湖北武湖日本沼虾的生长特性

从1998年9月至1999年9月对人工养殖湖泊——武湖日本沼虾生长特性作了研究. 以月龄来研究日本沼虾的生长,研究结果表明日本沼虾在7-1月份(1-7月龄)呈等速生长,在2-6月份(8-12月龄)呈异速生长.日本沼虾体重(W)与体长(L)呈幂函数相关,但在7-1月份时其b值接近于3,而在2-6月份时其b值明显小于3,其关系式如下: 1-7月龄:W♂=0. 0148L3. 2419(r=0. 9978,n=390),W♀=0. 0206L3. 0117(r=0. 9968,n=372); 8-12月龄:W

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^