Synthesis, structure, and magnetic properties of a dinuclear antiferromagnetically coupled iron(II) complex

The authors acknowledge the Algerian DGRSDT (Direction Générale de la Recherche Scientifique et du Développement Technologique) and Université Ferhat Abbas Sétif 1 for financial support.A new dinuclear Fe(II) complex with the general formula [Fe2(1,4-tpbd)(dca)4(H2O)2] ( 1 ) (in which 1,4-tpbd = N,N,N′,N′-tetrakis(2-pyridylmethyl)benzene-1,4-diamine; dca = dicyanamide, [N(CN)2]−), has been prepared under hydrothermal conditions and fully characterized by elemental analysis, infrared spectroscopy, X-ray diffraction, and magnetic measurements. The compound crystallizes in the triclinic system and P-1 space group with Z = 1 and the following unit cell parameters: a = 8.165(5) Å, b = 10.236(5) Å, c = 13.105(5) Å, α = 81.421(5)°, β = 78.810(5)°, γ = 72.941(5)°, and V = 1022.2(9) Å3. The Fe(II) ions are six-coordinated, in distorted octahedral fashion, by three N atoms of tpbd ligand, one water oxygen atom and two N atoms of two dicyanamide anions. The intra-dinuclear Fe⋯Fe distance via the bridged μ2-tpbd ligand is 8.293(8) Å. In the molecular arrangement, the combination of OH⋯N and CH⋯N hydrogen bonds links the title complex to form a three-dimensional supramolecular structure. Magnetic susceptibility measurements (2–300 K) show that 1 presents weak antiferromagnetic exchange between the two nearest Fe2+ ions with the coupling constant J = −1.05 cm−1.PostprintPeer reviewe

Daily Rhythmic Behaviors and Thermoregulatory Patterns Are Disrupted in Adult Female MeCP2-Deficient Mice

Mutations in the X-linked gene encoding Methyl-CpG-binding protein 2 (MECP2) have been associated with neurodevelopmental and neuropsychiatric disorders including Rett Syndrome, X-linked mental retardation syndrome, severe neonatal encephalopathy, and Angelman syndrome. Although alterations in the performance of MeCP2-deficient mice in specific behavioral tasks have been documented, it remains unclear whether or not MeCP2 dysfunction affects patterns of periodic behavioral and electroencephalographic (EEG) activity. The aim of the current study was therefore to determine whether a deficiency in MeCP2 is sufficient to alter the normal daily rhythmic patterns of core body temperature, gross motor activity and cortical delta power. To address this, we monitored individual wild-type and MeCP2-deficient mice in their home cage environment via telemetric recording over 24 hour cycles. Our results show that the normal daily rhythmic behavioral patterning of cortical delta wave activity, core body temperature and mobility are disrupted in one-year old female MeCP2-deficient mice. Moreover, female MeCP2-deficient mice display diminished overall motor activity, lower average core body temperature, and significantly greater body temperature fluctuation than wild-type mice in their home-cage environment. Finally, we show that the epileptiform discharge activity in female MeCP2-deficient mice is more predominant during times of behavioral activity compared to inactivity. Collectively, these results indicate that MeCP2 deficiency is sufficient to disrupt the normal patterning of daily biological rhythmic activities

Perturbative Approach to the Structure of a Planar Interface in the Landau-de Gennes Model : Elastic Anisotropy Effects

この論文は国立情報学研究所の電子図書館事業により電子化されました。研究会報

Zuverlässige Leistungselektronik für Windenergieanlagen: Abschlussbericht zum Fraunhofer-Innovationscluster Leistungselektronik für regenerative Energieversorgung

Frequenzumrichter in Windenergieanlagen sind häufig von Ausfällen betroffen und verursachen so beträchtliche Reparaturkosten und Ertragseinbußen. Zur weiteren Senkung der Energiegestehungskosten ist es daher wichtig, die Zuverlässigkeit dieser zur Netzanbindung nahezu aller modernen Windenergieanlagen eingesetzten Komponenten zu steigern. Mit diesem Ziel haben sich im Projekt "Zuverlässige Leistungselektronik für Windenergieanlagen" drei Forschungsinstitute und 16 Unternehmen zusammengetan, um die bis dahin nicht ausreichend verstandenen Ausfallursachen der Umrichter in der Windanwendung zu untersuchen und Maßnahmen zur Steigerung der Zuverlässigkeit abzuleiten. Neben der Auswertung von Felddaten von über 2700 Anlagen aus fast 7400 Betriebsjahren und Analysen von Defektkomponenten sind dazu Simulationsmodelle entwickelt und verwendet worden, die den Einfluss der Gesamtanlagendynamik und verschiedener Regelstrategien auf die Leistungselektronik abbilden. Darüber hinaus sind Ansätze zur Fehlerfrüherkennung in Umrichtern entwickelt und fehlertolerante Generator-Umrichter-Konzepte für Windenergieanlagen der nächsten Generation untersucht worden

Developed turbulence and nonlinear amplification of magnetic fields in laboratory and astrophysical plasmas

The visible matter in the universe is turbulent and magnetized. Turbulence in galaxy clusters is produced by mergers and by jets of the central galaxies and believed responsible for the amplification of magnetic fields. We report on experiments looking at the collision of two laser-produced plasma clouds, mimicking, in the laboratory, a cluster merger event. By measuring the spectrum of the density fluctuations, we infer developed, Kolmogorov-like turbulence. From spectral line broadening, we estimate a level of turbulence consistent with turbulent heating balancing radiative cooling, as it likely does in galaxy clusters. We show that the magnetic field is amplified by turbulent motions, reaching a nonlinear regime that is a precursor to turbulent dynamo. Thus, our experiment provides a promising platform for understanding the structure of turbulence and the amplification of magnetic fields in the universe

Proton imaging of an electrostatic field structure formed in laser-produced counter-streaming plasmas

We report the measurements of electrostatic field structures associated with an electrostatic shock formed in laser-produced counter-streaming plasmas with proton imaging. The thickness of the electrostatic structure is estimated from proton images with different proton kinetic energies from 4.7 MeV to 10.7 MeV. The width of the transition region is characterized by electron scale length in the laser-produced plasma, suggesting that the field structure is formed due to a collisionless electrostatic shock.ISSN:1742-6588ISSN:1742-659