70,446 research outputs found
Evidence for erbium-erbium energy migration in erbium(III) bis(perfluoro-p-tolyl)phosphinate
No full textCopyright 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Applied Physics Letters 92, 103303 (2008) and may be found at
Physical origin of Davydov splitting and resonant Raman spectroscopy of Davydov components in multilayer MoTe2
No full textWe systematically study the high-resolution and polarized Raman spectra of multilayer (ML) MoTe2. The layer-breathing (LB) and shear (C) modes are observed in the ultralow-frequency region, which are used to quantitatively evaluate the interlayer coupling in ML MoTe2 based on the linear chain model, in which only the nearest interlayer coupling is considered. The Raman spectra on three different substrates verify the negligible substrate effect on the phonon frequencies of ML MoTe2. Ten excitation energies are used to measure the high-frequency modes of N-layer MoTe2 (NL MoTe2; N is an integer). Under the resonant excitation condition, we observe N-dependent Davydov components in ML MoTe2, originating from the Raman-active A(1)' (A(1g)(2)) modes at similar to 172 cm(-1). More than two Davydov components are observed in NL MoTe2 for N > 4 by Raman spectroscopy. The N-dependent Davydov components are further investigated based on the symmetry analysis. A van der Waals model only considering the nearest interlayer coupling has been proposed to well understand the Davydov splitting of high-frequency A(1)' (A(1g)(2)) modes. The different resonant profiles for the two Davydov components in 3L MoTe2 indicate that proper excitation energy of similar to 1.8 - 2.2 eV must be chosen to observe the Davydov splitting in ML MoTe2. Our work presents a simple way to identify layer number of ultrathin MoTe2 flakes by the corresponding number and peak position of Davydov components. Our work also provides a direct evidence from Raman spectroscopy of how the nearest van der Waals interactions significantly affect the frequency of the high-frequency intralayer phonon modes in multilayer MoTe2 and expands the understanding on the lattice vibrations and interlayer coupling of transition metal dichalcogenides and other two-dimensional materials.National Basic Research Program of China [2013CB921901, 2012CB932703]; National Natural Science Foundation of China [11225421, 11434010, 11474277, 61125402, 51172004, 11474007]SCI(E)[email protected]; [email protected]
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Search for direct CP violation in D0→h−h+ modes using semileptonic B decays
No full textA search for direct CP violation in D0 → h-h+ (where h = K or π) is presented using data corresponding to an integrated luminosity of 1.0 fb-1 collected in 2011 by LHCb in pp collisions at a centre-of-mass energy of 7 TeV. The analysis uses D0 mesons produced in inclusive semileptonic b-hadron decays to the D0μX final state, where the charge of the accompanying muon is used to tag the flavour of the D0 meson. The difference in the CP-violating asymmetries between the two decay channels is measured to be ΔACP = ACP(K-K+) - ACP(π-π+) = (0.49± 0.30 (stat) ± 0.14 (syst))%
Miscellaneous correspondence from the H. B. Clawson papers, 1872-1895
No full textMiscellaneous Correspondence from the H. B. Clawson papers, 1872-1895: (1) Letter dated 24 December 1872 at Salt Lake City, Utah, by Robert Williams to Hiram B. Clawson, thanking him for gifts (1 page); (2) Letter dated 6 May 1878 at Liverpool, England, by Charles Nibley to Bradley Clawson (1 page); (3) Letter dated 21 December 1886? at Chicago, Illinois, by B. R. Wells of M.D. Wells & Company to Hiram B. Clawson, regretting missing him when he was in town (1 page); (4) Letter dated 2 March 1881 at Middlefield [State unknown] by Matthew Smith to "Mrs. Clawson" (Ellen S. Clawson, Hiram\u27s first wife) (2 pages); (5) Letter dated 29 January 1884 at South Bend, Indiana, by Mrs. G. Foote (probably mother of James Foote, who married Ellen\u27s daughter Georgia) to Mrs. [Ellen S.] Clawson, prior to the expected visit of Ivie Clawson (2 pages); (6) Letter dated 21 April 1881 at New York City by Titus B. Eldridge to H. B. Clawson, upon receiving a gift of the Book of Mormon (2 pages); (7) Letter dated 18 August 1891 at Hayden, Idaho, by "Ed" to Ivie Clawson at Soda Springs, Idaho, describing his travels from Salt Lake City through Idaho; (8) Letter dated 26 April 1892 at East Mill Creek by Nellie Fisher to Ellen Clawson, with questions about the history of "Primary" (2 pages); (9) Letter dated 29 March 1894 at San Francisco, California, by Florence [no surname given], to her cousin Ivie Clawson at Salt Lake City, Utah (4 pages); (10) Letter dated 23 August 1894 at Paris, Idaho, by Lilian Spencer to her cousin Ivie Clawson at Salt Lake City (3 pages); (11) Letter dated 1 January 1895 at Boston, Massachusetts, by Jean C. Thatcher to Ivie Clawson Greene, congratulating her on her marriage (pages); (12) Letter dated 13 April 1895 by Henry F. CLark, Manager of the Literary Bureau, Curtis Publishing Company, at Philadelphia, Pennsylvania, to E. C. Clawson, providing information on author Edward Bellamy; (13) Letter dated 6 April [no year] by John T. White to Ivie and Winnie Clawson; (14) Letter [undated] by Mary DeVol (?) at Council Bluffs to Mrs. [Ellen S.] Clawso
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Electroweak corrections to the decay H+ -> W(+)h in the minimal supersymmetric model
No full textWe calculate the O(alpha (ew)m(t(b))(2)/m(W)(2)) and O(alpha (ew)m(t(b))(4)/m(W)(4)) supersymmetric electroweak corrections to the process H+ --> W(+)h in the Minimal Supersymmetric Model. These corrections arise from the virtual effects of the third family quarks (top and bottom) and squarks (top-squark and bottom-squark). We find that for m(H+) > 200 GeV at low tan beta(less than or equal to 3), the corrections can increase the tree-level decay widths and the branching radios more than 20% and 40%, respectively. (C) 2001 Elsevier Science B.V. All rights reserved.Physics, MultidisciplinarySCI(E)4ARTICLE1-2101-11049
Figure 1 from: Yang B, Zhou S-S, Ding H-B, Li R, Maung KW, Tan Y-H (2018) Two new species of Trivalvaria (Annonaceae) from northern Myanmar. In: Jin X-H, Shui Y-M, Tan Y-H, Kang M (Eds) Plant diversity in Southeast Asia. PhytoKeys 94: 3-12. https://doi.org/10.3897/phytokeys.94.21553
No full textFigure 1 Trivalvaria rubra Y.H.Tan, S.S.Zhou & B.Yang, sp. nov. A Habitat B Branch with flowers (adaxial view) C Branch with flowers (abaxial view) D Male flower (abaxial view) E Flower bud (side view) F Female flower (abaxial view) G Flower (G1 Bracts; G2 Sepals; G3 Outer petals; G4 Inner petals; G5 Androphore) H Fruit. Photographed by Y.H. Tan, H.B. Ding and B. Yang
L(h,1,1)-Labeling of Outerplanar Graphs
No full textAn -labeling of a graph is an assignment of labels from the set of integers
to the vertices of the graph such that adjacent
vertices are assigned integers of at least distance apart
and all vertices of distance three or less must be assigned different labels.
%%(except for , where adjacent nodes may have the same label).
The aim of the -labeling problem is to minimize ,
denoted by and called \emph{span} of the -labeling.
As outerplanar graphs have bounded treewidth, the -labeling problem on outerplanar graphs can be exactly solved in , but the multiplicative factor depends on the maximum degree and is too big to be of practical use. %where the multiplicative constant is exponential in their maximum degree .
In this paper we give a linear time approximation algorithm for computing the more general -labeling for outerplanar graphs that is within additive constants of the optimum values
Figure 4 from: Ding H-B, Maw MB, Yang B, Bouamanivong S, Tan Y-H (2020) An updated checklist of Begonia (Begoniaceae) in Laos, with two new species and five new records. In: Jin X-H, Xia N-H, Tan Y-H (Eds) Plant diversity of Southeast Asia-II. PhytoKeys 138: 187-201. https://doi.org/10.3897/phytokeys.138.46718
No full textFigure 4 A–CBegonia lancangensis S.H. Huang: A habitat B staminate flower (front view) C staminate flower (back view) D–FBegonia sizemoreae Kiew: D habitat E staminate flower F pistillate flower G–IBegonia silletensis (A. DC.) C.B. Clarke subsp. mengyangensis M.C. Tebbitt & K.-Y. Guan: G habitat H inflorescence I staminate flower (front view). Photographed by H.B. Ding and Y.H. Tan
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