81,276 research outputs found
Evidence for erbium-erbium energy migration in erbium(III) bis(perfluoro-p-tolyl)phosphinate
Copyright 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
Letter from Arno B. Cammerer to J. R. Eakin
Letter from Arno B. Cammerer to J. R. Eakin describing the procedure for purchasing Bright Angel Trail
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Physical origin of Davydov splitting and resonant Raman spectroscopy of Davydov components in multilayer MoTe2
We 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]
Dispelling the Myths Behind First-author Citation Counts
We 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
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
The ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
Branching fraction and CP asymmetry of the decays B+→K0Sπ+ and B+→K0SK+
An analysis of B+ → K0
Sπ+ and B+ → K0
S K+ decays is performed with the LHCb experiment. The pp
collision data used correspond to integrated luminosities of 1 fb−1 and 2 fb−1 collected at centre-ofmass
energies of
√
s = 7 TeV and
√
s = 8 TeV, respectively. The ratio of branching fractions and the
direct CP asymmetries are measured to be B(B+ → K0
S K+
)/B(B+ → K0
Sπ+
) = 0.064 ± 0.009 (stat.) ±
0.004 (syst.), ACP(B+ → K0
Sπ+
) = −0.022 ± 0.025 (stat.) ± 0.010 (syst.) and ACP(B+ → K0
S K+
) =
−0.21 ± 0.14 (stat.) ± 0.01 (syst.). The data sample taken at
√
s = 7 TeV is used to search for
B+
c
→ K0
S K+ decays and results in the upper limit ( fc · B(B+
c
→ K0
S K+
))/( fu · B(B+ → K0
Sπ+
)) <
5.8 × 10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a ¯b
quark
into a B+
c or a B+ meson, respectively
Project Titan computers for R U Tan salons
E & T Consultants, Inc. received the objective of completing a project, by Professor Gary Moser, for the capstone project. With the aid of Professor Moser, our ITM 490A/B instructor, and our sponsor, Alan Guerra of Titan Computers for their client R U Tan Salons, we provided recommendations to fulfill the client’s request.
R U Tan Salons is a local tanning salon that began its business in Rancho Cordova, CA. From there, R U Tan Salons acquired two more salons located in downtown Sacramento, CA and Citrus Heights, CA. Because of its expanding business, R U Tan Salons is requesting to interconnect the three locations and merge the databases so that customers can use any salon. Additionally they wish to upgrade equipment and acquire a computerized cashiering system to enhance productivity as well as to simplify computer tasks.
The project sponsor, Alan Guerra, is the owner of Titan Computers. R U Tan Salons contracted with Alan to develop and implement the required system. In turn, Alan contracted with E & T Consultants, Inc. for their assistance as consultants in the development of a plan to implement their recommendations. The plan will demonstrate the network system, POS system, and software and hardware used that will allow employees and management to perform their job duties with ease by means of the user-friendly interfaces of the software.
However, due to changes in resources and sponsor requirements as of June 3, 2011, an alternative project procedure will be taken in accomplishing the sponsor’s request
A rapid method for the simulation of sloshing using a mathematical model based on the pendulum equation
A mathematical model for the rapid assessment of sloshing in faster than real time is developed using a phenomenological modelling approach with a pendulum equation. Based on observations of the consistent trajectory of the centre ofmass of a sloshing fluid, the imbalance force due to the displacement of the sloshing fluid is linked to the restoring force in the pendulum equation. The damping characteristics are replicated using a first and third-order damping model and impact dynamics are included using a modified impact potential. The equations are solved using a variable-order Adams–Bashforth–Moulton scheme and adequate error tolerances of the numerical scheme are established by reversing the direction of time marching. Solutions are obtained within 0.1% of real time. The proposed methodology is considered suitable for the fast time assessment of sloshing on Liquefied Natural Gas carriers, reduction of test matrices during gas carrier design and the simulation of coupled vessel-sloshing dynamics
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