Disordered Regimes of the one-dimensional complex Ginzburg-Landau equation

I review recent work on the ``phase diagram'' of the one-dimensional complex Ginzburg-Landau equation for system sizes at which chaos is extensive. Particular attention is paid to a detailed description of the spatiotemporally disordered regimes encountered. The nature of the transition lines separating these phases is discussed, and preliminary results are presented which aim at evaluating the phase diagram in the infinite-size, infinite-time, thermodynamic limit.Comment: 14 pages, LaTeX, 9 figures available by anonymous ftp to amoco.saclay.cea.fr in directory pub/chate, or by requesting them to [email protected]

Detection and construction of an elliptic solution to the complex cubic-quintic Ginzburg-Landau equation

In evolution equations for a complex amplitude, the phase obeys a much more intricate equation than the amplitude. Nevertheless, general methods should be applicable to both variables. On the example of the traveling wave reduction of the complex cubic-quintic Ginzburg-Landau equation (CGL5), we explain how to overcome the difficulties arising in two such methods: (i) the criterium that the sum of residues of an elliptic solution should be zero, (ii) the construction of a first order differential equation admitting the given equation as a differential consequence (subequation method).Comment: 12 pages, no figure, to appear, Theoretical and Mathematical Physic

Meromorphic traveling wave solutions of the complex cubic-quintic Ginzburg-Landau equation

We look for singlevalued solutions of the squared modulus M of the traveling wave reduction of the complex cubic-quintic Ginzburg-Landau equation. Using Clunie's lemma, we first prove that any meromorphic solution M is necessarily elliptic or degenerate elliptic. We then give the two canonical decompositions of the new elliptic solution recently obtained by the subequation method.Comment: 14 pages, no figure, to appear, Acta Applicandae Mathematica

Produtividade de soja e milho após coberturas de inverno e descompactação mecânica do solo.

Resumo ? O objetivo deste trabalho foi avaliar o efeito de coberturas de inverno e da descompactação mecânica do solo sobre o desempenho de soja e milho, em sistema de plantio direto. Foram conduzidos dois experimentos em Eldorado do Sul, RS, sobre Argissolo Vermelho compactado, nas safras 2005/2006 e 2006/2007. No primeiro, o delineamento experimental foi em blocos ao acaso, com parcelas subdivididas. Os tratamentos consistiram de duas profundidades teóricas de atuação da haste sulcadora da semeadora (0,06 e 0,12 m, subparcela) e de três tipos de coberturas do solo no inverno (parcela): pousio, aveia-preta (Avena strigosa) e aveia-preta+ervilhaca (Vicia Sativa). Em 2006, a cobertura aveia-preta+ervilhaca foi substituída por nabo-forrageiro (Raphanus sativus). No segundo experimento, realizado em blocos ao acaso, o solo foi escarificado e os tratamentos consistiram do uso de aveia-preta ou nabo-forrageiro como cobertura de inverno. Os cultivos de cobertura reduziram a compactação superficial do solo (0?0,06 m) em comparação ao pousio e, na safra 2006/2007, sob condições de baixa disponibilidade hídrica, proporcionaram maior produtividade de milho e soja. Isso não se repetiu em 2006/2007, quando a disponibilidade hídrica foi adequada. O aumento da profundidade de atuação das hastes sulcadoras não influenciou a produtividade da soja e do milho. A escarificação reduziu a produtividade da soja e do milho em relação ao SPD contínuo

Demanda de tração, mobilização de solo na linha de semeadura e rendimento da soja, em plantio direto.

Resumo O objetivo deste trabalho foi avaliar a relação entre a força de tração (FT) na haste sulcadora de adubo e o volume de solo mobilizado na linha de semeadura em função da quantidade de resíduos, do tráfego de rodados de trator e da profundidade de sulcamento, e sua influência sobre a performance agronômica da soja. Os tratamentos englobaram seis doses de resíduos culturais (DR), duas profundidades de trabalho das hastes sulcadoras (PT) e duas condições de tráfego – com e sem tráfego de rodados de trator –, em blocos ao acaso e parcelas subsubdivididas. Os tratamentos foram aplicados com e sem irrigação, em Argissolo Vermelho, sob plantio direto. As diferentes PT e condições de tráfego influenciaram significativamente a FT. Independentemente da condição de irrigação, as DR não influenciaram a produtividade de grãos e a massa seca da parte aérea da soja. Sem irrigação, a produtividade da soja aumentou em 180 kg ha?1 quando a PT passou de 0,064 para 0,10 m, o que demonstra que a aplicação do fertilizante a profundidades maiores é uma prática viável para diminuir os efeitos da seca sobre a cultura. Termos para indexação: Avena strigosa, Glycine max, doses de resíduo, força de tração, semeadora de precisão

Strong enhancement of d-wave superconducting state in the three-band Hubbard model coupled to an apical oxygen phonon

We study the hole binding energy and pairing correlations in the three-band Hubbard model coupled to an apical oxygen phonon, by exact diagonalization and constrained-path Monte Carlo simulations. In the physically relevant charge-transfer regime, we find that the hole binding energy is strongly enhanced by the electron-phonon interaction, which is due to a novel potential-energy-driven pairing mechanism involving reduction of both electronic potential energy and phonon related energy. The enhancement of hole binding energy, in combination with a phonon-induced increase of quasiparticle weight, leads to a dramatic enhancement of the long-range part of d-wave pairing correlations. Our results indicate that the apical oxygen phonon plays a significant role in the superconductivity of high-$T_c$ cuprates.Comment: 5 pages, 5 figure

Laser-driven quantum magnonics and THz dynamics of the order parameter in antiferromagnets

The impulsive generation of two-magnon modes in antiferromagnets by femtosecond optical pulses, so-called femto-nanomagnons, leads to coherent longitudinal oscillations of the antiferromagnetic order parameter that cannot be described by a thermodynamic Landau-Lifshitz approach. We argue that this dynamics is triggered as a result of a laser-induced modification of the exchange interaction. In order to describe the oscillations we have formulated a quantum mechanical description in terms of magnon pair operators and coherent states. Such an approach allowed us to} derive an effective macroscopic equation of motion for the temporal evolution of the antiferromagnetic order parameter. An implication of the latter is that the photo-induced spin dynamics represents a macroscopic entanglement of pairs of magnons with femtosecond period and nanometer wavelength. By performing magneto-optical pump-probe experiments with 10 femtosecond resolution in the cubic KNiF$_3$ and the uniaxial K$_2$NiF$_4$ collinear Heisenberg antiferromagnets, we observed coherent oscillations at the frequency of 22 THz and 16 THz, respectively. The detected frequencies as a function of the temperature ideally fit the two-magnon excitation up to the N\'eel point. The experimental signals are described as dynamics of magnetic linear dichroism due to longitudinal oscillations of the antiferromagnetic vector.Comment: 25 pages, 10 figure

Construction of Special Solutions for Nonintegrable Systems

The Painleve test is very useful to construct not only the Laurent series solutions of systems of nonlinear ordinary differential equations but also the elliptic and trigonometric ones. The standard methods for constructing the elliptic solutions consist of two independent steps: transformation of a nonlinear polynomial differential equation into a nonlinear algebraic system and a search for solutions of the obtained system. It has been demonstrated by the example of the generalized Henon-Heiles system that the use of the Laurent series solutions of the initial differential equation assists to solve the obtained algebraic system. This procedure has been automatized and generalized on some type of multivalued solutions. To find solutions of the initial differential equation in the form of the Laurent or Puiseux series we use the Painleve test. This test can also assist to solve the inverse problem: to find the form of a polynomial potential, which corresponds to the required type of solutions. We consider the five-dimensional gravitational model with a scalar field to demonstrate this.Comment: LaTeX, 14 pages, the paper has been published in the Journal of Nonlinear Mathematical Physics (http://www.sm.luth.se/math/JNMP/

Solitary waves of nonlinear nonintegrable equations

Our goal is to find closed form analytic expressions for the solitary waves of nonlinear nonintegrable partial differential equations. The suitable methods, which can only be nonperturbative, are classified in two classes. In the first class, which includes the well known so-called truncation methods, one \textit{a priori} assumes a given class of expressions (polynomials, etc) for the unknown solution; the involved work can easily be done by hand but all solutions outside the given class are surely missed. In the second class, instead of searching an expression for the solution, one builds an intermediate, equivalent information, namely the \textit{first order} autonomous ODE satisfied by the solitary wave; in principle, no solution can be missed, but the involved work requires computer algebra. We present the application to the cubic and quintic complex one-dimensional Ginzburg-Landau equations, and to the Kuramoto-Sivashinsky equation.Comment: 28 pages, chapter in book "Dissipative solitons", ed. Akhmediev, to appea

Sugars as source indicators of biogenic organic carbon in aerosols collected above the Howland Experimental Forest, Maine

Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Atmospheric Environment 40 (2006): 1694-1705, doi:10.1016/j.atmosenv.2005.11.001.Bulk aerosols (> 1 μm) were collected continuously above the canopy at the Howland Experimental Forest, Maine, USA from May to October 2002. Each sample integrated over an approximately two-week period. Mono- and disaccharide sugars were extracted using a microscale technique and were analyzed as their TMS derivatives by GC-MS. Concentrations of total aerosol sugars ranged from 10 to 180 ng m-3. Glucose was the most abundant sugar (40-75% of the total sugars). The monosaccharides arabinose, fructose, galactose, mannose, arabitol and mannitol, and the disaccharides sucrose, maltose and mycose (aka trehalose) were also present in lower concentrations. The sugar composition in the aerosols varied seasonally. Fructose and sucrose were prevalent in early spring and decreased in relative abundance as the growing season progressed. Sugar polyols (arabitol and mannitol) and the disaccharide mycose (a fungal metabolite) were more prevalent in autumn during the period of leaf senescence. The changes in the sugar composition in the aerosol samples appear to reflect the seasonality of sugar production and utilization by the ecosystem. Plant waxes were present as significant components also indicating an input from biogenic background. Smoke plumes from Quebec forest fires passed over the Howland site in early July 2002. Levoglucosan, a biomarker of biomass burning, increased by an order of magnitude in the aerosol samples collected during this time. Glucose, mannose, arabinose, galactose, and also, plant waxes increased in concentration by factors of 2-5 in the smoke-impacted samples, indicating that wildfires enhance atmospheric emissions of uncombusted organic compounds. In contrast, concentrations of fructose, sugar polyols and disaccharides were not significantly higher in the smoke-impacted samples and indicated that biomass burning was not a significant source of these compounds in the aerosols.This work was funded by a grant to MHC (DOE-NIGEC Grant 15460100) from the U.S. Department of Energy’s (DOE) National Institute for Global Environmental Change (NIGEC), through the NIGEC Northeast Regional Center at Harvard University