126,918 research outputs found
A Two-Step Etching Method to Fabricate Nanopores in Silicon
A cost effectively method to fabricate nanopores in silicon by only using the
conventional wet-etching technique is developed in this research. The main
concept of the proposed method is a two-step etching process, including a
premier double-sided wet etching and a succeeding track-etching. A special
fixture is designed to hold the pre-etched silicon wafer inside it such that
the track-etching can be effectively carried out. An electrochemical system is
employed to detect and record the ion diffusion current once the pre-etched
cavities are etched into a through nanopore. Experimental results indicate that
the proposed method can cost effectively fabricate nanopores in silicon.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/EDA-Publishing
An Improved NSGA-II and its Application for Reconfigurable Pixel Antenna Design
Based on the elitist non-dominated sorting genetic algorithm (NSGA-II) for multi-objective optimization problems, an improved scheme with self-adaptive crossover and mutation operators is proposed to obtain good optimization performance in this paper. The performance of the improved NSGA-II is demonstrated with a set of test functions and metrics taken from the standard literature on multi-objective optimization. Combined with the HFSS solver, one pixel antenna with reconfigurable radiation patterns, which can steer its beam into six different directions (θDOA = ± 15°, ± 30°, ± 50°) with a 5 % overlapping impedance bandwidth (S11 < − 10 dB) and a realized gain over 6 dB, is designed by the proposed self-adaptive NSGA-II
The shape of disorder broadened Landau subbands in graphene
Density of states (DOS) of graphene under a high uniform magnetic field and
white-noise random potential is numerically calculated. The disorder broadened
zero-energy Landau band has a Gaussian shape whose width is proportional to the
random potential variance and the square root of magnetic field. Wegner-type
calculation is used to justify the results
The 7-channel FIR HCN Interferometer on J-TEXT Tokamak
A seven-channel far-infrared hydrogen cyanide (HCN) laser interferometer has
been established aiming to provide the line integrated plasma density for the
J-TEXT experimental scenarios. A continuous wave glow discharge HCN laser
designed with a cavity length 3.4 m is used as the laser source with a
wavelength of 337 {\mu}m and an output power up to 100 mW. The system is
configured as a Mach-Zehnder type interferometer. Phase modulation is achieved
by a rotating grating, with a modulation frequency of 10 kHz which corresponds
to the temporal resolution of 0.1 ms. The beat signal is detected by TGS
detector. The phase shift induced by the plasma is derived by the comparator
with a phase sensitivity of 0.06 fringe. The experimental results measured by
the J-TEXT interferometer are presented in details. In addition, the inversed
electron density profile done by a conventional approach is also given. The
kinematic viscosity of dimethyl silicone and vibration control is key issues
for the system performance. The laser power stability under different kinematic
viscosity of silicone oil is presented. A visible improvement of measured
result on vibration reduction is shown in the paper.Comment: conference (15th-International Symposium on Laser-Aided Plasma
Diagnostics
- …