9,650 research outputs found
Investigation of the Physical and Electronic Properties of Indium Doped Zinc Oxide Nanofibers Synthesized by Electrospinning
Nanostructured metal oxides and particularly nanofiber based materials can provide significant advances for the miniaturization of electronic, optoelectronic, photonic, sensor, and energy conversion devices with enhanced performance based on their unique material properties. In this study, indium doped zinc oxide (IZO) nanofibers were synthesized by electrospinning. These nanofibers have diameters in the range 50-100 nm. The effects of indium addition on the structural, optical, and electrical properties of the zinc oxide nanofiber matrices were investigated. The IZO nanofibers undergo significant changes in their optical and electrical properties compared to undoped zinc oxide nanofibers
X-ray magnetic circular dichroism characterization of GaN/Ga1-xMnxN digital ferromagnetic heterostructure
We have investigated the magnetic properties of a GaN/Ga1-xMnxN (x = 0.1)
digital ferromagnetic heterostructure (DFH) showing ferromagnetic behavior
using soft x-ray absorption spectroscopy (XAS) and x-ray magnetic circular
dichroism (XMCD). The Mn L2,3-edge XAS spectra were similar to those of
Ga1-xMnxN random alloy thin films, indicating a substitutional doping of high
concentration Mn into GaN. From the XMCD measurements, it was revealed that
paramagnetic and ferromagnetic Mn atoms coexisted in the Ga1-xMnxN digital
layers. The ferromagnetic moment per Mn atom estimated from XMCD agreed well
with that estimated from SQUID measurements. From these results, we conclude
that the ferromagnetic behavior of the GaN/Ga1-xMnxN DFH sample arises only
from substitutional Mn2+ ions in the Ga1-xMnxN digital layers and not from
ferromagnetic precipitates. Subtle differences were also found from the XMCD
spectra between the electronic states of the ferromagnetic and paramagnetic
Mn2+ ions.Comment: 12 pages, 8 figure
What guidance are researchers given on how to present network meta-analyses to end-users such as policymakers and clinicians? A systematic review
© 2014 Sullivan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Introduction: Network meta-analyses (NMAs) are complex methodological approaches that may be challenging for non-technical end-users, such as policymakers and clinicians, to understand. Consideration should be given to identifying optimal approaches to presenting NMAs that help clarify analyses. It is unclear what guidance researchers currently have on how to present and tailor NMAs to different end-users. Methods: A systematic review of NMA guidelines was conducted to identify guidance on how to present NMAs. Electronic databases and supplementary sources were searched for NMA guidelines. Presentation format details related to sample formats, target audiences, data sources, analysis methods and results were extracted and frequencies tabulated. Guideline quality was assessed following criteria developed for clinical practice guidelines. Results: Seven guidelines were included. Current guidelines focus on how to conduct NMAs but provide limited guidance to researchers on how to best present analyses to different end-users. None of the guidelines provided reporting templates. Few guidelines provided advice on tailoring presentations to different end-users, such as policymakers. Available guidance on presentation formats focused on evidence networks, characteristics of individual trials, comparisons between direct and indirect estimates and assumptions of heterogeneity and/or inconsistency. Some guidelines also provided examples of figures and tables that could be used to present information. Conclusions: Limited guidance exists for researchers on how best to present NMAs in an accessible format, especially for non-technical end-users such as policymakers and clinicians. NMA guidelines may require further integration with end-users' needs, when NMAs are used to support healthcare policy and practice decisions. Developing presentation formats that enhance understanding and accessibility of NMAs could also enhance the transparency and legitimacy of decisions informed by NMAs.The Canadian Institute of Health Research (CIHR) Drug Safety and Effectiveness Network (Funding reference number – 116573)
Nontrivial Polydispersity Exponents in Aggregation Models
We consider the scaling solutions of Smoluchowski's equation of irreversible
aggregation, for a non gelling collision kernel. The scaling mass distribution
f(s) diverges as s^{-tau} when s->0. tau is non trivial and could, until now,
only be computed by numerical simulations. We develop here new general methods
to obtain exact bounds and good approximations of . For the specific
kernel KdD(x,y)=(x^{1/D}+y^{1/D})^d, describing a mean-field model of particles
moving in d dimensions and aggregating with conservation of ``mass'' s=R^D (R
is the particle radius), perturbative and nonperturbative expansions are
derived.
For a general kernel, we find exact inequalities for tau and develop a
variational approximation which is used to carry out the first systematic study
of tau(d,D) for KdD. The agreement is excellent both with the expansions we
derived and with existing numerical values. Finally, we discuss a possible
application to 2d decaying turbulence.Comment: 16 pages (multicol.sty), 6 eps figures (uses epsfig), Minor
corrections. Notations improved, as published in Phys. Rev. E 55, 546
Stamp transferred suspended graphene mechanical resonators for radio-frequency electrical readout
We present a simple micromanipulation technique to transfer suspended
graphene flakes onto any substrate and to assemble them with small localized
gates into mechanical resonators. The mechanical motion of the graphene is
detected using an electrical, radio-frequency (RF) reflection readout scheme
where the time-varying graphene capacitor reflects a RF carrier at f=5-6 GHz
producing modulation sidebands at f +/- fm. A mechanical resonance frequency up
to fm=178 MHz is demonstrated. We find both hardening/softening Duffing effects
on different samples, and obtain a critical amplitude of ~40 pm for the onset
of nonlinearity in graphene mechanical resonators. Measurements of the quality
factor of the mechanical resonance as a function of DC bias voltage Vdc
indicate that dissipation due to motion-induced displacement currents in
graphene electrode is important at high frequencies and large Vdc
Enhancement of the Higgs pair production at LHC; the MSSM and extra dimension effects
The neutral Higgs pair production at the LHC is studied in the MSSM, the
large extra dimensional (ADD) model and the Randall-Sundrum (RS) model, where
the total cross section can be significantly enhanced compared to that in the
SM. The , invariant mass and rapidity distributions of each model have
been shown to be distinctive: The ADD model raises the and invariant mass
distributions at high scales of and invariant mass; in the RS model
resonant peaks appear after the SM contribution dies away; the SM and the MSSM
distributions drop rapidly at those high scales; in the ADD and the RS models
the rapidity distributions congregate more around the center. It is concluded
that various distributions of the Higgs pair production at the LHC with
restrictive kinematic cuts would provide one of the most robust signals for the
extra dimensional effects.Comment: Revised version, 26 pages including 11 figures, ReVTe
Phosphate uptake and growth characteristics of transgenic rice with phosphate transporter 1 (OsPT1) gene overexpression under high phosphate soils
Farmers have used phosphate fertilizer to provide sufficient yields. However, overuse of phosphorus accumulate in soil and causes soil and water pollution. We evaluated the phosphate acquisition and growth characteristics of OsPT1 transgenic rice (OsPT1-OX, over-expressing the high affinity phosphate transporter 1) in high phosphate soils with different level of nitrogen fertilizer treatment to investigate its removal ability of excessive phosphate from soil. OsPT1-OX had shorter culm length but more tillers than those of wild-type plants in each soil conditions. Phosphate content per dry weight of OsPT1-OX was 1.8 times higher than that of wild-type under control fertilizer treated conditions. Although the dry weight of OsPT1-OX was not different from that of wild-type plants, whole plant phosphate content was 1.7 times higher than that of wild-type plants under control fertilizer conditions. Tiller number and phosphate content per dry weight of wild-type plants increased following high levels of phosphate application, but did not change following additional nitrogen application. Tiller number and phosphate content per dry weight of OsPT1-OX did not also change under the high phosphate condition, but increased following nitrogen application under similar conditions. Whole plant phosphate content was also highest under high nitrogen and high phosphate application conditions. These results suggest that OsPT1-OX may reduce phosphate content in soils containing excess phosphate and may be further effective under high nitrogen condition.Key words: Phosphate content, fertilizer treatment, phosphate transporter, rice, soil
- …