1,164 research outputs found

    (E)-4-Chloro­benzyl 3-(3-nitro­benzyl­idene)dithio­carbazate

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    In the title compound, C15H12ClN3O2S2, the dihedral angle between the aromatic rings is 89.71 (10)°. In the crystal, inversion dimers linked by pairs of N—H⋯S hydrogen bonds occur

    3-(4-Acetoxy­phen­yl)-4-oxo-4H-1-benzopyran-5,7-diyl diacetate

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    In the title mol­ecule, C21H16O8, the dihedral angle between the ring systems is 58.5 (1)°. In the crystal, C—H⋯O inter­actions help to establish the packing

    Orbital density wave induced by electron-lattice coupling in orthorhombic iron pnictides

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    In this paper we explore the magnetic and orbital properties closely related to a tetragonal-orthorhombic structural phase transition in iron pnictides based on both two- and five-orbital Hubbard models. The electron-lattice coupling, which interplays with electronic interaction, is self-consistently treated. Our results reveal that the orbital polarization stabilizes the spin density wave (SDW) order in both tetragonal and orthorhombic phases. However, the ferro-orbital density wave (F-ODW) only occurs in the orthorhombic phase rather than in the tetragonal one. Magnetic moments of Fe are small in the intermediate Coulomb interaction region for the striped antiferromangnetic phase in the realistic five orbital model. The anisotropic Fermi surface in the SDW/ODW orthorhombic phase is well in agreement with the recent angle-resolved photoemission spectroscopy experiments. These results suggest a scenario that the magnetic phase transition is driven by the ODW order mainly arising from the electron-lattice coupling.Comment: 21 pages, 10 figure

    Study of an Improved Fuzzy Direct Torque Control of Induction Motor

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    The conventional direct torque control will inevitably produce torque ripple because of its way of flux estimates. For the purpose of handling this problem, a new control strategy was presented in this paper. This strategy combined subdivides control with voltage vector and fuzzy logic control in traditional direct torque control. In this model, the fuzzy logic combined the phase angle of the flux, the flux error and torque error as fuzzy variables and classified these fuzzy variables, in order to optimize the choice of voltage space vector, and the same time the traditional PID regulator is replaced by a fuzzy regulator. Simulation results show that, a great improvement torque responses , a great reduction of torque ripples is achieved and the strategy has a better dynamic and steady performance, especially in low-speed area

    N-(2-Iodo­phen­yl)benzene­carbox­imid­amide

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    The title compound, C13H11IN2, crystallizes with two independent molecules (A and B) in the asymmetric unit. The two aromatic rings are inclined to one another by 73.3 (2)° in molecule A, and by 74.4 (1)° in molecule B. In molecule A, the iodophenyl and the phenyl rings are inlclined to the N=C—N plane by 88.0 (4) and 19.0 (4)°, respectively. In molecule B the corresponding angles are 85.0 (4) and 20.7 (4)°, respectively. In the crystal, the two molecules are not parallel but have a dihedral angle between the iodophenyl rings of 8.6 (1)°, and 44.5 (2)° between the phenyl rings. The A and B molecules are linked vvia N—H⋯N hydrogen bonds to form –A–B–A–B– chains propagating along direction [100]
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