aesthetics of Comics
Artists’ Books: Multiples
Authors: Peixoto Tania
Published: December 2003

Books reviewed in this article:

Richard Long Selected Walks

Deb Rindl The Bookmaker
Vast book, big Practice
Authors: Williams Richard J
Published: December 2003

Book Reviewed in this article:

Edited by David Jenkins On Foster . . . Foster On
Focus on Vermeer
Authors: Silver Larry , Kafel Anna Bentkowska , Tollfree Eleanor
Published: December 2003

Books reviewed in this article:

Walter Liedtke, Vermeer and the Delft School

Philip Steadman, Vermeer's Camera. Uncovering the Truth Behind the Masterpieces

Ivan Gaskell, Vermeer's Wager: Speculations on Art History, Theory and Art Museums
‘Heavy Metal’
Authors: Williams Richard J
Published: December 2003

Book reviewed in this article:

Edited by Hal Foster and Gordon Hughes, Richard Serra
Gender, Post‐Colonialism and the History of Art
Authors: Rowe Dorothy
Published: December 2003

Books reviewed in this article:

Deborah Cherry, Beyond the Frame: Feminism and Visual Culture, Britain 1850–1900

Gen Doy, Black Visual Culture: Modernity and Postmodernity

Marc Rosen and Susan Pinsky, Mary Cassatt: Prints and Drawings from the Artist's Studio
Women, Art and Gender
Authors: Dodd Sara M
Published: December 2003

Books reviewed in this article:

Germaine Greer, The Obstacle Race

Caroline Ascott and Katie Scott (eds), Manifestations of Venus: Art and Sexuality

Steven Adams and Anne Gruetzner Robins, Gendering Landscape Art
The Sacred and the Profane
Authors: Packwood David
Published: December 2003

Books reviewed in this article:

Edgar Wind, The Religious Symbolism of Michelangelo: The Sistine Ceiling

Ingrid Rowland, The Culture of the High Renaissance: Ancients and Moderns in Sixteenth‐Century Rome
What's it all about?
Authors: Hyman James
Published: December 2003

Books reviewed in this article:

Edgar Wind, The Battle for Realism Figurative Art in Britain During the Cold War 1945–1960
Dora Maar
Authors: Hoffeld Jeffrey
Published: December 2003

Books reviewed in this article:

Mary Ann Caws, Dora Maar – With and Without Picasso

Mary Ann Caws, (US) Picasso's Weeping Woman. The Life and Art of Dora Maar
A Renaissance Depicture of Nature: Pisanello at the National Gallery
Authors: Callan Guy
Published: December 2003

Book reviewed in this article:

Luke Syson and Dillian Gordon Pisanello: Painter to the Renaissance Court
Holbein – A Snapshot
Authors: Silver Larry
Published: December 2003

Book reviewed in this article:

Mark Roskill and John Oliver, (eds) Hans Holbein: Paintings, Prints and Reception
African Art Today
Authors: Arnold Marion
Published: December 2003

Books reviewed in this article:

Monica Blackmun Visonà, Robin Poynor, Herbert M Cole and Michael D Harris, A History of Art in Africa

Pamela McCluskey, Art from Africa: Long Steps Never Broke a Back

Christa Clark et al, A Personal Journey: Central African Art from the Lawrence Gussman Collection

Sidney Littlefield Kasfir, Contemporary African Art
Venice Reconsidered?
Authors: Neher Gabriele
Published: December 2003

Books reviewed in this article:

Simon Marsden, Venice. City of Haunting Dreams

John Martin and Dennis Romano (eds), Venice Reconsidered. The History and Civilization of an Italian City–State, 1297–1797

Filippo Pedrocco, Visions of Venice. Paintings of the 18th Century

David Rosand, Myths of Venice. The Figuration of a State
Two Centuries of American Art
Authors: Newman Geoffrey
Published: December 2003

Books reviewed in this article:

Andrew Wilton and Tim Barringer, American Sublime: Landscape Painting in the United States 1820–1880

Eric de Chassey (ed), American Art 1908–1947: From Winslow Homer to Jackson Pollock

Erika Doss, Twentieth Century American Art
Titian and the Problems of Style Criticism
Authors: Steer John
Published: December 2003

Book reviewed in this article:

Paul Joannides, Titian to 1518: The Assumption of Genius
Cubism – Time Will Tell?
Authors: Lynton Norbert
Published: December 2003

Books reviewed in this article:

Christopher Green (ed.), Picasso's Les Demoiselles d’Avignon

Robert Rosenblum, Cubism and Twentieth–Century Art

Natasha Staller, A Sum of Destructions
Fragments of Berlin and Other Cities
Authors: Rowe Dorothy
Published: December 2003

Books reviewed in this article:

Steven Spier (ed.), Urban Visions Experiencing and Envisioning the City

Filippo Maggia and Gabriele Basilico (eds.), Gabriele Basilico: Berlin

Jeremy Gilbert–Rolfe with Frank Gehry, Frank Gehry: The City and Music

Molly Donovan (ed.), Christo and Jean–Claude in the Vogel Collection

Ruth Eaton, Ideal Cities: Utopianism and the (Un) Built Environment
Border Crossings: French Painting and the Public
Authors: Packwood David
Published: December 2003

Robert W. Berger, Public Access to Art in Paris: A Documentary History from the Middle Ages to 1800

Todd P. Olson, Poussin and France: Painting, Humanism and the Politics of Style

Humphrey Wine, National Gallery Catalogues: The Seventeenth Century French Paintings
Transforming Nature: Art and Landscape
Authors: Haldane John
Published: December 2003

Essay by Paul Moorhouse Richard Long: Walking the Line

Essay by Paul Moorhouse Richard Long: A Moving World

Essay by Mel Gooding Song of the Earth: European Artists and the Landscape
The Mother of the Arts
Authors: Campbell Katie
Published: December 2003

Andrew Wilson, Influential Gardeners: The Designers Who Shaped 20th Century Garden Style

Denise Otis, Grounds for Pleasure: Four Cemturies of the American Garden

Jane Fearnley‐Whittingstall, The Garden: An English Love Affair
Very Nasty Great Art
Authors: Lynton Norbert
Published: December 2003

Patricia G. Berman, James Ensor – Christ's Entry into Brussels in 1889
Bohemian Experiments
Authors: Lawson Sarah
Published: December 2003

Virginia Nicholson, Among the Bohemians. Experiments in Living 1900–1939
Plots and Patterns in Art History
Authors: Walker John
Published: December 2003

James Elkins, Stories of Art