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281.
Naveen Kumar A. Karmakar A. Pukhov G. Shvets 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,55(2):415-420
A systematic study on the Weibel instability induced filamentation of a relativistic electron beam is made by including the
effects of collisions and temperature. The stabilization and de-stabilization of the beam filamentation due to beam temperature
and plasma collisions, respectively, is explored through an analytical model and PIC simulations. The de-stabilization of
the beam filamentation is attributed to the collision driven negative energy wave generation in the beam plasma system. 相似文献
282.
We report an efficient synthetic strategy to diverse hydantoins and thiohydantoins involving a three‐component reaction with the aid of deep eutectic solvent. Here, N,N′‐dimethyl urea and N,N′‐dimethyl thiourea play a dual role as reactant and reaction medium along with l ‐(+)‐tartaric acid. The three‐component reaction provides an easy access to 5‐amino‐1,3‐dialkyl‐substituted hydantoins and thiohydantoins in good yields. 相似文献
283.
Satish Shantaram Bhat Naveen Shivalingegowda Vidyanand Krishna Revankar Vitthal Ajinath Kawade Ray J. Butcher Neratur Krishnappagowda Lokanath 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(5):496-503
Two one‐dimensional (1D) coordination polymers (CPs), namely catena‐poly[[[aqua(2,2′‐bipyridine‐κ2N,N′)(nitrato‐κO)copper(II)]‐μ‐1,3‐bis(pyridin‐4‐yl)propane‐κ2N:N′] nitrate], {[Cu(NO3)(C10H8N2)(C13H14N2)(H2O)]·NO3}n ( 1 ), and catena‐poly[[[aqua(nitrato‐κO)(1,10‐phenanthroline‐κ2N,N′)copper(II)]‐μ‐1,3‐bis(pyridin‐4‐yl)propane‐κ2N:N′] nitrate], {[Cu(NO3)(C12H8N2)(C13H14N2)(H2O)]·NO3}n ( 2 ), have been synthesized using [Cu(NO3)(NN)(H2O)2]NO3, where NN = 2,2′‐bipyridine (bpy) or 1,10‐phenanthroline (phen), as a linker in a 1:1 molar ratio. The CPs were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single‐crystal X‐ray structure determination. The 1,3‐bis(pyridin‐4‐yl)propane (dpp) ligand acts as a bridging ligand, leading to the formation of a 1D polymer. The octahedral coordination sphere around copper consists of two N atoms from bpy for 1 or phen for 2 , two N atoms from dpp, one O atom from water and one O atom from a coordinated nitrate anion. Each structure contains two crystallographically independent chains in the asymmetric unit and the chains are linked via hydrogen bonds into a three‐dimensional network. 相似文献
284.
S. Naveen B. Dinesh K. Abiraj D. Channe Gowda M. A. Sridhar J. Shashidhara Prasad 《Journal of chemical crystallography》2007,37(11):721-725
Tert-butyl 2-((phenylthio)carbonyl)pyrrolidine-1-carboxylate, was synthesized by using iso-butoxycarbonyl chloride (i-BuOCOCl) via mixed anhydride method. The obtained product was characterized spectroscopically and finally confirmed by X-ray diffraction studies. The title compound C16 H21 N O3 S crystallizes in the triclinic space group P1 with the cell parameters a = 6.0250(7) Å, b = 8.2820(13) Å, c = 8.7700(14) Å, α = 102.352(4)°, β = 102.993(11)°, γ = 90.279(8)°, V = 415.89(10) Å3 and Z = 1. The proline ring in the structure is in a envelope conformation. The structure exhibits intermolecular hydrogen bonds of the type C–H...O. 相似文献
285.
Laksminarayana Rao Naveen Krishna Reddy Sylvain Coulombe Jean-Luc Meunier Richard J. Munz 《Journal of nanoparticle research》2007,9(4):689-695
This communication reports on a new method for the collection of nanoparticles using carbon nanotubes (CNT) as collecting
surfaces, by which the problem of agglomeration of nanoparticles can be circumvented. CNT (10–50 nm in diameter, 1–10 μm in
length) were grown by thermal CVD at 923 K in a 7 v/v% C2H2 in N2 mixture on electroless nickel-plated copper transmission electron microscopy (TEM) grids and Monel coupons. These samples
were then placed downstream of an arc plasma reactor to collect individual copper nanoparticles (5–30 nm in diameter). It
was observed that the Cu nanoparticles preferentially adhere onto CNT and that the macro-particles (diameter >1 μm), a usual
co-product obtained with metal nanoparticles in the arc plasma synthesis, are not collected. Cu–Ni nanoparticles, a catalyst
for CNT growth, were deposited on CNT to grow multibranched CNT. CNT-embedded thin films were produced by re-melting the deposited
nanoparticles. 相似文献
286.
The boxicity of a graph H, denoted by , is the minimum integer k such that H is an intersection graph of axis-parallel k-dimensional boxes in Rk. In this paper we show that for a line graph G of a multigraph, , where Δ(G) denotes the maximum degree of G. Since G is a line graph, Δ(G)≤2(χ(G)−1), where χ(G) denotes the chromatic number of G, and therefore, . For the d-dimensional hypercube Qd, we prove that . The question of finding a nontrivial lower bound for was left open by Chandran and Sivadasan in [L. Sunil Chandran, Naveen Sivadasan, The cubicity of Hypercube Graphs. Discrete Mathematics 308 (23) (2008) 5795–5800].The above results are consequences of bounds that we obtain for the boxicity of a fully subdivided graph (a graph that can be obtained by subdividing every edge of a graph exactly once). 相似文献
287.
Kamath A Kulkarni NV Netalkar PP Revankar VK 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1418-1424
Phenoxide bridged later first row transition metal(II) complexes have been prepared by the interaction of later 3d transition metal(II) chlorides with tetranucleating compartmental Schiff base ligand system derived from 2,6-diformyl-4-methylphenol, p-phenylenediamine and 2-hydrazinobenzothiazole. Ligand and complexes were characterized by analytical, spectral (IR, UV-visible, ESR, FAB-mass and fluorescence), magnetic and thermal studies. All complexes are found to have octahedral geometry. The mutual influence of metal centres in terms of cooperative effect on the electronic, magnetic, electrochemical and structural properties was investigated. The Schiff base and its complexes have been screened for their antibacterial (against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa) and antifungal activities (against Aspergillus niger, and Candida albicans). 相似文献
288.
Babajan Banaganapalli Chaitanya Mulakayala Gowsia D Naveen Mulakayala Madhusudana Pulaganti Noor Ahmad Shaik Anuradha CM Raja Mohan Rao Jumana Yousuf Al-Aama Suresh Kumar Chitta 《Applied biochemistry and biotechnology》2013,171(7):1639-1657
Resveratrol (RVS) is a naturally occurring antioxidant, able to display an array of biological activities. In the present investigation, a new derivative of RVS, RVS(a), was synthesized, and its biological activity was determined on U937 cells. It was observed that RVS(a) showed pronounced activity on U937 cells than RVS. RVS(a) is able to induce apoptosis in tumor cell lines through subsequent DNA fragmentation. From the EMSA results, it was evident that RVS(a) was able to suppress the activity of NFkB by interfering its DNA binding ability. Furthermore, the molecular interaction analysis (docking and dynamics) stated that RVS(a) has strong association with the IkB-alpha site of NFkB compared with RVS; this binding nature of RVS(a) might be prevent the NFkB binding ability with DNA. The present findings represent the potential activity of propynyl RVS on U937 cells and signifying it as a one of putative chemotherapeutic drugs against cancer. 相似文献
289.
Suresh Palla G. Ravi J. R. Reddy Naveen Kumar Veldurthi Radha Velchuri G. Prasad N. R. Munirathnam M. Vithal 《Journal of Sol-Gel Science and Technology》2013,67(3):507-518
Materials belonging to NASICON family of compositions NaHfM(PO4)3 and AgHfM(PO4)3 (M = Ti and Zr) are prepared by sol–gel and ion exchange methods, respectively. Ethylene glycol is used as a gelating agent. All the compositions are characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, 31P MAS NMR, UV–Vis DRS, XPS and energy dispersive spectral methods. All these phosphates are crystallized in rhombohedral lattice with space group $R\overline{3} c$ R 3 ¯ c . These compounds exhibit characteristic PO4 vibrational modes in their FT-IR spectra. The 31P MAS NMR gave broad signals indicating distribution of chemical environments around P ion. The dc and ac conductivity of AgHfM(PO4)3 (M = Ti and Zr) are higher compared to their sodium containing compounds. The Cole–Cole plots of impedance show semicircles between 373 and 623 K. The variation of dc conductivity with temperature follows the Arrhenius equation. The photocatalytic activity of all the samples was studied against methylene blue decomposition using sun light. AgHfM(PO4)3 (M = Ti and Zr) have shown higher photoactivity than the sodium containing Nasicons. 相似文献
290.
Naveen Gautam Yogesh Dixit Rahul Dixit Sudesh Kumar Gupta Dinesh Chand Gautam 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1127-1136
Abstract 4H-1,4-benzothiazines were prepared by condensation followed by oxidative cyclization of substituted 2-aminobenzenethiols with β-diketones in dimethylsulfoxide. On refluxing with 30% hydrogen peroxide in glacial acetic acid, 4H-1,4-benzothiazines yielded 4H-1,4-benzothiazine-1,1-dioxides. Structural evaluation has been done by spectral and elemental analysis. All the synthesized compounds were evaluated for their antibacterial and antifungal activity and all these have shown moderate to high activity against the test microbes. Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional text, figures and tables. 相似文献