4,038 research outputs found
THE ANALYSIS OF FIVE ELECTRONIC EMISSION SYSTEMS OF NIOBIUM NITRIDE (NbN) IN THE REGION 5000{\AA} – 6200{\AA}
No full textK. H. Rao and T. M. Dunn, Nature 222, 266 (1969). J. L. Femenias, C. Athenour, and T. M. Dunn, J. Chem. Phys. 63, 2861 (1975).Author Institution:Niobium nitride emission systems have been found at 5l37{\AA}, 5582{\AA}, 5740{\AA}, 5840{\AA}, 5860{\AA}, in addition to the already systems with subbands at 5930{\AA}, 6043{\AA}, and 6192{\AA}. Most of These systems show marked nuclear hyperfine structure of the rotational lines add this has been of assistance in the analysis of all of the systems. Systems of triplet-triplet, singlet-singlet and singlet-triplet are all present and the hyperfine structure also allows assignment of the ground and excited state electron configuration to be made with some confidence
Asymptotic convergence analysis and influence of initial guesses on composite Anderson acceleration
No full textAlthough Anderson acceleration AA(m) has been widely used to speed up nonlinear solvers, most authors are simply using and studying the stationary version of Anderson acceleration. The behavior and full potential of the non-stationary version of Anderson acceleration methods remain an open question. Motivated by the hybrid linear solver GMRESR (GMRES Recursive), we recently proposed a set of non-stationary Anderson acceleration algorithms with dynamic window sizes AA(m,AA(n)) for solving both linear and nonlinear problems. Significant gains are observed for our proposed algorithms but these gains are not well understood. In the present work, we first consider the case of using AA(m,AA(1)) for accelerating linear fixed-point iteration and derive the polynomial residual update formulas for non-stationary AA(m,AA(1)). Like stationary AA(m), we find that AA(m,AA(1)) with general initial guesses is also a multi-Krylov method and possesses a memory effect. However, AA(m,AA(1)) has higher order degree of polynomials and a stronger memory effect than that of AA(m) at the k-th iteration, which might explain the better performance of AA(m,AA(1)) compared to AA(m) as observed in our numerical experiments. Moreover, we further study the influence of initial guess on the asymptotic convergence factor of AA(1, AA(1)). We show a scaling invariance property of the initial guess x for the AA(1,AA(1)) method in the linear case. Then, we study the root-linear asymptotic convergence factor under scaling of the initial guess and we explicitly indicate the dependence of root-linear asymptotic convergence factors on the initial guess. Lastly, we numerically examine the influence of the initial guess on the asymptotic convergence factor of AA(m) and AA(m,AA(n)) for both linear and nonlinear problems.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public
TWO-PHOTON ABSORPTION AS A QUENCHING MECHANISM FOR STIMULATED RAMAN SCATTERING OF LASER RADIATION
No full textAuthor Institution: Electro-Optical Systems IncorporatedThis work was supported in part by the Air Force Avionics Laboratory, Research and Technology Division, Air Force Systems Command, U. S. Air Force. J. A. Giordmaine and J. A. Howe, Phys. Rev. Letters 11, 207 (1963). M. El-Sayed, F. M. Johnson and J. A. Duardo, J. Chem, Phys., to be published. J. A. Duardo and F. M. Johnson, J. Chem, Phys., to be published.Most investigations of stimulated Raman scattering involve the use of giant-pulsed ruby laser radiation . With the exception of the materials commonly used as scattering samples are free of absorption at wavelengths corresponding to two-photon energies () of this excitation source. However, when the second harmonic radiation () of the giant-pulsed neodymium laser is used, two-photon absorption becomes energetically possible for seattering materials such as benzene, and its substituted derivatives, and the alkyl Theoretical and experimental evidence will be presented which tends to confirm that, for those systems in which the selection rules for two-photon absorption are satisfied, two-photon absorption can occur to such an extent that it completely quenches the SRS process. On the other hand, for some materials which are transparent at , e.g., hexane, cyclohexane, acetonitrile, there is evidence that the radiation is more efficient than the radiation in the production of SRS
Open Access to Peer-Reviewed Research through Author/Institution Self-Archiving: Maximizing Research Impact by Maximizing Online Access
No full textAll refereed journals will soon be available online; most of them already are. This means that anyone will be able to access them from any networked desk-top. The literature will all be interconnected by citation, author, and keyword/subject links, allowing for unheard-of power and ease of access and navigability. Successive drafts of pre-refereeing preprints will be linked to the official refereed draft, as well as to any subsequent corrections, revisions, updates, comments, responses, and underlying empirical databases, all enhancing the self-correctiveness, interactivity and productivity of scholarly and scientific research and communication in remarkable new ways. New scientometric indicators of digital impact are also emerging <http://opcit.eprints.org> to chart the online course of knowledge. But there is still one last frontier to cross before science reaches the optimal and the inevitable: Just as there is no longer any need for research or researchers to be constrained by the access-blocking restrictions of paper distribution, there is no longer any need to be constrained by the impact-blocking financial fire-walls of Subscription/Site-License/Pay-Per-View (S/L/P) tolls for this give-away literature. Its author/researchers have always donated their research reports for free (and its referee/researchers have refereed for free), with the sole goal of maximizing their impact on subsequent research (by accessing the eyes and minds of fellow-researchers, present and future) and hence on society. Generic (OAi-compliant) software is now available free so that institutions can immediately create Eprint Archives in which their authors can self-archive all their refereed papers for free for all forever <http://www.eprints.org/>. These interoperable Open Archives <http://www.openarchives.org> will then be harvested into global, jointly searchable "virtual archives" (e.g., <http://arc.cs.odu.edu/>). "Scholarly Skywriting" in this PostGutenberg Galaxy will be dramatically (and measurably) more interactive and productive, spawning its own new digital metrics of productivity and impact, allowing for an online "embryology of knowledge.
Aspects of the fantastic grotesque in the works of V. Mayakovsky, M. Bulgakov and E. Schwartz
No full textThe grotesque in Soviet literature ls a field of study whlch has been neglected both in the Soviet Union and the West. In the Soviet Union interest in the grotesque reached a high point in the formalist criticism of the twenties, since the grotesque is one of the most clearly expressed devices of defamiliarisation. After a long period of taboo a revival takes place in the sixties. An attempt has been made in thls thesis to define the grotesque and to apply this definition to the works of V. Mayakovaky, M. Bulgakoy and E. Schwartz. We are primarily concerned with the structural features of their grotesque and the relationshlp of these to comedy and tragedy. While very similar in its structure and its use of comedy devices, the grotesque of all three writers differs substantially in its nature. We have attempted to establish the reasons for the differences and to define the function of their grotesque
Paratransitive algebras of linear operators
No full textIn this article we study a natural weakening – which we refer to as paratransitivity – of the well-known notion of transitivity of an algebra AA of linear operators acting on a finite-dimensional vector space VV. Given positive integers k and m, we shall say that such an algebra AA is (k,m)(k,m)-transitive if for every pair of subspaces W1W1 and W2W2 of VV of dimensions k and m respectively, we have AW1∩W2≠{0}AW1∩W2≠{0}. We consider the structure of minimal (k,m)(k,m)-transitive algebras and explore the connection of this notion to a measure of largeness for invariant subspaces of A
Supporting safe motherhood : a review of financial trends : summary
No full textAn estimated 500,000 women, 99 percent of them from the developing world, die each year from pregnancy-related causes. About three quarters of these deaths are the direct result of obstetrical complications -- hemorrhage, infection, toxemia, obstructed labor, and abortion (under primitive and illegal conditions). An estimated equivalent number of infants do not survive their mother's death. For surviving mothers, the consequences of pregnancy have a severe impact on health and family economics. The strategy for safe motherhood is based on two approaches. First, the encouragement of activities that indirectly improve maternal health. These include education, policies to improve women's rights and working conditions, health care and nutrition, transportation and communication systems, water and sanitation facilities, and increases in family income and food production. The second approach targets activities to reduce maternal deaths. These activities include reducing unwanted pregnancies through the provision of family planning services, and through national policies that recognize the importance of this issue. A second objective is to reduce the risks of pregnancy through providing community-based family planning and prenatal services to identify high-risk cases'adequate referral services for the complications of pregnancy, and communication and transport systems to support patient referral procedures.Health Monitoring&Evaluation,Health Systems Development&Reform,Gender and Health,Early Child and Children's Health,Agricultural Knowledge&Information Systems
Musicking Poulenc's ruins in Stellenbosch
No full textCITATION: Pauw, M. 2017. Musicking Poulenc's ruins in Stellenbosch. Acta Academica, 49(2):68-94, doi:10.18820/24150479/aa49i2.4.The original publication is available at http://journals.ufs.ac.za/index.php/aa/indexThis article investigates several performances of a flute solo (written by Francis Poulenc) as presented by the author in Stellenbosch, South Africa.1 Un joueur de flûte berce les ruines was written in the 1940s, ‘discovered’ in the late 1990s by Ransom Wilson and published in 2000 by Chester. The title of the solo carries an unidentified reference to the ‘serenading’ of ‘ruins’. This title, the shrouded originating circumstances of Poulenc’s composition, as well as its only-recent appearance, are central to the subsequent argument for music curations ‘after sound’ (Barrett). Douglas Barrett’s notion of ‘critical music’ directs this reflexive article enquiry. Curations ‘after sound’ take place when music compositions operate on platforms of socio-critical arts practice. ‘Musicking’, proposed by Christopher Small, probes the question: ‘What’s really going on here?’ The article asks this question by reflecting on the intentional
juxtapositions of time, place and context that occurred when the author presented the solo on performances respectively titled ‘Die Vlakte’, ‘Roesdorp’, and
‘Portrait’. The article analyses aspects of films by Aryan Kaganof (2016) that responded to the ‘Roesdorp’ performance and suggests that the films manifest as Rancière-ian ‘aesthetics as politics’: they expose and intertwine layers of complicity, critique, confusion and care. A fleeting juxtaposition of silence and echo as metaphorical extensions to the notion of ‘after sound’ concludes this article enquiry.http://journals.ufs.ac.za/index.php/aa/article/view/3352Publisher's versio
Paratransitive algebras of linear operators II
No full textIn this paper, the authors continue the analysis, first undertaken in Livshits et al. (2013) [2], of algebras AA of linear transformations on an n-dimensional complex vector space VV which have the property that if WW is a k-dimensional subspace of VV, then the image of WW under the action of the algebra AA intersects every m-dimensional subspace of VV. Here, we study the structure of such algebras under the stronger assumption that the image of WW under AA has codimension equal to m−1m−1 for all subspaces WW of dimension k in V
The art of speaking /
No full textSignatures: A-K⁸, L², R₃₋₈, S-Z⁸, Aa-Ll⁸, M⁴ (A₁ blank; Cc₃, M₁ incorrectly signed C₃, M, respectively; M₂₋₄, advertisements)Also attributed to Antoine Arnauld and Pierre Nicole, who wrote The art of thinking.Title within double line border.Translation of the author's De l'art de parler.WingMode of access: Internet
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