Search results for "Oct"

Structure and phase transitions in guanidinium halogenobismuthates(III)

2001

Abstract Differential scanning calorimetry (DSC), dilatometric and dielectric measurements have been used to study the phase transitions in [C(NH2)3]3BiBr6. The [C(NH2)3]3BiBr6 crystal undergoes four phase transitions: at 419, 429, 475 and 495 K (on heating). The high-temperature phase transition is clearly of first-order type and its high entropy effect allows classifying it as of the order–disorder type. X-ray diffraction studies showed that [C(NH2)3]3BiBr6 crystallises in monoclinic, centrosymmetric space group, C2/c. The anionic sublattice is composed of isolated BiBr63− octahedra. The infrared between 100 and 350 K and Raman spectra at room temperature in the frequency range related to…

High-pressure- and low-temperature-induced changes in [(CH3)2NH(CH2)2NH3][SbCl5].

2006

The structure of N,N-dimethylethylenediammonium pentachloroantimonate(III), [(CH3)2NH(CH2)2NH3][SbCl5], NNDP, was investigated at 100 and 15 K at ambient pressure, as well as at pressures up to 4.00 GPa at room temperature in the diamond-anvil cell. The stable structure at low temperatures and low pressures consists of isolated [SbCl5]2- anions and [(CH3)2NH(CH2)2NH3]2+ cations. The inorganic anions have a distorted square pyramidal geometry. They are arranged in linear chains parallel to the c axis. In contrast to the low-temperature studies, where no phase transition was detected, pressure induces a P2(1)/c --P2(1)/n phase transition between 0.55 and 1.00 GPa, accompanied by a doubling of…

PHASE TRANSITIONS IN HALOGENOANTIMONATE(V) CRYSTALS: [N(CH3)4]SbCl6 AND [N(C2H5)4]SbCl6

1998

Abstract New crystals of the family of alkylammonium chloroantimonates(V), [N(CH 3 ) 4 ]SbCl 6 and [N(C 2 H 5 ) 4 ]SbCl 6 , have been grown and systematically studied. X-ray studies show that [N(C 2 H 5 ) 4 ]SbCl 6 is composed of isolated cations and ideal SbCl 6 − octahedra. Differential scanning calorimetry, dilatometric and dielectric measurements reveal structural phase transitions in [N(CH 3 ) 4 ]SbCl 6 and [N(C 2 H 5 ) 4 ]SbCl 6 of first order at 236 and 345 K, respectively. The measurements of 1 H-NMR spin-lattice relaxation times, T 1 , show that mechanism of the phase transitions in [N(CH 3 ) 4 ]SbCl 6 and [N(C 2 H 5 ) 4 ]SbCl 6 is due to the reorientations of the tetraalkylammoniu…

Spinoza on Teaching and Indoctrination

2017

A Challenge to Boghossian's Incompatibilist Argument

1998

The paradox arises as we realize that (3) is clearly not knowable a priori, but (1) and (2) are. (2) holds 'a priori' because, according to Boghossian, it "just is the view that I have called the doctrine of privileged self-knowledge" (p. 202). The core of the paper is devoted, though, to argue that an externalist (i.e., someone who holds the view that "... facts external to a thinker's skin are relevant to the individuation of (certain of) his mental contents" (p. 199). is bound to concede that (1) is knowable 'a priori'. It would follow that, contrary to intuition, (3) can be known a priori since is the conclusion of an inference that relies on two premises that are, in

Umkehrung der Verhältnisse. Schellings Rezeption der Moralphilosophie Kants und ihre philosophiegeschichtliche Dimension

2020

Comparisons between Kant and Schelling are mostly used to systematically analyse topics of German idealism. However, such an approach often disregards the resulting historical aspects. This paper is an attempt to draw historical conclusions from such a systematic analysis. I do so by showing how Schelling’s critique of Kant’s moral doctrine in Philosophie und Religion allows to gain an insight into Schelling’s philosophical development. Specifically, I argue that this criticism rests upon the claim that the ordo cognoscendi must follow the ordo essendi. This claim will be rejected in Schelling’s Freiheitsschrift and Stuttgarter Privatvorlesungen. Finally, historical remarks conclude this co…

Electronic structure calculations forZnFe2O4

2011

Local density approximation was applied to scrutinize the electronic structure and magnetic properties of the spinel ferrite ${\mathrm{ZnFe}}_{2}{\mathrm{O}}_{4}$. Various cation distributions were established to obtain the ground state for the system. In magnetic crystals, the position of the atoms is not enough for symmetry determination. A structure prediction by decreasing the octahedral point group symmetry ${\mathrm{O}}_{h}$ of Fe to ${\mathrm{D}}_{4h}$, ${\mathrm{C}}_{4v}$, and ${\mathrm{C}}_{3v}$ was carried out. The effect of the exchange and correlation terms on the band structure of ${\mathrm{ZnFe}}_{2}{\mathrm{O}}_{4}$ was studied by the generalized gradient approximation $+$ th…

Interaction Of The Vector-Meson Octet With The Baryon Octet In Effective Field Theory

2015

We analyze the constraint structure of the interaction of vector mesons with baryons using the classical Dirac constraint analysis. We show that the standard interaction in terms of two independent SU(3) structures is consistent at the classical level. We then require the self-consistency condition of the interacting system in terms of perturbative renormalizability to obtain relations for the renormalized coupling constants at the one-loop level. As a result we find a universal interaction with one coupling constant which is the same as in the massive Yang-Mills Lagrangian of the vector-meson sector.

Spectroscopy of XY5Z (C4v) Molecules: A Tensorial Formalism Adapted to the O(3) ⊃ Oh ⊃ C4v Chain

2000

Abstract A tensorial formalism adapted to the case of XY 5 Z symmetric tops has been developed as an extension of the usual one for the octahedral molecules. We use the O (3) ⊃ O h ⊃ C 4 v group chain. All the coupling coefficients and formulas for the computation of matrix elements are given for this chain. Such relations are also deduced in the C 4 v group itself.

Supercontinuum spectral control

2009

Supercontinuum (SC) generation in photonic crystal fibers (PCFs) is a cutting-edge phenomenon extensively studied in recent years [1]. SC has found many scientific and technological applications. The control of the SC spectral characteristics is crucial in most of them. A pioneering attempt in this direction was reported in Ref. [2]. We point out that SC is typically generated by accessing the anomalous dispersion regime of the fiber, i.e., when the group velocity dispersion (GVD) coefficient is lower than zero, β 2 ≪0. The recent achievement of soft-glass PCFs, namely, PCFs made up of a transparent material that shows higher nonlinear response than the widely used fused silica, opens new p…