Search results for "osso"

Conformations, Transverse Fluctuations and Crossover Dynamics of a Semi-Flexible Chain in Two Dimensions

2014

We present a unified scaling description for the dynamics of monomers of a semiflexible chain under good solvent condition in the free draining limit. We consider both the cases where the contour length $L$ is comparable to the persistence length $\ell_p$ and the case $L\gg \ell_p$. Our theory captures the early time monomer dynamics of a stiff chain characterized by $t^{3/4}$ dependence for the mean square displacement(MSD) of the monomers, but predicts a first crossover to the Rouse regime of $t^{2\nu/{1+2\nu}}$ for $\tau_1 \sim \ell_p^3$, and a second crossover to the purely diffusive dynamics for the entire chain at $\tau_2 \sim L^{5/2}$. We confirm the predictions of this scaling descr…

Coordination polymers undergoing spin crossover and reversible ligand exchange in the solid

2006

Here we report the synthesis and characterisation of a polymer made up of a system of parallel 2-D grids of Fe(II) ions linked by [Au(CN)2]– bridges and its transformation into a new system of three interpenetrated 3-D coordination open frameworks with the NbO topology. Reversibility of this crystal-to-crystal transformation is evidenced by X-ray crystallographic data and from their spin crossover properties. Real Cabezos, Jose Antonio, Jose.A.Real@uv.es

Spin crossover properties of the [Fe(PM-BiA)2(NCS)2] complex - phases I and II

2003

International audience; In the present review, we reexamine the photomagnetic properties of the [Fe(PM-BiA)2(NCS)2], cis-bis(thiocyanato)-bis[(N-2'-pyridylmethylene)-4-(aminobiphenyl)]iron(II), compound which exhibits, depending on the synthetic method, an exceptionally abrupt spin transition (phase I) with a very narrow hysteresis (T1/2O = 168 K and T1/2N = 173 K) or a gradual spin conversion (phase II) occurring at 190 K. In both cases, light irradiation in the tail of the 1MLCT-LS absorption band, at 830 nm, results in the population of the high-spin state according to the light-induced excited spin-state trapping (LIESST) effect. The capacity of a compound to retain the light-induced HS…

Novel Iron(II) Microporous Spin-Crossover Coordination Polymers with Enhanced Pore Size

2012

In this Communication, we report the synthesis and characterization of novel Hofmann-like spin-crossover porous coordination polymers of composition {Fe(L)[M(CN)4]}·G [L = 1,4-bis(4-pyridylethynyl)- benzene and MII = Ni, Pd, and Pt]. The spin-crossover properties of the framework are closely related to the number and nature of the guest molecules included in the pores.

Plaque removal efficacy of an electric toothbrush: a comparative study.

2008

Temperature- and pressure-dependent structural study of {Fe(pmd) 2[Ag(CN)2 ]2}n spin-crossover compound by neutron Laue diffraction

2014

The effect of pressure (up to 0.17GPa) on the spin-crossover compound {Fe(pmd)2[Ag(CN)2]2} n [orthorhombic isomer (II), pmd = pyrimidine] has been investigated by temperature- and pressure-dependent neutron Laue diffraction and magnetometry. The cooperative high-spin ↔ low-spin transition, centred at ca 180K at ambient pressure, is shifted to higher temperatures as pressure is applied, showing a moderate sensitivity of the compound to pressure, since the spin transition is displaced by ca 140KGPa-1. The space-group symmetry (orthorhombic Pccn) remains unchanged over the pressure-temperature (P-T) range studied. The main structural consequence of the high-spin to low-spin transition is the c…

Reaction time paradigms in subjects at risk for schizophrenia.

1994

Abstract Deviant response patterns in experimental reaction time paradigms in schizophrenic probands are well documented. Although simple reaction times are strongly influenced by the current psychopathological status of the proband (e.g. florid psychotic patients versus remitted patients) these influences are less clear for measures obtained from more complex reaction time paradigms. These include the crossover paradigm (reaction time to stimuli presented after constant preparatory intervals in comparison to reaction time to stimuli presented after irregular preparatory intervals) and the modality shift paradigm (reaction time to a stimulus (light or tone) when the modality of the stimulus…

Metal-to-metal electron transfer and magnetic interactions in a mixed-valence Prussian Blue analogue

2006

Abstract In search of a new Prussian Blue analogue exhibiting fascinating magnetic properties, potassium manganese hexacyanoferrate, K 0.2 Mn 0 . 66 II Mn 1.44 III [ Fe 0.2 II Fe 0.8 III ( CN ) 6 ] O 0.66 ( CH 3 COO ) 1.32 ] , 7.6H2O, has been synthesized. This compound undergoes a paramagnetic to ferrimagnetic transition at 10 K. Temperature and magnetic field-dependent magnetization studies of this compound have revealed different spin alignments below and above 3 K. The nature of possible magnetic interactions between the nearest neighbor magnetic centers has been discussed in order to explore the origin of the observed magnetic interactions. Mossbauer spectroscopic study at different te…

Photomagnetism of Molecular Systems

2001

This article reviews various classes of transition metal compounds which display in the solid state light sensitive electronic structure modifications accompanied by drastic changes of their magnetic and/or optical properties, i.e., photomagnetism. Selected examples from this rapidly expanding field, include spin crossover, stilbenoid and nitrosyl complexes, as well as Prussian blue analogues.

Effect of beclomethasone dipropionate on the bronchial responsiveness to propranolol in asthmatics.

1990

The effect of four weeks of treatment with beclomethasone dipropionate (BDP, 500 micrograms twice daily) on the bronchial responsiveness to propranolol was examined in 16 patients with mild asthma in a placebo-controlled, double-blind crossover study. Propranolol was inhaled in doubling concentrations and the results were expressed as the cumulative dose producing a 20 percent fall in FEV1 (PC20). After four weeks of treatment with BDP, the mean FEV1 increased from 82.0 percent predicted to 88.1 percent predicted. The difference was significant (p less than 0.001). Treatment with BDP did not significantly change the responsiveness to propranolol, the geometric mean PC20 being 3.17 mg/ml bef…