Now showing items 11-20 of 31
Direct chemical analysis of UV laser ablation products of organic polymers by using selective ion monitoring mode in gas chromatography/mass spectrometry
(Elsevier, 1994-02)
Trace quantitites of laser ablated organic polymers were analyzed by using commercial capillary column gas chromatography / mass spectrometry; the instrument was modified so that the laser ablation products could be ...
Generation and cycloaddition of heteroatom-substituted 2-azaallyl anions with alkenes and alkynes. Synthesis of 1-pyrrolines and pyrroles
(Elsevier, 1994-04-25)
Imidates and thioimidates 1 bearing an N-(1-tri-n-butylstannyl)alkyl group (e.g., 7-9) were transmetalated with n-BuLi to generate heteroatom-substituted 2-azaallyl anions 2. These anions underwent [2[pi]s+4[pi]s] ...
Phase stability and structural properties of Ni7 +/- [delta]S6 and Ni9S8 Heat capacity and thermodynamic properties of Ni7S6 at temperatures from 5 K to 970 K and of Ni9S8 from 5 K to 673 K
(Elsevier, 1994-09)
Two stable solid phases with composition in the range from (45 to 48) moles per cent of S exist for (nickel + sulfur): Ni9S8 which disproportionates to Ni1 - [delta]S and Ni7 +/- [delta]S6 above T = (709 +/- 5) K, and Ni7 ...
Intermolecular 1,3-dipolar cycloadditions of muchnones with acetylenic dipolarophiles: Sorting out the regioselectivity
(Elsevier, 1994-04-03)
A series of 1,3-dipolar cycloadditions of munchnones with acetylenic dipolarophiles was studied, wherein factors related to regioselectivity were investigated. The results from munchnones with electronically divergent ...
Modular construction for the programmed assembly of molecular crystals and liquid crystals
(Wiley Periodicals, Inc.Hüthig & Wepf Verlag, 1994-01)
This research aims to develop schemes for the programmed assembly of molecular materials. The underlying premise guiding this work is that structural information stored in the molecular constituents dictates their condensed ...
[alpha]-(2 --> 3)- and [alpha]-(2 --> 6)-Sialyltransferase activities present in three variants of Ehrlich tumor cells: identification of the products derived from N-acetyllactosamine and [beta]--Gal-(1 --> 3)-[alpha] GalNAc-(1 --> O)-Bn
(Elsevier, 1994-11-01)
We compared several sialyltransferase activities related to synthesis of O-linked and N-linked sialylglycoproteins in Ehrlich ascites tumor cells that grow normally in murine ascites, but are not adherent nor grow in tissue ...
Control of gene expression at the level of translation initiation
(Elsevier, 1994-10)
Protein synthesis is controlled at the level of translation initiation. Cells rapidly respond to environmental changes by disassembly of polysomes and recruitment of specific mRNAs from inactive ribonucleoprotein particles ...
Carbon-hydrogen bond activation over tungsten carbide catalysts
(Elsevier, 1994-08-30)
Tungsten carbides with surface areas ranging from 4 to 39 m2/g were prepared by the temperature-programmed carburization of tungsten oxide and nitride powders with pure CH4 or a 48.9% CH4 in H2 mixture. Oxygen uptakes on ...
Elastic step interactions on vicinal surfaces of fcc metals
(Elsevier, 1994-09-20)
The structural and energetic properties of [100] and [110] steps on the (001) surface of fcc metal have been determined by T = 0 atomistic simulations. The interactions between [100] steps and between [110] steps on the ...
Polycrystalline surface properties from spherical crystallites: Ag, Au, Cu and Pt
(Elsevier, 1994-04-10)
We have performed a series of atomistic simulations of nearly spherical, crystalline (fcc) clusters of Ag, Au, Cu and Pt as a function of temperature and cluster size. Since both a spherical cluster and a random polycrystal ...