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排序方式: 共有191条查询结果,搜索用时 21 毫秒
31.
R. Abela G. Backenstoss A.Brandao DOliveira M. Izycki H.O. Meyer I. Schwanner L. Tauscher P. Blüm W. Fetscher D. Gotta H. Koch H. Poth L.M. Simons 《Physics letters. [Part B]》1977,68(5):429-432
Pionic 3He atoms have been produced in a gaseous target. Energies and strong absorption broadening of the 2 → 1 and the 3 → 1 transition lines have been measured. The 1s level is shifted by 44 ± 5 eV by the (attractive) strong interaction, and the natural 1s level width is 42 ± 14 eV. 相似文献
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It is suggested that the ideal smectic-C reorientation model be modified to include both some rotational slipping of the smectic-C domains and hindered reorientation of a small percentage of molecules to account for the behaviour of proton NMR in smectic-C di-heptyloxyazoxybenzene. The calculated poly-domain line shapes are rather insensitive to the characteristic biaxial order parameter predicted by molecular models of the smectic-C phase. 相似文献
34.
Koichi Fumino Dr. Alexander Wulf Dipl.‐Chem. Ralf Ludwig Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(17):3184-3186
Similarities and differences : Far‐infrared spectra of protic ionic liquids could be assigned to intermolecular bending and stretching modes of hydrogen bonds. The characteristics of the low‐frequency spectra resemble those of water. Both liquids form three‐dimensional network structures, but only water is capable of building tetrahedral configurations. EAN: ethylammonium nitrate, PAN: propylammonium nitrate, DMAN: dimethylammonium nitrate.
35.
Seliverstov AN Suleimanov EV Chuprunov EV Somov NV Zhuchkova EM Lelet MI Rozov KB Depmeier W Krivovichev SV Alekseev EV 《Dalton transactions (Cambridge, England : 2003)》2012,41(28):8512-8514
Three new uranyl tungstates, α-, β-Cs(2)[(UO(2))(2)(W(2)O(9))], and Rb(6)[(UO(2))(7)(WO(5))(2)(W(3)O(13))O(2)], have been obtained by high temperature solid state reactions. All three compounds display novel structure topologies: α- and β-Cs(2)[(UO(2))(2)(W(2)O(9))] are based upon layers with a new topology that can be related to the uranophane topology; Rb(6)[(UO(2))(7)(WO(5))(2)(W(3)O(13))O(2)] is a rare example of a non-molecular inorganic phase with layers containing oxo-tungstate trimers. The structural relationship between α- and β-Cs(2)[(UO(2))(2)(W(2)O(9))] can be assigned to polytypism. 相似文献
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W. Fetscher P. Kokkas P. Pavlopoulos Th. Ruf Th. Schietinger 《Zeitschrift fur Physik C Particles and Fields》1996,72(4):543-547
We propose a new method for measuring the difference $\Delta f = f(0) - \bar f(0)$ of the forward scattering amplitudes for K0 and $\bar K^0 $ by use of decay rates of initially pure strangeness states after passage through a regenerator. The phenomenology of coherent kaon regeneration is presented for arbitrary mixtures of K0 and $\bar K^0 $ . 相似文献
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Distinctive Molecular Abnormalities in Benign and Malignant Skin Lesions: Studies by Raman Spectroscopy 总被引:6,自引:0,他引:6
Monika Gniadecka Hans C. Wulf Ole F. Nielsen Daniel H. Christensen Jana Hercogova 《Photochemistry and photobiology》1997,66(4):418-423
Abstract— Near-infrared Fourier transform Raman spectroscopy is an analytical, nondestructive technique that provides information about the molecular structure of the investigated sample. The molecular structure of proteins and lipids differs between neoplastic and normal tissues and therefore Raman spectroscopy has been considered promising for the diagnosis of cancer. We aimed to compare the molecular structure of normal skin, benign and malignant skin lesions by the near-infrared Fourier transform Raman spectroscopy. Biopsies were obtained from the following skin lesions: skin tag, dermatofibroma, seborrhoeic keratosis, actinic keratosis, keratoacan-thoma, basal cell carcinoma, squamous cell carcinoma, nevus intradermal, nevus compositus, dysplastic nevus and lentigo maligna. Control skin was harvested from the vicinity of these lesions. In the Raman spectra, the secondary structure of the proteins was reflected by the amide vibrations of peptide bonds. The principal lipid vibrations were twisting and wagging (CH2 ) and CH stretching vibrations. Histologically distinguishable lesions showed specific combinations of band changes indicating alterations in the protein conformation and in the molecular structure of the lipids. Histogenetically related lesions (actinic keratosis and sqamous cell carcinoma) produced similar but not identical patterns of spectral changes. Because the examined skin lesions produced reproducible and unique spectra, we suggest that Raman spectroscopy will be useful for diagnosis of skin lesions. 相似文献
40.
In this study, magnetic cores made of amorphous rectangular tape layers are investigated. The quality factor Q of the tape material decreases rapidly, however, when stacking at least two tape layers. The hysteresis loop becomes non-linear, and the coercivity increases. These effects are principally independent of the frequency and occur whether tape layers are insulated or not. The Kerr-microscopy was used to monitor local hysteresis loops by varying the distance of two tape layers. The magnetization direction of each magnetic domain is influenced by the anisotropy axis, the external magnetic field and the stray field of magnetic domains of the neighboring tape layers. We found that crossed easy axes (as the extreme case for inclined axes) of congruent domains retain the remagnetization and induce a plateau of the local loop. Summarizing local loops leads to the observed increase of coercivity and non-linearity of the inductively measured loop. A high Q-factor can be preserved if the easy axes of stacked tape layers are identical within the interaction range in the order of mm. 相似文献