Parameter identification problem for the equation of motion of membrane with strong viscosity

The parameter identification problem of constant parameters in the equation of membrane with strong viscosity is studied. The problem is formulated by a minimization of quadratic cost functionals by distributive measurements. The existence of optimal parameters and necessary optimality conditions for the parameters are proved.     

Preliminary communicationPalladium-catalyzed carboxylation of aromatic compounds with carbon dioxide

Carbon dioxide has been found to react with aromatic compounds such as benzene, anisole, furane, and thiophene to give aromatic acids in modest yields with palladium(II) salts as catalysts. The addition of t-BuOOH increases the yield.     

Recent trends of industrial catalysts for resid hydroprocessing in Japan

To meet the gradual changes in petroleum demand, in particular a reduced demand for heavy fuel oil, advanced technology for resid hydroprocessing is now extremely necessary. The catalyst technology for resid hydroprocessing in Japan, especially fixed bed type of hydrodesulfurization and hydroconversion, is reviewed in this article.     

Subpicosecond photon echoes by using nanosecond laser pulses

Subpicosecond time resolutions have been obtained in photon echoes when a sample was excited by two nanosecond dye laser pulses with a smooth and broad spectrum. The dye laser was pumped by second harmonics of a Q-switched Nd:YAG laser, and the pulse width was 10 ns. The sample was 3% Nd³⁺-doped silicate glass, and the center frequency of the dye laser was tuned at 5910 Å on resonance with the ⁴I_{$\text{9}\text{2}$} ? ²G_{$\text{7}\text{2}$}, ⁴G_{$\text{5}\text{2}$} transition of Nd³⁺. The homogeneous transverse relaxation time T₂ was measured to be 91 ps at 10 K in agreement with the previous measurements by picosecond pulses.     

Self‐polyaddition of triethylsilyl perfluoroisopropenyl ether

The results on radical self‐polyaddition reactivity of two trialkylsilyl perfluoroisopropenyl ethers, triethysilyl perfluoroisopropenyl ether [CF₂?C(CF₃)OSi(C₂H₅)₃] (FTEE) and dimethylphenylsilyl perfluoroisopropenyl ether [CF₂?C(CF₃)OSi(CH₃)₂C₆H₅] (DMPE), and two perfluoroisopropenyl carboxylates, 2‐butyroxypentafluoropropene [CF₂?C(CF₃)OCOC₃H₇] (BuFPP) and 2‐(methoxyacetoxy)pentafluoropropene [CF₂?C(CF₃)OCOCH₂OCH₃] (MFPP), are described. Radical self‐polyaddition of FTEE afforded a polymer as high as 1.87 × 10⁴ in molecular weight in the presence of radical generators such as benzoyl peroxide and di‐tert‐butyl peroxide. DMPE gave only addition products with initiating radicals. BuFPP and MFPP scarcely yielded even addition products with radical. The mechanism that the self‐polyaddition of FTEE was initiated by the addition of radical onto the perfluoroisopropenyl group followed by a 1,5‐shift to afford a methyl radical that attacked the perfluoroisopropenyl group of another FTEE molecule is proposed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2743–2754, 2003     

Iodoetherification of 4-penten-1,3-diols: stereoselective synthesis of cis 2-iodomethyl-3-hydroxytetrahydrofurans

cis 2-Iodomethyl-3-hydroxytetrahydrofurans have been obtained in high yields and in high selectivities by treatment of 4-penten-1,3-diols with iodine (ether-H₂O, NaHCO₃).     

Pressure-induced magnetic transition in Fe2P

The weak field ac susceptibility and the resistivity of Fe₂P single crystals were measured as functions of temperature from 4.2–300 K and as functions of hydrostatic pressures up to 20 kbar, using a newly designed clamp-type pressure cell. The Curie temperature, and the first-order transition temperature, decreased rapidly with increasing pressure, and ferromagnetism vanished at about 13 kbar at 0 K. A second-order transition temperature, as well as the first-order transition, appeared in the region below 170 K and above 5 kbar (triple point) and a new pressure-induced magnetic phase was found. The phase is proposed to be antiferromagnetic for reasons discussed in the paper.