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881.
An average energy of a high temperature part of ions in turbulently heated plasmas was measured by use of a secondary emission detector, and availability of this simple method for a determination of an average ion energy was discussed.  相似文献   
882.
Tunable four-photon parametric fluorescence, which is valuable for investigating material nonlinearities and parametric devices, was studied theoretically and experimentally.Theoretical analysis leads to the conclusion that the emitted power depends directly on the focusing of the pumping beam, unlike the process of three-photon parametric fluorescence which is independent of the focusing of the pumping beam. The calculation of the phasematching conditions for nonlinear crystals such as KDP, ADP, TiO2 and CdS shows that collinear phase-matching can be realised over the visible region using a ruby laser for pumping. Experimentally, tunable emission was observed in the visible range from 4200 Å to 5300 Å with KDP and ADP crystals pumped by a Q-switched ruby laser.  相似文献   
883.
The derivation of the representations of BRS algebra in the Landau gauge is simplified by the superspace formalism. It is shown that the operation of the metric matrix can be interpreted as a kind of inversion of the superspace.  相似文献   
884.
Two-color fluorescence dip and multiphoton ionization (MPI) spectra have been observed for azabicyclo [2.2.2] octane in a supersonic jet. The spectra showed well-resolved structures consisting of five Rydberg series of n = 4–29. The five Rydberg series were assigned to s, pz, pxy, and two d orbitals. From the spectra obtained after exciting the molecule to various vibronic levels in the S1 (3s) state, the Δν = 0 selection rule was obtained for the Rydberg-Rydberg transition. The same selection rule was found to be preserved also for the transition from the S1 state to the ion. It was shown that the autoionization of the high Rydberg states to the ion is governed by Δν=?1. The existence of a very fast non-radiative channel was found for the Rydberg state from the ω2 power dependence on the two-color MPI spectra.  相似文献   
885.
In this paper an approximation method based upon spline functions is developed for the eigenvalue problem associated with functional differential equations. Convergence results are established and the rate of convergence is investigated. Numerical results for cubic and quintic spline based methods are given. The paper concludes with a brief discussion of other possible approximation methods.  相似文献   
886.
For locally compact groups G and H, let BM(G, H) denote the Banach space of bounded bilinear forms on C0(G) × C0(H). Using a consequence of the fundamental inequality of A. Grothendieck. a multiplication and an adjoint operation are introduced on BM(G, H) which generalize the convolution structure of M(G × H) and which make BM(G, H) into a KG2-Banach 1-algebra, where KG is Grothendieck's universal constant. Various topics relating to the ideal structure of BM(G, H) and the lifting of unitary representations of G × H to 1-representations of BM(G, H) are investigated.  相似文献   
887.
The adsorption behavior of iodine on zeolites and silver-loaded zeolites has been studied by127I Mössbauer spectroscopy. Iodine is adsorbed on zeolites in two forms. One is a physically adsorbed species and the other is a dissociative species. The former is the major form and their intermolecular interactions are suggested to be weakened. Iodine is converted to silver iodide on the surface of silver-loaded zeolites, although some portion is physically adsorbed.  相似文献   
888.
Various organocuprates react with β-propiolactones to give β-substituted propionic acids in high yields.  相似文献   
889.
Titanium reacts with 5-hydroxychromone and eleven of its derivatives to form water-insoluble yellow complexes, which exhibit yellow-green fluorescence on extraction into carbon tetrachloride. An investigation of the substituent effect on the fluorescence intensity of the titanium complexes of these reagents showed that the best fluorescent reagent for the determination of titanium is 2-methyl-3-ethyl-5-hydroxychromone. The maximum wavelengths of the excitation and emission spectra of 2-methyl-3-ethyl-5-hydroxychromone complex are 395 nm and 513 nm, respectively. The titanium complex shows constant fluorescence intensity when extracted from a solution of pH 6.5–8.5. When extraction is done with 10ml of carbon tetrachloride, 0.5–5.0 μg of titanium can be determined. The effects of diverse ions and of substituent position in the reagents are discussed.  相似文献   
890.
A series of monophospha-s-triazines, namely l-diphenylphospha-3,5-bis(perfluoro-n-heptyl)-2,4,6-triazine, 1-diphenylphospha-3,5-bis[C3F7-[OCF(CF3)CF2]xOCF(CF3)]-2,4,6-triazine (x = 1 and 2), and the penta-fluorophenyl-substituted analogues were prepared, in yields of 50-75%, from the respective imidoylamidines and trichlorophosphoranes. The physical properties of the corresponding phenyl and pentafluorophenyl monophospha-s-triazines did not differ significantly; the perfluoroalkyl-substituted materials were low melting solids whereas the perfluoroalkyl-ether-containing compositions were liquids. Preliminary degradative studies showed these compounds to be thermally and oxidatively stable. The l-diphenylphospha-3,5-bis[C3F7OCF(CF3)CF2OCF(CF3)]-2,4,6-triazine was found to be an effective anti-corrosion additive for perfluoroalkylether type fluids.  相似文献   
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