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71.
We have studied the role of defects on the magnetic properties of carbon materials using first-principles density functional methods. We show that, while the total magnetization decreases both for diamond and graphite with increase in vacancy density, the magnetization decreases more rapidly for graphitic structures. The presence of nitrogen nearby a vacancy is shown to produce larger macroscopic magnetic signals as compared to a standalone carbon vacancy. The results indicate the possibility of tuning magnetization in carbon by controlled defect generation and doping. 相似文献
72.
73.
Jena Sudipta Ray Asit Sahoo Ambika Kamila Pradeep Kumar Nayak Sanghamitra Panda Pratap Chandra 《Chemistry of Natural Compounds》2021,57(6):1147-1149
Chemistry of Natural Compounds - 相似文献
74.
Baburajan A. Sudheendran V. Gaikwad R. H. Ravi P. M. Nayak Rashmi S. D’Souza Shiny Renita Karunakara N. 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(1):441-443
Journal of Radioanalytical and Nuclear Chemistry - The original publication of the article contains errors in the text and Tables 3, 4 and 5. The corrected text and tables are provided in... 相似文献
75.
Gouranga C. Nayak 《Annals of Physics》2010,325(2):514-3898
Factorization theorem plays the central role at high energy colliders to study standard model and beyond standard model physics. The proof of factorization theorem is given by Collins, Soper and Sterman to all orders in perturbation theory by using diagrammatic approach. One might wonder if one can obtain the proof of factorization theorem through symmetry considerations at the lagrangian level. In this paper we provide such a proof. 相似文献
76.
Manohar Mahato Gaurav Rana Pradeep Kumar Ashwani Kumar Sharma 《Journal of polymer science. Part A, Polymer chemistry》2012,50(12):2344-2355
Highly toxic polyallylamine (PA) was reacted with a varying amount of a novel linker, 6‐(N,N,N′,N′‐tetramethylguanidinium chloride) hexanoic acid (Tmg‐HA), to prepare a series of tetramethylguanidinium‐PA (Tmg‐PA) polymers, which were used as vectors for gene transfection. The extent of attachment of the linker, Tmg‐HA, to the PA backbone was determined by 2,4,6‐trinitrobenzene sulfonic acid assay. The modified polymers (Tmg‐PAs), when complexed with pDNA, exhibited good condensation ability. The nanoparticles, so formed, were characterized by their size and zeta potential and were subsequently evaluated for their toxicity and transfection ability on various mammalian cells, viz., HeLa, CHO, and HEK 293 cells. Mobility shift assay revealed that on increasing the percent substitution of Tmg‐HA onto PA (from Tmg‐PA1 to Tmg‐PA6), relatively higher amounts of modified polymers were required to retard the mobility of a fixed amount of DNA. Besides, Tmg‐PA polymers provided sufficient protection (ca. 84–88%) to bound DNA against nucleases and one of the formulations, Tmg‐PA2 (ca. 15% substitution) displayed the highest transfection efficiency outcompeting the commercial transfection reagent, Lipofectamine? with minimal cytotoxicity. More impressively, the transfection efficiency increased despite recording a decrease in the buffering capacity of the grafted polymers suggesting that buffering capacity is not the sole parameter in determining the gene delivery efficiency of a vector system. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
77.
78.
Ram Manohar Yadav Dinesh Pratap Singh T. Shripathi O. N. Srivastava 《Journal of nanoparticle research》2008,10(8):1349-1354
We report the observations made on the synthesis and characterization of C–N nanotube blocks and Y-junctions in bamboo-like
C–N nanotubes. The C–N nanotube Blocks have been synthesized by pyrolyzing the mixture of silver nitrate acetonitrile solution
and ferrocene benzene solution. The structural/microstructural characterization of the as-synthesized material has been done
using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopic (XPS)
analysis has been carried out to confirm the presence of nitrogen in nanotubes. These investigations reveal the formation
of blocks of bamboo-like nanotubes having the dimension 300 × 200 × 30 μm and the diameter is 20–50 nm. We also observe the
formation of Y-junctions in bamboo-like nanotubes as we spray the acetonitrile ferrocene and AgNO3 mixture. The length of the synthesized Y-junction nanotube bundles is ~2 μm. Some more complex Ψ-shaped junctions are also
found to be present. The diameters of the Y-junction nanotubes is ~80 nm at the junction and 25–50 nm at the branches. 相似文献
79.
The paper reports a structural study of some memory and threshold chalcogenides in terms of coordination numberC, defined byC=8−N, and is the average coordination number for covalently bonded materials. The average number of nearest neighbours surrounding
a central atom, obtained for As-Ge-Te (memory) and Se-Ge-Te (threshold) systems have been used to estimate the cohesive energies,
assuming simple additivity of bond energies. The bonding pattern so obtained, explains certain properties of these glasses. 相似文献
80.
We study the phenomenon of gyroscopic precession and the analogues of inertial forces within the framework of general relativity. Covariant connections between the two are established for circular orbits in stationary spacetimes with axial symmetry. Specializing to static spacetimes, we prove that gyroscopic precession and centrifugal force both reverse at the photon orbits. Simultaneous non-reversal of these in the case of stationary spacetimes is discussed. Further insight is gained in the case of static spacetime by considering the phenomena in a spacetime conformal to the original one. Gravi-electric and gravi-magnetic fields are studied and their relation to inertial forces is established. 相似文献