Upconversion-like Photolysis of BODIPY-Based Prodrugs via a One-Photon Process

2019 ◽  
Vol 141 (44) ◽  
pp. 17482-17486 ◽  
Author(s):  
Wen Lv ◽  
Yafei Li ◽  
Feiyang Li ◽  
Xin Lan ◽  
Yaming Zhang ◽  
...  
Keyword(s):  
Photon Process

Proton Induced Structuring of a Photostructurable Glass

2002 ◽  
Vol 739 ◽  
Author(s):  
Meg Abraham ◽  
Inmaculada Gomez-Morilla ◽  
Mike Marsh ◽  
Geoff Grime
Keyword(s):  
Three Dimensional ◽  
Particle Beam ◽  
Nucleation Site ◽  
Buried Structures ◽  
Corning Glass ◽  
Nucleation Sites ◽  
Initial Nucleation ◽  
Similar Product ◽  
Photon Process ◽  
Meta Silicate

ABSTRACTThe use of photons to create intricate three-dimensional and buried structures [1] in photo-structurable glass has been well demonstrated at several institutions [2]. In these instances the glass used whether it be Foturan™, made by the Schott Group or a similar product made by Corning Glass, forms a silver nucleation sites on exposure to intense UV laser light via a two-photon process. Subsequent annealing causes a localized crystal growth to form a meta-silicate phase which can be etched in dilute hydrofluoric acid at rates of 20 to 50 times that of the unprocessed glass. The same formulation of glass can be “exposed” using a particle beam to create the nucleation site. In the case of particle beam exposure, experiments have shown that the mechanisms that cause this initial nucleation and eventual stochiometric transformation, after annealing, depend largely on the beam energy.

The coincidence approach to stochastic point processes

1975 ◽  
Vol 7 (1) ◽  
pp. 83-122 ◽  
Author(s):  
Odile Macchi
Keyword(s):  
Poisson Process ◽  
Probability Space ◽  
Point Processes ◽  
Counting Process ◽  
Regular Point ◽  
General Point ◽  
Completely Regular ◽  
Photon Process ◽  
Stochastic Point Processes

The structure of the probability space associated with a general point process, when regarded as a counting process, is reviewed using the coincidence formalism. The rest of the paper is devoted to the class of regular point processes for which all coincidence probabilities admit densities. It is shown that their distribution is completely specified by the system of coincidence densities. The specification formalism is stressed for ‘completely’ regular point processes. A construction theorem gives a characterization of the system of coincidence densities of such a process. It permits the study of most models of point processes. New results on the photon process, a particular type of conditioned Poisson process, are derived. New examples are exhibited, including the Gauss-Poisson process and the ‘fermion’ process that is suitable whenever the points are repulsive.

scholarly journals One Photon and Two Photon Process in Photo-Decomposition of Germanium Oxygen Deficient Centres

1998 ◽  
Vol 37 (S1) ◽  
pp. 12 ◽  
Author(s):  
L. Dong ◽  
V. N. Bagratashvili ◽  
S. I. Tsypina ◽  
Y. S. Zavorotny ◽  
A. O. Rybaltovskii ◽  
...  
Keyword(s):  
Two Photon ◽  
Photon Process ◽  
Photo Decomposition

scholarly journals Recent BaBar results in light hadron spectroscopy

2019 ◽  
Vol 212 ◽  
pp. 04006
Author(s):  
Evgeny Kozyrev ◽  
Evgeny Solodov ◽  
Vladimir Druzhinin
Keyword(s):  
Center Of Mass ◽  
Mass Energy ◽  
Full Data ◽  
Data Set ◽  
Hadron Spectroscopy ◽  
Center Of Mass Energy ◽  
Two Photon ◽  
Light Hadron ◽  
Photon Process ◽  
Babar Experiment

We report the results on the channels e+e−→ π+π−π0π0π0(η), e+e−→ π+π−η. Also we present the study of the two-photon process e+e−→ e+e−η' in the double-tag mode. The results for the form factor are compared with the predictions based on pQCD and VMD. The results are obtained by using the full data set of about 470 fb−1 collected by the BABAR experiment at the PEP-II e+e−collider at a center-of-mass energy of about 10.6 GeV.

scholarly journals Hydrogen spin oscillations in a background of axions and the 21-cm brightness temperature

2020 ◽  
Author(s):  
G Lambiase ◽  
S Mohanty
Keyword(s):  
Cosmic Strings ◽  
Transition Rates ◽  
Spin Temperature ◽  
Level Atom ◽  
Spin Flip ◽  
Coherent Field ◽  
Unique Method ◽  
Photon Process ◽  
The Right ◽  
The Universe

Abstract The 21-cm line signal arising from the hyperfine interaction in hydrogen has an important role in cosmology and provides a unique method for probing of the universe prior to the star formation era. We propose that the spin flip of Hydrogen by the coherent emission/absorption of axions causes a lowering of their spin temperature and can explain the stronger than expected absorption of 21-cm light reported by the EDGES collaboration. We find the analogy of axion interaction with the two level HI with the Jaynes-Cummings model of a two level atom in a cavity and we derive the spin flip frequency in this formalism and show that the coherent oscillations frequency Ω∝1/fa in contrast with the incoherent transitions between the HI hyperfine levels where the transition rates $\propto 1/f_a^2$. The axion emission and absorption rates are equal but the spin temperature is still lowered due to different selection rules for the spin flip transitions compared to the photon process. We show that the axion process goes in the right direction for explaining the EDGES observation. For this mechanism to work we require a coherent field of relativistic axions with energy Eν peaked at the 21-cm spin-flip energy. Such a coherent background of relativistic axions can arise from the decay of cosmic strings if the decay takes place in the electroweak era.

scholarly journals Interpretation of the Ultraviolet Spectrum of NGC 7662

1978 ◽  
Vol 76 ◽  
pp. 121-122
Author(s):  
R.C. Bohlin ◽  
J.P. Harrington ◽  
T.P. Stecher
Keyword(s):  
Neutral Hydrogen ◽  
Central Star ◽  
Dielectronic Recombination ◽  
Emission Lines ◽  
Ultraviolet Emission ◽  
Two Photon ◽  
Carbon Abundance ◽  
Photon Process ◽  
Ngc 7662

The ultraviolet emission lines that were me asured in the spectrum obtained from our rocket observation of NGC 7662 have been compared with those predicted by a set of models. The models allow a determination of the carbon abundance which is found to be solar and the C/0 ratio which is equal to unity. In order to obtain a good fit, dielectronic recombination and charge exchange between neutral hydrogen and C IV were included, both of which increase the concentration of C III. The observed continuum consists of light from the central star and from the nebula, which contributed primarily via the two photon process in the H° and the Balmer continuum.

Sign in / Sign up

Export Citation Format

Share Document