Applied Mechanics and Materials Vols. 316-317

Abstract: Jixi basin is one of the important coal basins in China. To explore the gas accumulation characteristics and its geological controls, it’s important for further exploration and development of coalbed methane (CBM). The gas content of Jixi Basin is high viable from 4.78 to 11.94 m3/t, indicating high gas content in the north and west but low gas content in the south and east. The further analysis results show that the delta plain and lake are favorable sedimentary environments for coal accumulation. The Chengzihe and Muleng formation are formed in these environments. Moreover, massive magmatic intrusion heat activities and subsequent continuous subside of strata increase coal rank of the coals. In the area of Pingma reverse fault and the area with thick Muleng formation, mud seals are favorable for CBM preservation. In these areas, CBM is sealed and accumulated by hydrodynamic condition. Finally, a comprehensive evaluation model for CBM was found. Based on the evaluation model, the most favorable zone for CBM exploration is forecasted to be J idong depression.

Abstract: Abstract. A mechanism of the dehydrogen-reforming of methane with carbon dioxide over Pt, Rh and Ru under a supercritical condition was investigated by B3LYP/Lanl2dz and MP2 methods. Results show that the reforming reaction divided into six steps under the supercritical state, the rate-determining steps of the reaction over the different transition metals were not the same. Dehydrogenation plays a significant role pin the process of reforming reaction. For Pt, Rh and Ru, the easiest step is the same-step 1. All of the other steps were exothermic reactions. The process of reaction over Pt, Rh and Ru were similar with the reaction over Ni. For Pt, the CO2 Specific activities of four kinds of the transition metals were in the order: Pt>Rh>Ru.

Abstract: Fluorinated emulsifier-free emulsion surface sizing agent (FEE) was prepared by emulsifier-free polymerization of hexafluoro-butyl methacrylate (FA), styrene (St) and so on in the presence of fuorinated random amphiphilic polymers (ASRF) copolymerized by FA, St and acrylatic acid. Effects of ASRF content and treatment temperature on the surface properties of the films were investigated. Effects of ASRF content and oxide starch on the application were also discussed. Additionally, fiber morphologies of the samples were characterized by SEM.The results show that the appropriate increases of ASRF content and treatment temperature are good for the decreases of surface free energies of the films. When the ASRF content and oxide starch content is 5% and less 50% respectively, the FEE and its combination with oxide starch have good sizing performance. After the treatment by FEE, the fiber surface becomes smooth, which provides lower surface free energy of the fibers.

Abstract: In ultrafiltration pretreatment system, regular cleaning is the key measure to prevent and control membrane fouling and scaling. The fouling model is modified and the criterion of cleaning is given in this paper. The cleaning method of membrane modules can be expressed as a mixed-integer non-linear programming (MINLP) problem with the minimum total operation cost as target function during two years projection period while one month one period. The results of the example indicate that the cleaning strategy and solving method provided is effective for the membrane maintenance.

Abstract: The triplet potential surface of the O (³P) + HCONH₂ reaction has been investigated at the CCSD (T)//B3LYP/6-311G (d,p) level. DFT calculations show that the reaction occurs dominantly via the H - abstraction rather than the O- addition mechanism on the triplet potential surface. The product of OH and CONH₂ should be the major product, which obtained by a direct dissociation of the adduct im6 without an exit barrier.

Abstract: NB reduction with NZVI will be effected by factors. In this study, batch experiments were carried out to evaluate the single and combined actions of common dissolved ions including HCO3-, Cl-, SO42-, NO3-, Mg2+ and Ca2+. The results showed that the removal efficiency of NB was enhanced with the increase of the concentration of added HCO3-, Cl-, SO42-, NO3- as a descending order, and SO42- would be an inhibitor when its concentration was lower than 250 mg/L. Mg2+ and Ca2+ themselves had no obvious influences on NB reduction with SM-NZVI, but they could weaken the positive effects of other coexisting ions like Cl- and SO42-. Coexistence of these dissolved ions would promote metal carbonate precipitations and thus made against NB degraded and aniline produced.

Abstract: The yield of epoxysuccinic acid was obtained by determining the content of unreacted maleic anhydride and tartaric acid as a by-product in synthesis system. This method could calculate the yield of epoxysuccinic acid precisely and overcome the disadvantage of obtaining inpure product by recrystallization method. Epoxysuccinic Acid was synthesized using maleic anhydride as raw material, hydrogen peroxide as oxidizer and tungstate as catalyst. The effects of reaction temperature, reaction time, ratio of materials, dosage of oxidizer and catalyst on epoxidation and hydrolysis reaction was investigated. The results showed that the yield of epoxysuccinic acid was 88% when the reaction conditions were as follows: reaction temperature 65°C, reaction time 1.5h, catalyst dosage 3%(based on mass of maleic anhydride), molar ratio of sodium hydrate to maleic anhydride 2:1, mass ratio of hydrogen peroxide to maleic anhydride 1:1.

Abstract: Understanding of the physisorption of H2 in metal-organic frameworks (MOFs) is critical to improving its performance for hydrogen storage. By using first-principles calculations employing the van der Waals density functional (vdW-DF) method which can properly describe the vdW interaction, we investigate the binding energy of H2 in MOF-5 crystal. The accuracy of this methodology is first examined and good accuracy comparable to the correlated wavefunction methods is found. Calculations for the true crystal structure show that the small fragment models used in previous calculations cannot represent well the property of the crystal. The good accuracy and the ability to deal with the true crystal structure make the vdW-DF method a good candidate for investigating hydrogen storage in MOFs.

Abstract: The SiO2 nanoparticles were synthesized with a ydrothermal method and modified by oleic acid. The tribological properties of the modified SiO2 nanoparticles as bricating oil additives are studied by friction test. It was found that the nanoparticles as additives in lubricant oil can effectively improve anti-friction and anti-wear roperties. The anti-friction and anti-wear mechanisms were discussed and the lubricating effect of SiO2 nanoparticles can be attributed to rolling effect and self-repairing effect of mechanism.

Abstract: When fire occurs in a concrete structure, it is hard to extinguish it because of its unique form and location, which results in a very high internal temperature of the maximum 1400°C. Due to the fine structural characteristic of concrete, the structure is likely to suffer fatal damages such as the reduction of resisting force and the damages to the cross section caused by explosive fracture. In this research, the author tested the effect of fire on structures by using fire boards with perlite-added silicone and confirmed that the fire resisting capacity varies according to the weight ratio of the addition agent, which shows what effect perlite has for the pyrolysis process. A fire resisting capacity test was also carried out by attaching a silicone composite fire board to a real size specimen. As a result of the test carried out by installing the fire boards with different thickness by section, most fire boards had excellent fire resisting capacity, and fire boards with 20mm or more thickness had also excellent fire resisting capacity