Abstract: Low-yield-strength steel shear panel damper (LYSPD) is widely applied to the seismic system by the large plastic deformation capacity and the damping function. It is designed to dissipate the energy result from earthquake or shocking and keep the main structure intact. Although there are several types of dampers made from low-yield-strength steel (LYS) in the world, the ultra large plastic deformation mechanism (ULPM) is not attached importance on by the past researches. Therefore, in order to clarify the ULPM, both the finite element method and the experimental method are conducted for gaining the strain distribution of the LYSPD. The research results show that the ULPM maybe affected by the interlaminar deformation.
Abstract: In this paper, the one-dimensional diffusion model about nano-TiO2 photocatalytic degradation of formaldehyde process was established ,through analyzing nano-TiO2 photocatalytic mechanism, and verifying the accuracy of the model by the experimental data combined with Fick's law. According to this model, it concluded that the degradation rate of the formaldehyde is related to the height of purification apparatus, and when the height is smaller, the degradation rate is greater. Within the same cleaning time (t = 200min), when the height is 0.15m, the rate of degradation of formaldehyde is 99%; when the height is 0.3m, the rate of degradation of formaldehyde is 88%; while the height is 0.7m , the rate is only 32%.
Abstract: The compressive properties of Mg-3Al-2Zn-2Y alloy at room temperature at strain rates in range of 0.001s-1~4800s-1 were investigated. To the alloy compressed at 1300s-1, its basal and non-basal slip produce the mixed dislocation configuration including parallel, bended and tangled dislocation. There is significant twinning in the alloys compressed at 1800s-1 and 4800s-1. The flow stress and ultimate trength show the strain rate hardening behavior at the range of 0.001s-1~1800s-1. There appears localized deformation zones formed with recrystal grains and twin crystals in the alloy compressed at 4800s-1, whose mechanical properties are lower than those of alloy compressed at 1800s-1.
Abstract: According to research requests of encapsulating materials used in anti-impact precision electron apparatus parts, the materials system was designed on the relation of mechanics performance and techniques properties. Then epoxy resin E-51 was toughening modified with a kind of self-synthesized polyester epoxy resin which had liquid crystal groups. The results showed that the optimized epoxy resin encapsulating materials has high compression strength and favorable operating properties. The impact strength of prepared epoxy resin encapsulating materials increased 4.0 times, and the gel time at room temperature was over 100 minutes.
Abstract: Alpha Hemihydrate gypsum was prepared through atmospheric pressure salt solution method based on orthogonal experiments. The morphology and phase composition of the samples were observed and analyzed by microscope and X-ray diffractmeter. The major experimental parameters of atmospheric salt solution that prepared alpha half water gypsum were determined. The experiment result indicates that the best speed is 190 R/min, most appropriate water slurry ratio is 3.5:1 and the most suitable reaction time is 4h. In addition, grain was growing longer first in one direction, but when the length of the gains reaches at a certain extent, they will grow in two dimentions to become thick.
Abstract: FGD gypsum-fly ash plaster material was prepared by desulfurization gypsum plaster and fly ash as main materials, compound retarder A (composed of citric acid, sodium metaphosphate and borax), methylcellulose (MC) as super absorbent polymers (SAP) and water reducing agent of lignosulfonate. Mix proportion was determined through studying effects of the experimental factors, including fly ash mixing amount, retarders of citric acid, bone glue and compound retarder A, and SAP of MC and dextrin, on plaster material properties. Final mix proportion was followed as: FGD gypsum to fly ash mass ratio of 4.0, compound retarder of 0.2%, methylcellulose of 0.2% and lignosulfonate of 0.1%.
Abstract: The cementing material is the desulfurization gypsum. The fly ash is a admixture. A moderate amount of additive is mixed. A gypsum plaster material of micro swelling and good workability, plasticity was produced. The representative two retarders, the sodium hexametaphosphate and the citric acid, were researched. The effects of the retarders on the setting times and the mechanical properties of the desulfurization gypsum were studied. The retarding effect of the citric acid is the most prominent, but its negative impact on the flexural and compressive strength of the plaster gypsum is very large. Considering the setting time and the strength, the sodium hexametaphosphate is the best retarder of the desulfurization gypsum plaster material.
Abstract: Red mud foam lightweight insulation material was prepared by using red mud, fly ash, coal gangue and so on as raw materials by the method of foaming and sintering process. Influences of sintering temperature on thermal insulation material properties were studied. The micro-structure of samples was characterized by scanning electron microscopy (SEM) and mechanism analysis was made. The results show that in this condition, the optimum sintering temperature is 1120°C. The flexural strength of the samples is 0.41MPa, the compressive strength is 1.15MPa and the density is 479kg/m3.
Abstract: The ordinary portland cement was used to prepare foamed cement insulation materials by physical foaming method. The influence of different process of fiber added to the foamed cement insulation materials on its performance was studied and the optimum mix ratio of raw materials was determined. The results showed that the glass fire could be evenly dispersed in the slurry by dry adding technology and got better enhanced effect. When the dosage of glass fire was 0.9%, the performance of the foamed cement material as follows: dry density of 318 kg/m3, 3d flexural strength of 0.61MPa, 3d compressive strength of 1.05MPa, thermal conductivity of 0.065W/(m·k). The reinforce mechanism of glass fire was explored.