20个燕麦品种饲草产量和品质比较分析

适宜的品种和收获时期是燕麦饲草高产和高品质的关键因素.研究了国内外20个主要饲用燕麦品种(7个裸燕麦Avena nuda L,13个皮燕麦Avena sativa L)在河北坝上地区连续种植三个生长季(2017～2019)不同生育期饲草产量的变化规律,同时比较了不同生育期燕麦的饲草品质.结果表明:(1)从孕穗期、抽穗期、开花期、乳熟期到完熟期,20个燕麦品种饲草产量(地上生物量干重)都在逐渐增加,在完熟期达到最大值.品种坝莜18号、远杂1号、GL381饲草产量在成熟期超过12 t ha~(-1).(2)随着生育期从孕穗期到完熟期,粗蛋白含量和代谢能逐渐下降,相对饲用价值先降低后增加,拐点出现在开花期或乳熟期.综合粗蛋白含量、相对饲用价值、代谢能三个品质指标,白燕9号、青引2号、陇燕3号和KONA的饲草品质较高.(3)随着生育期从孕穗期到完熟期,饲草品质产量指标粗蛋白产量、相对饲用价值产量和代谢能产量都在逐渐增加,在完熟期达到最大值,坝莜18号、远杂1号、GL381和Haywire最高.因此,建议在河北坝上及周边相似气候区种植饲草用燕麦时,根据最大生物量和最大饲草品质产量选择适宜的品种,推荐坝莜18号、远杂1号和GL381

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^