نتایج جستجو برای: alkaline earth metals
تعداد نتایج: 193458 فیلتر نتایج به سال:
A critical assessment of the various X-ray and electron-based methods of determining the structure of ultrafine metallic particles of colloidal dimension is given. In particular, examples of the use and potential of high-resolution electron microscopy of high-angle Rutherford scattering and of scanning tunneling microscopic procedures are illustrated. Several growth points of current and possib...
There is considerable interest in synthetic ionophores with high affinity and selectivity for Li(+). But so far, compounds that selectively bind Li(+) in the presence of other alkali and alkaline earth metal ions are rare and current approaches toward this goal are often accompanied with substantial synthetic efforts. Here we describe a trinuclear ruthenium metallamacrocyclic complex (1) that w...
We proposed a new solid state material for hydrogen storage, which consists of a combination of both transition and alkaline earth metal atoms decorating a boron-doped graphene surface. Hydrogen adsorption and desorption on this material was investigated using density functional theory calculations. We find that the diffusion barriers for H atom migration and desorption energies are lower than ...
A range of complexes based on the high-nuclearity [W36] isopolyoxotungstate cluster, [H12W36O120]12-, with a triangular topology has been isolated by using the organic cation, protonated triethanolamine. In analogy to an 18-crown-6 crown ether with six oxygen donors on a ring, the cluster can form alkali and alkaline earth metal complexes [M within W36] (M = K+, Rb+, Cs+, NH4+, Sr2+ and Ba2+, 1...
The photochemical behaviors of a series of 9-phenanthreneacetamide (PA) derivatives were investigated using UV, fluorescence, and (1)H-NMR spectroscopy in acetonitrile solutions. To apply the electron transfer (ET) action of PA as a detecting moiety of chemosensors, 4'-(9-phenanthreneacetamido)-benzo-15-crown-5 (1) and 3'-methyl-4'-(9-phenanthreneacetamido)-benzo-15-crown-5 (2) were synthesized...
—The diatom flora of selected sites in the Animas River Watershed, San Juan County, Colorado, was studied. Eighty diatom taxa were identified from 10 sites: 8 sites on the Animas River and 1 site each on the Cement and Cascade tributaries. The sample diatom abundance was dominated by Achnanthidium minutissimum, Encyonema silesiacum, Aulacoseira distans, Hannaea arcus, and Diatoma mesodon. The p...
New fluorescent ionophores containing the 1-naphthylacetanilide moiety based on oligo-ethylene oxide (1(4) and 1(5)) have been synthesized, and their photochemical behaviors have been studied. In the absence of a metal ion, the 1-naphthylacetanilide moiety showed a weak fluorescence emission (fluorescence "off state"). However, complexation with Ca(2+) induced a large enhancement effect on the ...
In order to use a hydrophilic solvent as an organic phase in liquid-liquid extraction by retaining it to a solid support, the occlusion and desorption of nine hydrophilic solvents, such as methanol, to three kinds of commercially available oil-adsorbent were examined. The combination of tetrahydrofuran and WOSEP made by fibrous polypropylene was finally selected, and was subjected to the extrac...
Professor Ulrich Dilthey’s passion for the science and technology of joining processes is amply reflected in the enormous archive of published work which will forever serve the community. It is a pleasure therefore to be able to present this small story as a tribute to someone who has been a scholar, a gentleman and a leader in this most difficult of subjects. The matter of our everyday world i...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید