Subphthalocyanines as narrow band red-light emitting materials

A series of new light emitting subphthalocyanines, lower homologues of phthalocyanines, were synthesized having color points covering the red-orange region of the visible spectrum. Additionally, they were found to be of potential use as narrow band emitters for red-light emitting diodes.     

Structural features of theClostridium thermocellum cellulase Ss gene

Applied Biochemistry and Biotechnology - TheClostridium thermocellum cellulase Ss is a subunit of the extracellular cellulase complex (cellulosome). It has previously been shown that Ss hydrolyzes...     

Constrained phosphite ester complexes of π-cyclopentadienylmolybdenum tricarbonyl halides

The synthesis of complexes of the type π-C₅H₅Mo(CO)₂LX and π-C₅H₅Mo(CO)L₂X, where XCl, Br, or I and LP(OCH₂)₃CR (RCH₃, C₂H₅, or C₃H₇), is reported. Infrared and conductance data verified that all compounds existed as covalent species in solution. Each of the three π-C₅H₅Mo(CO)₂LCl complexes was isolated as an inseparable mixture of cis and trans isomeric forms. Only the trans forms of the remaining π-C₅H₅Mo(CO)₂LX complexes were observed in solution, as indicated by infrared and PMR spectra. All of the π-C₅H₅Mo(CO)L₂X compounds apparently exist in primarily one isomeric form in solution; their PMR spectra, which exhibited a sharp triplet resonance for the ?OCH₂? protons of the phosphite ligands and a single sharp π-C₅H₅ proton signal, indicated a predominantly trans arrangement of the phosphite ligands at room temperature.     

Über eine zum Kreisproblem verwandte Summe

An equivalent form of the classical circle problem is the unproved conjecture (3) . In this note the corresponding conjecture with _k (.) (the 1-periodic Bernoulli polynomials of orderk2) instead of ₁(.) is settled in an affirmative way (even with =0). Moreover, a generalized sum (6) is estimated by means of an analogue to a classical result due tovan der Corput.     

Atomistic Simulation Study of Calcium,Phosphate and Fluoride Ion Association to the Teleopeptide‐Tails of Collagen – Initial Steps to Biomineral Formation

The attachment of single ions to putative adsorption sites in the tails of collagen fibers is investigated by means of molecular dynamics simulations and discussed with respect to the very early steps of apatite/collagen biomineral formation. Our studies clearly demonstrate an increased flexibility of the tails of the triple‐helical collagen protein. Apart from the termini of the backbone, several side chains were also observed to be freely accessible to ion attachment from aqueous solution. The teleopeptide was systematically scanned for suitable adsorption sites for calcium, phosphate and fluoride ions. Association of these ions was then explored from potential of mean force calculations. The resulting energy profiles reveal a variety of favorable protein‐ion bonds and hint at the suitability of the collagen tails to promote apatite aggregation.     

Finite-size scaling and the renormalization group

Renormalization group calculations ind = 4 andd = 4 – are performed for a system of finite size. A form of mean-field theory is used which yields a rounded transition for a finite system, and this allows a sensible expansion in fluctuations. A combination of Ewald and Poisson sum techniques is used to produce explicit numerical results for the specific heat ind = 4 which, with the setting of two nonuniversal metrical factors and the fourth-order coupling constant may be compared with simulations. The numerical visibility of logarithmic corrections is investigated. The universal scaling function for the specific heat to relativeO() is also evaluated numerically.     

Surface tension and universality in the three-dimensional Ising model

The amplitude ₀ of the interfacial free energy per unit area (or surface tension) of the body-centered-cubic Ising model is found using a direct monte carlo simulation technique. The combination ²/k_BT_c, where is the correlation length, is shown to agree within the precision of the simulations with a previously reported estimate for the simple cubic lattice. Evidence is also presented for the universality of the finite-size scaling amplitude for the surface tension.     

Soliton experiments in stimulated Raman scattering

Experimental observations of solitons in stimulated Raman scattering are reported. Soliton formation resulted from the introduction of a phase shift in the incident Stokes beam as predicted by theory. Pulse sharpening and retardation on propagation in the Raman medium have been observed along with amplitude diminution. The first two features were predicted and the third was not. Spontaneous soliton formation has been observed in the absense of any amplitude modulation or apparent phase shift in the optical fields, indicating that additional sets of initial conditions may result in soliton formation.Work performed under the auspices of the U.S. Department of Energy.