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101.
Robert J. Rubin 《Journal of statistical physics》1991,65(5-6):1207-1216
A one-dimensional lattice random walk in the presence ofm equally spaced traps is considered. The step length distribution is a symmetric exponential. An explicit analytic expression is obtained for the probability that the random walk will be trapped at thejth trapping site. 相似文献
102.
103.
Lerner E.J. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1989,17(2):259-263
A cosmological model is presented that produces He, C, O, D, Li, Be, and B in their observed abundances without a Big Bang. The elements are produced during the 1.5-Gy formation period of a galaxy, with C, O, and other heavy elements produced by stars of M >12 M3 , He by stars of 6 Ms<M <12 Ms, and D, Li, Be, and B by cosmic-ray reactions in a nearly pure H plasma halo. Thus, the model shows that the major elements used in astrophysical studies can be produced during galactic formation by exactly the same processes known to function today at much lower rates 相似文献
104.
N. Monnanteuil J.M. Colmont 《Journal of Quantitative Spectroscopy & Radiative Transfer》1983,29(2):131-136
Self broadened widths of seven lines of ozone between 75 and 120 GHz have been measured at room temperature. The variation with temperature of the self-broadening parameter for three of these lines has been studied in the range 245–292°K. 相似文献
105.
E. Goering M. Justen J. Geissler U. Rüdiger M. Rabe G. Güntherodt G. Schütz 《Applied Physics A: Materials Science & Processing》2002,74(6):747-753
Highly a-axis-textured CrO2 films have been deposited on Al2O3 (0001) substrates by chemical vapor deposition. CrO2 has been found to have highly a-axis (010)-oriented columnar growth on a Cr2O3 (0001) initial layer. The six-fold surface symmetry of the Cr2O3 initial layer leads to three equivalent in-plane orientations of the a-axis-oriented CrO2 unit cell. We report Cr L2,3 X-ray magnetic circular dichroism data along the surface normal and at 60° off-normal sample orientation. For a 60° sample
alignment, a strong increase of the projected orbital moment could be observed for unoccupied majority t2g states using moment analysis. Therefore, the c axis is identified as the intrinsic magnetic easy axis of CrO2. In addition, a small spin moment and a very strong magnetic dipole term Tz have been found.
Received: 8 January 2002 / Accepted: 8 January 2002 相似文献
106.
The effect of gradients in hardness, structure and composition in the surface layers on magnetic Barkhausen noise (MBN) was investigated in two widely used low alloy steels. One material was case hardened by induction hardening. The other was case carburised. Similar hardness profiles were produced by the two treatments. It was found that the variation in structure and hardness through the case in the induction-hardened steel had a minor effect on the MBN profile. In contrast, the inhomogeneity in the case-carburised material showed up clearly. This took the form of a broadened or two-peak MBN profile. When the surface layer containing the case was removed by etching, the broadened profile was replaced by a profile with a single peak. It is concluded that the shape and position of the MBN profile is significantly affected when a gradient in microstructure is induced by a gradient in carbon content. On the other hand, a gradient in microstructure induced by heat treatment with a constant carbon level has much less affect on the MBN profile for the induction-hardened steel. 相似文献
107.
108.
E. Baggio Saitovitch F. J. Litterst I. Souza Azevedo R. B. Scorzelli 《Hyperfine Interactions》1989,50(1-4):529-535
The Mössbauer spectra of YBa2(Cu1?x Fe x )3O7 at room temperature show several doublets attributed to Fe in Cu(1) sites with different oxygen configurations. Here we present a systematic study performed at 4.2 K forx=0.005, 0.01, 0.03, 0.05, 0.10, 0.15. To obtain information about the magnetic ordered state two samples, withx=0.005 andx=0.15, have been studied at 4.2 K underB ext=5 T. The Mössbauer spectra indicate that the iron moments are polarized forx=0.005, while in the ordered state (x=0.15) they have an antiferromagnetic or spin-glass-like arrangement with high anisotropy. 相似文献
109.
In recent years there has emerged significant interest in low pressure radio frequency (rf) glow discharges which are used widely particulary in IC fabrication. Various parameters of the rf glow discharge have been found to be useful for its electrical characterization; however, there is no uniformity and agreement. Extensive experimental investigations on various discharge systems have shown, that the self-bias on the rf driven electrode, the complex conductivity and the breakdown characteristic are preferable parameters of rf discharges. Advantageously the self-bias and the complex conductivity should be presented in dependence on the pressure and the applied rf voltage. The discharge current cannot be measured quite accurately due to currents via leaky capacitors and the deviations from a sinusoidal form of the current due to nonlinearities. 相似文献
110.
In this paper, we study the consistency of a variant of fractionalstep Runge–Kutta methods. These methods are designed tointegrate efficiently semi-linear multidimensional parabolicproblems by means of linearly implicit time integration processes.Such time discretization procedures are also related to a splittingof the space differential operator (or the spatial discretizationof it) as a sum of simpler linear differentialoperators and a nonlinear term. 相似文献