Vibrational frequencies,infrared absorption intensities and energy differences between rotational isomers of propyl halides

Infrared absorption intensities of fundamental bands of propyl halides n-C₃ H₇ Cl, n-C₃H₇ Br and n-C₃H₇I were measured in the pure liquid state. In order to obtain L matrix data necessary for the intensity computation, normal frequencies of the rotational isomers were calculated, and LSFF force constants were determined by the least squares method so as to attain the best fit between the observed and calculated frequencies. By applying the absolute intensity method, energy differences between the rotational isomers were evaluated, which are in quite good agreement with values obtained by the temperature variation method.     

A geometric method in nonlinear programming

A differential geometric approach to the constrained function maximization problem is presented. The continuous analogue of the Newton-Raphson method due to Branin for solving a system of nonlinear equations is extended to the case where the system is under-determined. The method is combined with the continuous analogue of the gradient-projection method to obtain a constrained maximization method with enforced constraint restoration. Detailed analysis of the global behavior of both methods is provided. It is shown that the conjugate-gradient algorithm can take advantage of the sparse structure of the problem in the computation of a vector field, which constitutes the main computational task in the methods.This is part of a paper issued as Stanford University, Computer Science Department Report No. STAN-CS-77-643 (Ref. 45), which was presented at the Gatlinburg VII Conference, Asilomar, California, 1977. This work was supported in part by NSF Grant No. NAT BUR OF ECON RES/PO No. 4369 and by Department of Energy Contract No. EY-76-C-02-0016.The main part of this work was presented at the Japan-France Seminar on Functional Analysis and Numerical Analysis, Tokyo, Japan, 1976. The paper was prepared in part while the author was a visitor at the Department of Mathematics, North Carolina State University, Raleigh, North Carolina, 1976–77, and was completed while he was a visitor at the Computer Science Department, Stanford University, Stanford, California, 1977. He acknowledges the hospitality and stimulating environment provided by Professor G. H. Golub, Stanford University, and Professors N. J. Rose and C. D. Meyer, North Carolina State University.     

Possible one-dimensional 3He quantum fluid formed in nanopores

Heat capacity measurements have been made down to 5 mK for 3He fluid films adsorbed in one-dimensional (1D) nanometer-scale pores, 28 A in diameter, preplated with 4He of 1.47 atomic layers. At low 3He density, the heat capacity shows a density-dependent, Schottky-like peak near 150 mK asymptoting to the value corresponding to a 2D Boltzmann gas at high temperatures. The peak behavior is attributed to the crossover from a 2D gas to a 1D state at low temperatures. The degenerate state of the 1D 3He fluid is indicated by a predominantly linear temperature dependence below about 30 mK.     

A novel action of terpendole E on the motor activity of mitotic Kinesin Eg5

To reveal the mechanism of mitosis, the development of M phase-specific inhibitors is an important strategy. We have been screening microbial products to find specific M phase inhibitors that do not directly target tubulins, and rediscovered terpendole E (TerE) as a novel Eg5 inhibitor. TerE did not affect microtubule integrity in interphase, but induced formation of a monoastral spindle in M phase. TerE inhibited both motor and microtubule-stimulated ATPase activities of human Eg5, but did not affect conventional kinesin from either Drosophila or bovine brain. Although terpendoles have been reported as inhibitors of acyl-CoA:cholesterol O-acyltransferase (ACAT), the Eg5 inhibitory activity of TerE was independent of ACAT inhibition. Taken together, we demonstrate that TerE is a novel Eg5 inhibitor isolated from a fungal strain.     

Near-infrared emissions with widely different widths in two kinds of Er-doped oxide glasses with high refractive indices and low phonon energies

Er³⁺-doped alkali-barium-bismuth-tellurite (LKBBT) and alkali-barium-bismuth-gallate (LKBBG) glasses with high refractive indices and low phonon energies have been designed, fabricated, characterized and compared. Intense 1.53 μm emissions with widely different widths in the two kinds of glasses were observed and recorded under 980 nm diode laser excitation. The full-widths at half-maximum of the 1.53 μm emission bands in LKBBT and LKBBG glasses are 58 and 40 nm, and the lifetimes of them were measured to be 3.21 and 3.97 ms, respectively. The quantum efficiencies for the ⁴I_13/2 level in both glasses are almost 100%. The 1.53 μm broad and narrow emissions with high spontaneous emission probabilities and large emission cross-sections indicate that Er³⁺-doped LKBBT and LKBBG glasses are suitable materials in developing broadband optical amplifier and infrared laser, respectively.