广东内伶仃岛的猕猴种群

广东内伶仃岛是一个封闭性的岛屿．很适合猕猴的栖息。由于人为干扰较少,岛上的猕猴已从1984年的200只增加到1998年的550600只．增长率为8.2%。如果保护措施得力,按现有的增长速度,预计5年后种群数量可能会达到900只

广东顺德生态乐园鹭科鸟类资源和保护

广东顺德生态乐园经过几年的改造和保护,生态环境已有良好的改善,己成为珠江三角洲地区典型的农业生态观光旅游度假为一体的自然景观.尤其是该生态乐园约占总面积三分之一的

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^