Applied Mechanics and Materials Vols. 513-517

Abstract: The amorphous state of poly (Narylenebenzimidazole ketone)(PNABIK) were determined using the Amorphous Cell Module of the Materials Studio program. The solubility improvement of PNABIK compared with traditional ploybenzimidazole (PBI) was also simulated by cohesive energy density (CED) calculating. PNABIK was synthesized by N-C coupling reaction to validate the rationality of simulation results and all the simulation results were consistent with the experimental tests.

Abstract: Using the CIS(Configuration Interaction with Single Substitute) method, and 6-31+G (d, p) basis set, we calculated the excited state structure and vibration frequency of cyclopentanone ion. Studies on the possible way of obtain C₃H₆⁺ small fragments by cyclopentanone ion.

Abstract: A model of combining of guard rings and buried n⁺ layer in mitigating charge collection and charge sharing is presented in this paper. 3-D TCAD simulation results indicate that for 90-nm CMOS process, PMOS charge collection and charge sharing can be mitigated more effectively with the combination model than the solely use of guard rings or buried n⁺ layer. With the combination, a noticeable improvement on angled ion strikes is also represented. The model shows a significant advantage in high-energy ion strikes and angled ion strikes.

Abstract: With the continuous production of the well development, sidewall instability phenomenon has become increasingly serious, mostly occurs in the shale formation, benefit for oilfield produced great harm. Water-based drilling fluid sidewall instability mechanism has been basically clear, the oil-base drilling fluid influence on sidewall stability is not yet concrete. So this paper mainly for oil-based drilling fluid hard brittle shale sidewall instability mechanism research. This article first from the perspective of chemistry, the hard brittle shale borehole wall instability is studied, the experiment tested respectively by the white oil and water treatment of hard brittle shale of cation exchange capacity (CEC) value, so as to analyze the same and the hydration of clay mineral equivalent after processing samples, through analysis of the temperature, time, media's impact on hard brittle shale wellbore stability. Secondly, from the Angle of mechanics, stress and mechanical properties of mud shale formation is analyzed, and the minimum drilling fluid density model, gives a variety of analysis and calculation formula. In addition, this paper adopted the X ray diffraction (XRD)

Abstract: Analyze mechanical behavior of over-thick concrete filled steel tube ( over-thick CFST ) subjected to axial compression and revealed adhesive slip law of steel tube/concrete. Axial symmetry elasticity modeling of the concrete column which is constrained by over-thick steel tube and pushed out under axial compressive load is set up. The push-out test was carried out and axial displacements of concrete column and steel tube were measured. On the base of the test,the adhesive layer between the concrete and the steel tube is introduced and shearing stress-shearing strain curve is set up. The results show that the adhesive stress between steel tube and concrete is uniform along the height,and uniform slipping along the height exists.Therefore the adhesive stress between steel tube and concrete can be precisely measured by push-out test of over-Thick CFST subjected to axial compression. The following conclusions can be drown that axial symmetry elasticity modeling is correct for simulating push-out test of over-thick CFST. There is an adhesive thin player between steel tube and concrete, the slip can be equivalent to shearing deformation of the adhesive layer. The relation of shearing stress-shearing strain can be determined by the push-out test.

Abstract: We studied moisture determination in lignitic coal samples through near-infrared (NIR) technique. This research was developed by applying partical least squares regression (PLS) and discrete wavelet transform (DWT). Firstly, the NIR spectra were pre-processed by DWT for fitting and compression. Then, the compressed data were used to build regression model with PLS for moisture determination in coal samples. Three type DWTs were investigated.Determination performance at different resolution scales was studied. The results show that DWT is a very efficient pre-processing method for NIR spectra analysis.

Abstract: It is important to assess the condition of the cellulose insulation in transformer. However, taking paper samples from a transformer is both impractical and destructive. In this paper, a new method for assessment ageing condition of oil impregnated insulation pressboard based on frequency domain spectroscopy (FDS) was proposed. The FDS measurements were taken on oil impregnated insulation pressboards with five ageing levels at moisture content of 1.22%, 2.06%, 3.02% and 3.87%. The dielectric loss of all the samples were calculated by tanδ (f) interpolation and the ageing condition assessment database which contains data of five ageing levels and 1%-4% moisture content was built. It is found that the tanδ (f) interpolation is more sencentive to ageing and moisture. It could realize the ageing condition assessment by comparing the tanδ (f) interpolation curve with the curves in the database.The assessing result of the middle-low main insulation life of a 220kV transformer valided that it is effective and time saving to use the new method for ageing condition assessment.

Abstract: There are many researches about the effect of oil/paper proportion, testing temperature, AC/DC ratio and other effects on the breakdown characteristics of oil-paper insulation under the composite electric field. However, the breakdown characteristics of oil-paper insulation under the composite electric field in the process of ageing are rarely reported. In this paper, the breakdown characteristics of the oil impregnated insulation paper with different ageing condition under the composite electric field were investigated. Results show that there is no necessary link between the breakdown characteristics and the ageing degree of oil-paper insulation. The breakdown voltage value decreased with the rise of the AC component under the composite electric field. The breakdown voltage with aged paper changed by new paper is slightly higher than that of the aged oil being changed by new oil.

Abstract: The paper discusses the role of ultrasonic time, ultrasonic power, solid-liquid ratio and extraction temperature on the extraction yield of coix seed, the results show that: with the increase of extraction time, extraction temperature with increasing rates of coix seed polysaccharides upward trend, coix seed polysaccharides first increased and then decreased with the increase of the amount of solvent, coix seed polysaccharides and first increased and then leveled off with the ultrasonic power increases, coix seed polysaccharides first increased and then decreased. Compared with conventional extraction methods, ultrasonic extraction of polysaccharides coix seed is fast, solvent savings, save time, extraction rate and so on.

Abstract: High temperature stability of asphalt mixture is one of asphalt pavement major performance which concerns the permanent deformation of the pavement. Four different gradations were used to detect the mixture high temperature stability, dynamic stability or short for rut distortion for regress time was obtained from regression for the data of rutting test, and the test indicates that either of these two indexes can better characterize high temperature stability of asphalt mixture.