11,428 research outputs found
catena-Poly[[[bis(1,10-phenanthroline-κ2 N,N′)manganese(II)]-μ-9,10-dioxoanthracene-1,5-disulfonato-κ2 O 1:O 5] tetrahydrate]
The title complex, {[Mn(C14H6O8S2)(C12H8N2)2]·4H2O}n, exhibits a chain-like polymeric structure with 9,10-dioxoanthracene-1,5-disulfonate anions bridging MnII atoms in a bis-monodentate mode. The unique MnII atom is located on a crystallographic centre of inversion. Four N atoms from two chelating 1,10-phenanthroline ligands and two sulfonate O atoms from two symmetry-related 9,10-dioxoanthracene-1,5-disulfonate anions give rise to a slightly distorted octahedral coordination environment around the MnII centre. The centroid of the central ring of the anthraquinone ligand represents another crystallographic centre of inversion. In the crystal structure, interligand π–π stacking [centroid-to-centroid distances 3.532 (1) and 3.497 (3) Å] and intermolecular O—H⋯O hydrogen-bonding interactions assemble the chains into a three-dimensional supramolecular network
Tris{2-methoxy-6-[(4-methylphenyl)iminiomethyl]phenolate-κ2 O,O′}tris(thiocyanato-κN)europium(III)
The metal center in the structure of the title compound, [Eu(NCS)3(C15H15NO2)3], is coordinated by three Schiff base 2-methoxy-6-[(4-methylphenyl)iminiomethyl]phenolate (L) ligands and three independent thiocyanate ions. In the crystal structure, the acidic H atom is located on the Schiff base N atom and hydrogen bonded to the phenolate O atom. The coordination environment of the EuIII ion is nine-coordinate by three chelating methoxyphenolate pairs of O atoms and three N-atom terminals of the thiocyanate ions. The compound is isostructural with the CeIII analogue [Liu et al. (2009 ▶). Acta Cryst. E65, m650]
Transport theory for topological Josephson junctions with a Majorana qubit
We construct a semiclassical theory for the transport of topological
junctions starting from a microscopic Hamiltonian that comprehensively includes
the interplay among the Majorana qubit, the Josephson phase, and the
dissipation process. With the path integral approach, we derive a set of
semiclassical equations of motion that can be used to calculate the time
evolution of the Josephson phase and the Majorana qubit. In the equations we
reveal rich dynamical phenomena such as the qubit induced charge pumping, the
effective spin-orbit torque, and the Gilbert damping. We demonstrate the
influence of these dynamical phenomena on the transport signatures of the
junction. We apply the theory to study the Shapiro steps of the junction, and
find the suppression of the first Shapiro step due to the dynamical feedback of
the Majorana qubit.Comment: 6 pages, 3 figure
Tris{2-methoxy-6-[(4-methylphenyl)iminiomethyl]phenolato-κ2 O,O′}tris(thiocyanato-κN)praseodymium(III) monohydrate
The asymmetric unit of title compound, [Pr(NCS)3(C15H15NO2)3]·H2O, consists of three Schiff base 2-methoxy-6-[(4-methylphenyl)iminomethyl]phenol (HL) ligands, three independent thiocyanate anions and an uncoordinated water molecule. The PrIII ion is nine-coordinated. The thiocyanate anions coordinate to the PrIII ion via the N atoms and the three HL ligands chelate the PrIII ion via the phenoxy and methoxy O atoms. The protonated imine N atoms are involved in intramolecular hydrogen bonds with the phenolate groups
Analysis And Control Of Severe Vibration Of A Screw Compressor Outlet Piping System
The severe vibration of a screw compressor outlet piping system caused the fatigue failure of some thermowells and the unscheduled shut down of the system. The main reasons of the abnormal vibration in the outlet piping system were investigated by developing an acoustic model to simulate the gas pulsation and establishing two finite element models to conduct the mechanical vibration analyses. The acoustic analysis results showed that the pulsation amplitudes of most nodes in the outlet piping system exceeded the allowable values. The results of mechanical vibration analyses indicated that the insufficient stiffness of the outlet piping system and the first-order structure resonance occurred on thermowells were also the key factors inducing vibration. Several methods were put forward to attenuate vibration amplitude of the outlet piping system as well as the thermowells. A new pulsation attenuator was installed and the piping layout was rearranged to reduce pulsation amplitudes and shaking forces of all nodes in the outlet piping system. Several reasonable supports were added to improve the stiffness of the outlet piping system. After reinforcing the thermowells, the first-order natural frequency of the thermowells increased from 207.4Hz to 280.7Hz, away from the excitation frequency of 196.67Hz. The field measurement results showed that vibration amplitude and the vibration velocity decreased significantly after modifications
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