The Proxy of Seabed Tectonic Process: CaCO_3/Fe_2O_3 and MgCO_3/Fe_2O_3 Ratios in Polymetallic Nodules

研究了中太平洋 3个多金属结核中共 5个侧面CaCO3 /Fe2 O3 和MgCO3 /Fe2 O3 比值的深度分布 .根据CaCO3 的热力学性质 ,我们认为结核中的CaCO3 /Fe2 O3 比值与沉积物中的CaCO3 保存量类似 ,与古水深之间存在着负相关关系 .结核中由表及里 ,CaCO3 /Fe2 O3 比值逐渐增大 ,说明结核所处海域 ,即中太平洋海盆的水深逐渐增大 ,这在一定程度上也反映了中太平洋海盆的下降 ,因而结核中的CaCO3 /Fe2 O3 比值也许可以作为海底构造运动的指示物 .而MgCO3 /Fe2 O3 比值与其有着良好的一致性 ,说明其与CaCO3 /Fe2 O3 比值一样 ,也可以作为海底构造运动的指示物 【英文摘要】 CaCO 3/Fe 2O 3 and MgCO 3/Fe 2O 3 ratios' depth profiles of 5 sides in 3 polymetallic nodules from central Pacific Ocean were studied. Basing on the thermodynamics of CaCO 3, we find that the CaCO 3/Fe 2O 3 ratios in nodules, like the preservation of CaCO 3 in the sediment, show the negative correlation with paleo-depth of the ocean. The inward increase of CaCO 3/Fe 2O 3 ratios in nodules reflects the gradually increasing of depth of central Pacific Ocean basin, where these nodules locating. T...中国大洋矿产资源研究开发协会“九五”国家专项资助项目 (DY95 0 2 15

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^