Integrated-EBG Ridge Waveguide and Its Application to an E-Band Waveguide 32 732 Slot Array Antenna

A methodology of designing an E-band waveguide 32 732 slot array antenna with high-efficiency and low-cost manufacturing characteristics is proposed in this article, which is based on an integrated electronic bandgap (EBG) ridge waveguide designed by integrating a cross rectangle-hollow EBG structures in the conventional ridge waveguide. The integrated EBG structure intercepts the leakage from the unconnected gap in between the two metallic plates of the waveguide, and then it decreases the manufacturing cost without using the diffusion bonding technology and multi-layer welding assembly process. The design guideline is discussed, and then the antenna is fabricated. The measured radiation characteristics are in good agreement with predicted ones, which confirms that the proposed cross rectangle-hollow EBG structures is an attractive candidate of high-performance millimeter wave antenna

Paeoniflorin Attenuated Oxidative Stress in Rat COPD Model Induced by Cigarette Smoke

Paeoniflorin (PF), a monoterpene glucoside, might have an effect on the oxidative stress. However, the mechanism is still unknown. In this study, we made the COPD model in Sprague-Dawley (SD) rats by exposing them to the smoke of 20 cigarettes for 1 hour/day and 6 days/week, for 12 weeks, 24 weeks, or 36 weeks. Our findings suggested that smoke inhalation can trigger the oxidative stress from the very beginning. A 24-week treatment of PF especially in the dosage of 40 mg/kg·d can attenuate oxygen stress by partially quenching reactive oxygen species (ROS) and upregulating antioxidant enzymes via an Nrf2-dependent mechanism

Acknowledgements

In real life the investment return is not normally distributed and the investors ’ attitudes to upside potential and downside risk with respect to a benchmark are different. The upper partial moment (UPM) and the lower partial moment (LPM) in place of mean and variance as reward and risk measure have been suggested to solve this asymmetric problem (Farinelli and Tibiletti (2002)/Moreno, Cumova and Nawrocki (2004)). In this master thesis, we discuss the empirical properties of the UPM/LPM framework as performance measure and also applications to portfolio optimization. In order to evaluate the benefit of the performance measurement, we contrast the ranking results from the UPM/LPM performance measurement and conventional sets. The model sensitivity to parameter change and the estimation risk are also tested. Regarding portfolio optimization problems, when employing the skewness student-t distributed sample, we show that the UPM/LPM portfolio optimization model provides different weights from conventional models, and it exhibits a more efficient frontier. We find that higher moments can be of great significance for performance ranking and portfolio selection based on UPM/LPM framework. And by choosing appropriate benchmark and upper or lower order, the UPM/LPM model is able to reflect investors ’ various asymmetric preferences

Research Progress of EPR Spectrometer Under High Frequency and High Field

Electron paramagnetic resonance (EPR) is a measurement method to research the microscopic information of magnetic materials. Because early EPR studies were limited by magnetic field strength and microwave frequency, some microscopic information of materials could not be clearly displayed. In recent years, with the development of high magnetic field technology and microwave technology, continuous wave electron paramagnetic resonance (cw-EPR) spectrometer and pulsed electron paramagnetic resonance (pulsed EPR) spectrometer have been fully used under high frequency and high field, and the sensitivity, spectral resolution and other performance indicators of the spectrometer have also been improved. This paper mainly introduces the principle and structure of EPR spectrometer under high frequency and high field, its development history and research status both domestically and internationally, and the latest application in related fields

Self-mixing Grating Interferometer with Dual Laser Diodes for Sensing of Two-dimensional Dynamic Displacement

In this paper, a novel self-mixing grating interferometer (SMGI) with dual laser diodes (LDs) is proposed for two-dimensional (2D) dynamic displacement measurement. The light beams emitted from the LDs are incident onto a reflection grating with ±1st order auto-collimation diffraction angles and then diffracted back into the lasers respectively, which can cause self-mixing interference effect in each LD. Theoretical analysis on the SMGI signals corresponding to 2D displacement is presented and verified with the experimental observations. Measurement results of 2D dynamic displacement demonstrate that the proposed system can achieve the measurement resolution better than 10nm. The proposed SMGI sensing system has the advantages of high stability, compact mechanical structure and relatively straightforward operation

Low-Cost mmWave Metallic Waveguide Based on Multilayer Integrated Vertical-EBG Structure and its Application to Slot Array Antenna Design

A novel methodology to create metallic waveguides with multilayer integrated vertical-electromagnetic bandgap (EBG) structure is proposed in this article, and the structure realizes low-cost millimeter-wave (mmWave) slot array antennas. A multilayer stack of easy-to-process thin metallic etching plates is introduced to design mmWave waveguide using compression fit instead of diffusion bonding and welding assembly process. The electromagnetic (EM) wave leakage from the gaps between the metallic plates is suppressed using the vertical-EBG structure and antiphasing feeding. The dispersion diagrams of the vertical-EBG unit cell are investigated to illustrate the suppression of leakage. Another leakage wave intercepting methodology is adopted by antiphase feeding to prevent leakage wave from the adjacent slot subarrays. Finally, two examples of 2 $\times$ 8 and 8 $\times$ 8 slot array antennas are presented to verify our design concept. The measured impedance bandwidths of the two antennas are 77.1-84.6 GHz (9.3%) and 78.6-84.9 GHz (7.7%). In addition, the 3 dB broadside gain bandwidths are 73.1-85.3 GHz (15.1%) and 76.8-84.4 GHz (9.4%). The results show the aperture efficiencies up to 56.4%