A high-density crowd state judgment model based on entropy theory.

A high-density crowd state is prone to cause large-scale crowd stampede accidents that seriously threaten the people's security and property. The key to preventing crowd congestion is to accurately predict the location and time of crowd events, particularly when there is a high density of people. In this paper, the entropy theory is used to characterize the state of a crowded system.

Effect of Carbon Black on Rutting and Fatigue Performance of Asphalt.

As an additive to improve the performance of asphalt binder, tire pyrolysis carbon black is gradually being used in road engineering, but the effect of carbon black (CB) with different particle sizes on asphalt modification remains to be further studied. In this study, three kinds of particle sizes and three kinds of contents of CB were used to modify asphalt, and different tests were conducted to research the high temperature performance and fatigue resistance of carbon black modified asphalt binder. It is found that the addition of CB can enhance the rutting resistance and medium temperature fatigue performance of virgin asphalt binder in general.

α-FeO hollow meso-microspheres grown on graphene sheets function as a promising counter electrode in dye-sensitized solar cells.

Although nanoparticles, nanorods, and nanosheets of α-FeO on graphene sheets have been synthesized, it remains a challenge to grow 3D α-FeO nanomaterials with more sophisticated compositions and structures on the graphene sheets. Herein, we demonstrate a facile solvothermal route under controlled conditions to successfully fabricate 3D α-FeO hollow meso-microspheres on the graphene sheets (α-FeO/RGO HMM). Attributed to the combination of the catalytic features of α-FeO hollow meso-microspheres and the high conductivity of graphene, α-FeO/RGO HMM exhibited promising electrocatalytic performance as a counter electrode in dye-sensitized solar cells (DSSCs).

Evaluation of Asphalt with Different Combinations of Fire Retardants.

When a fire takes place in a tunnel, the surface of the asphalt pavement will burn and release a large amount of smoke, which is toxic to human health. Thus, in order to prevent the combustion of the asphalt pavement under fire, it is necessary to propose some methods to retard its physical and chemical reaction under the high temperature. In this study, ten different combinations of fire retardants and a control case where no fire retardant was applied were prepared for evaluation.

Study on the Effect of Demulsification Speed of Emulsified Asphalt based on Surface Characteristics of Aggregates.

Aggregate is an indispensable raw material for emulsified asphalt construction. For the purpose of explaining the influence of aggregate characteristics on the demulsification speed of emulsified asphalt, the surface energy and specific surface area (SSA) characteristics of aggregates were calculated based on the capillary rise method and the BET (Brunauer-Emmett-Teller) adsorption test. Afterwards, the effect of the surface energy and specific surface area of the aggregate on the emulsified asphalt demulsification speed was systematically studied by using ultraviolet spectroscopy as well as the orthogonal test.

[Spectroscopic characterization and properties of Mg2B2O5w/AZ91D magnesium composites].

Magnesium borate whisker (Mg2B2O5 w) reinforced Mg matrix composite was fabricated by vacuum-gas pressure infiltration process. The Mg2B2O5 w preforms forming process was determined. The Mg2B2O5 whiskers were fabricated into a preform by wet forming method without any binder.