896 research outputs found
THEORETICAL CALCULATIONS OF HYPERFINE INTERACTIONS OF THE JAHN-TELLER DISTORTED SINGLE VACANCY IN SILICON
Physics, Condensed MatterSCI(E)1ARTICLE52605-26123
EFFECTS OF HYDROGEN ON AL/P-SI SCHOTTKY-BARRIER DIODES
Physics, AppliedSCI(E)18ARTICLE7641-6435
Relativistic charged balls
It is proven that the relativistic charged ball with its charge less than its mass (in natural units) cannot have a nonsingular static configuration while its radius approaches its external horizon size. This conclusion does not depend on the details of charge distribution and the equation of state. The involved assumptions are (i) the ball is made of perfect fluid; (ii) the energy density is everywhere non-negative.Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)7ARTICLE4571-5763
CHARACTERIZATION OF STAIN ETCHED POROUS SI WITH PHOTOLUMINESCENCE, ELECTRON-PARAMAGNETIC-RESONANCE, AND INFRARED-ABSORPTION SPECTROSCOPY
Porous Si (PS) layers are prepared by stain etching in a HF/NaNO2 solution on both p- and n-type crystal Si substrates, and are characterized by photoluminescence (PL), electron paramagnetic resonance (EPR), and infrared absorption (IR) spectroscopy. The PL spectra under 488 nm laser excitation exhibit a strong peak at 680-720 nm for various samples of different substrate parameters and remain stable upon aging in air or gamma irradiation; as-etched (approximately 20 min in air before measurement) and aged (for up to six months) samples show no detectable EPR signal but the gamma-irradiated samples show an isotropic g = 2.006 signal of peak-to-peak linewidth of 1.1 mT supporting an amorphous Si structure; the IR spectra show both hydrogen and oxygen related IR modes in the as-etched samples and the former decreases with aging time in air while the latter increases. Comparing our results with those of anodically etched PS samples we conclude that: (1) the PL peak position of the stain PS seems to be unique and stable as compared with that of the anodic PS varying in 620-830 nm; (2) the isotropic EPR signal of the stain PS reflects no crystallinity, in contrast with the anisotropic signal of the anodic PS; and (3) obvious oxidation in the as-etched stain PS is also in contrast with the nonobservation of oxygen-related IR modes in the as-etched anodic PS. We discuss the results in terms of structural properties and PL mechanism of PS.Physics, AppliedSCI(E)8NOTE127615-76177
Radiation-induced root surface caries restored with glass-ionomer cement placed in conventional and ART cavity preparations: Results at two years
The document attached has been archived with permission from the Australian Dental Association (8th Jan 2008). An external link to the publisher’s copy is included.Background: There are no published studies comparing the clinical performances of more-viscous glass-ionomer cement (GIC) restorations when placed using conventional and atraumatic restorative treatment (ART) cavity preparation methods to restore root surface caries. Methods: One dentist used encapsulated Fuji IX GP and Ketac-Molar to restore 72 conventional and 74 ART cavity preparations for 15 patients who had received cervicofacial radiation therapy. Two assessors evaluated the restorations at six, 12, and 24 months for retention, marginal defects and surface wear, and recurrent caries. Results: After two years, the cumulative restoration successes were 65.2 per cent for the conventional and 66.2 per cent for the ART cavity preparations, without statistical or clinical significance (P>0.50). Restoration dislodgement accounted for 82.8 per cent and marginal defects for 17.2 per cent of all failures. There were no instances of unsatisfactory restoration wear or recurrent caries observed. Teeth with three or more restored cervical surfaces accounted for 79.3 per cent of all failures (P<0.0001). Conclusions: For root surface caries restored with GIC, the use of hand instruments only with the ART method was an equally effective alternative to conventional rotary instrumentation for cavity preparation. Larger restorations had higher failures, usually from dislodgement.JY Hu, XC Chen, YQ Li, RJ Smales and KH Yi
Qualitative analysis for a model of forest with diffusion and nonlocal effects
This study addresses an integro-differential system with a given time delay. The equation to this problem is reduced to a lower-dimensional reaction-cross-diffusion model to study travelling wave solutions. Both the decoupling method and invariant rectangle are used to prove the global existence and boundedness of solution. In addition, based on some differential inequality, the global stability of zero solution is proven.Mathematics, AppliedMathematicsSCI(E)EI2ARTICLE2217-2293
Pseudoautosomal abnormalities in terminal AZFb+c deletions are associated with isochromosomes Yp and may lead to abnormal growth and neuropsychiatric function
© The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. STUDY QUESTION: Are copy number variations (CNVs) in the pseudoautosomal regions (PARs) frequent in subjects with Y-chromosome microdeletions and can they lead to abnormal stature and/or neuropsychiatric disorders? SUMMARY ANSWER: Only subjects diagnosed with azoospermia factor (AZF)b+c deletions spanning to the end of the Y chromosome (i.e. terminal deletions) harbor Y isochromosomes and/or cells 45, X that lead to pseudoautosomal gene CNVs, which were associated with abnormal stature and/or neuropsychiatric disorders. WHAT IS KNOWN ALREADY: The microdeletions in the long arm of the Y chromosome (Yq) that include the loss of one to three AZF regions, referred to as Yq microdeletions, constitute the most important known etiological factor for primary spermatogenic failure. Recently, controversy has arisen about whether Yq microdeletions a
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