Many-body dynamics of a Bose system with attractive interactions on a ring

We investigate the many-body dynamics of an effectively attractive one-dimensional Bose system confined in a toroidal trap. The mean-field theory predicts that a bright-soliton state will be formed when increasing the interparticle interaction over a critical point. The study of quantum many-body dynamics in this paper reveals that there is a modulation instability in a finite Bose system correspondingly. We show that Shannon entropy becomes irregular near and above the critical point due to quantum correlations. We also study the dynamical behavior of the instability by exploring the momentum distribution and the fringe visibility, which can be verified experimentally by releasing the trapComment: 6 pages,5 figure

Incidence of Anxiety and Depression in Patients with Chronic Obstructive Pulmonary Disease: A Meta-Analysis

Objective: To systematically evaluate the incidence of COPD with anxiety and depression in the past 5 years. Methods: The databases of CNKI, Wanfang, VIP, CBM, PubMed, WebofScience, TheCochraneLibrary and EMbase were searched by computer. The study type was cross-sectional study or other types of study that included baseline data.  Outcome indicators included the incidence of anxiety or depression; The cross-sectional study evaluation scale recommended by AHRQ was used to evaluate the quality of the included literature, and StataSE 16 was used to complete the meta-analysis. Results: A total of 35 literatures were included, including 27 Chinese literatures and 9 English literatures. Meta-analysis results showed that: The overall incidence of COPD combined with anxiety or depression was 50.00%, the overall incidence of COPD combined with anxiety was 40%, the incidence of COPD combined with depression was 42%, and the incidence of COPD combined with anxiety and depression was 20%. Conclusion: The incidence of COPD combined with anxiety and depression is high. Clinicians and patients' families should pay attention to COPD, and the psychological problems of patients, and prevent the occurrence of anxiety and depression

NUMERICAL INVESTIGATION OF GAS SAMPLING FROM FLUIDIZED BEDS

Gas mixing in a tall narrow fluidized bed operated in the slugging fluidization regime is studied with the aid of computational fluid dynamics. Three-dimensional numerical simulations are performed with an Eulerian-Eulerian model. Predicted axial and radial tracer concentration profiles for various operating conditions are generally in good agreement with experimental data from the literature. Different field variables including voidage, tracer concentration, and gas velocity at upstream and downstream levels are analysed to study gas mixing. Mean tracer concentrations in the dense phase and the bubble phase are evaluated and significant differences between them are found. The time-mean concentration is weighted heavily towards the dense phase concentration which may lead to misinterpretation of sampling data in dispersion models. Caution is needed when interpreting time-mean tracer concentration data. A flux-based mean tracer concentration is introduced to characterize the gas mixing in numerical simulations of two-phase fluidized beds