نتایج جستجو برای: ultra weak photon emission

تعداد نتایج: 421912  

2000
Richard F. Lebed

We discuss a little-studied class of weak decay modes sensitive to only one quark topology at leading order in GF : M → mγ, where M,m are mesons with completely distinct flavor quantum numbers. Specifically, they proceed via the annihilation of the valence quarks through a W and the emission of a single hard photon, and thus provide a clear separation between CKM and strong interaction physics....

Introduction: This paper analyses the ability of single-photon avalanche diodes (SPADs) for neural imaging. The current trend in the production of SPADs moves toward the minimumdark count rate (DCR) and maximum photon detection probability (PDP). Moreover, the jitter response which is the main measurement characteristic for the timing uncertainty is progressing. Methods: The neural imaging pro...

Journal: :Nano letters 2010
Liselotte Jauffred Lene B Oddershede

A single CW infrared laser beam can simultaneously trap and excite an individual colloidal quantum dot. Though the laser light is relatively weak, the excitation occurs through two-photon absorption. This finding eliminates the demand for an excitation light source in addition to a trapping laser in nanoscale experiments with simultaneous force-manipulation and quantum dot visualization. Also, ...

Journal: :archives of cardiovascular imaging 0
arash gholoobi preventive cardiovascular care research center, imam reza hospital, faculty of medicine, mashhad university of medical sciences, mashhad, ir iran; preventive cardiovascular care research center, imam reza hospital, faculty of medicine, mashhad university of medical sciences, p. o. box: 9137913316, mashhad, ir iran. tel/fax: +98-5138544504

discussion the reason is that we assess the relative and not absolute differences of the tracer uptake in this imaging modality. there may be other findings on mpi images which could help us overcome this pitfall, including detecting wall motion abnormalities, lung uptake of the tracer, or transient ischemic dilation. another important issue is the ecg changes during exercise stress testing, wh...

2012
Klaus Kruttwig Diego R. Yankelevich Chantal Brueggemann Chuqiao Tu Noelle L’Etoile André Knoesen Angelique Y. Louie

Photoswitchable spiropyran has been conjugated to the crowned ring system DO3A, which improves its solubility in dipolar and polar media and stabilizes the merocyanine isomer. Adding the lanthanide ion gadolinium(III) to the macrocyclic ring system leads to a photoresponsive magnetic resonance imaging contrast agent that displays an increased spin-lattice relaxation time (T₁) upon visible light...

Journal: :The Review of scientific instruments 2012
R Loetzsch O Jäckel S Höfer T Kämpfer J Polz I Uschmann M C Kaluza E Förster E Stambulchik E Kroupp Y Maron

We developed a detection scheme, capable of measuring X-ray line shape of tracer ions in μm thick layers at the rear side of a target foil irradiated by ultra intense laser pulses. We performed simulations of the effect of strong electric fields on the K-shell emission of silicon and developed a spectrometer dedicated to record this emission. The combination of a cylindrically bent crystal in v...

2016
A. K. Kembhavi

We perform X-ray/UV spectral and X-ray variability studies of the radio-loud Narrow Line Seyfert 1 (NLS1) galaxy RXJ1633.3+4719 using XMM-Newton and Suzaku observations from 2011 and 2012. The 0.3−10 keV spectra consist of an ultra-soft component described by an accretion disc blackbody (kTin = 39.6 +11.2 −5.5 eV) and a power-law due to the thermal Comptonization (Γ = 1.96 −0.31) of the disc em...

Journal: :New Journal of Physics 2013

Journal: :Optics express 2013
Henri Thyrrestrup Alex Hartsuiker Jean-Michel Gérard Willem L Vos

We have theoretically studied the effect of deterministic temporal control of spontaneous emission in a dynamic optical microcavity. We propose a new paradigm in light emission: we envision an ensemble of two-level emitters in an environment where the local density of optical states is modified on a time scale shorter than the decay time. A rate equation model is developed for the excited state...

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