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Phase change materials (PCMs) have been widely used in passive thermal management and energy storage due to their high latent heat capacity. However, the low thermal conductivity and leakage problems of PCMs are two bottlenecks for its application in the field of heat-related applications. Although many present studies can tackle one or two of these problems by preparing phase change composites (PCCs), it is still a challenge to achieve high performance PCCs with excellent thermal, mechanical, and phase change properties simultaneously. In this work, we report a spatial confining forced network assembly (SCFNA) method to efficiently prepare the thermal conductive, flexible, leak-proof hexagonal boron nitride/paraffin wax/ polydimethylsiloxane (hBN/PW/PDMS) PCCs by constructing hBN and PW thermal conductive networks as the functional matrix of PCCs. In the hBN/PW/PDMS PCCs, PW is served as the PCM, a dense hBN network provides the high thermal conductivity, and the mechanical properties and shape stability are provided by PDMS. The hBN/PW/PDMS PCCs as thermal interface materials reduce the LED chips surface temperature and exhibit efficient and reliable thermal management performance. Our work provides an efficient and economical method for the preparation of PCCs with outstanding thermal management capability. [ABSTRACT FROM AUTHOR]

An energy pile alters the ground temperature fields around it, which may lead to uneven settlements and a higher risk of failure. The thermomechanical behaviors of soils have been studied extensively in laboratory experiments, while in situ investigations are rare. In this research, flat dilatometer tests (DMTs) are first employed to investigate the thermomechanical behaviors of soil under in situ conditions. The soils were heated by a full-scale precast high-strength concrete (PHC) energy pile, and a series of DMTs were conducted. The results show that temperature changes had a substantial impact on the DMT data of the silt and clay layers. The measured pressures p0 and p1 of the silt and clay layers decreased with increasing ground temperature, and the measured pressure p2 of the silt and clay layers decreased at the beginning and then increased with increasing ground temperature. Although the silt and clay layers have similar variations in the measured pressures, the clay layer has a greater thermal response than the silt layer. Finally, the critical state soil mechanics theory is used to analyze the pore water pressure and thermomechanical properties of in situ overconsolidated soil. The results indicate that the elastic region (yield surface) and mean effective stress of in situ soil decrease with increasing ground temperature, potentially resulting in more irreversible deformation and a higher probability of failure. [ABSTRACT FROM AUTHOR]

Humans show a clear left-side bias in face processing. A chimeric face constructed with the left side (from the viewer's perspective) of a face and its mirror image is usually rated as more resemblant to the original face than a chimeric face constructed with the right side of the same face. Previous studies have characterized the left-side bias mainly with own-race faces, but it remains unclear whether this effect is race specific or if it reflects an universal visual expertise. One hundred and five Chinese students completed two versions of a chimeric face-identification task. The results revealed a significant left-side bias for both own-race (Chinese) and other-race (Caucasian) faces, suggesting that the left-side bias reflects an universal visual expertise in face processing. [ABSTRACT FROM AUTHOR]

This paper is concerned with a fractional diffusion predator-prey system with Holling type-II functional response in a bounded domain with no flux boundary condition. The local and global stabilities are investigated and sufficient conditions of stabilities are obtained. The existence of the non-constant steady states is considered and the sufficient conditions of the existence for the non-constant steady states are also obtained. The results show that the predator and the prey can coexist under some suitable conditions with fractional diffusion. [ABSTRACT FROM AUTHOR]

This paper is purported to investigate a food chain reaction-diffusion predator-prey system with nonlocal delays in a bounded domain with no flux boundary condition. We investigate the global stability and find the sufficient conditions of global stability of the unique positive equilibrium for this system. The derived results show that delays often restrain stability. Using the method of linearizing this system, we see that the zero equilibrium is unstable. Moreover, by constructing upper-lower solutions, we find that there exist traveling wavefronts which connect the zero equilibrium and positive equilibrium when the wave speed is large enough and the prey intrinsic growth rate and the death rate of the predator are relatively big. [ABSTRACT FROM AUTHOR]

A ratio-dependent diffusion predator-prey system with free boundary is investigated to understand the impact of free boundary on spreading-vanishing dichotomy and a long time behavior of species. The existence and uniqueness of solutions are verified and the behavior of positive solutions is considered for this system. Moreover, the criteria for spreading-vanishing dichotomy are also derived. The results show that if the length of the initial occupying area is longer than a critical size for the predators or the length of the initial occupying area is shorter than a critical size, but the moving coefficient of free boundary is relatively big, then the spreading of predators always happens under relatively small rate of death for the predator. On the other hand, it is found that if the initial value of free boundary is smaller than a threshold value and the moving coefficient of free boundary is relatively small depending on initial size of predator or the rate of death is relatively big, the predators fail in spreading to new environment. [ABSTRACT FROM AUTHOR]

The aim of this study was to test the effects of including sweet potato tuber and stem powder in feed on the body composition and digestive enzyme activities of the sea cucumber Apostichopus japonicas Selenka. Different proportions of sweet potato tuber and stem powders (from 10% to 50%) were added into compound feeds, which were supplied to A. japonicas during a 60-day experiment. The results showed that the two sweet potato ingredients had different effects on the nutrient contents of the sea cucumber body wall. The group supplied with feed containing 20% sweet potato tuber powder (T2) had the highest level of crude protein in body walls (P <0.05), while there were no significant differences in the moisture and ash contents of body walls among the groups (P >0.05). In all the groups fed with powdered sweet potato tubers (T groups), the proportions of glutamic acid and lysine in body walls were higher than those in the control, whereas the proportion of methionine decreased slightly. Different proportions of sweet potato ingredients in compound feeds also affected digestive enzyme activities in the sea cucumbers. The activities of protease and lipase first increased and then gradually decreased with increasing proportions of sweet potato materials in the feed. The highest protease activity was in the T2 and the group and the highest lipase activity was in the 10% sweet potato stem (S1) group. These results show that feed components can stimulate digestive enzyme activities in sea cucumber, and that the proportions of tubers and stems of sweet potato in feed can be adjusted to improve the digestion and growth of A. japonicas in marine farms. [ABSTRACT FROM AUTHOR]

In this paper we consider a family of singularly perturbed delay differential equation of convection diffusion type. When the perturbation parameter is very small, the solution of the problem exhibits layer behavior. In the layer region the solution changes rapidly, while away from this region the change in the solution is moderate. This simultaneous presence of two different scales phenomena makes the problem stiff. In this work, the problem is solved by applying a new Liouville-Green transform and the asymptotic solutions are obtained. Application to multi-point boundary value problem is also illustrated. Several test examples are taken into account so as to test the efficiency of the proposed method. The method presented is compared with other existing numerical or asymptotic methods. It is observed that the method presented is very easy to implement and is capable of reducing the size of calculations significantly while still maintaining high accuracy of the solution. [ABSTRACT FROM AUTHOR]