Advanced Materials Research Vols. 168-170

Abstract: In this paper, grey relational analysis (GRA) was used in consistency test of group judgment matrixes. The evaluation indicator weight was obtained through the judgment matrix calculated with expert evaluating method in analytical hierarchy process (AHP). The judgment method and the adjustment process for consistency of group judgment matrixes were studied. First, the consistency indicators were put forward, and then the definitions and the theorems of consistency indicators in the judgment method were defined based on GRA. Then the theorems were given proof. A method using GRA to judge the consistency of group judgment matrixes was proposed for the first time. Second, adjustment modeling was developed to solve the consistency of group judgment matrixes. Finally, the applications of the judgment method and the adjustment process have been illustrated by given example. It is believed that the proposed methods are applicable to test consistency of evaluation indicators of new rural economic building materials.

Abstract: The ratio of the dissolved amount difference between in cool hydrochloride and hot hydrochloride to the bound water amount of the samples is regarded as crystallinity degree; approximate expressed the proportion relation of crystal and gel in the samples. And studied the relationship of compressive strength and dissolved amount difference, bound water amount and crystallinity degree of autoclaved silicate products using solid waste. The results shown, dissolved amount difference, bound water amount and crystallinity degree of autoclaved samples are related to kinds of hydration products. When well-crystallized hydrated amount is smaller, the crystallinity degree and its change are also smaller, and compressive strength of the sample increases with bound water amount increasing. When well-crystallized hydrated amount is larger, dissolved amount difference is larger, and crystallinity degree is larger, compressive strength of the sample increases with crystallinity degree decreased. There is an optimal value of crystallinity degree for compressive strength of the autoclaved samples.

Abstract: A study on a new lithium salt accelerator was conducted in this paper aiming at the low temperature environment in deepwater cementing. The acceleration mechanism and comprehensive performance of the lithium salt accelerator were thoroughly discussed. Results show that the lithium salt accelerator can accelerate the low-temperature hydration rate of C3S and C2S by speeding up the rupture of protective hydration film and shortening the hydration induction period, and thereby significantly shortens the low-temperature thickening time and the 48-240 Pa transition time for the static gel strength of oil well cement slurry, dramatically improves the compressive strength at low temperatures and shows no effect on the initial consistency of cement slurry. The lithium salt accelerator shows favorable low-temperature early strength accelerating property and has no effect on the types of hydration product, which still remains the same with that of conventional oil well cement, namely the calcium silicate gel, Ca(OH)2 crystal and a small amount of ettringite AFt crystal. But the micro-structure of the system with the lithium salt accelerator is more compact than that of conventional set cement.

Abstract: Based on the finite element software COMSOL, the magnetic-circuit field of the complex coupling between the magnetic and hydrodynamic forces is analyzed. The results of computer simulation show that the flow field is disturbed near the magnet and at the left end there is a laminar flow profile, where there is a maximum throughput in the pipeline; the magnetic fluid is not rest but rather agitated in local eddies where the net throughput is zero.

Abstract: The aim of this study is to establish a certain Quantitative Structure-Activity Relationship (QSAR) between compound molecular characteristics and nanofiltration (NF) separation efficiency. Measurements were carried out in a crossflow NF unit and using ten organic compounds (ethanol, butyl alcohol, glycerin, phenol, glucose, sorbitolum, dodecanoic acid, Imidacloprid, sucrose and Dimethomorph) in aqueous solution and two commercial NF membranes (DK and NF90). Four kind compound characteristics of Molecular weight (Mw), Octanol-Water Partition Coefficient (logP), Molar Refraction (CMR), Henry’s law (H) are selected. Through regression, F test and t test, QSAR analysis was accomplished to prove the validity of regression equation with confidence probability of equation coefficient above 85%. It could be concluded that Mw contributed most to rejection of DK and NF90 according to QSAR at constant flux (500mg/L) and feed concentration (500mg/L). The contribution of CMR is less than MW for NF90 rejection, following by logP, H.

Abstract: Large stone porous asphalt mixes have well drainage ability, as well as higher modulus and durability when used as base course. Large stone porous asphalt mixes have good effect on repairing the semi-rigid base course which have longitudinal cracks. It not only can delay the reflection of cracks, but also plays the role of excluding water in structural layer owing to relatively large porosity. Deflection value of upper base's top surface decreases and deflection difference between left and right wheel track reduces after paving large-stone asphalt mixes upper base. When there are longitudinal cracks in lower base course, top surface tensile stress of upper base(large-stone asphalt mixes flexible upper base course)has significantly reduced compared with semi-rigid base course upper base. And maximum shear stress declined slightly. It can play a very well crack resistance effect when using large-stone asphalt mixes to repair broken cement stability upper base.

Abstract: In order to research deeply on the measure of energy efficiency reconstruction of existing rural residence in hot summer and cold winter area, the typical rural residence building in the country of Ningbo, Zhejiang province is chosen as the object. On the basis of comparing the thermal status of existing and reconstruction rural residence, which were simulated by DEST-H software, some practicable suggestion on energy efficiency reconstruction are put forward.

Abstract: the self-igniting coal gangue in Gaode Mine, Fuxin city of Liaoning Province by physical and chemical method.first,orthogonal test was applied to study the influence of the fineness of coal gangue on strength of the bonding material;then on the basic of it,use this method again to clarify the effects of self-igniting coal gangue's addition on th strength of bonding material.The results of this experiment showed that self-igniting coal gangue can be used as cement’s active admixture .range analysis and variance analysis indicated that the amount of coal gangue had significant influence on binding material’s strength ,and it will make the material have outstanding performance when proportion reaches to 25%~35% of material sum, at the premise that the variety and the content of activator is suitable.The study on self-igniting coal gangue cement could not only widen the application area of coal gangue and the variety of cement ,but also solve the problem of environmental pollution caused by the great quantity of coal gangue.According with building materials industry's developing concept about saving energy,reduceing pollution,protecting the environment, green environmental protection etc in 21st century .

Abstract: Plasma electrolyte oxidation films (PEO) on AZ31 magnesium alloy were prepared in alkaline silicate solutions with two kinds of voltage waveforms (constant voltage waveform and escalating voltage waveform). Discharge characteristics and the dielectric barrier layer formation of the films formed under two voltage waveforms were investigated. Structure, composition, morphology and corrosion resistance characteristics of the films were studied with scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and potentiodynamic corrosion testing. The porosity of the films was calculated with Mat lab software. Structure, composition and porosity of the films are correlated with changes in behaviors of spark discharges on the surface in oxidation process. The escalating voltage waveform strongly affects the transformation of Mg2+ from the substrate but not the SiO32- ions in the electrolyte and the compactness of dielectric barrier layer. The films formed under escalation voltage waveform exhibited lower porosity and higher corrosion resistance than the films formed under constant voltage waveform because of less defects on the surface of the films. The voltage waveform change has little influence on the thickness of the films.

Abstract: The model of Helmholtz free energy serves as the constitutive functional expression for a damaged material, and was expanded into Taylor's series with respect to some state variables εij and Ω, the generalized expressions of isotropic elastic damage constitutive equations and the damage strain energy release rate with a configuration of isotropic damage scale were derived directly from the second law of thermodynamics. From the aspect of relationship between the porosity and damage variable, the different influence to damage effective functions were discussed theoretically and some valuable conclusions were carried out from the variation of material properties. The limitations of the classical damage constitutive equation based on the well-known strain equivalence hypothesis were overcome, and the method developed in this article can be applied to study different damage problems. It is shown that the applied method and obtained conclusions are useful to study the damage mechanics problems further.