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991.
Biswas PK Lees MR Balakrishnan G Liao DQ Keeble DS Gavilano JL Egetenmeyer N Dewhurst CD Paul DM 《Physical review letters》2012,108(7):077001
The flux-line lattice in CaAlSi has been studied by small-angle neutron scattering. A well-defined hexagonal flux-line lattice is seen just above H(c1) in an applied field of only 54 Oe. A 30° reorientation of this vortex lattice has been observed in a very low field of 200 Oe. This reorientation transition appears to be first-order and could be explained by nonlocal effects. The magnetic field dependence of the form factor is well-described by a single penetration depth of λ=1496(1) ? and a single coherence length of ξ=307(1) ? at 2 K. At 1.5 K, the penetration depth anisotropy is γ(λ)=2.7(1), with the field applied perpendicular to the c axis, and agrees with the coherence length anisotropy determined from critical field measurements. 相似文献
992.
The multiple-scale perturbation analysis is used to study the perturbed nonlinear Schrödinger’s equation, that describes the Langmuir waves in plasmas. The perturbation terms include the non-local term due to nonlinear Landau damping. The WKB type ansatz is used to define the phase of the soliton that captures the corrections to the pulse where the standard soliton perturbation theory fails. 相似文献
993.
C. Masood Khalique Anjan Biswas 《Communications in Nonlinear Science & Numerical Simulation》2009,14(12):4033-4040
This paper obtains the stationary 1-soliton solution of the nonlinear Schrödinger’s equation in non-Kerr law media. The types of nonlinearity that are considered are Kerr law, power law, parabolic law and the dual-power law. The technique that is used to carry out the integration of this equation is the Lie symmetry analysis. 相似文献
994.
Anjan Biswas Essaid Zerrad 《Communications in Nonlinear Science & Numerical Simulation》2009,14(9-10):3574-3577
In this paper, the Zakharov–Kuznetsov equation, with dual-power law nonlinearity is solved by using the solitary wave ansatze and 1-soliton solution is obtained. Using this soliton solution, a couple of conserved quantities, of this equation, are calculated. 相似文献
995.
Dynamics of topological optical solitons with time-dependent dispersion,nonlinearity and attenuation
Benjamin J.M. Sturdevant Dawn A. Lott Anjan Biswas 《Communications in Nonlinear Science & Numerical Simulation》2009,14(8):3305-3308
In this paper, the dark or topological optical 1-soliton solution of the nonlinear Schrödinger’s equation is obtained. The time-dependent coefficients of the group velocity dispersion, Kerr nonlinearity and the attenuation terms are considered. This leads to the constraint relation between these coefficients for the topological solitons to exist. All what is necessary is that these time-dependent coefficients be simply Riemann integrable. 相似文献
996.
Geometriae Dedicata - Let X be a compact connected Riemann surface of genus g, with $$g\, \ge \, 2$$ , and let $${\text {G}}$$ be a connected semisimple affine algebraic group defined over... 相似文献
997.
998.
Kar P Biswas R Drew MG Ida Y Ishida T Ghosh A 《Dalton transactions (Cambridge, England : 2003)》2011,40(13):3295-3304
The preparation, crystal structures and magnetic properties of two new isoelectronic and isomorphous formate- and nitrite-bridged 1D chains of Mn(III)-salen complexes, [Mn(salen)(HCOO)](n) (1) and [Mn(salen)(NO(2))](n) (2), where salen is the dianion of N,N'-bis(salicylidene)-1,2-diaminoethane, are presented. The structures show that the salen ligand coordinates to the four equatorial sites of the metal ion and the formate or nitrite ions coordinate to the axial positions to bridge the Mn(III)-salen units through a syn-antiμ-1κO:2κO' coordination mode. Such a bridging mode is unprecedented in Mn(III) for formate and in any transition metal ion for nitrite. Variable-temperature magnetic susceptibility measurements of complexes 1 and 2 indicate the presence of ferromagnetic exchange interactions with J values of 0.0607 cm(-1) (for 1) and 0.0883 cm(-1) (for 2). The ac measurements indicate negligible frequency dependence for 1 whereas compound 2 exhibits a decrease of χ(ac)' and a concomitant increase of χ(ac)' on elevating frequency around 2 K. This finding is an indication of slow magnetization reversal characteristic of single-chain magnets or spin-glasses. The μ-nitrito-1κO:2κO' bridge seems to be a potentially superior magnetic coupler to the formate bridge for the construction of single-molecule/-chain magnets as its coupling constant is greater and the χ(ac)' and χ(ac)' show frequency dependence. 相似文献
999.
Three stereocenters are formed in the carbene catalyzed cascade reaction of enals with various β-diketones to give the corresponding indane derivatives with excellent stereoselectivities. The products are readily transformed to the corresponding 1,2,3-trisubstituted indane derivatives, which represent privileged substructures in medicinal chemistry. 相似文献
1000.
We report here a robust automated active site detection, docking, and scoring (AADS) protocol for proteins with known structures. The active site finder identifies all cavities in a protein and scores them based on the physicochemical properties of functional groups lining the cavities in the protein. The accuracy realized on 620 proteins with sizes ranging from 100 to 600 amino acids with known drug active sites is 100% when the top ten cavity points are considered. These top ten cavity points identified are then submitted for an automated docking of an input ligand/candidate molecule. The docking protocol uses an all atom energy based Monte Carlo method. Eight low energy docked structures corresponding to different locations and orientations of the candidate molecule are stored at each cavity point giving 80 docked structures overall which are then ranked using an effective free energy function and top five structures are selected. The predicted structure and energetics of the complexes agree quite well with experiment when tested on a data set of 170 protein-ligand complexes with known structures and binding affinities. The AADS methodology is implemented on an 80 processor cluster and presented as a freely accessible, easy to use tool at http://www.scfbio-iitd.res.in/dock/ActiveSite_new.jsp . 相似文献