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排序方式: 共有163条查询结果,搜索用时 265 毫秒
1.
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
2.
White biotechnology is a fast emerging area that concerns itself with the use of biotechnological approaches in the production
of bulk and fine chemicals, biofuels, and agricultural products. It is a truly multidisciplinary area and further progress
depends critically on the role of chemists. This article outlines the emerging contours of white biotechnology and encourages
chemists to take up some of the challenges that this area has thrown up. 相似文献
3.
Smita Rai 《Tetrahedron》2007,63(11):2455-2465
Three porphyrin building blocks with N4, N3S and N2S2 cores having three meso-furyl groups and one meso-iodophenyl group were synthesized and characterized. The porphyrin building blocks were used to synthesize six porphyrin dyads such as N4-N4, N3S-N3S, N2S2-N2S2, N4-N3S, N4-N2S2 and N3S-N2S2 containing meso-tolyl and meso-furyl porphyrin sub-units under mild Pd(0) mediated coupling conditions. Steady state fluorescence studies indicated an efficient energy transfer from the meso-tolyl porphyrin sub-unit to the meso-furyl porphyrin sub-unit in all six dyads. This study supported the argument that the meso-furyl porphyrins can be used as good energy acceptors when meso-aryl porphyrins act as energy donors in their metal free form. 相似文献
4.
Archika?C.?Barve Smita?Ghosh Anupa?A.?Kumbhar Avinash?S.?KumbharEmail author Vedavati?G.?Puranik 《Transition Metal Chemistry》2005,30(3):312-316
The DNA binding characteristics of mixed ligand complexes of the type [Co(en)2(L)]Br3 where en = N,N′-ethylenediamine and L = 1,10-phenanthroline (phen), 2,2′-bipyridine (bpy), 1,10-phenanthroline-5,6-dione (phendione), dipyrido[3,2-a:2′,3′-c]phenazine (dppz) have been investigated by absorption titration, competitive binding fluorescence spectroscopy and viscosity measurements. The order of intercalative ability of the coordinated ligands is dppz > phen > phendione > bpy in this series of complexes. 相似文献
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7.
N-((2-chloroquinolin-3-yl)methylene)aniline (CQM) and N-((2-chloroquinolin-3-yl)methylene)-5-methylthiazol-2-amine (CQMA) were synthesized. The effect of CQM and CQMA have been investigated against mild steel (MS) in 1 N HCl solutions using conventional weight loss, potentiodynamic polarization, linear polarization, electrochemical impedance spectroscopy, UV–Vis spectroscopy and scanning electron microscopic studies. The losses in the weights of MS samples have proved that both CQM and CQMA are efficient inhibitors. The mixed mode of inhibition was confirmed by electrochemical polarizations. The adsorptions of these inhibitors are found to follow the Langmuir adsorption isotherm. CQM and CQMA adsorbs on the MS sample by chemisorptions. 相似文献
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9.
A method to track a grid of cardiac material points in three dimensions using slice-following (SF) tagged magnetic resonance imaging (MRI) and harmonic-phase MRI is presented. A three-dimensional grid of material points on the lines of intersections of short-axis (SA) and long-axis (LA) planes is automatically tracked by combining two-dimensional pathlines that are computed on both SA and LA image planes. This process yields the true three-dimensional motion of points originating on the image plane intersections. Experimental data from normal volunteers, each obtained in four short breath-holds using the SF harmonic phase MRI pulse sequence, is presented. A validation of two-dimensional in-plane tracks using this pulse sequence on a moving phantom is also presented. 相似文献
10.
Kesiya George Bishnu P Panda Manoranjan Biswal Smita Mohanty Sanjay K Nayak 《先进技术聚合物》2020,31(6):1280-1290
This work scrutinizes the utilization of ethylene propylene diene monomer rubber matrix (EPDM) with an embodiment of aramid fiber for the heat shielding applications in solid rocket motor (SRM). Aramid fibers are aromatic poly‐paraphenylene terephthalamide, here deployed are Kevlar fibers (KF). However, the literature that encompasses the thermal and mechanical behavior with the fiber loading is reported nowhere else. The effect of fiber addition on the surface morphology and density was thoroughly studied, and it revealed that the EHSMs were of lower density to act as an efficient payload for the SRM. In this regard, the thermal conductivity, heat capacity, thermal diffusivity, fire behavior, and mechanical properties of the EPDM/KF‐based EHSMs were explored. The results revealed that the EHSMs are thermally insulating and thermally stable material with balanced mechanical properties that can engender the thermal and mechanical strains of the rocket motor. Furthermore, other analytical techniques such as scanning electron microscopy and energy dispersive X‐ray spectroscopy have been exploited to monitor the performance of the char residues of the EHSM to delineate its performance in the fire atmosphere. 相似文献