Because soluble salt in saline soil dissolves with water, utility tunnels built in saline soil foundation are more likely to damage due to by groundwater and earthquake. In this study, new cementitious composite materials were developed by using slag, building gypsum, quicklime, and magnesia. The unconfined compressive strengths of the saline soil solidified by new cementitious composite materials and cement are investigated, and the optimum proportion of the different components of the new cementitious composite materials is determined. We found from microscopic characteristics of the saline soil solidified by the new cementitious composite materials and cement that the new materials could better absorb chloride ions. Finally, the new cementitious composite materials were applied to saline soil foundation reinforcement of a utility tunnel. By using the finite element method (FEM) and shaking table tests, it can be seen that the displacement, acceleration and extent of damage of the utility tunnel after saline soil foundation reinforcement using new cementitious composite materials significantly decreased; therefore, the new cementitious composite materials can improve the seismic behaviour of the utility tunnel and shows potential future engineering application value.
The present study was designed to elucidate the Catalase (CAT) activity and malondialdehyde (MDA) contents in gills and muscle tissues of Zebrafish in exposure to different concentrations of deicing salt. According to the value of 96 h LC50, five different concentration treatments (4.30, 5.38, 6.73, 8.41 and 10.51 g/L) of deicing salt were set up with no application of deicing salt (0 g/L) as control treatment, and the activity of CAT and MDA in the gills and muscle tissues of Zebrafish were measured at 1d, 4d, and 7 d exposure. The results showed that the 96 h LC50 value of deicing salt for Zebrafish was 13.49 g/L and the safe concentration was 4.26 g/L. The CAT activity in muscle tissues of Zebrafish was activated significantly (P<0.01) at 1d, and was inhibited significantly with the concentration of 10.51 g/L (P<0.05) by comparing with the control treatment during the whole experimental time. However, the CAT activity in gills was activated significantly (P<0.01) with the concentration of 5.38 g/L, and inhibited significantly (P<0.05) with the concentration of 10.51 g/L. The MDA contents in gills of Zebrafish enhanced gradually with the deicing salt concentration increased. In muscle tissues of Zebrafish, MDA contents decreased gradually during the whole experimental time.
In this article, we select corresponding Tersoff potential energy to build potential energy model and investigate the thermal conductivities of single-crystal carbon thin-film. The equilibrium molecular dynamics (EMD) method is used to calculate the nanometer thin film thermal conductivity of diamond crystal at crystal direction (001), and the non-equilibrium molecular dynamics (NEMD) is used to calculate the nanometer thin film thermal conductivity of diamond crystal at crystal direction (111). The results of calculations demonstrate that the nanometer thin film thermal conductivity of diamond crystal is remarkably lower than the corresponding bulk experimental data and increase with increasing the film thickness, and the nanometer thin film thermal conductivity of diamond crystal relates to film thickness linearly in the simulative range. The nanometer thin film thermal conductivity also demonstrates certain regularity with the change of temperature. This work shows that molecular dynamics, applied under the correct conditions, is a viable tool for calculating the thermal conductivity of nanometer thin films.
In consider of construction characteristics of drilling bitten pile in Kunming metro engineering, this paper study on preparation and performance of super retarded concrete. Meanwhile, this paper find appropriate raw materials and mixing amount, which can meet construction requirement of high flowability and long setting time for this engineering. Combined theory with experiments, it lay the foundation of popularization and application of super retarded concrete to find the influence law of performance of super retarded concrete by mixing amount of all materials.
Taking a rise steel as a study, study response of the structure to the dynamic characteristics under fluctuating wind load. The results showed that: deformation of structure under the fluctuating wind load is shear deformation; Structural displacement response curve is similar to the curve of the pressure time history. Because of consider different heights the structure of spatial correlation affect, Displacement positions on different floors response curves are differ.
For the problem of module division for distributed reconfigurable satellite system. A satellite function tree top-down is set up in this paper. And the genetic algorithm was applied in the module division. Finally the entire satellite was decomposed into various standard parts. In practice, users only need to combine those standard parts into a specific function module according to the requirements. Then send those modules into their orbit. And those modules through the way of formation flight, wireless connection to fulfill the task. Considering China's space development strategy, satellite systems long life and high reliability, upgrading, expansibility, satellite systems planning, running, production all kinds of uncertainty factors. Finally the satellite system was divided into 15 standard parts.
This paper introduces a variety of viscous damper installation form, including brace, herringbone and cantilever wall installation. By an example, install the bracing form, herringbone installation form and type cantilever wall installation condition are compared, And to calculate the results of its damping effect has carried on the comparative study, The superiority of the cantilever wall type layout pattern is obtained.
In order to study the structure random vibration analysis technology that material properties and temperature should be considered. We have developed a set of structure random vibration parameter engineering analysis tools that under thermal environment conditions. This paper, mainly introduces this software’s architecture, development process and function characteristics. This software is developed based on NASTRAN. User not only can establish a ball cone column finite element model according to actual demand but also can select model’s material properties. At last, we have an example dealt with this software. The analysis results of temperature field, stress modal and random vibration are in good effect. And reached the anticipate design goals of this software
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.