منابع مشابه
Distant protonated pyridine groups in water-soluble iron porphyrin electrocatalysts promote selective oxygen reduction to water.
Fe(III)-meso-tetra(pyridyl)porphyrins are electrocatalysts for the reduction of dioxygen in aqueous acidic solution. The 2-pyridyl derivatives, both the triflate and chloride salts, are more selective for the desired 4e(-) reduction than the isomeric 4-pyridyl complexes. The inward-pointing pyridinium groups influence proton delivery despite their distance from the iron centre.
متن کاملBacterial Growth on Distant Naphthalene Diffusing through Water, Air, and Water-Saturated and Nonsaturated Porous Media.
The influence of substrate diffusion on bacterial growth was investigated. Crystalline naphthalene was supplied as the substrate at various distances in the range of centimeters from naphthalene-degrading organisms separated from the substrate by agar-solidified mineral medium. Within 2 weeks, the cells grew to final numbers which were negatively correlated with the distance from the substrate....
متن کاملComparing Powers and Symbolic Powers of Ideals
We develop tools to study the problem of containment of symbolic powers I(m) in powers I for a homogeneous ideal I in a polynomial ring k[P ] in N + 1 variables over an arbitrary algebraically closed field k. We obtain results on the structure of the set of pairs (r, m) such that I(m) ⊆ I. As corollaries, we show that I2 contains I(3) whenever S is a finite generic set of points in P2 (thereby ...
متن کاملPowers of Two Modulo Powers of Three
Since 2 is a primitive root of 3 for each positive integer m, the set of points {(n, 2 mod 3) : n > 0}, viewed as a subset of Z>0×Z>0 is bi-periodic, with minimal periods φ(3) (horizontally) and 3 (vertically). We show that if one considers the classes of n modulo 6, one obtains a finer structural classification. This result is presented within the context of the question of strong normality of...
متن کاملDomination number of graph fractional powers
For any $k in mathbb{N}$, the $k$-subdivision of graph $G$ is a simple graph $G^{frac{1}{k}}$, which is constructed by replacing each edge of $G$ with a path of length $k$. In [Moharram N. Iradmusa, On colorings of graph fractional powers, Discrete Math., (310) 2010, No. 10-11, 1551-1556] the $m$th power of the $n$-subdivision of $G$ has been introduced as a fractional power of $G$, denoted by ...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1900
ISSN: 0036-8733
DOI: 10.1038/scientificamerican09221900-179b