1,335 research outputs found
Electronic transitions of cobalt monoboride
Electronic transition spectrum of cobalt monoboride (CoB) in the visible region between 495 and 560 nm has been observed and analyzed using laser-induced fluorescence spectroscopy. CoB molecule was produced by the reaction of laser-ablated cobalt atom and diborane (B 2H 6) seeded in argon. Fifteen vibrational bands with resolved rotational structure have been recorded, which included transitions of both Co 10B and Co 11B isotopic species. Our analysis showed that the observed transition bands are ΔΩ=0 transitions with Ω″ = 2 and Ω″ = 3 lower states. Four transition systems have been assigned, namely, the [18.1] 3Π2-X 3Δ 2, the [18.3]φ 3φ 3-X 3Δ 3, the [18.6]3-X 3Δ 3, and the [19.0]2-X 3Δ 2 systems. The bond length, r o, of the X 3Δ 3 state of CoB is determined to be 1.705 Å. The observed rotational lines showed unresolved hyperfine structure arising from the nuclei, which conforms to the Hunds case (a β) coupling scheme. This work represents the first experimental investigation of the CoB spectrum. © 2011 American Institute of Physics.published_or_final_versio
Iterative algorithms based on decoupling of deblurring and denoising for image restoration
In this paper, we propose iterative algorithms for solving image restoration problems. The iterative algorithms are based on decoupling of deblurring and denoising steps in the restoration process. In the deblurring step, an efficient deblurring method using fast transforms can be employed. In the denoising step, effective methods such as the wavelet shrinkage denoising method or the total variation denoising method can be used. The main advantage of this proposal is that the resulting algorithms can be very efficient and can produce better restored images in visual quality and signalto-noise ratio than those by the restoration methods using the combination of a data-fitting term and a regularization term. The convergence of the proposed algorithms is shown in the paper. Numerical examples are also given to demonstrate the effectiveness of these algorithms. © 2008 Society for Industrial and Applied Mathematics.published_or_final_versio
Block diagonal and schur complement preconditioners for block-toeplitz systems with small size blocks
In this paper we consider the solution of Hermitian positive definite block-Toeplitz systems with small size blocks. We propose and study block diagonal and Schur complement preconditioners for such block-Toeplitz matrices. We show that for some block-Toeplitz matrices, the spectra of the preconditioned matrices are uniformly bounded except for a fixed number of outliers where this fixed number depends only on the size of the block. Hence, conjugate gradient type methods, when applied to solving these preconditioned block-Toeplitz systems with small size blocks, converge very fast. Recursive computation of such block diagonal and Schur complement preconditioners is considered by using the nice matrix representation of the inverse of a block-Toeplitz matrix. Applications to block-Toeplitz systems arising from least squares filtering problems and queueing networks are presented. Numerical examples are given to demonstrate the effectiveness of the proposed method. © 2007 Society for Industrial and Applied Mathematics.published_or_final_versio
A hybrid algorithm for spatial and wavelet domain image restoration
The recent algorithm ForWaRD based on the two steps: (i) the Fourier domain deblurring and (ii) wavelet domain denoising, shows better restoration results than those using traditional image restoration methods. In this paper, we study other deblurring schemes in ForWaRD and demonstrate such two-step approach is effective for image restoration.published_or_final_versionS P I E Conference on Visual Communications and Image Processing 2005, Beijing, China, 12-15 July 2005. In Proceedings Of Spie - The International Society For Optical Engineering, 2005, v. 5960 n. 4, p. 59605V-1 - 59605V-
A New Triplet Transition of the V2 Molecule
Section: High resolution spectroscopy of molecules, including radicals, ions, complexes, molecules in nanostructurespostprin
Phylogenetic analysis of planarian collagens and their roles in regeneration
Poster Presentation - Theme 3: Development & stem cellsStem cells are regulated by the microenvironment or niche they reside in, which consists of growth factors, niche cells and the extracellular matrix. The ECM acts as both a structural component and as a reservoir for growth factors that are released upon degradation. During regeneration, stem cells in the planarian are activated to migrate and proliferate; however, the role of the ECM in stem cell regulation is still unclear. Analysis of an EST library of planarian transcripts revealed nine fibrillar-related collagen chains (DjCol1-9). Sequence and structural analysis ...postprin
Electronic transitions of iridium monoboride
Electronic transition spectrum of iridium monoboride in the spectral region between 400 and 545 nm has been recorded and analyzed using laser vaporization/reaction free jet expansion source and laser induced fluorescence spectroscopy. Thirteen vibrational bands belonging to four electronic transitions, namely the [18.8] 3Δ 3 - X 3Δ 3, [21.1] 3Φ 4 - X 3Δ 3, [22.8] 3Φ 3 - X 3Δ 3, and [22.4] 1Φ 3 - a 1Δ 2 transitions, have been identified and rotationally analyzed. Spectra of all four isotopic molecules were observed. © 2010 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex
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