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We evaluate the non-singlet spin-dependent structure function g1NS at leading order (LO) and next-to-leading order (NLO) by using the Laplace-transform technique and method of characteristics and also obtain its first moment at NLO. The polarized non-singlet structure function results are compared with the data from HERMES (A. Airapetian et al., Phys. Rev. D 75, 012007 (2007)) and E143 (K. Abe et al. (E143 Collab.), Phys. Rev. D 58, 112003 (1998)) at LO and NLO analyses and the first-moment the result at NLO is compared with the result of the NLO GRSV2000 fit. Considering the solution, this method is valid at low- and large-x regions. 相似文献
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R. Dadfar N. Fabbiane S. Bagheri D. S. Henningson 《Flow, Turbulence and Combustion》2014,93(4):537-553
We use linear control theory to construct an output feedback controller for the attenuation of small-amplitude three-dimensional Tollmien-Schlichting (TS) wavepackets in a flat-plate boundary layer. A three-dimensional viscous, incompressible flow developing on a zero-pressure gradient boundary layer in a low Reynolds number environment is analyzed using direct numerical simulations. In this configuration, we distribute evenly in the spanwise direction up to 72 localised objects near the wall (18 disturbances sources, 18 actuators, 18 estimation sensors and 18 objective sensors). In a fully three-dimensional configuration, the interconnection between inputs and outputs becomes quickly unfeasible when the number of actuators and sensors increases in the spanwise direction. The objective of this work is to understand how an efficient controller may be designed by connecting only a subset of the actuators to sensors, thereby reducing the complexity of the controller, without comprising the efficiency. If n and m are the number of sensor-actuator pairs for the whole system and for a single control unit, respectively, then in a decentralised strategy, the number of interconnections deceases mn compared to a centralized strategy, which has n 2 interconnections. We find that using a semi-decentralized approach – where small control units consisting of 3 estimation sensors connected to 3 actuators are replicated 6 times along the spanwise direction – results only in a 11 % reduction of control performance. We explain how “wide” in the spanwise direction a control unit should be for a satisfactory control performance. Moreover, the control unit should be designed to account for the perturbations that are coming from the lateral sides (crosstalk) of the estimation sensors. We have also found that the influence of crosstalk is not as essential as the spreading effect. 相似文献
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SrFe12O19–TiO2 nanocomposites are usually used for absorbing microwaves in military and civil applications. In this work, microwave absorption properties of porous SrFe12O19 nanocomposites with 50% weight ratio of TiO2 have been investigated. 50% TiO2–50% SrFe12O19 nanocomposites were prepared by a controlled hydrolysis of titanium tetraisopropoxide in which SrFe12O19 nanoparticles were synthesized by a sol–gel auto combustion route. The morphology, crystalline structure and crystallite size of SrFe12O19–TiO2 nanocomposites were characterized by field emission scanning electron microscopy and X-ray powder diffraction. The magnetic measurements were carried out with a vibrating sample magnetometer. The microwave absorption was measured by a Vector Network Analyzer. The microwave absorption results indicated that the reflection losses for specimens with 52%–56% porosity and thicknesses of 1.8, 2.1 and 2.6 mm were not very low but minimum reflection loss for a specimen with 4.2 mm thickness reached upto −33 dB. 相似文献
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International Journal of Theoretical Physics - We present a set of formulas to extract the longitudinal proton structure function FL(x, Q2) and the reduced cross section σr(x, Q2) by using... 相似文献
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Karimian Somaye Ranjbar Sara Dadfar Mahsa Khoshneviszadeh Mahsima Gholampour Maryam Sakhteman Amirhossein Khoshneviszadeh Mehdi 《Molecular diversity》2021,25(4):2339-2349
Molecular Diversity - A series of ethyl 2-amino-4H-benzo[h]chromene-3-carboxylate derivatives, having phenyl ring with diverse substituents at C4 position of 4H-benzochromene nucleus, were... 相似文献
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