Enhancing understanding of healthy aging based on time-varying dependencies among multidimensional health, life satisfaction, and health behaviors of older adults aged 60 years and over.

BACKGROUND: Healthy aging is a process of not only achieving good health but also increasing the life satisfaction of older adults aged 60 years and over, in which health behaviors play an important role. There is a lack of research on the time-varying dependencies between health, life satisfaction, and health behaviors, impeding a deeper understanding of healthy aging. PURPOSE: To develop an integrated framework for modeling the interrelationships among the components of healthy aging between multiple time slices. METHODS: Based on the Chinese Longitudinal Healthy Living Survey (CLHLS) data in the three waves of 2011/2012, 2014, and 2017/2018, Bayesian network and dynamic Bayesian network are jointly employed to study the relationships among the components of healthy aging within one time slice, as well as to explore the time-varying dependencies among the components between time slices. RESULTS: The results of structure learning reveal the direction of effects between different dimensions of health, with mental health and social health affecting physical health and self-rated health affecting both physical and mental health. In addition, health behaviors are found to affect mental health and social health, while self-rated health can influence life satisfaction. The parameters learned from the data show the magnitude and direction of concurrent effects, one-period lagged effects and two-period lagged effects between the factors, which find that the time-varying dependencies vary but are generally positive, long-term, and accumulative over time. In addition, the results of autoregressive effects show the positive predictive effects of health and life satisfaction. CONCLUSIONS: It confirms the influence pathway from health behaviors to multidimensional health to life satisfaction, and the time-varying dependencies among the components of healthy aging, which facilitates a deeper understanding of healthy aging. Combining the results of autoregressive effects and descriptive statistics, it further indicates that healthy aging is a comprehensive result arising from interactions of multiple factors. Policymakers should guide older adults aged 60 years and over to adopt healthier behaviors and ensure the long-term sustainability and continuity of policies.

Synthesis and performance evaluation of temperature and salt-resistant organic/inorganic composite copolymers.

Ordinary polymers have poor adaptability in high-temperature and high-salt reservoir environments due to their properties. Organic/inorganic composite copolymer microspheres have the advantages of both of them, which are expected to break through their applicability limitations in such oil reservoirs. Therefore, its preparation and performance have always been of great concern to researchers. In this paper, AM/AMPS/Si-St ternary copolymers were synthesized by precipitation polymerization; then modified nano-silica particles were added to synthesize AM/AMPS/Si-St/g-SiO2 organic/inorganic composite quaternary copolymers. FT-IR and SEM characterized the copolymers to confirm that they were prepared successfully. Experiments were carried out to investigate the concentration and ratio of monomers, which showed that the Weissenberg effect could be avoided. The number of polymer molecules could be stabilized under AM concentration of 12 wt%, AM/AMPS/Si-St ratio of 8:1:1, nano silica of 3.3% and the modification conditions of KH570:SiO2 = 1:1. The experiments of temperature and salt resistance of two copolymers were evaluated and compared were conducted by using viscosity and particle size as parameters. The results showed that quaternary copolymers could increase the viscosity retention rate by about 10% compared with ternary copolymers under high content of Na+ and Mg2+. When the two copolymers were placed at 150°C, the appearance and morphology of the terpolymer changed obviously. Through the SEM image of the quaternary copolymers, it could be seen that although the spherical shape of the microsphere had been gradually lost, no degradation occurred, and the stable time of the modified microspheres had been effectively extended.

Relationship between the Molecular Coil Dimension and the Energy Storage Modulus of Polymer Solution Configured with Oilfield-Produced Sewage.

Polymer viscoelastic solution is the non-Newtonian fluid and widely used in oil production. In the process of seepage, the mechanism of the polymer solution with different molecular coil dimensions (Dh) flooding on remaining oil is unknown. By using the dynamic light scattering instrument, the molecular coil dimension of the polymer solution is tested. By using the HAAKE rheometer, the creep recovery test data of the polymer solution under the same creep time condition are obtained. The effects of polymer solutions with different Dh on residual oil are observed, by using the visible pore model. The results show that the higher the molecular weight (M w) of the polymer, the larger the size of the molecular coil dimension. The elasticity characteristics of the polymer solution are sensitive to the molecular coil dimension. As Dh of polymer molecules becomes larger, the contribution of the elastic portion to the viscosity of the polymer solution increases. The higher the M w of polymer is, the longer the molecular chain is and the size of Dh is larger. On the condition of the polymer solution with different M w with 2.5 g/L, when Dh is between 320.0 nm and 327.8 nm, the ratio of the elastic part in the apparent viscosity exceeds the proportion of the viscous part, and the polymer solution composition after these data can be used as a comparative study of elasticity for residual oil use. In the visible pore model, the pore-throat ratio is 3.5, the E R of water flooding is 54.26%, the E R of the polymer solution with Dh = 159.7 nm is 75.28%, and the increase of E R is 21.02% than that of water flooding. With the increase of Dh to 327.8 nm, the final E R of the experimental polymer solution is 97.82%, and the increase of E R of the polymer solution than that of water flooding is 43.56%. However, in the model with a pore-throat ratio of 7.0 and the same polymer solution with Dh = 327.8 nm, the increase of E R of the polymer solution is only 10.44% higher than that of water flooding. The effect of the polymer solution with the same Dh is deteriorated with the increase of the pore-throat ratio.

Experimental Study on Injection and Plugging Effect of Core-Shell Polymer Microspheres: Take Bohai Oil Reservoir as an Example.

To meet the technical requirements of deep fluid diversion in Bohai oilfield, the swelling property, plugging effect, transport characteristics of polymer microspheres, and fluid diversion effect in heterogeneous cores are studied in this paper. There are two kinds of polymer microspheres including core-shell microspheres and traditional microspheres. The instruments used in this study include a biomicroscope, a metallurgical microscope, a scanning electron microscope, and core displacement experimental devices. The results of microscopes indicated that the core-shell microspheres were successfully synthesized, and the microspheres had good hydration expansion effect. The expanded microspheres could attract each other through the electrostatic force of anions and cations to achieve the purpose of coalescence. Compared with traditional microspheres (initial particle size is 3.8 µm), the initial particle size of the synthesized core-shell microspheres is close to 3.3 µm, but the particle size distribution is more concentrated, so the injection performance is close to that of traditional microspheres (initial particle size is 3.8 µm). After 8 days of hydration expansion, although the expansion multiple is small, it can coalesce and enhance the plugging effect, which can adapt to a wider range of permeability, ranging from 200 × 10-3 to 3000 × 10-3 µm2 (200 × 10-3-1500 × 10-3 µm2 for traditional microspheres). Under the same conditions (heterogeneous core), compared with the traditional microspheres, the core-shell microspheres have the characteristics of coalescence. Therefore, its fluid diversion effect is better, and the oil recovery is increased by 5.5%. Nevertheless, there is the "end effect" during the injection process, which weakens the steering effect of deep liquid flow. The results show that the "end effect" can be effectively reduced by alternate injection of microspheres and water. Meanwhile, the effect of deep fluid diversion is improved, and the increase of oil recovery is increased by 2.06%.