Advanced Materials Research Vols. 217-218

Abstract: The waste brown-rotted wood was liquefied in phenol with phosphoric acid as a catalyst and the resulting liquefied products were condensed with formaldehyde to yield novolak liquefied wood-based phenol formaldehyde resin (LWF). The results showed that brown-rotted wood could be almost completely liquefied within 0.5 h at phenol to wood (P/W) ratio 2. An increase in P/W ratio from 2 to 3 slightly improved the flow property of LWF, but accompanied by decreasing the product yield from approximately 140 to 120 %. The increase of liquefaction time from 30 min to 60 min did not have a significant influence on the resulting LWF. The thermofluidity of LWF were compared to that of the commercial novolak PF resin, and could be used to make moldings with similar thermal property and mechanical properties to those obtained from the conventional novolak PF resin.

Abstract: It studies the influence of resin content on composite materials railway sleepers for physical and mechanical properties,which is for the preparation of composite materials railway sleepers.It used resol resin setting hot pressure at 2.5Mpa, hot pressing temperature at 170°C, pressing time at 5-6min. The results showed that as the resin content increases, the static bending strength (MOR) first increased and then decreased, the internal bond strength (IB) rised, 2h thickness swelling (2h TS) decreased. Through the analysis of experimental data by using DPS data processing system, resin content had a significant impact on 2h TS.It also affected MOR, IB.But it had little effect on measured density (D), water content (W) and impact strength (IL).

Abstract: Cement-free castables bonded by hydratable alumina with or without SiO2 fine powder were prepared with bauxite as main raw materials. The mechanism of castables’ mechanical performance, as sintering temperature increased, was investigated. The results showed that the strength of these castables decreased at relatively low temperature because of the hydrates de-watering and the transforming of crystal type of Al2O3, while the strength improved at high temperature. And the addition of SiO2 fine powder can improve the castables’ strength and advance the temperature point, from which castables’ strength started to raise up.

Abstract: The fatigue crack growth experiment was carried out at room temperature for the standard SEB(3) specimens of 40Cr steel, the distribution of the surface magnetic field of the specimen under same load and different cycle numbers (N) was studied. By analyzing relations between the magnetic signals and the crack propagation life, a new damage parameter model has been established by magnetic signals. According to this model, we can evaluate the residual life of ferromagnetic components excellently. This belong to basic research on early damage inspecting and residual life assessment for ferromagnetic materials, it confirmed that residual life assessment and safety estimating for ferromagnetic components based on metal magnetic memory technology is feasible.

Abstract: In this research, the wood residues of mixed birch and larix gmelini rupr are used as the bulk material, and phenolic resin glue and moso bamboo slice as reinforcing material to make flakeboard through three-phase pressure process. Data Processing System (DPS) is used to analyze glue volume, density and other technical parameters’ impact on the performance of wood composite product, establish multiple linear regressive mathematic models, compare and optimize experiment plan, find out and verify the best technical conditions. The result shows that the overall objective function will reach 6.908 when glue volume is 8.107%, density 0.870 g/cm3, thickness 2.015cm and moisture content of 9.799%.

Abstract: Under the high electric field, discharge sometimes occurs along the surface of solid in vacuum, gas or liquid dielectrics, which is called surface flashover.SiO2-B2O3-K2O-Li2O-Al2O3-ZnO-MgO-F system glass ceramics has great machinability and excellent dielectronic property.This paper tries to study different time of ion-exchanged samples and their microstructures，which affect surface flashover performance of this novel material under the systerm of high voltage in vacuum. Compared to traditional coating method on alumina ceramic, the ion exchange treatment on glass ceramic can produce a tremendous improvement of flashover characteristics. The results show that the 10 hours ion-exchanged glass ceramic enjoys the most prominent insulation strength.Based on the theory of SEEA (Secondary Electron Emission Avalanche), these phenomena can be reasonably explained by the charge carrier injection and transport behaviors.

Abstract: We respectively conduct performance contrast test on cement paste, cement mortar, and high-performance concrete which have been added naphthalene water-reducing agent and polycarboxylate water-reducing agent. Studies show that naphthalene water-reducing agent can better improve the performance of concrete and increase the fluidity of concrete to ensure its keeping slump. Meanwhile, the age strength and the growth rate of strength of concrete with mixing polycarboxylate water-reducing agent has been significantly improved than those of naphthalene water-reducing agent, which can better meet the strength requirements of concrete and get a bright application prospect that naphthalene water-reducing agent can not reach.

Abstract: In recent years wireless body area sensor networks (WBASN) has gained a lot of attention from researchers for its promising application in medical care and health care field. However, previous studies are typically involved in the deployment and performance of WBASN, and most research has barely considered the details of the hardware and software platforms. Furthermore, few existing platforms can meet the need of the practical application for their larger physical size, higher power consumption, etc. In this paper, a hardware-software platform (HSPF) is presented, which is especially designed for the application in WBASN. HSPF provides a “core” of the WBASN solution, which puts the most required hardware and software in a small package (24.8×19.0 mm). We discuss how the hardware components are selected to achieve the design goals: low power consumption and small size. Meanwhile, the current consumption of the hardware module of HSPF is evaluated. In addition, the architecture of the software module of HSPF and the design of the integrated star network transport (SNT) protocol are detailedly described. HSPF has been successfully used in our recent research project.

Abstract: A kind of hybrid material was synthesized via sol-gel process with PMMA and TEOS as reactants, and 4’-Iodo-4-dimethylaminoazobenzene (IDMA) as nonlinear optical organic chromophore. The second order nonlinear optical properties of hybrid material in thin films were investigated by using All-optical poling technique, and the influences of films thickness, structure and poling temperature on SHG properties were discussed. The experimental results indicated that the absorption spectrum of PMMA/SiO2/IDMA film was wider than the spectrum of PMMA/IDMA film. As a consequence of the experiment, we found that different thickness films had different SHG saturation values, there was an optimum thickness for the films. In addition, the higher the sample temperature is, the smaller the SHG intensity is. We also found that the existence of SiO2 network in the film significantly improved the azo orientation stability.

Abstract: Recycled concrete research is one of the hot points at home and abroad currently. Whether the recycled concrete can be used in construction or not depends on its strength. Mixture ratio is an important factor deciding strength, while in which, the water cement ratio is one crucial parameter. So the calculation of unit water use in recycled concrete becomes an important research topic. The form of mixed coarse aggregate adding natural sand has already been studied by authors, the calculating formula for increasing water use has been put forward, but the calculation in other else case of aggregate combination form is not discussed. In this paper, the calculation for unit water use in recycled concrete in this case is discussed in detail, which can be used as a reference for designing the recycled concrete mixture ratio.