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191.
P. Arumugam A. Ganga Deb S. K. Patra 《The European Physical Journal A - Hadrons and Nuclei》2005,25(2):199-209
We discuss the shape transitions in few medium heavy-mass nuclei with emphasis on low-temperature behaviour of the giant dipole resonance (GDR) observables. We employ a macroscopic approach towards GDR in which the GDR observables are related to the nuclear shapes. Shape calculations were done using the cranked Nilsson-Strutinsky method (CNSM) extended to finite temperature. Thermal shape fluctuations are computed with free energies calculated employing Landau parameterization as well as those calculated exactly (without using parameterizations) at given spin and temperature. The results obtained are confronted with the experimental data wherever available. Our study reveals that if the fluctuations are treated properly, then, in spite of thermal fluctuations, GDR observables could very well reflect the shape transitions at low temperature. 相似文献
192.
Every graph G contains a minimum vertex-coloring with the property that at least one color class of the coloring is a maximal independent set (equivalently, a dominating set) in G. Among all such minimum vertex-colorings of the vertices of G, a coloring with the maximum number of color classes that are dominating sets in G is called a dominating-χ-coloring of G. The number of color classes that are dominating sets in a dominating-χ-coloring of G is defined to be the dominating-χ-color number of G. In this paper, we continue to investigate the dominating-χ-color number of a graph first defined and studied in [1]. 相似文献
193.
For any vertex x in a connected graph G of order n ≥ 2, a set S x ? V (G) is an x-detour monophonic set of G if each vertex v ∈ V (G) lies on an x-y detour monophonic path for some element y in S x . The minimum cardinality of an x-detour monophonic set of G is the x-detour monophonic number of G, denoted by dm x (G). A connected x-detour monophonic set of G is an x-detour monophonic set S x such that the subgraph induced by S x is connected. The minimum cardinality of a connected x-detour monophonic set of G is the connected x-detour monophonic number of G, denoted by cdm x (G). A connected x-detour monophonic set S x of G is called a minimal connected x-detour monophonic set if no proper subset of S x is a connected x-detour monophonic set. The upper connected x-detour monophonic number of G, denoted by cdm+ x (G), is defined to be the maximum cardinality of a minimal connected x-detour monophonic set of G. We determine bounds and exact values of these parameters for some special classes of graphs. We also prove that for positive integers r,d and k with 2 ≤ r ≤ d and k ≥ 2, there exists a connected graph G with monophonic radius r, monophonic diameter d and upper connected x-detour monophonic number k for some vertex x in G. Also, it is shown that for positive integers j,k,l and n with 2 ≤ j ≤ k ≤ l ≤ n - 3, there exists a connected graph G of order n with dm x (G) = j,dm+ x (G) = k and cdm+ x (G) = l for some vertex x in G. 相似文献
194.
A high yielding enantioselective synthesis of the indolizidine alkaloid, (+)-lentiginosine, has been described based on asymmetric aza-Cope rearrangement and the l-proline catalyzed α-aminooxylation of aldehydes. The strategy also makes use of ring-closing metathesis for the construction of piperidine core. 相似文献
195.
K. Marimuthu R.T. Karunakaran S. Surendra Babu G. Muralidharan S. Arumugam C.K. Jayasankar 《Solid State Sciences》2009,11(7):1297-1302
Eu3+-doped alkali fluoroborate glasses B2O3–XCO3–NaF–Eu2O3 (where X = Li2, Na2, K2, and Ca, Mg) have been prepared using the conventional melting technique and their structural and optical properties have been evaluated. The XRD pattern of the glasses confirmed the amorphous nature and the FTIR spectra reveal the presence of BO3 and BO4 units as their local structures along with the strong OH? groups. From the absorption spectra the bonding parameters have been calculated and confirmed that the Eu–O bonds in the studied glasses are of covalent nature. Judd–Ofelt (JO) analysis has been carried out from the emission spectra. The JO parameters have been used to calculate transition probabilities (A), lifetime (τR) and branching ratios (βR) and peak stimulated emission cross-section (σPE) for the 5D0 → 7FJ (J = 1, 2, 3 and 4) transitions of the Eu3+ ions. The decay from the 5D0 level of Eu3+ ions in the title glasses has been measured and analysed. The lifetime of the 5D0 level is found to be shorter than the reported glasses which may be due to the presence of OH? groups. 相似文献
196.
Natarajan Arumugam 《Tetrahedron letters》2006,47(50):8855-8857
The synthesis of a series of macrocyclic bis-β-lactam derivatives via a highly stereoselective (2+2) cycloaddition is described. 相似文献
197.
Abdulrahman I. Almansour Raju Suresh Kumar Natarajan Arumugam Giulia Bianchini J. Carlos Menéndez Dhaifallah M. Al-thamili Govindasami Periyasami Mohammad Altaf 《Tetrahedron letters》2019,60(23):1514-1517
A small library of A- and D-ring modified luotonin-inspired heterocyclic systems have been synthesised in moderate to good yields following a six-step route that starts from phenylalanine and has the final key stage an intramolecular Povarov reaction of imines obtained from a tetrahydroquinoline-derived alkynyl aldehyde and various arylamines. 相似文献
198.
199.
Dr. Jiarui He Dr. Amruth Bhargav Hyunki Sul Prof. Arumugam Manthiram 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(3):e202216267
Lithium-organosulfur (Li-OS) batteries, despite possessing high theoretical specific capacity, encounter a few practical challenges, including unsatisfactory lifespan and low active material utilization under realistic conditions. Here, diisoropyl xanthogen polysulfide (DIXPS) has been selected as a model organosulfur compound to investigate the practical feasibility of Li-OS batteries under realistic conditions. A well-designed freestanding carbon sponge decorated with Fe3N nanoparticles (C@Fe3N) is introduced into the Li-OS cells as a scaffold for both Li and DIXPS. The lithiophilic property of the C@Fe3N host guides uniform lithium deposition at the anode, and the catalysis of the DIXPS conversion reaction promotes the kinetics at the cathode. Impressively, the synergistic effect of C@Fe3N leads to an extremely stable cycling performance over 1 000 cycles in a Li-OS full cell under realistic conditions. 相似文献
200.
Vino Palani Santhosh Chinnaraj Murugesh Shanmugasundaram Arunkumar Malaisamy Viji Maluventhen Vijaya Anand Arumugam Kannan R. R. Rengasamy Balamuralikrishnan Balasubramanian Wen-Chao Liu Maruthupandian Arumugam 《Molecules (Basel, Switzerland)》2022,27(20)
The tracing of an alternative drug, Phytochemicals is a promising approach to the viral threats that have emerged over the past two years. Across the world, herbal medicine is a better solution against anti-viral diseases during pandemic periods. Goniothalamus wightii is an herbal plant, which has diverse bioactive compounds with anticancer, antioxidant, and anti-viral properties. The aim of the study was to isolate the compound by chromatography studies and functionalization by FT-IR, LC-MS, and NMR (C-NMR, H-NMR). As a result, the current work focuses on whether (S)-Goniathalamin and its analogue could act as natural anti-viral molecules for multiple target proteins viz., MPro, RdRp, and SPro, which are required for SARS-CoV-2 infection. Overall, 954 compounds were examined and the molecular-docking studies were performed on the maestro platform of Schrodinger software. Molecular-dynamics simulation studies were performed on two complex major compounds to confirm their affinity across 150 simulations. This research suggests that plant-based drugs have high levels of antiviral properties against coronavirus. However, more research is needed to verify its antiviral properties. 相似文献