The weak connection performances between the waterproof adhesive layer, the bridge deck, and asphalt pavement are important factors that cause the bridge deck slippage and upheaval and affect the safety and durability of the bridge. In this paper, styrene-butadiene-styrene- (SBS-) modified asphalt, SBS-emulsified asphalt, rubber-modified asphalt, and AMP-100 waterproof materials are selected to study the performance of the bridge deck waterproof adhesive layer in the seasonal frozen region. The shear strength and bond strength of the four waterproof adhesive materials were obtained through the shear test and pull-out test of the composite specimens composed of four kinds of adhesive materials, diatomite rubber-particle asphalt mixture, and concrete bridge deck at different dosages and temperatures. According to the priority analysis of the factors including cost, construction difficulty, and environmental protection for the four kinds of materials by using analytic hierarchy process (AHP), SBS-modified asphalt is obtained as the most suitable waterproof adhesive layer of diatomite rubber particle asphalt mixture bridge deck in seasonal frozen region.
Prefabricated box culvert is a new structure in road engineering, whose health is very important to road safety. The use of acoustic emission (AE) as a detection method and the use of other improved algorithms to evaluate the damage of prefabricated box culverts are still insufficient. In this paper, two kinds of prefabricated box culverts are tested and studied, and the damage process of the box culverts is analysed based on the AE parameters of the box culvert using the traditional fuzzy C-means method (FCM). In addition, an improved algorithm based on the combination of grid density and distance (G-DFCM) was proposed, which was simulated and applied to the AE data analysis of the prefabricated box culvert. The research results show that the application effect of the G-DFCM algorithm is good, which not only overcomes the shortcomings of the original algorithm but also improves the effectiveness of the algorithm. This work can provide a supplement to the damage identification of fabricated box culverts.
Porous nanocomposites of M/Ce-K-O (M=Co, Ni, Cu) were prepared by the citrate-gel thermal decomposition and selective reduction process, and the effect of transition metal nanoparticles on their microstructure, catalytic performance were studied by XRD, SEM, BET, XPS and TG analysis. The nanocomposites consist of the fluorite-type matrix of CeO2 nanoparticles about 13-20 nm and metallic nanoparticles ~26 nm. These nanocomposites have a nanoporous structure with high specific surface area and their pore sizes, pore structures, surface morphologies are largely affected by the dispersed nano metal species. For M/Ce-K-O (M=Co, Ni, Cu) nanocomposites, all the catalysts show a high catalytic activity for soot combustion, and among them, the Cu/Ce-K-O nanocomposite has a lowest T50 of 315 °C mainly due to a higher lattice oxygen content and a weaker Cu-O interaction intensity.
With the rapid increasing of web data, deep web is the fastest growing web data carrier. Therefore, the research of deep web, especially on extracting data records from Result pages, has already become an urgent task. We present a data records extraction based on Global Schema method, which automatically extracts the query result records from web pages. This method first analyzes the Query interface and result records instances to build a Global Schema by ontology. Then, the Global Schema is used in the process of extracting data records from result pages and storing these data in a table. Experimental results indicate that this method is accurate to extract data records, as well as to save in a table with a Global Schema.
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