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991.
Jung-Hyung Kim Seek-Min Yun Hong-Yeung Chang 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1996,24(6):1364-1370
The characteristics of plasma produced by plane polarized m=±1 and m=±2 mode helicon waves were investigated for the first time. Plane polarized m=±1 and m=±2 mode helicon waves were mainly excited using a Nagoya type III antenna and a quadrupole antenna, respectively. Two-dimensional cross-field measurements of ArII optical emission induced by hot electrons were made to investigate the RF power deposition. The components of the wave magnetic field measured with a magnetic probe were compared with the field profiles computed for the m=±1 and m=±2 modes. Two and four high intensity plasma columns were observed for the m=±1 and m=±2modes, respectively. These columns were located at the regions between the antenna legs. The radial profiles of the wave magnetic field were in good agreement with computations 相似文献
992.
Synthesis of cordierite gels was performed using Si(OC2H5)4 and aluminum and magnesium nitrates as starting materials under basic conditions. Further heat treatment yields the successive
crystallisation of μ and α-cordierites and of some amounts of spinel as a secondary phase as revealed by X-ray diffraction.
The poor final densification (84% of the theoretical value) of samples obtained from the as-prepared powders has been improved
by ball-milling to values up to 95–98% of the theoretical value, the spinel proportion being simultaneously decreased. 相似文献
993.
Aromatic and aliphatic nitro compounds were readily reduced to amino compounds in excellant yields with graphite and hydrazine hydrate. 相似文献
994.
The fluorescence produced by the catalytic effect of the manganese (III)-tetrakis-(N-methylpyridinium)porphyrin complex (Mn-TMPyP) on the oxidation of homovanillic acid by hydrogen peroxide has been studied. The reaction product fluoresces at 424 nm (with excitation at 316 nm). Traces of hydrogen peroxide (1.3 × 10–7–2.4 × 10–6
M) and glucose (1.5–5.0 g/ml) can be determined with good accuracy and reproducibility. The characteristics of the mimetic enzyme Mn-TMPyP have been compared with those of horseradish peroxidase. 相似文献
995.
996.
Hybrid density-functional theory (B3LYP) calculations were carried out to determine the structures and energies of endohedral complexes of non-pi C(60)H(60) with H(2), CO, and LiH. It was demonstrated that the endohedral complexes of C(60)H(60) with the above three guest molecules are more stable than the corresponding complexes with C(60). Furthermore, the interaction between C(60)H(60) and the inside H(2) or CO is negligible, but the formation of the LiH-C(60)H(60) complex is exothermic with a stabilization energy of -6.0 kcal/mol. While the bond lengths of H(2) and CO changed a little when placed inside the cages, that of the LiH molecule increased and decreased inside C(60)H(60) and C(60), respectively. 相似文献
997.
A new, air stable and well-defined carbene-copper(II) complex has been prepared, which is an efficient precatalyst for the 1,2- and 1,4-reduction of carbonyl compounds under hydrosilylation conditions. 相似文献
998.
999.
In this paper, a semidiscrete finite element Galerkin methodfor the equations of motion arising in the 2D Oldroyd modelof viscoelastic fluids with zero forcing function is analysed.Some new a priori bounds for the exact solutions are derivedunder realistically assumed conditions on the data. Moreover,the long-time behaviour of the solution is established. By introducinga StokesVolterra projection, optimal error bounds forthe velocity in the L(L2) as well as in the L(H1)-norms andfor the pressure in the L(L2)-norm are derived which are validuniformly in time t > 0. 相似文献
1000.