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In this study, we conducted indoor temporary plugging and diverting fracturing (TPDF) experiments on samples of natural deep and shallow coal seams using a small-scale true triaxial fracturing simulation system. By integrating high-precision CT scanning technology and crack reconstruction techniques, and relying on the quantitative characterization of the crack complexity coefficient, we investigated the differences in internal structures between deep and shallow coal seam samples and the variations in the expansion of TPDF cracks. Furthermore, the study primarily focused on exploring the influence of temporary plugging agent (TPA) parameters (quantity and particle size) on the expansion patterns of TPDF cracks in deep coal seam coal-rock samples. The experimental results reveal that in shallow coal samples, artificially induced fractures are notably longer and extend to various surfaces of the samples. Conversely, in deep coal samples, the expansion of artificially induced fractures is influenced by well-developed cleavage and cleats. The crack complexity coefficient of artificial fractures in deep coal samples is 1.54 higher than that in shallow coal samples, with an increased crack width of 98 μm. However, the expansion distance of the fractures is shorter and does not extend to the S3 and S6 surfaces. Increasing the dosage of the TPA is advantageous for inducing frequent redirection of fractures and communication with previously untouched areas. When the dosage of the TPA is increased from 30 g/L to 60 g/L, the expansion distance of artificial fractures significantly increases, extending to various surfaces of the samples. The crack complexity coefficient increases by 1.1, and the crack width enlarges by 84 μm. Appropriate particle sizes of the TPA can effectively form seals. However, small particle sizes (200/400 mesh) struggle to seal initial fractures, while large particle sizes (10/20 mesh) can lead to excessive wellhead blockage, causing rapid shut-in pressure, destructive fracturing in deep coal samples, and the generation of a large amount of coal fines. This study holds significant guidance for the optimal selection of process parameters in the temporary plugging hydraulic fracturing of deep coal rock.

Optical polarization has attracted considerable research attention by extra detection dimension in angular space, flourishing modern optoelectronic applications. Nonetheless, purposive polarization controlling at nanoscales and even at the single-particle level constitutes a challenge. Plasmonic nanoantenna opens up new perspectives in polarization state modification. Herein, we report angular-dependent upconversion luminescence (UCL) of rare-earth ions doped upconversion nanoparticles (UCNPs) in both emission and excitation polarization via constructing angularly anisotropic plasmonic local-field distributions in gold nanorods (Au NRs) antennae with different configurations at a single-particle level. The UCL of UCNP tailored by plasmonic Au NRs nanoantennae is enhanced and exhibits linear polarization. The highest enhancement factor of 138 is obtained in the collinear Au NR-UCNP-Au NR configuration under parallel excitation. Simultaneously, the maximum degree of linear polarization (DOLP) of UCL with factors of 85% and 81% are achieved in the same structure in emission and excitation polarization measurements, respectively. The observed linear polarizations and UCL enhancements are due to varied resonant responses at 660 nm and the anisotropic near-field enhancement in different nanoantennae-load UCNP. The theoretical simulations reveal the periodic changing of near-field enhancement factors of nanoantennae in angular space with the incident light polarization angles and are well-matched with the experimental results.

Much effort has been devoted to predicting fish migration routes to assist target species migration, and yet, fish migration science and practice remain imperfect. This study aimed to predict the migration paths of Gymnocypris przewalskii at the river confluence in the Qinghai Lake basin. The authors proposed an approach for fish migration route prediction, which involves a hydrodynamic module, a habitat model and a fish migration module. The TELEMAC‐MASCARET system was used to simulate hydrodynamic conditions and statistical analyses were carried out. During the flood season, G. przewalskii migrates downstream, whereas during the migratory season, they migrate upstream. The results indicate that flow velocity was the most significant hydrodynamic parameter affecting fish migration behaviour. The optimal flow velocity range for the target fish species was between 0.7 and 1.7 m/s. The impact of water depth was only observed in low discharge situations. Besides, the temperature plays a vital role in determining fish migration and abundance. However, the results reveal that in the morning hours, the temperature exhibits a range of 10°C to 16°C, and in the noon, the average temperature ranges from 16°C to 19°C, with a maximum temperature reaching 23°C. These temperature variations enable fish to migrate towards the tributary offering a more favourable water temperature during route selection at a river confluence. The study concludes that future research should consider incorporating the swimming capacity of the focal fish species to provide insights into fish migration patterns. [ABSTRACT FROM AUTHOR]

Understanding the relationship between individuals social networks and health could help devise public health interventions for reducing incidence of unhealthy behaviors or increasing prevalence of healthy ones. In this context, we explore the co-evolution of individuals social network positions and physical activities. We are able to do so because the NetHealth study at the University of Notre Dame has generated both high-resolution longitudinal social network (e.g., SMS) data and high-resolution longitudinal health-related behavioral (e.g., Fitbit physical activity) data. We examine trait differences between (i) users whose social network positions (i.e., centralities) change over time versus those whose centralities remain stable, (ii) users whose Fitbit physical activities change over time versus those whose physical activities remain stable, and (iii) users whose centralities and their physical activities co-evolve, i.e., correlate with each other over time. We find that centralities of a majority of all nodes change with time. These users do not show any trait difference compared to time-stable users. However, if out of all users whose centralities change with time we focus on those whose physical activities also change with time, then the resulting users are more likely to be introverted than time-stable users. Moreover, users whose centralities and physical activities both change with time and whose evolving centralities are significantly correlated (i.e., co-evolve) with evolving physical activities are more likely to be introverted as well as anxious compared to those users who are time-stable and do not have a co-evolution relationship. Our network analysis framework reveals several links between individuals social network structure, health-related behaviors, and the other (e.g., personality) traits. In the future, our study could lead to development of a predictive model of social network structure from behavioral/trait information and vice versa.

The downstream migration of fish is impacted by accelerating flow. This study coupled computational fluid dynamics (CFD) modelling and laboratory observations to investigate the effects of two different accelerating flow hydrodynamics on the swimming behaviours of two fish species. The silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis) were chosen as target fish species and four hydrodynamic parameters were selected as main indicators to affect fish swimming behaviours. Four specific swimming behaviours were classified in the contraction flume based on fish downstream trajectories. The results indicated that high accelerating flow, low turbulent kinetic energy (Tke) and shear stress generated the symmetric distribution of fish along two boundaries of the contraction flume. It also indicated that discharge increase would increase the fish entrainment risk from intakes to diversion pipe, while two fish species exhibited different swimming behaviour patterns. Velocity and velocity gradient had more significant effects than other hydrodynamic parameters on fish swimming strategies. There was mutual compensation among fish tail-beat frequency, angle and amplitude. The results illustrated the relationship between the swimming behaviours and hydrodynamics, which could contribute to understanding the fish downstream migration behaviours in accelerating flow. [ABSTRACT FROM AUTHOR]

Dam construction alters the hydrodynamic conditions, consequently impacting the swimming behavior of fish. To explore the effect of flow hydrodynamics on fish swimming behavior, five endemic fish species in the upper Yangtze River basin were selected. Through high‐speed video visualization and computer analysis, these species' swimming patterns under different flow velocities (0.1–1.2 m/s) were investigated. The kinematic and morphological characteristics of the fish were presented. The principal component analysis was used to analyse the main factors influencing the swimming ability of fish and to determine the correlation coefficients among fish behavior indicators. Fish exhibited three different swimming patterns under different flow velocities. Low velocity (0.1–0.3 m/s) corresponds to free motion, middle velocity (0.4–0.7 m/s) corresponds to cruising motion, and high velocity corresponds to stress motion (0.8–1.2 m/s). The fish kinematic index curves were obtained, and four of five fish species showed two extreme points, which means the optimal and adverse swimming strategies can be determined. With the increase in flow velocity, the tail‐beat frequency showed an increasing trend, whereas the tail‐beat angle and amplitude showed a decreasing trend. Morphological and kinematic parameters were the two main indexes that affect the swimming ability of fish, which accounts for 41.9% and 26.9%, respectively. [ABSTRACT FROM AUTHOR]

In order to build an appropriate prediction model of pavement friction coefficient attenuation, the effects of aggregate texture, on a basis of texture scanning and pavement testing of the dynamic friction coefficient, traffic volume, and rock characteristics on pavement slide decay resistance were studied, and the accuracy of the developed prediction model of friction coefficient was thereafter compared and analysed. First, based on the tire-pavement dynamic friction analyzer independently developed by the research group, accelerated loading tests under different traffic conditions were conducted by the orthogonal test method, and the dynamic friction coefficient of pavement during the abrasion process was recorded. At the same time, the non-contact laser profile measurement system was used to collect three-dimensional micro-texture data of coarse aggregate surface at different abrasion stages, and characteristic parameters such as height, wavelength, and shape were calculated. Second, the factors such as traffic volume and rock characteristics were incorporated, and the algorithms such as multiple linear stepwise regression, feedforward neural network, and random forest regression were adopted to develop estimation models of pavement friction. The results showed that the model constructed based on only texture feature parameters poorly represented pavement skid resistance. After introducing the two indicators of total traffic volume and rock type, the correlation coefficients of the model significantly improved, reaching 0.63, 0.58, and 0.82 respectively, indicating that the latter two factors have significant effects on the anti-skid attenuation of pavement. Moreover, the above three models can achieve satisfactory prediction results. In addition, when a large sample size can be obtained, a random forest algorithm is recommended to acquire higher prediction accuracy of pavement friction coefficient attenuation. [ABSTRACT FROM AUTHOR]

BACKGROUND. Low vitamin D status in pregnancy was proposed as a risk factor of preeclampsia. METHODS. We assessed the effect of vitamin D supplementation (4,400 vs. 400 IU/day), initiated early in pregnancy (10-18 weeks), on the development of preeclampsia. The effects of serum vitamin D (25-hydroxyvitamin D [25OHD]) levels on preeclampsia incidence at trial entry and in the third trimester (32-38 weeks) were studied. We also conducted a nested case-control study of 157 women to investigate peripheral blood vitamin D-associated gene expression profiles at 10 to 18 weeks in 47 participants who developed preeclampsia. RESULTS. Of 881 women randomized, outcome data were available for 816, with 67 (8.2%) developing preeclampsia. There was no significant difference between treatment (N = 408) or control (N = 408) groups in the incidence of preeclampsia (8.08% vs. 8.33%, respectively; relative risk: 0.97; 95% CI, 0.61-1.53). However, in a cohort analysis and after adjustment for confounders, a significant effect of sufficient vitamin D status (25OHD ≥ 30 ng/ml) was observed in both early and late pregnancy compared with insufficient levels (25OHD CONCLUSIONS. Vitamin D supplementation initiated in weeks 10-18 of pregnancy did not reduce preeclampsia incidence in the intention-to-treat paradigm. However, vitamin D levels of 30 ng/ml or higher at trial entry and in late pregnancy were associated with a lower risk of preeclampsia. Differentially expressed vitamin D-associated transcriptomes implicated the emergence of an early pregnancy, distinctive immune response in women who went on to develop preeclampsia. TRIAL REGISTRATION. ClinicalTrials.gov NCT00920621. FUNDING. Quebec Breast Cancer Foundation and Genome Canada Innovation Network. This trial was funded by the National Heart, Lung, and Blood Institute. For details see Acknowledgments., Introduction Preeclampsia is a multisystem complex disease of pregnancy with grave maternal-fetal and neonatal consequences that complicates up to 8% of pregnancies (1, 2). Low vitamin D status, among other [...]