The Physical and Physiological Demands of Elite International Female Field Hockey Players During Competitive Match-Play.

The aim of the current investigation was to quantify the physical and physiological demands of elite international female field hockey match-play across halves of play. Thirty-eight participants (24 ± 5 years; 173 ± 5 cm; 72 ± 5 kg) took part in nineteen competitive matches during the 2014 - 2015 season. Participants were monitored with GPS technology and heart rate monitors. Players were categorized based on three different playing positions. Activity was categorized into total (m), high-speed running distance (m; >16 km·h) and relative distance (m·min) due to the use of rolling substitutions. Heart rate was classified based on the percentage of players individual HRpeak determined via a Yo-Yo intermittent recovery level 1 test. Players spent on average 44 ± 7 min in match-play. The total distance covered was 5558 ± 527 m (125 ± 23 m·min) with 589 ± 160 m (13 ± 4 m·min) completed at high-speed. Defenders covered a greater total distance compared to other positions of play (p ≤ 0.001). Midfield players covered a greater distance at high-speed (p ≤ 0.001) with the forwards having a higher relative distance (p ≤ 0.001). The HRpeak of the players was 199 ± 1 bmin with a mean exercise intensity of 86 ± 7.8 % of HRpeak. The time spent >85% HRpeak decreased significantly across the halves (p = 0.04, η = 0.09, Small). Defenders were found to spend more time >85 % HRpeak when compared to forwards (p ≤ 0.001). The current investigation provides normative data that coaches should consider when constructing training regimen

Quasi-Particle Spectra, Charge-Density-Wave, Superconductivity and Electron-Phonon Coupling in 2H-NbSe2

High-resolution photoemission has been used to study the electronic structure of the charge density wave (CDW) and superconducting (SC) dichalcogenide, 2H- NbSe2. From the extracted self-energies, important components of the quasiparticle (QP) interactions have been identified. In contrast to previously studied TaSe2, the CDW transition does not affect the electronic properties significantly. The electron-phonon coupling is identified as a dominant contribution to the QP self-energy and is shown to be very anisotropic (k-dependent) and much stronger than in TaSe2.Comment: 4 pages, 3 figures, minor changes, to appear in PR

Photon pair-state preparation with tailored spectral properties by spontaneous four-wave mixing in photonic-crystal fiber

We study theoretically the generation of photon pairs by spontaneous four-wave mixing (SFWM) in photonic crystal optical fiber. We show that it is possible to engineer two-photon states with specific spectral correlation (``entanglement'') properties suitable for quantum information processing applications. We focus on the case exhibiting no spectral correlations in the two-photon component of the state, which we call factorability, and which allows heralding of single-photon pure-state wave packets without the need for spectral post filtering. We show that spontaneous four wave mixing exhibits a remarkable flexibility, permitting a wider class of two-photon states, including ultra-broadband, highly-anticorrelated states.Comment: 17 pages, 7 figures, submitte

3d absorption-spectra of Sr I through Sr IV

The extreme ultraviolet photoabsorption spectra of neutral to three-times-ionized strontium have been recorded in a comprehensive series of experiments with the dual laser-produced plasma technique. Striking differences were found in the spectra, which can be attributed to the transfer of oscillator strength from 3d→np to 3d→nf transitions at Sr2+ due to nf wave-function contraction. In Sr and Sr+, 3d→5p transitions dominate; in Sr2+, 3d→nf transitions are most intense, while in Sr3+ the 4p subshell opens and 3d→4p transitions are the strongest features. Partial cross sections for 3d→ɛf and 3d→ɛp photoionization were calculated and compared with experiment