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991.
992.
Summary A recently improved model capable of extracting the wind field from SAR imagery without the aid of ?sea truth? is applied
to ERS-1 SAR data for the Mediterranean Sea. The model is based on the properties of the relationship between the first two
moments of the probabilistic distribution function of SAR signals as well as on spectral analysis of the SAR signal itself. 相似文献
993.
Fissile radionuclides in thyroid of the inhabitants of the gomel region in belarus and peculiarities of their distribution 总被引:1,自引:0,他引:1
A. F. Malenchenko N. V. Kanash N. N. Bazhanova I. V. Zhuk E. M. Lomonosova M. K. Kievetz S. F. Boulyga 《Radiation measurements》1997,28(1-6):397-400
Severe radiation damages with the following substitution of connective tissue are the effect of high doses in microvolumes of the thyroid. Calcium, strontium and uranium deposited into these sections was more as compared to a normal tissue of the thyroid. An estimation of the microdistribution of fissile radionuclides was carried out using the method of fragmental radiography. The analysis of tracks done visually using a microscope magnification of 300 revealed the local density of fission fragments up to 103 mm−2. The irradiation of the surrounded cells which contain the hidden genetic damages, initiated by radioiodine, does not exclude their possible promoter role in thyroid cancerogenesis. 相似文献
994.
Borabenzene Derivatives. 25 [1]. Methylbis(1-methylboratabenzene)indium: Synthesis and Structure. An Example for the Variability of Soft Structural Parameters in the Crystalline Environment The new boratabenzene derivative InMe(C5H5BMe)2 has been synthesized from 2-(Me3Sn)C5H5BMe and InMe3. The compound proves fluxional on the nmr time scale with average C2v symmetry in solution. An x-ray structure determination shows the existence of four molecules in the asymmetric unit differing mainly in the bonding geometry of the metal atoms with respect to the eight symmetrically independent boratabenzene ligands. Thus the dynamical behaviour in solution is reflected in the solid state by the soft structural parameters of the indium-ring coordination, with their variability exceeding the standard deviations of the corresponding individual observations by an order of magnitude. 相似文献
995.
Hervé Kunz 《Journal of statistical physics》1994,76(1-2):183-207
We compute the surface correction to the density of states of a particle in a convex box subjected to a magnetic field. Applying these results to orbital magnetism, we find that at high temperatures or weak magnetic fields the surface magnetization is always paramagnetic, but oscillations appear at low temperatures. In two dimensions they can give very large paramagnetic contributions near integer values of the filling factor. Explicit formulas are given for the zero-field susceptibility and for samples with a cylindrical shape in arbitrary magnetic field. 相似文献
996.
997.
Nuclear resonance studies of the two different types impurity doped potassium hexachloro-stannates, the isomorphic system
such as (K–Rb)2SnCl6 and K2(Sn–Re)Cl6 and the nonisomorphic system K2SnCl6:Al3+ in the high temperature cubic phase revealed contrasting features with one the other characterized by static in the former
and dynamic feature in the latter case respectively. The resonance spectra of the nonisomorphic system indicate additionally
a sign of the local structural transition above the conventional structural phase transition temperature. This seems to be
triggered by the ligand-deficient octahedral defects and can be explained in terms of the enhanced activity of the octahedral
defects for the hindered rotation. 相似文献
998.
S. Ohsugi S. Matsumoto Y. Kitaoka M. Matsuda M. Uehara T. Nagata J. Akimitsu 《Hyperfine Interactions》2004,159(1-4):9-14
Nuclear spin–lattice relaxation rate T
1
−1 has been measured for the ladder sites of two single crystals Sr14Cu24O41 (Sr14-A,B) by 63Cu NMR/NQR. The hole localization around 100 K appears as a peak in the T variation of T
1
−1(NQR). On the other hand, it is suppressed in the T
1
−1 (NMR) data under the magnetic field H ∼ 11 T, and a new peak appears around 20 K. T
1
−1(NMR) around the peak is more enlarged for Sr14-B than for Sr14-A. Hence, holes on the ladders of Sr14-B tend to be more localized.
This is considered to be an origin for the occurrence of the magnetic order in Sr14-B under H ∼ 11 T. 相似文献
999.
The acrylamide‐based terpolymers (PADB) with 4‐butylstyrene (BST) as the hydrophobic monomer and dimethyldiallyammonium chloride (DMDAAC) were synthesized by the micellar free radical technique. The polymer was determined by UV, FT‐IR and 1HNMR, and the hydrophobic microblock structure of PADB was characterized successfully by the conventional DSC measurement. The use of DMDAAC improves the water solubility and intermolecular association of terpolymers. The feed amount of BST affects greatly the apparent viscosity of PADB solution. The polymer exhibits good viscosification property, salt resistance, temperature‐thickening, thixotropy, pseudoplastic behavior and shear‐thickening at low shear rate. The apparent viscosities of PADB solution remarkably increase by the addition of a small amount of surfactant. AFM measurements show that hydrophobic aggregates have been formed in 0.1 g dL?1 PADB aqueous solution, indicative of strong associations of hydrophobic groups, which are reinforced with increasing PADB concentration. The microstructures of PADB are disrupted by the addition of small amounts of salt, resulting in the decrease in solution viscosity. However, with increasing NaCl concentration, the tree‐like associating structures are formed, leading to the increase in the solution viscosity of PADB. The AFM results reveal that the solution properties of PADB are due to the associating structures in the aqueous solution and brine solution. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 826–839, 2007 相似文献
1000.
Ruckert T. Keune W. Sahoo B. Sturhahn W. Toellner T. S. Alp E. E. Röhlsberger R. 《Hyperfine Interactions》2002,144(1-4):65-76
Hyperfine Interactions - Nuclear resonant inelastic X-ray scattering (NRIXS) of 14.4125 keV synchrotron radiation was used to measure directly the partial vibrational density of states (VDOS),... 相似文献