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CV Tomy D Pal SS Banerjee S Ramakrishnan AK Grover S Bhattacharya MJ Higgins G Balakrishnan McK Paul 《Pramana》2002,58(5-6):925-935
The weakly pinned single crystals of the hexagonal 2H-NbSe2 compound have emerged as prototypes for determining and characterizing the phase boundaries of the possible order-disorder
transformations in the vortex matter. We present here a status report based on the ac and dc magnetization measurements of
the peak effect phenomenon in three crystals of 2H-NbSe2, in which the critical current densities vary over two orders of magnitude. We sketch the generic vortex phase diagram of
a weakly pinned superconductor, which also utilizes theoretical proposals. We also establish the connection between the metastability
effects and pinning. 相似文献
3.
4.
Nilgün KABAY Yasemin BAYGU Metin AK zzet KARA EsraNur KAYA Mahmut DURMU Yaar G
K 《Turkish Journal of Chemistry》2021,45(1):143
The current study describes the synthesis, electrochemical, computational, and photochemical properties of octa (3-hydroxypropylthio) substituted cobalt (II) ( 4 ), copper (II) ( 5 ), nickel (II) ( 6 ) and zinc(II) ( 7 ) phthalocyanine derivatives. These novel compounds were characterized by elemental analysis,1H,13C NMR, FT-IR, UV-Vis, and MS. The redox behaviors of these metallo-phthalocyanines were investigated by the cyclic voltammetric method. The optimized molecular structure and gauge-including atomic orbital (GIAO)1H and13C NMR chemical shift values of these phthalocyanines in the ground state had been calculated by using B3LYP/6–31G(d,p) basis set. The outcomes of the optimized molecular structure were given and compared with the experimental NMR values. The photochemical properties including photodegradation and singlet oxygen generation of zinc(II) phthalocyanine were studied in DMSO solution for the determination of its photosensitizer behaviors. 相似文献
5.
R. Talukdar A. Tripathy P.N. Bajaj P.K. Chakraborti G.D. Saksena 《Optics Communications》1983,45(3):179-182
Crossed laser molecular beam configuration was used to study the photoionization of U and UO by the UV-lines of an argon ion laser. Photoionization efficiencies of both U and UO were found to be line sensitive. Photoionization by the 3638 Å line was observed for the first time. Uranium atom ionization efficiency being higher for the 3345 Å and 3511 Å groups of lines, while UO ionization efficiency being maximum for the 3638 Å line. Dependence of photoion signal on laser power and relative photoionization efficiencies of the two isotopic species of uranium are also investigated. 相似文献
6.
A glycosyl acceptor and a glycosyl donor having the N-3-deoxy-L-glycero-tetronic acid side chain already attached have been prepared and used for the synthesis of the di-through to the hexasaccharide that mimic the upsteam terminus of the O-specific polysaccharide of Vibrio cholerae O:1, serotype Inaba. The target tetra- and the hexasaccharide, which were obtained in the form of 5-methoxycarbonylpentyl glycosides, were linked to BSA using squaric acid diester chemistry. The conjugation reactions were monitored by surface enhanced laser desorption ionization-time of flight mass spectrometry (SELDI-TOF MS). This allowed the progression of the conjugation of the synthetic oligosaccharides in a controlled way and termination of the reaction when the desired molar hapten/BSA ratio had been reached, yielding neoglycoconjugates with predetermined carbohydrate/carrier ratios. The ability to monitor the conjugation by the SELDI-TOF MS technique made it possible to prepare, from one hapten in a one-pot reaction, several neoglycoconjugates having different, predetermined carbohydrate/carrier ratios. 相似文献
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8.
Study of magnetoresistance and conductance of bicrystal grain boundary in La0.67Ba0.33MnO3 thin film
La0.67Ba0.33MnO3 (LBMO) thin film is deposited on a 36.7°C SrTiO3 bicrystal substrate using laser ablation technique. A microbridge is created across bicrystal grain boundary and its characteristics
are compared with a microbridge on the LBMO film having no grain boundary. Presence of grain boundary exhibits substantial
magnetoresistance ratio (MRR) in the low field and low temperature region. Bicrystal grain boundary contribution in MRR disappears
at temperature T>175 K. At low temperature, I-V characteristic of the microbridge across bicrystal grain boundary is nonlinear. Analysis of temperature dependence of dynamic
conductance-voltage characteristics of the bicrystal grain boundary indicates that at low temperatures (T<175 K) carrier transport across the grain boundary in LBMO film is dominated by inelastic tunneling via pairs of manganese
atoms and tunneling through disordered oxides. At higher temperatures (T>175 K), magnetic scattering process is dominating. Decrease of bicrystal grain boundary contribution in magnetoresistance
with the increase in temperature is due to enhanced spin-flip scattering process. 相似文献
9.
The first synthesis of β‐L ‐glycoside 17 of the tetrasaccharide β‐Ant‐(1 → 3)‐α‐L ‐Rhap‐(1 → 3)‐α‐L ‐Rhap‐(1 → 2)‐L ‐Rhap is described (Schemes 1–3). Its spacer can be functionalized to make it amenable to conjugation to proteins by different conjugation methods. The synthesis was performed in a stepwise manner starting from the aglycon‐bearing terminal saccharide with thioglycosides as glycosyl donors. To attach the upstream terminal anthrose residue, the assembled linker‐equipped trisaccharide was glycosylated with ethyl 4‐azido‐3‐O‐benzyl‐2‐O‐(bromoacetyl)‐4,6‐dideoxy‐1‐thio‐β‐D ‐glucopyranoside ( 11 ). Further functionalization of the tetrasaccharide thus obtained, followed by deprotection gave the target substance 17 . Synthesis of substructures of 17 equipped with the same spacer, namely β‐L ‐Rhap‐1‐O‐(CH2)5COOMe ( 21 ), α‐L ‐Rhap‐(1 → 2)‐β‐L ‐Rhap‐1‐O‐(CH2)5COOMe ( 22 ), and α‐L ‐Rhap‐(1 → 3)‐α‐L ‐Rhap‐(1 → 2)‐β‐L ‐Rhap‐1‐O‐(CH2)5COOMe ( 23 ), is also described (Scheme 4). 相似文献
10.