Small-angle x-ray scattering, nitrogen adsorption, and scanning tunneling microscopy show that a series of activated carbons host an extended fractal network of channels with dimension D(p) = 2.8-3.0 (pore fractal), channel width 15-20 A (lower end of scaling), network diameter 3000-3400 A (upper end of scaling), and porosity of 0.3-0.6. We interpret the network as a stack of quasiplanar invasi...

An Extended Ruckel (E. H.) calculation was performed for the energy of Fex clusters (with x = 9, 10, 13, 15, 18) that are used to model the 111, 100, 110 surface planes of an iron single-crystal. Interaction energies of atomic and molecular nitrogen with each cluster were calculated for different geometrical configurations of the system. From this data thermodynamic and kinetic considerations a...

Cyanobacteria, which perform oxygen-evolving photosynthesis as do chloroplasts of plants and algae, are one of the best-studied prokaryotic phyla and one from which many representative genomes have been sequenced. Lack of a suitable comparative genomic database has been a problem in cyanobacterial genomics because many proteins involved in physiological functions such as photosynthesis and nitr...

nitrogen use efficiency (nue) is usually lower in paddy rice (oryza sativa l.) than in upland crops. for this reason, any attempt to improve nue through the use of different nitrogen (n) carriers, different rice cultivars, properly timed n application, the use of ni-trification and urease inhibitorsis of prime interest. moreover, zinc (zn) next to n seems to be the most important soil factor af...

In this paper, we report the cloning and characterization of three Paenibacillus azotofixans DNA regions containing genes involved in nitrogen fixation. Sequencing analysis revealed the presence of nifB1H1D1K1 gene organization in the 4,607-bp SacI DNA fragment. This is the first report of linkage of a nifB open reading frame upstream of the structural nif genes. The second (nifB2H2) and third ...

Cyanobacteria, which perform oxygen-evolving photosynthesis as do chloroplasts of plants and algae, are one of the best-studied prokaryotic phyla and one from which many representative genomes have been sequenced. Lack of a suitable comparative genomic database has been a problem in cyanobacterial genomics because many proteins involved in physiological functions such as photosynthesis and nitr...

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