Observed photodetachment in parallel electric and magnetic fields

We investigate photodetachment from negative ions in a homogeneous 1.0-T magnetic field and a parallel electric field of approximately 10 V/cm. A theoretical model for detachment in combined fields is presented. Calculations show that a field of 10 V/cm or more should considerably diminish the Landau structure in the detachment cross section. The ions are produced and stored in a Penning ion trap and illuminated by a single-mode dye laser. We present preliminary results for detachment from S- showing qualitative agreement with the model. Future directions of the work are also discussed.Comment: Nine pages, five figures, minor revisions showing final publicatio

Biochemical evaluation of the nutrition status of urban primary school children: Vitamin-A status

No Abstract

Observation of diffractive orbits in the spectrum of excited NO in a magnetic field

We investigate the experimental spectra of excited NO molecules in the diamagnetic regime and develop a quantitative semiclassical framework to account for the results. We show the dynamics can be interpreted in terms of classical orbits provided that in addition to the geometric orbits, diffractive effects are appropriately taken into account. We also show how individual orbits can be extracted from the experimental signal and use this procedure to reveal the first experimental manifestation of inelastic diffractive orbits.Comment: 4 fig

Birman-Wenzl-Murakami Algebra and the Topological Basis

In this paper, we use entangled states to construct 9x9-matrix representations of Temperley-Lieb algebra (TLA), then a family of 9x9-matrix representations of Birman-Wenzl-Murakami algebra (BWMA) have been presented. Based on which, three topological basis states have been found. And we apply topological basis states to recast nine-dimensional BWMA into its three-dimensional counterpart. Finally, we find the topological basis states are spin singlet states in special case.Comment: 11pages, 1 figur

Semiclassical evaluation of average nuclear one and two body matrix elements

Thomas-Fermi theory is developed to evaluate nuclear matrix elements averaged on the energy shell, on the basis of independent particle Hamiltonians. One- and two-body matrix elements are compared with the quantal results and it is demonstrated that the semiclassical matrix elements, as function of energy, well pass through the average of the scattered quantum values. For the one-body matrix elements it is shown how the Thomas-Fermi approach can be projected on good parity and also on good angular momentum. For the two-body case the pairing matrix elements are considered explicitly.Comment: 15 pages, REVTeX, 6 ps figures; changed conten

Contribution of forbidden orbits in the photoabsorption spectra of atoms and molecules in a magnetic field

In a previous work [Phys. Rev. A \textbf{66}, 0134XX (2002)] we noted a partial disagreement between quantum R-matrix and semiclassical calculations of photoabsorption spectra of molecules in a magnetic field. We show this disagreement is due to a non-vanishing contribution of processes which are forbidden according to the usual semiclassical formalism. Formulas to include these processes are obtained by using a refined stationary phase approximation. The resulting higher order in $\hbar$ contributions also account for previously unexplained ``recurrences without closed-orbits''. Quantum and semiclassical photoabsorption spectra for Rydberg atoms and molecules in a magnetic field are calculated and compared to assess the validity of the first-order forbidden orbit contributions.Comment: 12 pages, 6 figure

Studies in mineral metabolism. XXXII. The effect of different forms of sulphur in the diet upon the growth and wool production of sheep

(1) Details are presented of an experiment on the effects of sulphur and of compounds containing sulphur on the food consumption, weight increase, wool yield and disease of young wethers kept on a production ration for two years. (2) The sheep were fed in individual feeding boxes except for the hay which was given ad lib. (3) The supplements given were dosed daily except Sundays and were given as follows:-Group I: No supplement. Group II: Cystine. Group III: Sulphates. Group IV: KCNS. Group V: 5 gm. sulphur. Group VI: •12 gm. sulphur. (4) No significant effects of the supplements on the sheep could be detected after 12 months' supplementary feeding nor did the experimental groups differ significantly from the control group at the end of the experimental period. (5) The supplement of cystine had no effect on the quantity of wool produced. (6) The mortality and disease due to the presence of urinary calculi were apparently not associated with the supplements. (7) The analyses of the wool will be reported on in due course.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Phase transition in the transverse Ising model using the extended coupled-cluster method

The phase transition present in the linear-chain and square-lattice cases of the transverse Ising model is examined. The extended coupled cluster method (ECCM) can describe both sides of the phase transition with a unified approach. The correlation length and the excitation energy are determined. We demonstrate the ability of the ECCM to use both the weak- and the strong-coupling starting state in a unified approach for the study of critical behavior.Comment: 10 pages, 7 eps-figure

A Review of Unsupervised Spectral Target Analysis for Hyperspectral Imagery

One of great challenges in unsupervised hyperspectral target analysis is how to obtain desired knowledge in an unsupervised means directly from the data for image analysis. This paper provides a review of unsupervised target analysis by first addressing two fundamental issues, "what are material substances of interest, referred to as targets?" and "how can these targets be extracted from the data?" and then further developing least squares (LS)-based unsupervised algorithms for finding spectral targets for analysis. In order to validate and substantiate the proposed unsupervised hyperspectral target analysis, three applications in endmember extraction, target detection and linear spectral unmixing are considered where custom-designed synthetic images and real image scenes are used to conduct experiments