排序方式: 共有10条查询结果,搜索用时 46 毫秒
1
1.
Self-injection length in La0.7Ca0.3MnO3-YBa2Cu3O7-δ ferromagnet-superconductor multilayer thin films
We have carried out extensive studies on the self-injection problem in barrierless heterojunctions between La0.7Ca0.3MnO3 (LCMO) and YBa2Cu3O7-δ (YBCO) thin films. The heterojunctions were formed in situ by sequentially growing LCMO and YBCO films on 〈100〉 LaAlO3 (LAO) substrate using a pulsed laser deposition (PLD) system. YBCO micro-bridges with 64 μm width were patterned both on
the LAO (control) and LCMO side of the substrate. Critical current, I
c, was measured at 77 K on both the control side as well as the LCMO side for different YBCO film thickness. It was observed
that while the control side showed a J
c of ∼ 2 × 106 A/cm2, the LCMO side showed about half the value for the same thickness (1800 ?). The difference in J
c indicates that a certain thickness of YBCO has become ‘effectively’ normal due to self-injection. From the measurement of
J
c at two different thicknesses (1800 ? and 1500 ?) of YBCO films both on the LAO as well as the LCMO side, the value of self-injection
length (at 77 K) was estimated to be ∼ 900 ?. To the authors’ best knowledge, this is the first time that self-injection length
has been quantified. A control experiment carried out with LaNiO3 deposited by PLD on YBCO did not show any evidence of self-injection. 相似文献
2.
3.
CoFe2O4-BaTiO3 composites were prepared using conventional ceramic double sintering process with various compositions. Presence of two phases
in the composites was confirmed using X-ray diffraction. The dc resistivity and thermoemf as a function of temperature in
the temperature range 300 K to 600 K were measured. Variation of dielectric constant (ɛ′) with frequency in the range 100 Hz to 1 MHz and also with temperature at a fixed frequency of 1 kHz was studied. The ac
conductivity was derived from dielectric constant (ɛ′) and loss tangent (tan δ). The nature of conduction is discussed on the basis of small polaron hopping model. The static value of magnetoelectric
conversion factor has been studied as a function of magnetic field. 相似文献
4.
A Gurtu P K Malhotra I S Mittra P M Sood SC Gupta VK Gupta GL Kaul LK Mangotra Y Prakash NK Rao ML Sharma 《Pramana》1974,3(5):311-322
This is a continuation of our earlier investigation (Gurtuet al 1974Phys. Lett. 50 B 391) on multiparticle production in proton-nucleus collisions based on an exposure of emulsion stack to 200 GeV/c beam at the NAL. It is found that the ratioR em = 〈n s〉/〈n ch〉, where 〈n ch〉 is the charged particle multiplicity in pp-collisions, increases slowly from about 1 at 10 GeV/c to 1·6 at 68 GeV/c and attains a constant value of 1·71 ± 0·04 in the region 200 to 8000 GeV/c. Furthermore,R em = 1·71 implies an effectiveA-dependence ofR A =A 0.18,i.e., a very weak dependence. Predictions ofR em on various models are discussed and compared with the emulsion data. Data seem to favour models of hadron-nucleon collisions in which production of particles takes place through adouble step mechanism,e.g., diffractive excitation, hydrodynamical and energy flux cascade as opposed to models which envisage instantaneous production. 相似文献
5.
Munshi G Mustafa Sudhir Raniwala T Awes B Rai RS Bhalerao JG Contreras RV Gavai SK Ghosh P Jaikumar GC Mishra AP Mishra H Mishra B Mohanty J Nayak J-Y Ollitrault SC Phatak L Ramello R Ray PK Sahu AM Srivastava DK Srivastava VK Tiwari 《Pramana》2006,67(5):961-981
This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and
work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported. 相似文献
6.
KB McTiernan SC Jarvis D Allen R Bol D Scholefield 《Rapid communications in mass spectrometry : RCM》1999,13(18):1803-1807
The composition of dissolved organic matter (DOM) in a soil is the product of a variety of soil processes. Changes in the composition of DOM in water discharged from soil should, therefore, give an important insight into modifications in these soil processes. We hypothesise that these processes in soils, under different grassland management regimes, would be affected to different extents by the short-term disturbance of a storm event and that evidence of this could be detected in delta(13)C and delta(15)N signatures in drainage and surface runoff waters. During a storm event we collected discharge waters from 1 ha grassland lysimeters, with or without artificial drainage, which received contrasting fertiliser inputs, and delta(13)C and delta(15)N signatures were determined. Changes in (13)C enrichment during the storm event were clearly identifiable, as were differences between plots for (13)C and (15)N, illustrating that this technique has potential to be a useful tool for identifying and investigating short- and long-term changes in soil organic matter dynamics. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
7.
8.
Attilio Milanese Pier Marzocca Mels Belubekyan Karen Ghazaryan 《International Journal of Solids and Structures》2009,46(10):2126-2135
This paper reports an analytical and numerical study of localized bending waves in a thin elastic isotropic semi-infinite strip with a rib reinforment. Such waves can be considered as spatially non-uniform bending perturbations localized near free edges, similar to Rayleigh waves decaying exponentially with the distance. From the analysis of localized bending waves in thin elastic structures it may be possible to infer the presence of imperfections, cracks or inclusions, in the structure. In this study, a semi-infinite strip, simply supported on two edges and reinforced on the free one, is considered. A general solution is presented and the conditions under which localized bending waves exist are derived. The mathematical model, accompanied by numerical simulations, reveals that the presence of a reinforcement rib can suppress localized bending waves. This effect is mainly due to the stiffness coming from the rib, rather than from its added inertia terms. 相似文献
9.
Trifonov Lena Yurchenko Mariya Skjesol Astrid Cohen Guy Espevik Terje Korshin Edward E. Grøvdal Lene Melsæther Husebye Harald Gruzman Arie 《Molecular diversity》2022,26(4):2175-2188
Molecular Diversity - IFN-β is a cytokine that plays a significant role in the immune system. Inhibition of IFN-β might be used as a therapeutic approach to treat septic shock. A... 相似文献
10.
Richter SN Maggi S Mels SC Palumbo M Freccero M 《Journal of the American Chemical Society》2004,126(43):13973-13979
The photogeneration and detection of new binol quinone methides undergoing mono- and bisalkylation of free nucleophiles was investigated by product distribution analysis and laser flash photolysis in water solution using binol quaternary ammonium derivatives 2 and 12 as photoactivated precursors. The alkylation processes of N and S nucleophiles are strongly competitive with the hydration reaction. DNA cross-linking potency of the water-soluble binol quaternary ammonium salt 2 was investigated as a pH function and compared to that of other quaternary ammonium salts capable of benzo-QM (QM = quinone methide) photogeneration by gel electrophoresis. DFT calculations in the gas phase and in water bulk on the binol and benzo quaternary ammonium salts 2 and 4 evidence structural and electrostatic features of the binol derivative which might offer a rationalization of its promising high photo-cross-linking efficiency. 相似文献
1