Optically-Nonactive Assorted Helices Array with Interchangeable Magnetic/Electric Resonance

We report here the designing of optically-nonactive metamaterial by assembling metallic helices with different chirality. With linearly polarized incident light, pure electric or magnetic resonance can be selectively realized, which leads to negative permittivity or negative permeability accordingly. Further, we show that pure electric or magnetic resonance can be interchanged at the same frequency band by merely changing the polarization of incident light for 90 degrees. This design demonstrates a unique approach to construct metamaterial.Comment: 15 pages, 4 figure

Multi-Modal Human Authentication Using Silhouettes, Gait and RGB

Whole-body-based human authentication is a promising approach for remote biometrics scenarios. Current literature focuses on either body recognition based on RGB images or gait recognition based on body shapes and walking patterns; both have their advantages and drawbacks. In this work, we propose Dual-Modal Ensemble (DME), which combines both RGB and silhouette data to achieve more robust performances for indoor and outdoor whole-body based recognition. Within DME, we propose GaitPattern, which is inspired by the double helical gait pattern used in traditional gait analysis. The GaitPattern contributes to robust identification performance over a large range of viewing angles. Extensive experimental results on the CASIA-B dataset demonstrate that the proposed method outperforms state-of-the-art recognition systems. We also provide experimental results using the newly collected BRIAR dataset

The Performance of FAST with Ultra-Wide Bandwidth Receiver at 500-3300 MHz

The Five-hundred-meter Aperture Spherical radio Telescope (FAST) has been running for several years. A new Ultra-Wide Bandwidth (UWB) receiver, simultaneously covering 500-3300 MHz, has been mounted in the FAST feed cabin and passed a series of observational tests. The whole UWB band is separated into four independent bands. Each band has 1048576 channels in total, resulted in a spectral resolution of 1 kHz. At 500-3300 MHz, the antenna gain is around 14.3-7.7 K/Jy, the aperture efficiency is around 0.56-0.30, the system temperature is around 88-130 K, and the HPBW is around 7.6-1.6 arcmin. The measured standard deviation of pointing accuracy is better than ~7.9 arcsec, when zenith angle (ZA) is within 26.4deg. The sensitivity and stability of the UWB receiver are confirmed to satisfy expectation by spectral observations, e.g., HI and OH. The FAST UWB receiver already has a good performance for taking sensitive observations in various scientific goals.Comment: 11 pages, 7 figures, 2 tables, submitted to Research in Astronomy and Astrophysic

KINETIC ANALYSIS OF THE UPPER EXTREMITY BETWEEN DIFFERENT STANCES IN TENNIS TWO-HANDED BACKHAND

INTRODUCTION: Now the tennis players could explore more racket capabilities through the change of racket materials and design. The open stance comes out in modern tennis relative to the traditional square stance. This study was conducted to analyze the upper extremity joint forces and moments between the different stances in advanced and intermediate athletes, who separated from ITN rating system, during two-handed stroke

catena-Poly[[diaqua­bis­{μ2-3,5-bis­[(pyridin-4-yl)methyl­amino]­benzoato}nickel] monohydrate]

In the title coordination polymer, {[Ni(C19H17N4O2)2(H2O)2]·H2O}n, the Ni2+ cation is located on an inversion center and coordinated by two carboxyl­ate O atoms from two different 3,5-bis­(pyridin-4-yl­methyl­amino)­benzoate anions, two O atoms from two coordinated water mol­ecules and two N atoms from two different 3,5-bis­(pyridin-4-yl­methyl­amino)­benzoate anions, displaying a slightly distorted NiN2O4 octa­hedral geometry. Each 3,5-bis­(pyridin-4-yl­methyl­amino)­benzoate anion acts as a μ2-bridge, linking different nickel ions into a chain along [010]. In the crystal, adjacent chains are further linked through N—H⋯O, O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds into a three-dimensional network. The coordinated water mol­ecules and a disordered water mol­ecule of hydration with 0.50 site occupancy play an important role in the formation of these hydrogen-bonding inter­actions