不同初始分布向列相液晶电容特性的相场法研究

液晶盒内的液晶分子在不同的外加电场作用下重新排布,其极化指向发生改变,从而影响液晶盒整体的电学特性。本文考虑液晶材料的挠曲电效应,分析液晶盒的整体自由能表达式,包含弹性形变自..

Experimental study on flashing front propagation in vertical small tubes

Flashing is a classical phenomenon in the discharging process of liquid to the high vacuum environment in space, as well as in nuclear power engineering, chemical engineering, and other engineering fields. To predict the discharge process and ensure the safety of space activities, a better understanding of its laws is needed. In this paper, flashing front propagation in vertical small tubes is experimentally studied under the condition of rapid depressurization. Experiments are carried out with degassed distilled water under different tube diameters and initial temperatures (superheats). The sustainability of flashing front propagation is confirmed to be influenced by superheat, tube diameter and gravity. A correlation is proposed with the Jacob number and Bond number to summarize the sustainability condition. The superficial velocity of flashing front propagation shows to be related to multiple factors such as superheat, tube diameter and downstream pressure. An empirical correlation is proposed to predict the superficial velocity and it agrees well with existing data

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