Advanced Materials Research Vol. 937

Abstract: Trichoderma asperellum is an important biocontrol fungus which has been shown to control plant soil-borne pathogens, such as: Pythium ultimum, Fusarium oxysporum, Cytospora chrysosperma and Sclerotinia sclerotiorum. The goal of this research is to study whether the cell wall degrading enzymes genes were induced by pathogens or not in the process of T. asperellum mycoparasitism. The results suggest that chitinase gene ech42, β-1,3 glucanase gene bgn13.1, and β-1,6 glucanase gene bgn16.1 can be induced by pathogens. However, two N-acetyl-amino glycosidase nag1 and nag2 can not be induced by pathogens.

Abstract: Allergy and complications caused by jewelry are prevalent among overseas college students, while there has no relevant study in China. To survey the prevalence of this problem among college students, questionnaire was designed and students randomly from three higher vocational colleges in south China joined this survey. The results show that 32.3% students have ever worn jewelry. The proportion of wearing jewelry is different for various specialties, which shows business students rank the highest, Arts and science &engineering students follow successively, while medical students keep in the last. Necklace, ring and bracelet are the main jewelry types worn by students. 1.3% boys and 10.2% girls have ever worn piercing jewelry, and ear is the dominant piercing site, which accounts for 93.1% overall. Among those students who have ever worn metal jewelry, 3.6% boys and 13.7% girls have ever suffered jewelry allergy or complications, which is mainly caused by costume jewelry and piercing jewelry.

Abstract: In order to study the effect of food-microorganism (F/M) ratio on gas properties in batch biogas fermentation experiments with walnut peel, by batch fermentation under the condition of 30°C, with walnut peel as fermentation raw materials, and respectively choose F/M(vs/vs)=0.20, 0.15, the effect of food-microorganism (F/M) ratio on the gas properties was studied in biogas fermentation with walnut peel. The experimental results showed that in the fermentation with walnut peel as raw materials, the potential of TS and VS, the total volume and the time reaching to 80% gas production volume of the time of experimental group F/M(vs/vs)=0.20 were respectively 202ml/gTS, 226ml/gVS, 2840ml, 19d. However, the values of experimental group F/M(vs/vs)=0.15 were respectively 152ml/gTS, 170ml/gVS, 2140ml, 24d. Therefore, food-microorganism (F/M) ratio has a great influence on batch biogas fermentation with walnut peel as the fermentation raw material.

Abstract: To better understand the roles of microorganisms in oil production, diversity and distribution of microbes in Jilin oilfield was studied. Firstly, chromosomal DNA wassuccessfully extracted directly from crude oil samples. Diversity and distribution of microbes was then analyzed based on 16S rDNA libraries. There were totally 21 OTUs were obtained through 16S rDNA sequencing. Of those OTUs, 13 are bacteria in which Proteobacteria is the major family, while 8 are archaea in which Methanomicrobia is the dominant. Finally, SRB was found in all samples by amplifying the apsA gene using PCR. SRB found in Jilin oil samples belong to δ-Proteobacteria.

Abstract: To better regulate (up and down) the activation of SRB thereby contributing to EOR, efficiency of growth and inhibition of SRB was studied in this paper.Six different growth media were tested in total.The optimal growth media were selected based on growth rate and variations of pH between the start and end point of growth. Of the six media, complex I was selected as the best medium in which SRB grew to stationary-phase in less than 8 days with the highest cells’ concentration. Finally, the effects of NO₃^- on growth and persistence of SRB were studied by using abroad range concentrations of NO₃^-. The result indicated that SRB growth could be significantly inhibited at NO₃^- of 80 mM.

Abstract: Based on the molecular topology information and adjacency matrix, the 38 electrical state indices of molecules of inhibitor of thymidylic acid-based synthetase as five-membered heterocyclic pyrimidine derivatives were calculated to provide theoretical basis for molecular design of new drugs. By using variable regression method, the best subset of structural parameters of E₁, E₂, E₇, E₁₆ and E₃₁ were optimized. When the five structural parameters were used as the BP neural network input neurons and the neural network structure of 5:3:1 was used, an ideal prediction model of biological activity was obtained. Its total correlation coefficient r and average relative error were 0.972 and 2.13%, respectively. The result showed that the biological activity and E₁, E₂, E₇, E₁₆ and E₃₁ have a good non-linear relationship with the biological activity, and the results predicted by neural networks was better than that by multiple regression method. The test proved that the model had good robust and predictive capabilities. Our research would provide theoretical guidance for the development of new drugs of inhibitor of thymidylic acid-based synthetase with efficient and low toxicity.

Abstract: Abstract: With the increase of the service time of shipborne aircraft, the overlarge impact load can affect the life of the hydraulic system accessories. At the same time, the vibration and the corrosion of the ser water will also affect negatively the accessories’ life. The accessories are the important composition of the hydraulic system. Therefore, it is necessary to study the possible faults and their rules. This paper aims to establish the suitable model to predict the faults by use of the FEM and experiments.

Abstract: A large number of cracks are found in the 1500m³ Liquefied Light hydrocarbons vessel during the inspection after two years of running.In totally,six vessels being fully heated treated is made of 15MnNbR. Researchers used X-ray stress analyzer measured the welding residual stress of vessels that have been cracked and uncracked. The results show that, residual stress of uncracked spherical vessels are in good condition, while those value of cracked is high, the value of the highest is 1.05σs. It indicates that the possible reason for the separation is the residual stress in the high state. Through welding and heat treated for the second time, the welding residual stress decreased obviously. It indicates the impact of this measure is good.

Abstract: This paper supposes a S-shape low yield steel damper. Based on the mechanical behaviors of the damper, its analytical model is established. Meanwhile, the damper’s hysteretic characteristics are numerically simulated by the FEM ABAQUS to obtain the main mechanical parameters of this damper. These parameters are compared with the results from the established analytical model. Results indicate that the analytical model is a-greeable to the FEM analysis. In addition, Analytical results also show that the S-shape low yield damper pos-sesses superior mechanical behaviors and hysteretic characteristics to fit extremely for mitigating the vibrationof engineering structures.

Abstract: Aiming at the need of aircraft de-icing system design, a study of the adhesive mechanism between impact ice and substrate has been made. Based on the discussion of electrostatic force and van der Waals force which contribute to ice adhesion, the related factors are listed. A systematic study has been made of the distribution of shear adhesive strength of impact ice as a function of the roughness and material of substrates, the ambient temperature and the mean volume diameter of supercooled droplets through experimental research. The experimental results has been compared with foreign research and error analysis has been given.