Papers by Keyword: Pd

Abstract: In this work, we report a size-dependent study of Pd nanostructured films fabricated by ns pulsed laser on its plasmonic properties. More explanation and analysis of some results taken from our previous work are conducted. Statistical studies of the size distribution for different Pd films irradiated with the laser fluences (0.5, 0.75, and 1 J/cm²) are presented. For the three above fluences, an average diameter of (94±2, 38±0.8, and 44±1 nm) was calculated, respectively.

Abstract: We report on time-dependent Positron annihilation induced Auger Electron Spectroscopy (PAES) study on 0.5 monolayers (ML) Ni on polycrystalline Pd accompanied by complementary X-ray induced Photoelectron Spectroscopy (XPS). The normalized PAES spectra showed a significant decrease in the Ni intensity and an increase in the Pd intensity as a function of time. To rule out varying influence on the elements e.g. from surface contaminates due to the residual gas, a time-dependent XPS analysis was performed on pure Ni and Pd as well as to analyze the main contaminants C and O. The O fraction was found to be constant within the measurement time and the time constants for C significantly differ from those of Ni and Pd in the PAES data. Consequently, it was concluded that the PAES data show a superposition of C contamination and structural changes at the surface of Ni/Pd.

Abstract: It’s important to get accurate carrier phase and frequency information when using a standalone GPS receiver. In weak signal applications, to keep a stable tracking is hard to achieve because measuring error will be huge when the SNR is low. Different methods are used to improve the SNR before the detector in a tracking process, such as coherence integration. And this paper keeps eyes on a different viewpoint, on how to refine estimation results. A cascade structure is introduced for weak signal tracking. This structure is divided into two levels. In the first level, raw phase estimation and accurate frequency estimation is provided to achieve stable work in low CNR environment. In the second level, the raw phase estimation is refined to achieve accurate tracking requirement. This cascade structure can also work jointly with any other SNR-improving technology to get a better performance.

Abstract: A Two-Wheeled Self-Balancing Electric vehicle control system was developed base on the system design, hardware development and software strategies.The paper designed the posture acquisition module by gyroscopes and accelerometer sensors, and improved the control ccuracy using Calman filtering algorithm. Based on the system structure model, construction of Two-Wheeled Self-Balancing Electric vehicle dynamic equations by using the analysis method of Newtonian echanics was developed.A fuzzy PD controller was designed,the displacement and velocity as the input variable is controlled by fuzzy controller, and the tilt angle and angular velocity is controlled by PD controller. Finally, the platform of real-time control system was established for parameters adjustment and real-time control.Experiments show that the system has good robustness,high real-time response and has a higher market value.

Abstract: Most high-voltage faults are caused by the insulation degradation of electrical equipment, while partial discharge is the main reason of insulation breakdown of electrical equipment. This paper introduces partial discharge types of GIS, transformer, switchgear and other substation equipment based on the study of partial discharge types and summarizes five types of partial discharge of substation equipment, namely: spike discharge, free particle discharge, insulation defects discharge, surface discharge and suspended click discharge.

Abstract: Partial discharge (PD) detection using UHF signal is a well known advanced detecting method in GIS and has been actively studied. Numerical simulation using finite difference time domain (FDTD) algorithm is performed to investigate the transmission characteristics of W-M waves excited by partial discharge through straight closed tank of a GIS bus in. The time domain decaying characteristics and frequency domain resonance characteristics is studied in this paper. The simulation results shown that for the closed tank, E-M waves attenuate little during transmission and distribute oscillating in the tank. The distributions are symmetrical at 0 degree and 180 degrees and the energy at the two types of degrees is the same.

Abstract: Universal serial bus is put forward by seven corporations which are led by the Intel. It cost lowly, fast and easily expandable. USB is widely used in serial communication interface, widely used in computer peripherals and digital products. The USB protocol layer is the core unit of the USB device, which handles most of the contents of the USB protocol provides. This paper studies USB protocol layer design and implementation. Then USB protocol layer is completed based on FPGA.

Abstract: Surface Acoustic Wave Sensor is one of the most promising detection systems due tosmaller size, lower weight, power requirements and great sensitivity. It is known from the liter-ature that Pd and ZnO are the most promising materials for detecting hydrogen. A nanoporousPd and ZnO based layered SAW sensors have been developed and investigated for hydrogen,at room temperature. The sensors were of a delay line type (quartz substrate, 70 MHz cen-tral frequency). The nanoporous sensitive layer was directly deposited onto a quartz substrateusing a picosecond laser ablation method. Lasers with picosecond pulses or a high repetitionrate leads to major changes in the ablation process and implicit in the deposited lm struc-ture. Thus, using such a regime, at a certain ambient gas pressure, we have the advantage ofdirectly obtaining a nanoporous lm. The sensor performances (sensitivity, limit of detectionand response time), for a hydrogen concentration in synthetic air of 0.015 2 % were studied.For a concentration between 0.2 - 0.8 % hydrogen/synthetic airs, the response times was 15 -44 s and 6 - 27 s in case of Pd lms and ZnO respectively. Limit of detection was about 6.3times better at Pd sensors (50 ppm) than ZnO sensors (315 ppm).

Abstract: Partial discharge (PD) is the important detection parameter for power equipment, with the development of high voltage test technology, PD detection under impulse voltage is more attention. In order to detect the partial discharge signal under the impulse voltage, this paper designs a high-frequency current sensor and broadband measurement impedance. A set of partial discharge measurement system under impulse voltage is built up. The frequency characteristics of current sensor and measurement impedance are detected. In order to test the measurement system, the PD signals of a needle defect under impulse voltage is detected, the test results show that the PD measurement system can detect the PD signals effectively.

Abstract: We report the facile synthesis of triangular Pd nanoplates using aqueous extract of Syzygium Samarangense leaf. The morphology and structure of the obtained Pd nanoplates were characterized by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analysis. FTIR spectra indicated that C=C, COH, and OCOH were mainly responsible for the formation of the Pd nanoplates.