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41.
42.
Birk T Pedersen KS Piligkos S Thuesen CA Weihe H Bendix J 《Inorganic chemistry》2011,50(12):5312-5314
In the solid state, MnF(salen) forms chains wherein fairly linear fluoride bridges between high-spin Mn(III) centers are observed. We interpret the magnetic properties of these chains by use of the classical Fisher model and by use of the high-temperature expansion approach, as well as by exact matrix diagonalization of the spin Hamiltonian, of model rings. In solution, electron paramagnetic resonance shows the chains to be symmetrically cleaved to monomeric MnF(salen). 相似文献
43.
44.
Jesper L. Mortensen Alan McWilliam Christopher G. Leburn Peter Tidemand-Lichtenberg Morten Thorhauge Jirí Janousek Christian T.A. Brown Alexander A. Lagatsky Preben Buchhave Wilson Sibbett 《Optics Communications》2006,260(2):637-640
Efficient generation of continuous-wave (CW) tunable light in the yellow region is reported. The method is based on sum-frequency mixing of a tunable Cr4+:forsterite laser with a Nd:YVO4 laser. A periodically poled lithium niobate crystal was placed intra-cavity in a Nd:YVO4 laser, and the Cr4+:forsterite laser was single-passed through the non-linear media. With this setup, it was possible to generate up to 3 mW of yellow light smoothly tunable from 573 to 587 nm. This is the highest output demonstrated to date for a tunable diode pumped solid-state CW laser in this wavelength region. The ways to improve the efficiency further are discussed. 相似文献
45.
Jesper Møller 《Annals of the Institute of Statistical Mathematics》1989,41(3):565-581
Sufficient conditions for geometrical fast convergence of general spatial birth-and-death processes to equilibrium are established. 相似文献
46.
Guoyu Yang Jesper Kabel Bert Van Rietbergen Anders Odgaard Rik Huiskes Stephen C. Cown 《Journal of Elasticity》1998,53(2):125-146
A method of data analysis for a set of elastic constant measurements is applied to data bases for wood and cancellous bone.
For these materials the identification of the type of elastic symmetry is complicated by the variable composition of the material.
The data analysis method permits the identification of the type of elastic symmetry to be accomplished independent of the
examination of the variable composition. This method of analysis may be applied to any set of elastic constant measurements,
but is illustrated here by application to hardwoods and softwoods, and to an extraordinary data base of cancellous bone elastic
constants. The solid volume fraction or bulk density is the compositional variable for the elastic constants of these natural
materials. The final results are the solid volume fraction dependent orthotropic Hooke's law for cancellous bone and a bulk
density dependent one for hardwoods and softwoods.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
47.
48.
Noordegraaf D Scolari L Laegsgaard J Tanggaard Alkeskjold T Tartarini G Borelli E Bassi P Li J Wu ST 《Optics letters》2008,33(9):986-988
We demonstrate a highly tunable deep notch filter realized in a liquid-crystal photonic-bandgap (LCPBG) fiber. The filter is realized without inducing a long-period grating in the fiber but simply by filling a solid-core photonic-crystal fiber with a liquid crystal and exploiting avoided crossings within the bandgap of the LCPBG fiber. The filter is demonstrated experimentally and investigated using numerical simulations. A high degree of tuning of the spectral position of the deep notch is also demonstrated. 相似文献
50.
The antiferromagnetic critical point of the Potts model on the square lattice was identified by Baxter [R.J. Baxter, Proc. R. Soc. London A 383 (1982) 43] as a staggered integrable six-vertex model. In this work, we investigate the integrable structure of this model. It enables us to derive some new properties, such as the Hamiltonian limit of the model, an equivalent vertex model, and the structure resulting from the Z2 symmetry. Using this material, we discuss the low-energy spectrum, and relate it to geometrical excitations. We also compute the critical exponents by solving the Bethe equations for a large lattice width N . The results confirm that the low-energy spectrum is a collection of continua with typical exponent gaps of order (logN)−2. 相似文献