Applied Mechanics and Materials Vols. 48-49

Abstract: The solid-reaction was applied to synthesize perovskite-phase Lanthanum Aluminate powders by using AlOOH and La2(C2O4)3 as raw materials, mineralizer AlCl3 and AlF3 as the additives, graund and mixed, then calcined at 800°C and 1200°C for 3 h. The XRD pattern shows that mono-phase LaAlO3 powders can be obtained at 1200°C, and the SEM analysis indicates that the AlCl3 and AlF3 can promote the grain growth and have a good control of morphology.

Abstract: In order to analyses the effect of structure of collection loop on two-phase flow field in quenching furnace, the complex flow field in furnace for mixture of Nitrogen and spray water ejecting quenching under normal pressure and high velocity is numerically simulated with Mixture model of two-phase flow by CFD software FLUENT. Different inlet velocity, different volume percent of spray water, different velocity differences between Nitrogen and spray water, and different angle and dimension of collection loop affected on outlet velocity are analyzed. The research results show that the flow field is really complex, and around inner and outside canister and collection loop back flow exists. The angle of collection loop has less effect on outlet velocity, and the inner diameter of collection loop has more effect on outlet velocity. The simulation results show that the furnace can accelerate the flow of quenching media, which can cool specimen quickly.

Abstract: According to the characteristics of the Chinese e-government development, the paper presents the customer satisfaction indicators about e-government measurement. It takes Yongchuan District in Chongqing for example and designs the questionnaire to collect sample data. It goes on an empirical analysis of customer satisfaction using weighted average method. The weights are determined by the survey data which are done factor analysis. This method will be more objective in calculating weights. Finally, from the public point of view, it raises reasonable recommendations on the level of e-government in Yongchuan District.

Abstract: The identification of stability about flame combustion plays a vital role in the industrial production of plants. Paper integrates the phase information into identification system extracted by higher order spectral, and stresses on identifying the stability of flame combustion with the application of the Mahalanobis Distance, combined with the other two characteristic quantities: the flame intensity variance and flicker frequency. The Mahalanobis Distance can overcome the interference correlation of the flame characteristic quantities and the impact of different dimensions, so the identification rate reaches to 93%, which effectively verifies the correctness of the Mahalanobis Distance.

Abstract: B-MAC was a kind of MAC protocol which was widely used in Wireless Sensor Networks (WSNs), and some high requirements had been provided for users. However, there were always challenges due to the high energy consumption and packets loss rate. A new MAC protocol called B-MAC++ based on B-MAC was proposed in this paper. The preamble mechanism was improved and funneling effect alleviation mechanism was brought out in B-MAC++. For the combination of the strengths of TDMA and CSMA, the preamble mechanism improvement achieved better energy-efficient, and made up to the weakness of WSNs, and a kind of CSMA/TDMA mechanism was introduced to alleviate funneling effect, and the sink-node’s packet loss had been reduced. Experiments show that B-MAC++ is better than B-MAC in the performance of energy consumption and packet loss rate.

Abstract: The number of construction machinery faults is too much and its diagnosis are fuzzy and complex. We construct the fault hierarchy model by the means of hierarchy analysis and obtain all kinds of Possibility degree of faults factors through the triangular fuzzy complementary judgment matrix .Take the fault diagnosis of diesel engine fuel system, this paper establish intelligent fault diagnosis system, which has the ability of self-learning and self-correction using multi-agent technology.

Abstract: Much information in MES is unstructured, such as drawing and document. It is very important for MES to reasonably manage and reuse the unstructured information. A new management strategy of the unstructured information is put forward in the paper, First the basic management method and realization procedure are simply presented; Second the technologies related to the management strategy such as layout analysis, content structured, data management based on xml schema and data query & analysis are analyzed in details; Last the practical use and further research direction of the strategy are depicted. The value of the unstructured information can greatly enhanced through the strategy put forward in the paper.

Abstract: We proposed a categorized method of DNA sequences matrix by FCM (fuzzy cluster means). FCM avoided the errors caused by the reduction of dimensions. It further reached comprehensive machine learning. In our experiment, there are 40 training data which are artificial samples, and we verify the proposed method with 182 natural DNA sequences. The result showed the proposed method enhanced the accuracy of the classification of genes from 76% to 93%.

Abstract: This paper analyzes the difference between the changes of the grid structure in its break mode and the normal operational mode. A secondary system analytic mode is built based on the relaying setting principles and the logic behavior. Combined the gird structure’s mode analysis and the dynamic fault tree mode, it can analyze the overall fault process using the process-matched ways.

Abstract: Polybutadiene-graft-polystyrene (PB-g-PS) latex were prepared via emulsion graft copolymerization method. The weight ratios of polybutadiene to styrene ranged from 70/30, 50/50 to 30/70, then the PB-g-PS latex was used to modify cement mortar. This study examines the effects of core-shell ratios（c/s） on the typical properties and morphology of PB-g-PS latex modified mortars. The PB-g-PS latex modified cement mortar were prepared at different polymer-cement ratios（p/c）, and tested to obtain the water-cement ratios（w/c）, fluidity, water retention rate, flexural and compressive strengths. SEM was used to investigate the microstructure of polymer- modified mortars（PMMs）. On the basis of the test results, effect of the c/s and p/c on the typical properties and morphology of PMMs were discussed. It is concluded that PB-g-PS core-shell latex can be incorporated into cement as modifier.