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In this paper, we propose a phase field-lattice Boltzmann (LB) model with an equation of state (EOS) inputting for two-phase flow containing soluble surfactants. In this model, both the order parameter for the phase field and the surfactant concentration are described by second-order partial differential equations, along with Navier–Stokes equations for the flow field. Changes in surfactant concentration do not affect the order parameter distribution; hence, an unwanted sharpening effect cannot arise. Most importantly, in the existing models, the EOS of surface tension is determined by posterior simulation tests instead of being directly set as an input parameter before the simulations. Hence, it is difficult to determine the model parameters in practical applications. To address this issue, we systematically develop a fully analytical EOS for surface tension based on the Gibbs–Duhem equation. Subsequently, an approximate explicit form for EOS is provided by utilizing the Jacobi–Gauss quadrature rule. Furthermore, a multiple-relaxation-time LB scheme is utilized to numerically solve the governing equations of three physical fields. Two benchmark examples are simulated to validate the accuracy of the present model. The consistency between the numerical results and the analytical EOS is verified. Moreover, the dynamics of droplets with surfactant in simple shear flow is investigated, unveiling the profound impact of various factors, such as surfactant bulk concentration, capillary number, and viscosity ratio, on single droplet deformation and two equal-sized droplets interaction. A detailed exploration of the fluid mechanism involved in two-phase flow with soluble surfactants is presented. [ABSTRACT FROM AUTHOR]

Objective: To study the prevalent situation of Japanese encephalitis (JE) virus among healthy people in Heilongjiang province and to analyze its risk factors., Methods: 7 national surveillance counties were selected and divided into 5 age groups as 1-2, 3-5, 6-10, 11-20 and 21-59 years and randomly sampled 7 person in each age group per county with the sample size as 1050. Quantitative Elisa test was used to detect Japanese encephalitis antibody IgG., Results: The adjusted standard antibody positive rate of people on 1-59 year olds was 70.62%, with lowest in 3-5 age group, and increasing by age (chi2 for trend test = 40.52, P < 0.001). The overall titer of IgG was low in general population but was different with age (Kruskal-Wallis test chi2 = 76.9, P < 0.001). Older age and lower latitude seemed to be two risk factors on JE antibody IgG., Conclusion: JE virus infection had a long-term effect with low level, among general population. Age and latitude were two risk factors which suggesting the necessarily of strengthening the surveillance system for JE cases at risk in the prevalent areas on Heilongjiang province.

By using a Li-6400 portable photosynthesis system, this paper measured the maximal photosynthetic capacity (P(max)) and water use efficiency (WUE) of the seedlings or saplings of 150 species of tropical montane rainforest in Hainan Island. The results showed that among the test 150 species, Quercus bambusifolia (Fagaceae) had the highest P(max) (13.27 micromol x m(-2) x s(-1)) and Macaranga denticulate (Euphorbiaceae) had the highest WUE (5.99 mmol x mol(-1)), while Decaspermum cambodianum (Myrtaceae) had the lowest P(max) (1.35 micromol x m(-2) x s(-1)) and Sapium discolor (Euphorbiaceae) had the lowest WUE (2.4 mmol x mol(-1)). The average P(max) was the highest in Moraceae but the lowest in Myrtaceae, and the average WUE was the highest in Symplocaceae but the lowest in Moraceae. However, there were no significant differences (P > 0.05) among the families. No significant differences (P > 0.05) in P(max) and WUE were also observed among arbors and shrubs. The P(max) value increased significantly (P < 0.05) with the widening of families' geographical distribution range, in the order of narrow distribution families < medium distribution families < wide distribution families, while no significant differences were existed among their WUE (P > 0.05). The P(max) value also increased with the widening of species' geographical distribution range, in the order of endemic species in Hainan Island < tropical species < tropical-subtropical species < tropical-subtropical-temperate species, but WUE was opposite to P(max), namely, in the order of endemic species in Hainan Island > tropical-subtropical species > tropical species > tropical-subtropical-temperate species.