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61.
Javier Gonzalez 《国际射频与微波计算机辅助工程杂志》1996,6(2):107-114
The design and performance of a wide band active GaAs IC 180° differential phase shifter are presented. A two-stage GaAs IC was developed containing a microwave differential amplifier and a matched common-gate input. The active phase shifter achieved a 10° phase unbalance and an isolation at the output ports of better than 10 dB in the 1-10-GHz band. A large percentage of the GaAs chip contains active devices thereby providing a very large operating bandwidth and a reduced surface area. This active phase shifter presents an interesting alternative to the passive rat-race or an equivalent coupler for radio mobile communications. © 1996 John Wiley & Sons, Inc. 相似文献
62.
Irina Terekhova Iliya Kritskiy Mikhail Agafonov Roman Kumeev Carlos Martínez-Corts Horacio Prez-Snchez 《International journal of molecular sciences》2020,21(23)
The selectivity of encapsulation of leflunomide and teriflunomide by native α-, β- and γ-cyclodextrins was investigated through 1H NMR and molecular modeling. Thermodynamic analysis revealed the main driving forces involved in the binding. For α-cyclodextrin, the partial encapsulation was obtained while deep penetration was characterized for the other two cyclodextrins, where the remaining polar fragment of the molecule is located outside the macrocyclic cavity. The interactions via hydrogen bonding are responsible for high negative enthalpy and entropy changes accompanying the complexation of cyclodextrins with teriflunomide. These results were in agreement with the molecular modeling calculations, which provide a clearer picture of the involved interactions at the atomic level. 相似文献
63.
Gonzalez L. Julio C. Li Wei Gong Yu Jin XueJun 《Metallurgical and Materials Transactions B》2019,50(3):1417-1427
Metallurgical and Materials Transactions B - This paper reports a Galerkin finite-element analysis of carbon partitioning from martensite into austenite during the quenching and partitioning... 相似文献
64.
Gonzalez M.B. Simoen E. Vissouvanadin B. Verheyen P. Loo R. Claeys C. 《Electron Devices, IEEE Transactions on》2009,56(7):1418-1423
The purpose of this paper is to evaluate the impact of process-induced stress on the generation current of fully strained Si1- xGex source/drain junctions. The Ge content of the compressively strained SiGe epitaxial layer plays a key role in the tensile stress levels present in the underlying Si substrate. Current-voltage (I-V) measurements were employed to further investigate the leakage current enhancement due to the stress-induced bandgap narrowing in the Si depletion region, when no extended defects are formed. An empirical approach is proposed to describe the Ge content dependence of the bandgap-shrinkage-induced leakage current. An increase of the intrinsic carrier concentration as a function of the stress mismatch is observed. Moreover, the role of the epilayer thickness in the generation current is also discussed. 相似文献
65.
J. A. Blanco A. O. Rucci S. C. Revuelto A. A. Dubini R. A. Gonzalez 《Propellants, Explosives, Pyrotechnics》1979,4(2):27-29
A gas-liquid chromatographic procedure was developed in connection with the determination of water in nitroglycerin-nitrocellulose pastes. The method is based on the reaction of water with 2,2-dimethoxypropane and its conversion to acetone which is subsequently determined. The technique is simple, rapid, and shows good accuracy and precision. A simplified method, which is less accurate but does not involve chromatography, is also proposed. 相似文献
66.
M. Gonzalez B. Schmidt M. Ortiz 《International journal for numerical methods in engineering》2010,82(2):205-241
We present a class of integration schemes for Lagrangian mechanics, referred to as energy‐stepping integrators, that are momentum and energy conserving, symplectic and convergent. In order to achieve these properties we replace the original potential energy by a piecewise constant, or terraced approximation at steps of uniform height. By taking steps of diminishing height, an approximating sequence of energies is generated. The trajectories of the resulting approximating Lagrangians can be characterized explicitly and consist of intervals of piecewise rectilinear motion. We show that the energy‐stepping trajectories are symplectic, exactly conserve all the momentum maps of the original system and, subject to a transversality condition, converge to trajectories of the original system when the energy step is decreased to zero. These properties, the excellent long‐term behavior of energy‐stepping and its automatic time‐step selection property, are born out by selected examples of application, including the dynamics of a frozen Argon cluster, the spinning of an elastic cube and the collision of two elastic spheres. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
67.
Agustín Jiménez Avello Basil Mohammed Al‐Hadithi Marta Ines Gonzalez Garcia Jose Maria Lopez Rubio 《风能》2014,17(1):57-74
In this paper, a new algorithm, difference equation matrix model (DEMM), in the framework of model predictive control (MPC) is introduced. Instead of the standard dynamic matrix control (DMC), which is based upon step response method that has been used in most research works, we propose a new approach based upon a DEMM for model prediction. It has shown that DEMM has proven to be less computational and thus faster than the original DMC for real time applications. Thus, the drawbacks of DMC for online identification or adaptive design could be avoided. The control of wind turbines is carried out in order to decrease the cost of wind energy by increasing the efficiency, and thus the energy capture, or by reducing structural loading and increasing the lifetimes of the components and turbine structures. Modeling of wind turbine has been carried out. Effect of noise and disturbance on the system has been also studied. The results obtained show that the proposed DEMM minimizes the effect of the disturbance and produces an accurate and smooth control. Significant improvements in the regulation of rotor speed at high wind speeds are obtained from the proposed DEMM, where control set points are obtained ahead of the disturbance, saving the turbine of the negative effects of them and thus increasing its lifetime. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
68.
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70.
Based on our comprehensive theoretical investigation and known experimental results for small boron clusters, we predict the
existence of a novel aromatic inorganic molecule, B12H6. This molecule, which we refer to as borozene, has remarkably similar properties to the well-known benzene. Borozene is planar, possesses a large first excitation energy,
D
3h symmetry, and more importantly is aromatic. Furthermore, the calculated anisotropy of the magnetic susceptibility of borozene
is three times larger in absolute value than for benzene. Finally, we show that borozene molecules may be fused together to
give larger aromatic compounds with even larger anisotropic susceptibilities. 相似文献