CsMoO2(HO3P–CH2–PO3): a new metallodiphosphonate with a hybrid framework

Crystals of caesium molybdeno­methyl­enedi­phospho­nate, [CsMoO₂(CH₃O₆P₂)], were hydro­thermally synthesized at 473 K. The monoclinic structure, as determined from single‐crystal X‐ray diffraction, is two‐dimensional and consists of stacked mixed layers of corner‐sharing tetrahedral di­phosphon­ate groups and MoO₆ octahedra, between which Cs⁺ cations are intercalated.     

Chemical Synthesis of Oligonucleotides Containing N6-Methyladenine Residues in the GATC Site

To investigate by NMR the effects of adenine methylation, a set of oligodeoxynucleotides has been synthesized by phosphotriester or phosphoramidite procedures on silica-gel support. The preparation of fully protected 2′-deoxy-N⁶-methyladenosine 3′-phosphate 4 and (2′-deoxy-N⁶-methyladenosin-3′-O-yl)(methoxy)morpholinophosphine 5 is described. The large-scale chemical synthesis, purification by HPLC, and characterization by MS of these molecules containing N⁶-methyladenine is reported.     

Chemical ionization desorption mass spectrometry of some quaternary ammonium salts

The ammonia chemical ionization desorption spectra of N,N-dimethyl quaternary ammonium iodides in addition to high protonated molecular ion [M + H]⁺ intensity, show signals for an ion radical composed of N-methyl abstracted salt cation and ammonia [C + NH₃? CH₃]^+˙. These ions corresponding to the cation +2 show increased importance in the chemical ionization mode, using the same reagent gas. The technique of chemical ionization desorption appears suitable for the analysis of salts, and thus for the determination of the molecular weight of both anion and cation.     

Convergence of the parabolic Ginzburg–Landau equation to motion by mean curvature

We present some new results for the asymptotic behavior of the complex parabolic Ginzburg–Landau equation. In particular, we establish that, as the parameter ε tends to 0, vorticity evolves according to motion by mean curvature in Brakke's weak formulation. The only assumption we make is a natural energy bound on the initial data. In some cases, we also prove convergence to enhanced motion in the sense of Ilmanen. To cite this article: F. Bethuel et al., C. R. Acad. Sci. Paris, Ser. I 336 (2003).     

Confined plasmonic modes in a nanocavity

The effect of confinement on surface plasmon polariton in a planar nanocavity was studied. The generalized modes were obtained and studied in detail. It was demonstrated that these modes result from the strong coupling of plasmon-like and photon-like modes.     

Surface characterizations of fluorescent-functionalized silica nanoparticles: from the macroscale to the nanoscale

Journal of Nanoparticle Research - Fluorescent silica nanoparticles are widely used for various applications from mechanical reinforcement to biology. In many cases, their surface has to be...     

Semiclassical results in the linear response theory

We consider a quantum system of non-interacting fermions at temperature T, in the framework of linear response theory. We show that semiclassical theory is an appropriate framework to describe some of their thermodynamic properties, in particular through asymptotic expansions in ? (Planck constant) of the dynamical susceptibilities. We show how the closed orbits of the classical motion in phase space manifest themselves in these expansions, in the regime where T is of the order of ?.     

Roughness-Induced Effects on the Quasi-Geostrophic Model

We study in this paper the effect of small-scale irregularities on the quasi-geostrophic model. This study is motivated by some problems related to oceanography, as the Gulf Stream separation, or the impact of the topography on the global circulation. We first consider the role of coastal roughness in the phenomenon of western intensification of boundary currents. We show that the roughness is responsible for a nonlinear dynamics of the boundary layers, governed by a quasilinear elliptic equation. We thus extend substantially the classical derivation of Munk layers [15] and the results of convergence obtained in [10]. We then discuss the effect of a rough topography, by generalizing and justifying some formal computations of [17]. In particular, we derive rigorously a simplified model of oceanic circulation, with a nonlinear and nonlocal dissipative term due to the roughness.Acknowledgement This work has been partially supported by the GDR Amplitude Equations and Qualitative Properties (GDR CNRS 2103: EAQP) and by the IDOPT project in Grenoble.     

Evidence of a worldwide stock market log-periodic anti-bubble since mid-2000

Following our investigation of the USA Standard and Poor index anti-bubble that started in August 2000 (Quant. Finance 2 (2002) 468), we analyze 38 world stock market indices and identify 21 “bearish anti-bubbles” and six “bullish anti-bubbles”. An “anti-bubble” is defined as a self-reinforcing price trajectory with self-similar expanding log-periodic oscillations. Mathematically, a bearish anti-bubble is characterize by a power law decrease of the price (or of the logarithm of the price) as a function of time and by expanding log-periodic oscillations. We propose that bearish anti-bubbles are created by positive price-to-price feedbacks feeding overall pessimism and negative market sentiment further strengthened by inter-personal interactions. Bullish anti-bubbles are here identified for the first time. The most striking discovery is that the majority of European and Western stock market indices as well as other stock indices exhibit practically the same log-periodic power law anti-bubble structure as found for the USA S&P500 index. These anti-bubbles are found to start approximately at the same time, August 2000, in all these markets. This shows a remarkable degree of worldwide synchronization. The descent of the worldwide stock markets since 2000 is thus an international event, suggesting the strengthening of globalization.