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991.
There are presented measurements of the NMR field shifts for aqueous protons in aqueous solutions containing paramagnetic inorganic compounds of Cu2+, Cr3+, Fe3+ and Mn2+ ions. The measurements have been performed on samples in the form of transversally magnetized long cylinders using both the internal and external NMR standards. The experimentally determined shifts are related to the NMR field position of protons in pure water. The results for demagnetizing shifts are compared with the data which were computed from the magnetic susceptibility values (measured by magnetostatic method), the chemical shifts are compared with the results of other authors. Results of measurements indicate a small chemical shift of internal standards in some solutions. 相似文献
992.
The oxidation of Fe(110) by O2 and H2O vapour has been studied by AES and LEED at room temperature in well ordered and in Ar bombarded surfaces. Ion irradiation causes in both cases an enhancement of the rate of oxidation. For O2 adsorption, it has been found that ion bombardment increases the rate of surface oxide growth, whereas in the case of H2O adsorption, the effect of the irradiation consists in facilitating the penetration of oxygen into the crystal bulk. 相似文献
993.
Collisional and Doppler linewidths (v
C
and v
D
) of the 469.4 nm and 473.9 nm Kr ion lines were measured in a He-Kr hollow cathode discharge using Fabry-Perot technique. A linear dependence of v
C
on He pressure was found for both lines. Significant differences were found between the temperature values deduced from the v
D
-s of the two lines, and an unexpected temperature dependence of the broadening parameter for the Kr+ 469 nm line was also observed. The temperature difference between the two lines is explained by excitation of the upper level of the 469 nm line by second kind collisions between metastable He atoms and ground-state Kr ions, while the temperature dependence of the broadening parameter of the Kr+ 469 nm line is suggested to be due to the inverse process. 相似文献
994.
F. Soška F. Beneš S. Jura B. Gross Z. šimša F. Kosek J. Horák J. Kašpar K. čermák J. Lipták M. Ryba E. F. Holländer A. Havránek E. Havránková A. Kochanovská J. Sommer F. Vilím P. Lukáš C. Rumler S. Kadečková F. Vávra M. Matyáš J. Beneš J. Kučera L. DvoŘák Z. KudĚlásek J. Hájek A. Marek Z. Malec J. Janků B. Sojka L. Karmazin M. Ryšavá L. Janko K. Huml 《Czechoslovak Journal of Physics》1961,11(11):852-862
995.
The separated 2–5 lines of the Mössbauer spectrum of amorphous Fe90Zr10 alloys has been obtained from the linear combination of the spectra of unpolarized and magnetically polarized samples. The hyperfine field distribution has been determined from the original spectra and from the separated 2–5 lines using different evaluation methods (binomial distribution method. Fourier method and Window method). 相似文献
996.
997.
A. Jánosi 《Zeitschrift für Physik B Condensed Matter》1990,80(3):393-400
We study the effects of some of the most important and typical structural changes in two-phase systems on selected structural parameters obtained from small-angle x-ray scattering (SAXS) measurements. To limit the present study, it was assumed that the Phase, 1, embedded in the matrix
- is monodispersed and homogeneous,
- possesses one of the three most extreme shapes (spherical, fibrillar or lamellar) and
- changes its behaviour
- through type change (spinodal or nucleotic or coarsening), without changing the shape,
- through a change of the shape only, or
- through a) (type change) and b) (shape change) simultaneously.
- chord lengthl 1 (and/or radius of gyrationR),
- volume partw 1 of the Phase 1, and
- relative inner surfaceS v of the system.
- spinodal change, all three SAXRS parameters are increasing or decreasing simultaneously and proportional to a power of the intensity of the change,
- nucleotic change,l 1 (and/orR) is unchanged, the other two (w 1 andS v ) are increasing or decreasing simultaneously and directly proportional to the intensity,
- coarsening change,w 1 is unchanged and anincreasing ofl 1 is always accompanied by adecreasing ofS v and vice versa.
998.
Ariel Fernández 《Zeitschrift für Physik B Condensed Matter》1990,79(2):255-258
We establish the existence ofФ 4-solitons travelling along the backbone of an RNA double stranded helix. Taking advantage of the catalytic activity of RNA in proton transfer events, we device a probe for such coherent solitary-wave excitations: We prove that the density of domain walls is increased by the same phonon excitations which would enhance proton exchange. The rationale behind our conclusion is that the uracil bases contained within the domain wall are tautomerized. 相似文献
999.
J. Červenák 《Czechoslovak Journal of Physics》1969,19(11):1379-1388
The VA characteristics of thin-film metal-InSb-metal structures are analyzed in the temperature interval from –100 °C to 140 °C, up to an electric field intensity ofE 2×104 V/cm, on samples having an InSb resistivity of 104 cm, and prepared by cathodic sputtering. In interpreting the VA characteristics, we start out from Lampert's theory on space charged limited electric currents, according to which the injection of carriers of one kind is considered and the mobility of the carriers depends upon the electric field intensity. Attention is drawn to the qualitative agreement of the experimental and theoretical results. 相似文献
1000.
Z. Sedláček 《Czechoslovak Journal of Physics》1972,22(6):439-458
The van Kampen-Case treatment of the linearized Vlasov equation is generalized to cases of non-uniform plasmas in non-uniform equilibrium fields. This is done by transforming the Vlasov operator into the representation of the eigenfunctions of the streaming operator. The Vlasov operator is thus reduced to the form of a multiplication operator perturbed by an integral operator so that the continuum eigenfunctions may be constructed by adapting a method originally devised in neutron transport theory. The calculation leads to solving a non-singular Fredholm-type integral equation. Various kinds of degeneracy of the continuous spectrum are discussed and an example is given.Nademlýnská 600, Praha 9, Czechoslovakia. 相似文献