Combined Isolation Foundation by Elastic Base Plate and Ground Barriers

A high sensitive and large semi-anechoic chamber, designed by a new system of isolation is reported in this paper. The combined isolation of a large size elastic plate on sand cushion and pile barriers was used in this system. By properly designing the stiffness of elastic base plate, the amplitude of the anechoic chamber floor under the action of dynamic toad of testing vehicle can be controlled within the allowed range of accuracy. This new system has been conformed with the disturbance of outside of vibration on anechoic chamber (passive vibration isolation) and with that of vehicle testing inside the anechoic chamber (active vibration isolation). The cost of the anechoic chamber designed by the new system has been reduced by 93% compared with the traditional chamber, and also the period of construction was much shorter. It has been tested by the “Acoustics Research Institute of the China Academy of Science” that the background vibration of the anechoic chamber has met accurate requirement. It has been in use for quite a few years and great economic benefit has been made

Mechanism of microstructural modification of the interfacial transition zone by using blended materials

Applying blended materials with finer particle size or high reactivity could be an effective and economic way for improving the microsturcture of interfacial transition zone (ITZ). In this study, the porosity characteristics of ITZ in concrete made with OPC and blended binders were determined quantitatively by using backscattered electron microscopy (BSE) image analysis and mercury intrusion porosimetry (MIP) measurements. This paper especially focused on the effects of slag and limestone filler on the thickness and pore structure of the ITZ. Results indicated that the porosity at each distance reduces with increasing limestone filler from 0 to 5%, and a significant increase is observed in the sample with 10% of limestone filler. The addition of 5% of limestone filler is able to densify the pore structure of both ITZ and bulk matrix. The reduction in pore volume in the range coarser than 100 nm contributed to the largest decrease in the total pores. Increasing the incorporation level of limestone filler to 10% resulted in an increase in the total porosity. The influences of slag on the porosity characteristics were highly dependent on the replacement level and the determined pore size regions. The addition of 35% of slag reduces the porosity at all distances and produces a denser microstructure both in the ITZ and bulk cement matrix. However, this improvement disappears when the substitution amount reaches to 70%. The incorporation of slag as a partial substitute for Portland cement tends to refine the pore structure

Investigation of the deterioration of blended cement concrete under sulfate attack in terms of interfacial transition zone

The importance of the porous interfacial transition zone to the chemical aggression of concrete is obvious when one considers the relations existing between porosity, permeability, chemical composition and the sulfate attack. In this study, the effect of ITZ quantity through varying aggregate content on the deterioration of blended cement concrete under sulfate attack, was determined to understand better the relationship between sulfate ions and concrete microstructure. The ITZ quantity was directly proportional to the aggregate volume fraction. Therefore, the effect of ITZ on sulfate resistance ability of concrete made with pure OPC and blended binders was evaluated by a comparison among mortars with systematically varied aggregate volume fraction. The porosity distribution with the ITZ was determined by using a quantitative backscattered electron microscopy (BSE) image analysis. It was found that the incorporation of moderate amount of Limestone filler is able to compact the microstructure of both ITZ and bulk matrix by filling effect and nucleation sites effect. The effects of slag on the porosity of ITZ were dependent on the replacement rate. The degree of deterioration had a slight tendency to increase for the samples prepared with higher aggregate volume content, which means high ITZ volume fraction. For the sulfate to reach the interior of the samples, it must move through the bulk cement matrix. The effect of aggregate and ITZ can only be notable when the interior structure was exposed to the sulfate ions. The presence of ITZ was normally accompanied by a denser bulk cement matrix. This could limit the ingress of sulfate ions and delay the formation of expansive products in initial stage. After the sulfate penetrates into the interior of the samples, the inner structure was expected to exert more significant influences on the deterioration

Nanocrystals in silicon photonic crystal standing-wave cavities as spin-photon phase gates for quantum information processing

By virtue of a silicon high-Q photonic crystal nanocavity, we propose and examine theoretically interactions between a stationary electron spin qubit of a semiconductor nanocrystal and a flying photon qubit. Firstly, we introduce, derive and demonstrate for the first time the explicit conditions towards realization of a spin-photon two-qubit phase gate, and propose these interactions as a generalized quantum interface for quantum information processing. Secondly, we examine novel single-spin-induced reflections as direct evidence of intrinsic bare and dressed modes in our coupled nanocrystal-cavity system. The excellent physical integration of this silicon system provides tremendous potential for large-scale quantum information processing

A Study of Lateral Bearing Capacity of Pile by Dynamic Test

In order to improve the knowledge of the Lateral Loading behavior of artificially drilled cast-in-place concrete piles, the full-scale lateral static and dynamic loading tests of eleven piles had been carried out by the authors in Louyang, China. In this paper, the principle of laterally dynamic pile test is discussed. The results of the static and dynamic tests performed in the light of different diameter piles are analyzed comparatively. It is found that the critical loads defined by the dynamic testing are almost identical with results of the static testing ones. Thus we come to a conclusion that the lateral critical loading of the single pile in the area can be determined by dynamic testing method

Experimental investigation of hydration of ternary blended cement paste

In this paper, ternary and binary blended cement pastes as well as pure Portland cement paste were prepared by Portland cement, ground granulated blast-furnace slag (GGBFS), limestone powder and water, which were then hydrated from 1 to 91 days at 20 °C in a sealed environment. At each curing age, the hydration kinetics of cement and slag was determined by XRD/Rietveld and selective dissolution method (EDTA), respectively. The content of CaCO3 (limestone) was quantified by Thermogravimetric analysis (TGA) technique. The degree of hydration of cement clinker was distinctly accelerated by the single addition of slag or limestone within 91 days of hydration. The coexistence of slag and limestone in ternary blended cement accelerated the hydration of cement clinker within the first 14 days of hydration, but lowered the degree of hydration of cement clinker after 91 days of hydration compared with other pastes. The degree of reaction of slag in blended cement pastes was about 8% and 35% after 1 and 91 days of hydration, respectively, which was almost not influenced by the addition of limestone powder. A small amount of limestone, i.e. around 2% of the total solid raw materials, was reacted in pastes, and mainly occurred at the early age. Based on the experimental investigation, the results show that the hydration of calcium silicate phases of cement in pastes was enhanced by the presence of limestone, but hampered by slag. The hydration of calcium alumina phases of cement was greatly accelerated by the addition of slag, and also enhanced by the presence of limestone powder in binary blended limestone cement paste at early age. However, the coexistence of limestone with slag in ternary blended cement paste restrained the hydration of calcium alumina phases of cement

Behavior Analysis of User Interaction on Online Short Video Platform

Online short video platform (OSVP) can disseminate information in an intuitive and three-dimensional (3D) way, and achieve commercial value in a mobile, socialized, life-oriented manner. To fully understand the information dissemination mode of short videos, it is of practical significance to explore user behaviors and their interactive relationship. Therefore, this paper carries out a behavior analysis on user interaction on OSVP. Firstly, an OSVP user interaction model was established based on three aspects: activity, attention, and interactivity. Next, user preference for short videos was examined through cluster analysis and evaluation. Finally, the authors summarized the behavior features of OSVP user interaction and investigated user interaction to decide which videos should be pushed to users. The average utility and average cost of user interaction behavior were compared, indicators of degree centrality were summarized, and the validity of the proposed algorithm was verified by experimental results