1,721,096 research outputs found
Reply To "comment On 'photoionization Of Helium Atoms Irradiated With Intense Vacuum Ultraviolet Free-electron Laser Light. Part I. Experimental Study Of Multiphoton And Single-photon Processes'"
Full text linkWe do not agree with the conclusion of the Comment by Charalambidis questioning our observation of two-photon ionization of helium by intense radiation with 13 eV photons from a vuv free-electron laser. Two-photon ionization is clearly established by the detection of low-energy photoelectrons at ∼1.7 eV, which agrees very well with the expected energy for a two-photon ionization process. © 2006 The American Physical Society.743Laarmann, T., De Castro, A.R.B., Schulz, J., Wabnitz, H., Möller, T., (2005) Phys. Rev. A, 72, p. 023409. , PLRAAN. 1050-2947. 10.1103/PhysRevA.72.023409Ayvazyan, V., Baboi, N., Bohnet, I., Brinkmann, R., Castellano, M., Castro, P., Catani, L., Zapfe, K., (2002) Phys. Rev. Lett., 88, p. 104802. , PRLTAO. 0031-9007. 10.1103/PhysRevLett.88.104802Ayvazyan, V., Baboi, N., Bähr, J., Balandin, V., Beutner, B., Brandt, A., Bohnet, I., Schreiber H, -J., (2006) Eur. Phys. J. D, 37, p. 297. , EPJDF6. 1434-6060. 10.1140/epjd/e2005-00308-1Wabnitz, H., Bittner, L., De Castro, A.R.B., Döhrmann, R., Gürtler, P., Laarmann, T., Laasch, W., Yurkov, M., (2002) Nature (London), 420, p. 482. , NATUAS. 0028-0836. 10.1038/nature01197Laarmann, T., De Castro, A.R.B., Gürtler, P., Laasch, W., Schulz, J., Wabnitz, H., Möller, T., (2004) Phys. Rev. Lett., 92, p. 143401. , PRLTAO. 0031-9007. 10.1103/PhysRevLett.92.143401Laarmann, T., Rusek, M., Wabnitz, H., Schulz, J., De Castro, A.R.B., Gürtler, P., Laasch, W., Möller, T., (2005) Phys. Rev. Lett., 95, p. 063402. , PRLTAO. 0031-9007. 10.1103/PhysRevLett.95.063402Wabnitz, H., De Castro, A.R.B., Gürtler, P., Laarmann, T., Laasch, W., Schulz, J., Möller, T., (2005) Phys. Rev. Lett., 94, p. 023001. , PRLTAO. 0031-9007. 10.1103/PhysRevLett.94.023001Santra, R., Greene, C.H., (2004) Phys. Rev. A, 70, p. 053401. , PLRAAN 1050-2947 10.1103/PhysRevA.70.053401Tzallas, P., Charalambidis, D., Papadogiannis, N.A., Witte, K., Tsakiris, G.D., (2003) Nature (London), 426, p. 267. , NATUAS 0028-0836 10.1038/nature02091Papadogiannis, N.A., Nikolopoulos, L.A.A., Charalambidis, D., Tsakiris, G.D., Tzallas, P., Witte, K., (2003) Appl. Phys. B, 76, p. 721. , APDOEM 0946-2171Papadogiannis, N.A., Nikolopoulos, L.A.A., Charalambidis, D., Tsakiris, G.D., Tzallas, P., Witte, K., (2003) Phys. Rev. Lett., 90, p. 133902. , PRLTAO 0031-9007 10.1103/PhysRevLett.90.133902De Castro, A.R.B., Laarmann, T., Schulz, J., Wabnitz, H., Möller, T., (2005) Phys. Rev. A, 72, p. 023410. , PLRAAN. 1050-2947. 10.1103/PhysRevA.72.02341
Depth-selective data analysis for time-domain fNIRS: Moments vs. time windows
Full text linkTime-domain measurements facilitate the elimination of the influence of extracerebral, systemic effects, a key problem in functional near-infrared spectroscopy (fNIRS) of the adult human brain. The analysis of measured time-of-flight distributions of photons often relies on moments or time windows. However, a systematic and quantitative characterization of the performance of these measurands is still lacking. Based on perturbation simulations for small localized absorption changes, we compared spatial sensitivity profiles and depth selectivity for moments (integral, mean time of flight and variance), photon counts in time windows and their ratios for different time windows. The influence of the instrument response function (IRF) was investigated for all measurands and for various source-detector separations. Variance exhibits the highest depth selectivity among the moments. Ratios of photon counts in different late time windows can achieve even higher selectivity. An advantage of moments is their robustness against the shape of the IRF and instrumental drifts
An adaptive scheme for diffuse-optical tomography based on combined structured-light illumination and single-pixel camera detection
Full text linkDiffuse Optical Tomography (DOT) is a tool for 3D reconstruction of absorption and scattering inside a tissue. Typically, this method requires a dense distribution of sources and detectors, thus hampering the possibility of fully exploring a time-resolved detection. Recently, techniques based on structured-light illumination and compressing detection have been developed, opening the possibility of fully exploiting a source/detector spatial modulation for compression at the measurement stage. Here we propose a combined Continuous-Wave (CW) and time-domain (TD) adaptive scheme based on the singular-value decomposition (SVD) for optimal-patterns calculation. Patterns are firstly computed based on a fast acquisition via a CCD, and consequently projected for time-resolved measurements
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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