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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
922.
In this paper we present several results about local MV-algebras, extending existing results given for MV-chains. The role
of local MV-algebras in sheaf representation and weak boolean product is stressed and the relationship of local MV-algebras
with varieties of MV-algebras is analyzed.
Presented by S. Pulmannova.
Received November 11, 2005; accepted in final form December 20, 2005. 相似文献
923.
I. Bretos J. Ricote R.J. Jiménez-Riobóo L. Pardo M.L. Calzada 《Applied Physics A: Materials Science & Processing》2007,89(4):967-973
A novel method to investigate the early formation stages of polycrystalline (Pb1-xCax)TiO3 (PCT) perovskite films by means of traditional Brillouin and micro-Brillouin spectroscopy (BS, mBS) is described in the present
work. The films were prepared by chemical solution deposition (CSD) onto oxidized (100)Si substrates and treated at temperatures
between 350–650 °C by rapid thermal processing (RTP). The elastic instability observed by Brillouin spectroscopy at the nano-structured
state of the PCT films was used here to determine their crystallization temperatures. Coexistence of different nanocrystalline
phases (e.g., pyrochlore, perovskite) in the films could also be detected by this technique. The reliability of these results
is demonstrated by complementary information obtained by X-ray diffraction (XRD) and scanning force microscopy (SFM). The
effects of the annealing temperature and of the Ca2+ content on the crystallization process of these films are also discussed.
PACS 78.35.+c; 77.84.-s; 61.82.Rx 相似文献
924.
B. B. Alchagirov B. S. Karamurzov T. A. Sizhazhev T. M. Taova R. Kh. Arkhestov 《Technical Physics》2006,51(12):1627-1629
The temperature and concentration dependences of the electron work function (EWF) of rubidium, cesium, and nine Rb-Cs alloys are studied by the Fowler photoelectric method under the conditions of an ultra-high vacuum. It is shown that the polytherms of the electron work function for the pure components and alloys decrease by a linear law with increasing temperature. Based on the experimental data obtained, it is concluded that the concentration dependence of the EWF for the binary Rb-Cs system has a linear (additive) character within the limits of experimental error (about 1%). The presence of the azeotropic point on the state diagram of the system is not visualized in the concentration dependence of the work function. 相似文献
925.
V. V. Panić A. B. Dekanski S. K. Milonjić V. B. Mišković-Stanković B. Ž. Nikolić 《Russian Journal of Electrochemistry》2006,42(10):1055-1060
Electrocatalytic properties of RuO2/Ti anode with different coating masses, which are prepared by the alkoxide sol-gel procedure, are investigated in chlorine
and oxygen evolution reactions by polarization measurements and electrochemical impedance spectroscopy in H2SO4 and NaCl electrolytes. According to polarization measurements, the activity of anodes at overpotentials below 100 mV is independent
of coating mass. However, impedance measurements above 100 mV reveal changes in the activity of anodes in chlorine evolution
reaction for different coating masses. The diffusion limitations related to the evolved chlorine are registered in low-frequency
domain at 1.10 V (SCE), diminishing with the increase in potential to the 1.15 V (SCE). The observed impedance behavior is
discussed with respect to the activity model for activated titanium anodes in chlorine evolution reaction involving formation
of gas channels within porous coating structure. Gas channels enhance the mass transfer rate similarly to the forced convection,
which also increases the activity of anode. This is more pronounced for the anode of greater coating mass due to its more
compact surface structure. The more compact structure appears to be beneficial for gas channels formation.
Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 10, pp. 1173–1179.
The text was submitted by the authors in English. 相似文献
926.
B. G. Sidharth 《Foundations of Physics Letters》2006,19(6):611-617
In this note we consider a variable G cosmology which is consistent with observation and which had successfully predicted an ever expanding accelerating universe
with a small cosmological constant amongst other things. Three further tests are proposed in this note: First, the inexplicable
anomalous accelerations of the Pioneer spacecrafts can be explained. It is then shown that the observed shortening of the
orbital periods of binary pulsars is in good agreement with this model. Finally, more general changes in orbital parameters
are deduced, which may be observed in the future. 相似文献
927.
We investigate the electronic properties of multiwalled carbon nanotubes both before and after acid treatment with concentrated sulphuric and nitric acids. Magnetic susceptibility measurements were performed using a SQUID magnetometer and show that there is a considerable enhancement in the density of states at the Fermi level. The data shows that the diamagnetic influence from the graphitic nanotubes dominates. We experimentally observe, after acid treatment, that the diamagnetic susceptibility remains unchanged at 5 K but notably decreases at 77 K. We propose the acid treatment has increased the Van Vleck paramagnetic contribution lowering the diamagnetic response from the π-electron orbital magnetisation. The Van Vleck paramagnetic contribution is finite-temperature dependent with a diminishing contribution at higher fields. 相似文献
928.
929.
Recently commercial equipment using sedimentation field flow fractionation (SFFF) has become available for analysis of particulate materials in the sub-micron range. This paper describes the DuPont instrument and discusses its performance. A particular study is described on the comparison of the SFFF technique with that of quasi-elastic light scattering (QELS). The paper concludes that the instrument is capable of measuring particle size distributions with high resolution and precision, provided that no particles above the upper size limit — about 1 μm — are present. 相似文献
930.
B. Sanjeeva Rao M. Ramakrishna Murthy 《Journal of Polymer Science.Polymer Physics》1989,27(6):1187-1194
Electron spin resonance (ESR) spectra of poly(acrylic acid) (PAA) γ-irradiated in air at room temperature and recorded at room temperature and at liquid-nitrogen temperature have been studied to identify the radiation products. The ESR spectra are composed of eight lines with hyperfine splittings of 23 ± 1 G and 11 ± 1 G. The method of least-squares total curve fitting, employing the Lorentzian line shape function, to the observed spectra enabled the assignment of the spectra. Computed spectra obtained by the superposition of a singlet and the spectra due to chain radicals are considered to give the best fits to the observed ESR spectra. The singlet is assigned to the radicals COOH, and the component 10-line spectra are assigned to the chain radicals CH3? CH? CH2 ~ and/or ~ CH2? CH? CH2 ~. The observed change in line shape with temperature of the ESR spectra is attributed to the hindered oscillations of the methyl groups about the Cα? Cβ bond axis of the chain radicals. The existence of the methyl groups is confirmed by the measurement of infrared absorption. 相似文献