No abstract

By the method of EVA emulsion coating, cron stalk-magnesium oxychloride cement composites (C-MOC) was modified to study the effect of EVA emulsion content on C-MOC density, the coefficient of thermal conductivity, water resistance and mechanical properties. Furthermore microstructure of C-MOC was analyzed by SEM. The results show that: with the increase of EVA emulsion content, the coefficient of thermal conductivity and softening of C-MOC increase, but water absorption reduces. When the content is 80%, the flexural strength after 28 days could reach 3.65 MPa and the compressive strength is 4.69 MPa, reaching the maximum. At the same time, C-MOC density is 816 kg/m3 and thermal conductivity is 0.111 W/(m·k). Water absorption is 36% and softening coefficient was 0.47. It is believed that EVA emulsion could form a thin film on the outer surface of the corn stalk by microscopic analysis, increasing the roughness of the straw surface and reducing the gap between the stalk. Since the EVA emulsion has good compatibility with the magnesium oxychloride cement, they could constitute a whole jointly with glue liquid, crystal and fiber, playing the role of enhancing the surface. Therefore, water resistance, thermal conductivity and mechanical properties of C-MOC have been improved effectively.

The lacustrine dolomicrites of Unit II of the lower Xingouzui Formation deposited in the southern part of the Qianjiang Depression provide a good "tight carbonate" hydrocarbon reservoir. The dolomicrites are typically interbedded with and sourced from organic-rich argillite, which together form a source-reservoir assemblage characterized by thin single-layer thicknesses, far lateral extent and continuous lateral distribution. Systematic sedimentological and geochemical studies indicate that the depositional environment and organic matter evolution of the dark argillites (with TOC of 0.5-2%) are favorable for formation of the dolomicrites. The dolomicrite was mainly formed in a shallow-water evaporative environment; crystals are anhedral under SEM, in non-surface contact, and include a number of honeycomb intergranular micropores associated with replacement. The dolomicrite shows orange-orangered light by cathodoluminescence, indicative of association with minor terrigenous debris; X-ray diffraction results indicate that the dolomicrite is characterized by high calcium content (CaCO 3 molar contents of 52.28-52.28%), low degree of orders of 0.2-0.4), and high content of Fe. The dolomicrite has δ 18 O values of 2.47-2.47‰ PDB, more positive than micrite, and δ 13 C values as moderately negative as 9.4-4.21‰ PDB, similar to micrite. Both values indicate the dolomicrite formed in a low-temperature genetic zone. Together, these characteristics indicate that the dolomicrite in the study area was formed in a high-salinity, confined lake basin, characterized by low temperature, shallow burial, and rapid nucleation and crystallization. The dolomicrite experienced a contemporaneous period with formation of dark mudstone, shale and calcite, and a penecontemporaneous period with formation of dolomicrite via seepage-reflux and a diagenetic period when ferrodolomite was formed via burial.

Because of low strength, the expanded perlite insulation boards application in building energy saving is restricted. This paper discuss change rules of the expanded perlite insulation board apparent density and mechanical strength with adjusting the amount of sodium silicate, pressing pressure, heating system. It turned out that good thermal insulation performance and high strength expansion perlite insulation board is prepared by mass ratio of 2.5:1 of 30% of the content of solid sodium silicate solution to expanded perlite, 0.38MPa of pressing pressure and 105°C condition of heating temperature.

At high temperature conditions, the glass molten by the combined action of gravity and surface tension form an oval. Through digital image measurement system we can obtain glass molten oval contours and the contact angle. By the Bashforth-Adams equation which deduced from Young- Laplace equation to obtain the glass molten' surface tension at the corresponding temperature conditions. This method has good reproducibility and accuracy.