5,887 research outputs found
Improved I-V characteristics of SiC MOSFETs by TCE thermal gate oxidation
The effects of TCE (trichloroethylene) thermal gate oxidation on the electrical characteristics of SiC MOSFETs are investigated. It is found that TCE thermal gate oxidation can improve the I d-V d characteristics, increase the field-effect mobility, and reduce the threshold voltage and sub-threshold slope of the devices. The better device characteristics are believed to be attributed to the TCE-induced reductions of charges in the gate oxide and traps at the SiO/SiO 2 interface, and also to the gettering of charged impurities and reduction of physical defects by the chlorine incorporated in the gate oxide. ©2005 IEEE.published_or_final_versio
Unification of Radio Galaxies and Their Accretion/Jet Properties
We investigate the relation between black hole mass, M_bh, and jet power,
Q_jet, for a sample of BL Lacs and radio quasars. We find that BL Lacs are
separated from radio quasars by the FR I/II dividing line in M_bh-Q_jet plane,
which strongly supports the unification scheme of FR I/BL Lac and FR II/radio
quasar. The Eddington ratio distribution of BL Lacs and radio quasars exhibits
a bimodal nature with a rough division at L_bol/L_Edd~0.01, which imply that
they may have different accretion modes. We calculate the jet power extracted
from advection dominated accretion flow (ADAF), and find that it require
dimensionless angular momentum of black hole j~0.9-0.99 to reproduce the
dividing line between FR I/II or BL Lac/radio quasar if dimensionless accretion
rate mdot=0.01 is adopted, which is required by above bimodal distribution of
Eddington ratios. Our results suggest that black holes in radio galaxies are
rapidly spinning.Comment: To appear JAA in Jun
Quantifying Inactive Lithium in Lithium Metal Batteries
Inactive lithium (Li) formation is the immediate cause of capacity loss and
catastrophic failure of Li metal batteries. However, the chemical component and
the atomic level structure of inactive Li have rarely been studied due to the
lack of effective diagnosis tools to accurately differentiate and quantify Li+
in solid electrolyte interphase (SEI) components and the electrically isolated
unreacted metallic Li0, which together comprise the inactive Li. Here, by
introducing a new analytical method, Titration Gas Chromatography (TGC), we can
accurately quantify the contribution from metallic Li0 to the total amount of
inactive Li. We uncover that the Li0, rather than the electrochemically formed
SEI, dominates the inactive Li and capacity loss. Using cryogenic electron
microscopies to further study the microstructure and nanostructure of inactive
Li, we find that the Li0 is surrounded by insulating SEI, losing the electronic
conductive pathway to the bulk electrode. Coupling the measurements of the Li0
global content to observations of its local atomic structure, we reveal the
formation mechanism of inactive Li in different types of electrolytes, and
identify the true underlying cause of low Coulombic efficiency in Li metal
deposition and stripping. We ultimately propose strategies to enable the highly
efficient Li deposition and stripping to enable Li metal anode for next
generation high energy batteries
Transiting Disintegrating Planetary Debris around WD 1145+017
More than a decade after astronomers realized that disrupted planetary
material likely pollutes the surfaces of many white dwarf stars, the discovery
of transiting debris orbiting the white dwarf WD 1145+017 has opened the door
to new explorations of this process. We describe the observational evidence for
transiting planetary material and the current theoretical understanding (and in
some cases lack thereof) of the phenomenon.Comment: Invited review chapter. Accepted March 23, 2017 and published October
7, 2017 in the Handbook of Exoplanets. 15 pages, 10 figure
Modes of Foreign Entry under Asymmetric Information about Potential Technology Spillovers
This paper studies the effect of technology spillovers on the entry decision of a multinational enterprise into a foreign market. Two alternative entry modes for a foreign direct investment are considered: Greenfield investment versus acquisition. We find that with quantity competition a spillover makes acquisitions less attractive, while with price competition acquisitions become more attractive. Asymmetric information about potential spillovers always reduces the number of
acquisitions independently of whether the host country or the entrant has private information. Interestingly, we find that asymmetric information always hurts the entrant, while it sometimes is in favor of the host country
Composite Leptoquarks at the LHC
If electroweak symmetry breaking arises via strongly-coupled physics, the
observed suppression of flavour-changing processes suggests that fermion masses
should arise via mixing of elementary fermions with composite fermions of the
strong sector. The strong sector then carries colour charge, and may contain
composite leptoquark states, arising either as TeV scale resonances, or even as
light, pseudo-Nambu-Goldstone bosons. The latter, since they are coupled to
colour, get a mass of the order of several hundred GeV, beyond the reach of
current searches at the Tevatron. The same generic mechanism that suppresses
flavour-changing processes suppresses leptoquark-mediated rare processes,
making it conceivable that the many stringent constraints may be evaded. The
leptoquarks couple predominantly to third-generation quarks and leptons, and
the prospects for discovery at LHC appear to be good. As an illustration, a
model based on the Pati-Salam symmetry is described, and its embedding in
models with a larger symmetry incorporating unification of gauge couplings,
which provide additional motivation for leptoquark states at or below the TeV
scale, is discussed.Comment: 10 pp, version to appear in JHE
SIZER: A Dataset and Model for Parsing 3D Clothing and Learning Size Sensitive 3D Clothing
While models of 3D clothing learned from real data exist, no method can
predict clothing deformation as a function of garment size. In this paper, we
introduce SizerNet to predict 3D clothing conditioned on human body shape and
garment size parameters, and ParserNet to infer garment meshes and shape under
clothing with personal details in a single pass from an input mesh. SizerNet
allows to estimate and visualize the dressing effect of a garment in various
sizes, and ParserNet allows to edit clothing of an input mesh directly,
removing the need for scan segmentation, which is a challenging problem in
itself. To learn these models, we introduce the SIZER dataset of clothing size
variation which includes different subjects wearing casual clothing items
in various sizes, totaling to approximately 2000 scans. This dataset includes
the scans, registrations to the SMPL model, scans segmented in clothing parts,
garment category and size labels. Our experiments show better parsing accuracy
and size prediction than baseline methods trained on SIZER. The code, model and
dataset will be released for research purposes.Comment: European Conference on Computer Vision 202
Quality of reporting of trial abstracts needs to be improved: using the CONSORT for abstracts to assess the four leading Chinese medical journals of traditional Chinese medicine
<p>Abstract</p> <p>Background</p> <p>Due to language limitations, the abstract of journal article may be the only way for people of non-Chinese speaking countries to know about trials in traditional Chinese medicine (TCM). However, little is known about the reporting quality of these trial abstracts. Our study is to assess the reporting quality of abstracts of randomized controlled trials (RCT) published in four leading Chinese medical journals of TCM, and to identify any differences in reporting between the Chinese and English version of the same abstract publication.</p> <p>Method</p> <p>Two reviewers hand-searched the Chinese Journal of Integrated Traditional and Western Medicine, the Chinese Journal of Integrative Medicine, the China Journal of Chinese Materia Medica and the Chinese Acupuncture & Moxibustion for all abstracts of RCTs published between 2006 and 2007. Two reviewers independently assessed the reporting quality of the Chinese and English version of all eligible abstracts based on a modified version of the CONSORT for reporting randomised trials in journal and conference abstracts (CONSORT for abstracts).</p> <p>Results</p> <p>We identified a total of 345 RCTs of TCM with both a Chinese and English abstract. More than half of Chinese abstracts reported details of the trial participants (68%; 234/345), control group intervention (52%; 179/345), the number of participants randomized (73%; 253/345) and benefits when interpreting the trial results (55%; 190/345). Reporting of methodological quality or key features of trial design and trial results were poor; only 2% (7/345) included details of the trial design, 3% (11/345) defined the primary outcome, 5% (17/345) described the methods of random sequence generation, and only 4% (13/345) reported the number of participants analyzed. No abstracts provided details on allocation concealment and trial registration. The percentage agreement in reporting (between the Chinese and English version of the same abstract) ranged from 84% to 100% across individual checklist item.</p> <p>Conclusion</p> <p>The reporting quality of abstracts of RCTs published in these four TCM journals needs to be improved. Since none of the four journals adopted CONSORT for Abstracts, we hope that the introduction and adoption of CONSORT for Abstracts by TCM journals will lead to an improvement in reporting quality.</p
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