Drawdown of Atmospheric pCO 2 via Variable Particle Flux Stoichiometry in the Ocean Twilight Zone

Author(s):  
Tatsuro Tanioka ◽  
Katsumi Matsumoto ◽  
Michael W. Lomas
Keyword(s):  
2009 ◽  
Vol 56 (18) ◽  
pp. 1363-1368 ◽  
Author(s):  
Cindy Lee ◽  
Robert A. Armstrong ◽  
J. Kirk Cochran ◽  
Anja Engel ◽  
Scott W. Fowler ◽  
...  
Keyword(s):  

2008 ◽  
Vol 53 (4) ◽  
pp. 1327-1338 ◽  
Author(s):  
Deborah K. Steinberg ◽  
Benjamin A. S. Van Mooy ◽  
Ken O. Buesseler ◽  
Philip W. Boyd ◽  
Toru Kobari ◽  
...  
Keyword(s):  

2007 ◽  
Vol 54 (10) ◽  
pp. 1758-1772 ◽  
Author(s):  
Ayako Okubo ◽  
Hajime Obata ◽  
Shangde Luo ◽  
Toshitaka Gamo ◽  
Yoshiyuki Yamamoto ◽  
...  

Author(s):  
Robert M. Glaeser

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.


Author(s):  
Charles W. Allen

With respect to structural consequences within a material, energetic electrons, above a threshold value of energy characteristic of a particular material, produce vacancy-interstial pairs (Frenkel pairs) by displacement of individual atoms, as illustrated for several materials in Table 1. Ion projectiles produce cascades of Frenkel pairs. Such displacement cascades result from high energy primary knock-on atoms which produce many secondary defects. These defects rearrange to form a variety of defect complexes on the time scale of tens of picoseconds following the primary displacement. A convenient measure of the extent of irradiation damage, both for electrons and ions, is the number of displacements per atom (dpa). 1 dpa means, on average, each atom in the irradiated region of material has been displaced once from its original lattice position. Displacement rate (dpa/s) is proportional to particle flux (cm-2s-1), the proportionality factor being the “displacement cross-section” σD (cm2). The cross-section σD depends mainly on the masses of target and projectile and on the kinetic energy of the projectile particle.


Sign in / Sign up

Export Citation Format

Share Document