The photophysical properties of o-aminoacetophenone (o-AAP) in solution have been studied by using a femtosecond laserÈsingle photon counting system and time-resolved thermal lensing (TRTL) method. The Ñuorescence quantum yield and lifetime of o-AAP depend strongly on the nature of the solvent. In f (qf) nonpolar solvents, o-AAP gives very small values in n-hexane) and remarkably short f (Uf\ 2...

Helical polymers of isocyanotripeptides derived from alanine have been synthesized and their architectures studied in detail. The helical conformation of the polyisocyanotripeptides is stabilized by internal hydrogen-bonding arrays between the tripeptide side chains. The possibility of extending the well-defined hydrogen-bonded array, from dipeptide to tripeptide side chains, depends strongly o...

In this paper, a compression-to-tensile load converter device is developed to determine the anisotropic tensile strength of brittle material. A cubic sample with an internal pore was used as the test specimen, and a series of finite element analysis and DDM simulations were performed thereafter to analyse the effect of pore dimensions on the stress concentration, as well as to render a suitable...

Aiming at the lack of a precise discrete element model in simulation analysis corn straw crushing, this paper established bond models with different structure and particle properties based on Hertz-Mindlin bonding, verified by combining physical test optimization design methods. Firstly, study generates bonded bonding for epidermis-epidermis, inner flesh-internal flesh, epidermis-internal respe...

In order to investigate the topological effects of chain molecules, united-atom molecular dynamics simulations of a 500-mer polyethylene linked by 50 hexyl groups (a grafted polymer having 52 ends) are carried out and analyzed in terms of Voronoi space division. We find that the volume of a Voronoi polyhedron for a chain end is larger than that for an internal or junction atom, and that it is t...

In biomolecules, bifurcated H-bonds typically involve the interaction of two donor protons with the two lone pairs of oxygen. Here, we present direct NMR evidence for a bifurcated H-bonding arrangement involving nitrogen as the acceptor atom. Specifically, the H-bond network comprises the Nδ1 atom of histidine and both the backbone N-H and side-chain Oγ-H of threonine within the conserved TXXH ...

Electron capture by both bare and microsolvated small peptide dications was investigated by colliding these ions with sodium vapor in an accelerator mass spectrometer to provide insight into processes that occur on the microsecond time frame. Survival of the intact peptide monocation after electron capture depends strongly on molecular size. For dipeptides, no intact reduced species were observ...

In this study, Wedge statistical analysis tools were used to collect, collate, clean up, plot, and analyze several years of operational data from a commercial paper machine. The z-direction tensile (ZDT) Scott Bond tests chosen as representative fiber bond strength. After analyzing thousands parameters, the ones with most significant impact upon ZDT involved starch application method, penetrati...