World Library  


 
  • Cover Image

Review of Scientific Instruments : Radio-frequency reflectometry o...

By: L. J. Taskinen, R. P. Starrett, T. P. Martin, A. P. Micolich, A. R. Hamilton et al

Description: We have embedded an AlGaAs/GaAs based, gated two-dimensional (2D) hole system (2DHS) into an impedance transformer LC circuit and show that by using radio-frequency reflectometry it is possible to perform sensitive, large bandwidth, electrical resistance measurements of 2D systems at millikelvin temperatures. We construct a simple lumped element model where the gated 2DHS is described as a resistive transmission line. The model gives a qualitative understand...

Read More
  • Cover Image

Review of Scientific Instruments : Photothermal excitation and las...

By: Shuhei Nishida, Dai Kobayashi, Takeo Sakurada, Tomonori Nakazawa, Yasuo Hoshi et al

Description: The authors present an optically based method combining photothermal excitation and laser Doppler velocimetry of higher cantilever vibration modes for dynamic atomic force microscopy in liquid. The frequency spectrum of a silicon cantilever measured in water over frequencies ranging up to 10 MHz shows that the method allows us to excite and detect higher modes, from fundamental to fifth flexural, without enhancing spurious resonances. By reducing the tip osc...

Read More
  • Cover Image

Journal of Applied Physics : Laser annealing characteristics of mu...

By: Paul DeMange, Christopher W. Carr, Raluca A. Negres, Harry B. Radousky, and Stavros G. Demos

Description: Laser annealing by pre-exposure to subdamage threshold laser pulses is a well-established method to increase the damage performance of bulk KH2PO4 and KDxH2−xPO4 nonlinear optical materials. The origin of laser-induced damage is believed to be localized absorption by a defect structure, either a light-absorbing foreign nanoparticle or a cluster of stoichiometric defects. It has been recently shown that there are at least three populations of such defect stru...

Read More
  • Cover Image

Applied Physics Letters : Enhanced field emission from ZnO nanotet...

By: Chi Li, Kai Hou, Xiaxi Yang, Ke Qu, Wei Lei et al

Description: Field emission properties of screen-printed ZnO nanotetrapods on a carbon nanofiber buffered Ag electrode were studied. The turn-on electric field (at a current of 0.1 μA/cm2) and maximum emission current are 0.6 V/μm and 2.8 mA/cm2 (at a field of 2.2 V/μm), which were significantly improved compared to the control device made of ZnO nanotetrapods on Ag directly without a carbon nanofiber buffer. The improved field emission is due to the better contact (both...

Read More
  • Cover Image

Biblioteca Hispanica : List of Gentlemen Who Compose the Spanish S...

By: Madrid
Read More
  • Cover Image

Journal of Applied Physics : Growth and field emission characteris...

By: S. K. Arora, S. Chhoker, N. K. Sharma, V. N. Singh, and V. D. Vankar

Description: The effect of substrate pretreatments such as ultrasonication or scratching by diamond powder on the microstructure and field emission characteristics of diamond grown over silicon and macroporous (anodized) silicon substrates was investigated. These films were grown in a hot filament chemical vapor deposition (CVD) system. Scanning electron microscope (SEM) studies revealed that ultrasonic pretreatment of the substrates increases nucleation density of CVD d...

Read More
  • Cover Image

Physics of Fluids : Quantifying the linear stability of a flowing ...

By: A. Kerem Uguz and N. Aubry

Description: Motivated by the destabilization of a two-fluid layer flowing in a microchannel for efficient mixing or droplet formation, we study quantitatively the linear stability of the interface between two liquids subjected to an electric field parallel or normal to the flat interface. In the case of fast electric charge relaxation times, the equations for the perturbation can be significantly reduced [ A. K. Uguz, O. Ozen, and N. Aubry, Phys. Fluids 20, 031702 (2008...

Read More
  • Cover Image

Journal of Applied Physics : Spectroscopic determination of electr...

By: J. E. Maslar, W. S. Hurst, and C. A. Wang

Description: Phonon-plasmon coupled mode Raman spectra of n-type GaSb were measured at room temperature as a function of electron concentration. These spectra were obtained using an optical system based on 752.55 nm excitation. Utilization of this wavelength permits greater sensitivity to GaSb coupled mode Raman scattering over a wider doping range than is possible with visible wavelength excitation-based systems. A relatively simple spectral model for the electronic con...

Read More
  • Cover Image

Review of Scientific Instruments : Velocity map imaging in time of...

By: M. Brouard, E. K. Campbell, A. J. Johnsen, C. Vallance, W. H. Yuen et al

Description: A new variation on time of flight mass spectrometry is presented, which uses a fast framing charge coupled device camera to velocity map image multiple product masses in a single acquisition. The technique is demonstrated on two photofragmentation processes, those of CS2 and CH3S2CH3 (dimethyldisulfide) at a photolysis wavelength of 193 nm. In both cases, several mass fragments are imaged simultaneously, and speed distributions and anisotropy parameters are ...

Read More
  • Cover Image

Chaos : Filtering by nonlinear systems

By: E. Campos Cantón, J. S. González Salas, and J. Urías

Description: Synchronization of nonlinear systems forced by external signals is formalized as the response of a nonlinear filter. Sufficient conditions for a nonlinear system to behave as a filter are given. Some examples of generalized chaos synchronization are shown to actually be special cases of nonlinear filtering.

Read More
  • Cover Image

Applied Physics Letters : Misfit strain…misfit strain diagram of e...

By: G. Sheng, J. X. Zhang, Y. L. Li, S. Choudhury, Q. X. Jia et al

Description: The effect of anisotropic strains on the phase transitions and domains structures of BaTiO3 thin films was studied using both thermodynamic calculations and phase-field simulations. The misfit strain–misfit strain domain stability diagrams were predicted. The similarity and significant differences between the diagrams from thermodynamic calculations assuming single domains and from phase-field simulations were analyzed. Typical domain structures as a result ...

Read More
  • Cover Image

Physics of Fluids : Numerical study of the Guderley and Vasilev re...

By: Andrea Defina, Francesca Maria Susin, and Daniele Pietro Viero

Description: We present high-resolution numerical solutions of the depth-averaged two-dimensional inviscid shallow water equations which provide new information on shock reflection configuration within the von Neumann paradox conditions. The computed flow field and shock wave patterns close to the triple point for the Guderley and the Vasilev reflections confirm the four-wave theory. We suggest that the most likely Guderley reflection model is a four-wave pattern with a ...

Read More
  • Cover Image

The Journal of Chemical Physics : Analysis of polyatomic molecules...

By: Peter C. Chen and Kamilah Mitchell

Description: The peak-sorting capabilities of high resolution coherent two-dimensional (2D) spectroscopy provide a new way of dealing with severe rotational congestion. This paper describes the application of this technique to the polyatomic molecule, NO2. NO2 is a primary component of photochemical smog and has a notoriously complex and congested spectrum that extends from the infrared to the ultraviolet regions. This spectrum is infamous for having an unusually high de...

Read More
  • Cover Image

Journal of Applied Physics : Effect of grain refinement on enhanci...

By: A. Malagoli, V. Braccini, M. Tropeano, M. Vignolo, C. Bernini et al

Description: Ex situ powder-in-tube MgB2 tapes prepared with ball-milled, undoped powders showed a strong enhancement of the irreversibility field H∗, the upper critical field Hc2, and the critical current density Jc(H) together with the suppression of the anisotropy of all of these quantities. Jc reached 104 A/cm2 at 4.2 K and 10 T, with an irreversibility field of about 14 T at 4.2 K, and Hc2 of 9 T at 25 K, high values for not-doped MgB2. The enhanced Jc and H∗ values...

Read More
  • Cover Image

Journal of Applied Physics : Geometric optimization of an active m...

By: Peng Li, Maoqiong Gong, and Jianfeng Wu

Description: Previous analyses [ Z. Yan and J. Chen, J. Appl. Phys. 72, 1 (1992) ; J. Chen and Z. Yan, ibid., 84, 1791 (1998) ; Lin et al., Physica B 344, 147 (2004) ; Yang et al., ibid., 364, 33 (2005) ; Xia et al., ibid., 381, 246 (2006). ] of irreversibilities in magnetic refrigerators overlooked several important losses that could be dominant in a real active magnetic regenerative refrigerator (AMRR). No quantitative expressions have been provided yet to estimate the...

Read More
  • Cover Image

Journal of Applied Physics : Influence of interfacial dislocations...

By: Y. L. Li, S. Y. Hu, S. Choudhury, M. I. Baskes, A. Saxena et al

Description: We investigated the influence of dislocations, located at the interface of a ferroelectric film and its underlying substrate, on the ferroelectric hysteresis loop including the remanent polarization and coercive field using phase-field simulations. We considered epitaxial ferroelectric BaTiO3 films and found that the hysteresis loop is strongly dependent on the type and density of interfacial dislocations. The dislocations that stabilize multiple ferroelectr...

Read More
  • Cover Image

Biblioteca Hispanica : Programme Course Notions of Natural History

By: Sandalio of. Pereda and Martinez
Read More
  • Cover Image

Physics of Plasmas : Existence of weakly damped kinetic Alfvén eig...

By: N. N. Gorelenkov

Description: A kinetic theory of weakly damped Alfvén eigenmode solutions strongly interacting with the continuum is developed for tokamak plasmas with reversed magnetic shear. It is shown that finite Larmor radius (FLR) effects are required for global eigenmode solutions. FLR effects induce multiple kinetic subeigenmodes and collisionless radiative damping. The theory explains the existence of experimentally observed Alfvénic instabilities with frequencies sweeping down...

Read More
  • Cover Image

Applied Physics Letters : Coherent control of magnetization preces...

By: E. Rozkotová, P. Nemec, N. Tesarová, P. Malý, V. Novák et al

Description: We report single-color, time-resolved magneto-optical measurements in ferromagnetic semiconductor (Ga,Mn)As. We demonstrate coherent optical control of the magnetization precession by applying two successive ultrashort laser pulses. The magnetic field and temperature dependent experiments reveal the collective Mn-moment nature of the oscillatory part of the time-dependent Kerr rotation, as well as contributions to the magneto-optical signal that are not conn...

Read More
  • Cover Image

Journal of Applied Physics : Microstructure and crystal defects in...

By: J. R. Wang, Y. Z. Zhang, Z. Z. Ye, J. G. Lu, H. P. He et al

Description: Dislocations in the ZnMgO pleated nanosheets were observed from high-resolution transmission electron microscopy (TEM). The Burgers vector was identified as 1/3〈113〉 from the Fourier filtered TEM images. Raman spectra revealed that there were microstructure defects in the ZnMgO nanosheets with the increasing Mg content. The incorporation of the Mg impurities in the ZnMgO nanosheets may promote the congregation of oxygen vacancies and thus facilitate the gene...

Read More
 
1
|
2
|
3
Records: 1 - 20 of 45 - Pages: 



Copyright © World Library Foundation. All rights reserved. eBooks from Hawaii eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.