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531.
In the present work we investigate the behavior of all three components of persistent spin current in a quasi-periodic Fibonacci ring subjected to Rashba and Dresselhaus spin–orbit interactions. Analogous to persistent charge current in a conducting ring where electrons gain a Berry phase in presence of magnetic flux, spin Berry phase is associated during the motion of electrons in presence of a spin–orbit field which is responsible for the generation of spin current. The interplay between two spin–orbit fields along with quasi-periodic Fibonacci sequence on persistent spin current is described elaborately, and from our analysis, we can estimate the strength of any one of two spin–orbit couplings together with on-site energy, provided the other is known. 相似文献
532.
A delayed prey–predator model with Crowley–Martin‐type functional response including prey refuge
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Atasi Patra Maiti B. Dubey Jai Tushar 《Mathematical Methods in the Applied Sciences》2017,40(16):5792-5809
In this paper, we have studied a prey–predator model living in a habitat that divided into two regions: an unreserved region and a reserved (refuge) region. The migration between these two regions is allowed. The interaction between unreserved prey and predator is Crowley–Martin‐type functional response. The local and global stability of the system is discussed. Further, the system is extended to incorporate the effect of time delay. Then the dynamical behavior of the system is analyzed, taking delay as a bifurcation parameter. The direction of Hopf bifurcation and the stability of the bifurcated periodic solution are determined with the help of normal form theory and centre manifold theorem. We have also discussed the influence of prey refuge on densities of prey and predator species. The analytical results are supplemented with numerical simulations. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
533.
Dr. Avijit Maiti Benedict J. Elvers Dr. Sachinath Bera Felix Lindl Dr. Ivo Krummenacher Prof. Prasanta Ghosh Prof. Dr. Holger Braunschweig Prof. Cem B. Yildiz Prof. Dr. Carola Schulzke Dr. Anukul Jana 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(28):e202104567
Herein, we disclose cyclic(alkyl)(amino)carbenes (CAACs) to be one-electron reductants under the formation of a transient radical cation as indicated by EPR spectroscopy. The disclosed CAAC reducing reactivity was used to synthesize acyclic(amino)(aryl)carbene-based Thiele and Chichibabin hydrocarbons, a new class of Kekulé diradicaloids. The results demonstrate CAACs to be potent organic reductants. Notably, the acyclic(amino)(aryl)carbene-based Chichibabin's hydrocarbon shows an appreciable population of the triplet state at room temperature, as evidenced by both variable-temperature NMR and EPR spectroscopy. 相似文献
534.
Paramita Bera Jhansi Narmada Reddy Kotamreddy Tanmoy Samanta Saborni Maiti 《Natural product research》2015,29(14):1328-1335
Jasmines are commercially grown for their fragrant flowers and essential oil production. The flowers of jasmine emit sweet-smelling fragrance from evening till midnight. This study was designed to study the composition and inter-specific variation of the emitted scent volatiles from flowers of four commercially cultivated Jasminum species namely, Jasminum sambac, Jasminum auriculatum, Jasminum grandiflorum and Jasminum multiflorum. Gas chromatography-mass spectrometry analysis revealed that the scent volatiles composition of these flowers was predominantly enriched with both terpenoid and benzenoid compounds. Linalool and (3E,6E)-α-farnesene were identified as the major monoterpene and sesquiterpene in all the four species, respectively. The most abundant benzenoid detected in all flowers was benzyl acetate. Comparison of volatile profiles indicated a variation in fragrance contents and types emitted from these four jasmine flowers. The outcome of this study shall help in elucidating the enzymes and genes of fragrance biosynthesis in jasmines and in aiming to create flowers with improved scent quality. 相似文献
535.
536.
Gourhari Maiti Rajiv KarmakarRudraksha N. Bhattacharya Utpal Kayal 《Tetrahedron letters》2011,52(43):5610-5612
Substituted phenylacetylenes react with various o-hydroxy aromatic aldehydes under dual catalysis of piperidine and FeCl3 in refluxing toluene to yield flavones in good to excellent yield. Atmospheric oxygen acts as stoichiometric oxidant in the process. Some of these compounds had been recently reported to show fair insecticidal activity against Spodoptera frugiperda. 相似文献
537.
Superconducting 123 powders have been deposited on silver metal wire and foil by an electrophoretic deposition technique, followed by appropriate heat treatment, to obtain superconducting wires and tapes. At the present stage the critical current density is rather low (85 A/cm2), however there remains a considerable scope for improvement. 相似文献
538.
Abstract Lac is the only known natural resin of animal origin. It is the secretion of a tiny insect known as Kerriar lacca (formally called Laceifer lacca). The lac-forming tiny insect grows on some types of trees, mostly abundant in tropical countries, including India. The secretion of the lac insect hardens in air and forms a covering on the body of the insect. This covering or the nest forms a continuous incrustation on the branches of the host trees. Lac is collected by scraping the incrustation from the branches of the trees. 相似文献
539.
540.
Christophe Bénard Rahim Mohammad Neerja Saraswat Rudong Shan Samarendra N. Maiti Peter G. M. Wuts 《合成通讯》2013,43(4):517-524
Chiral 3‐methanesulfonyl‐1‐Boc‐pyrrolidine and piperidine were reacted with sodium phenolates, resulting in a mixture of displacement and elimination products. Following carbamate deprotection and pH adjustment, the 3‐pyrroline and tetrahydropyridine by‐products resulting from elimination were easily removed through aqueous partitioning and/or concentration. Although the pyrrolidines were formed with a high degree of optical purity, slight racemization was observed for the piperidine case because elevated temperatures were required to effect displacement. 相似文献