2,672 research outputs found
Dimensional perturbation theory for vibration-rotation spectra of linear triatomic molecules
A very efficient large-order perturbation theory is formulated for the
nuclear motion of a linear triatomic molecule. To demonstrate the method, all
of the experimentally observed rotational energies, with values of almost
up to 100, for the ground and first excited vibrational states of CO and
for the ground vibrational states of NO and of OCS are calculated. All
coupling between vibration and rotation is included. The perturbation
expansions reported here are rapidly convergent. The perturbation parameter is
, where is the dimensionality of space. Increasing is
qualitatively similar to increasing the angular momentum quantum number .
Therefore, this approach is especially suited for states with high rotational
excitation. The computational cost of the method scales only as ,
where is the size of the vibrational basis set.Comment: submitted to Journal of Chemical Physics, 23 pages, REVTeX, no
figure
Furthering alternative cultures of valuation in higher education research
The value of higher education is often implicit or assumed in educational research. The underlying and antecedent premises that shape and influence debates about value remain unchallenged which perpetuates the dominant, but limiting, terms of the debate and fosters reductionism. I proceed on the premise that analyses of value are not selfâsupporting or self-referential but are embedded within prevailing cultures of valuation. I contend that challenging, and providing alternatives to, dominant narratives of higher education requires an appreciation of those cultures. I therefore highlight some of the existing cultures of valuation and their influence. I then propose Sayerâs concept of lay normativity as a culture of valuation and discuss how it translates into the practices of research into higher education, specifically the practice of analysis. I animate the discussion by detecting the presence of lay normativity in the evaluative space of the capability approach
Invariance of the correlation energy at high density and large dimension in two-electron systems
We prove that, in the large-dimension limit, the high-density correlation
energy \Ec of two opposite-spin electrons confined in a -dimensional space
and interacting {\em via} a Coulomb potential is given by \Ec \sim -1/(8D^2)
for any radial confining potential . This result explains the observed
similarity of \Ec in a variety of two-electron systems in three-dimensional
space.Comment: 4 pages, 1 figure, to appear in Phys. Rev. Let
Academic training in oral and maxillofacial surgery - when and how to enter the pathway
Entering into surgical academia can seem a daunting prospect for an oral and maxillofacial surgery (OMFS) trainee. However, the streamlining of academic training by the NIHR to create the integrated academic training (IAT) pathway has simplified academic training and more clearly defined academic positions and entry points for trainees. In this article we review the current NIHR IAT pathway and the various grades and entry points available to OMF surgeons, both pre- and post-doctoral. We highlight the unique challenges facing OMF trainees and provide advice and insight from both junior and senior OMFS academics. Finally, we focus on the planning and application for a doctoral research fellowship - discussing funding streams available to OMF surgeons
Enhanced X-ray variability from V1647 Ori, the young star in outburst illuminating McNeil's Nebula
We report a ~38 ks X-ray observation of McNeil's Nebula obtained with XMM on
2004 April 4. V1647 Ori, the young star in outburst illuminating McNeil's
Nebula, is detected with XMM and appears variable in X-rays. We investigate the
hardness ratio variability and time variations of the event energy distribution
with quantile analysis, and show that the large increase of the count rate from
V1647 Ori observed during the second half of the observation is not associated
with any large plasma temperature variations as for typical X-ray flares from
young low-mass stars. X-ray spectral fitting shows that the bulk (~75%) of the
intrinsic X-ray emission in the 0.5-8 keV energy band comes from a soft plasma
component (0.9 keV) reminiscent of the X-ray spectrum of the classical T Tauri
star TW Hya, for which X-ray emission is believed to be generated by an
accretion shock onto the photosphere of a low-mass star. The hard plasma
component (4.2 keV) contributes ~25% of the total X-ray emission, and can be
understood only in the framework of plasma heating sustained by magnetic
reconnection events. We find a hydrogen column density of NH=4.1E22 cm-2, which
points out a significant excess of hydrogen column density compared to the
value derived from optical/IR observations, consistent with the picture of the
rise of a wind/jet unveiled from ground optical spectroscopy. The X-ray flux
observed with XMM ranges from roughly the flux observed by Chandra on 2004
March 22 (~10 times greater than the pre-outburst X-ray flux) to a value two
times greater than that caught by Chandra on 2004 March 7 (~200 times greater
than the pre-outburst X-ray flux). We have investigated the possibility that
V1647 Ori displays a periodic variation in X-ray brightness as suggested by the
combined Chandra+XMM data set (abridged).Comment: 11 pages and 8 Figures. Accepted for publication by Astronomy &
Astrophysic
Synthesis and characterization of monomeric manganese(II) and cobalt(III) complexes of the hexadentate amine ligand N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine, C26H28N6 (tpen)
The syntheses and characterization of complexes of manganese(II) and cobalt(III) with the potentially hexadentate ligand N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine, C26H28N6 (tpen), are described. The monomeric manganese(II) complex [Mn(C26H28N6)(H2O)](ClO4)2 (1) crystallizes in the monoclinic space group C2/c with 4 formula units in a cell of dimensions a = 15.080(1) Ă
, b = 10.101(1) Ă
, c = 19.426(2) Ă
and b = 94.6l(l)°. The structure has been refined to a final value of the conventional R-factor of 0.0401 based on 2586 observed independent reflections. The geometry at the manganese center is seven-coordinate, and is best described as a capped trigonal pyramid with the water molecule forming the cap and the six nitrogen atoms of the tpen ligand occupying the pyramidal sites. The manganese atom and the water molecule lie on a crystallographic twofold axis. The related cobalt(III) complex, [Co(C26H28N6)] (C1O4)3 (4) crystallizes in the monoclinic space group P21/n with 4 formula units in a cell of dimensions a = 9.829(2) Ă
, b = 18.364(4) Ă
, c = 18.128(4) Ă
and b = 93.64(3)°. The structure has been refined to a final value of the conventional R-factor of 0.0526 based on 3574 observed independent reflections. The complex is approximately octahedral, the coordination being provided by the six nitrogen atoms of the tpen ligand. The EPR spectrum of 1 diluted into the corresponding Cd(II) host has been simulated with the parameters g = 2.00, A = 0.0080 cm-1, D = 0.116 cm-1, and E = 0.0013 cm-1. The small value of E/D is consistent with the observed symmetry of the complex. KEY WORDS: Monomeric manganese(II) complex, Monomeric cobalt(III) complex, Hexadentate ligand, N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine  Bull. Chem. Soc. Ethiop. 2004, 18(1), 17-28.
Recognising Desire: A psychosocial approach to understanding education policy implementation and effect
It is argued that in order to understand the ways in which teachers experience their work - including the idiosyncratic ways in which they respond to and implement mandated education policy - it is necessary to take account both of sociological and of psychological issues. The paper draws on original research with practising and beginning teachers, and on theories of social and psychic induction, to illustrate the potential benefits of this bipartisan approach for both teachers and researchers. Recognising the significance of (but somewhat arbitrary distinction between) structure and agency in teachersâ practical and ideological positionings, it is suggested that teachersâ responses to local and central policy changes are governed by a mix of pragmatism, social determinism and often hidden desires. It is the often underacknowledged strength of desire that may tip teachers into accepting and implementing policies with which they are not ideologically comfortable
Non-steroidal anti-inflammatory drug use does not appear to be associated with increased cardiovascular mortality in patients with inflammatory polyarthritis: results from a primary care based inception cohort of patients
Graduate Students as Academic Writers: Writing Anxiety, Self-Efficacy, and Emotional Intelligence
Researchers interested in psychological factors affecting writers in higher-education institutions, or academic writers, are concerned with internal variables affecting writing productivity; however few empirical studies explore these factors with samples of students who are in the process of earning masterâs or doctoral degrees (i.e., graduate students). In this study, we examined writing anxiety, self-efficacy, and emotional intelligence in a sample of graduate students at a large, research-intensive university in the United States. Using a survey, we collected measures on these variables in addition to demographic information from the participants. We then used the measures to descriptively compare groups of students with similar characteristics and to run three regression models to identify which variables best predicted writing anxiety. Our findings indicate self-efficacy is a statistically significant and large predictor of writing anxiety while emotional intelligence (EI) is not, though descriptive data showed moderate effects between EI and first language (i.e., whether or not a student reported English as a first language). In the presence of self-efficacy, gender remained a significant predictor of writing anxiety, while first language did not. We discuss implications for future research and practice focused on helping graduate student academic writers succeed
High orders of the perturbation theory for hydrogen atom in magnetic field
The states of hydrogen atom with principal quantum number and zero
magnetic quantum number in constant homogeneous magnetic field are
considered. The coefficients of energy eigenvalues expansion up to 75th order
in powers of are obtained for these states. The series for energy
eigenvalues and wave functions are summed up to values of the order
of atomic magnetic field. The calculations are based on generalization of the
moment method, which may be used in other cases of the hydrogen atom
perturbation by a polynomial in coordinates potential.Comment: 16 pages, LaTeX, 6 figures (ps, eps
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