Advanced Materials Research Vols. 468-471

Abstract: Military information system has unusually tough restrictions on the rank, and attaches weight to the safety and secrecy of the information. This makes the higher demands on access control on information. So a new access control model based on RBAC is prompted against the limitation of the existing models of RBAC. This model is named as fine-grained access control model based on RBAC. This model not only assigns different roles to different users, but also adds an attribute of department ,so the role and the department are combined; It realizes fine-grained access control and refines to controls of pages, so this keeps access control more precise; Role tree is used to define roles and in order to prevent the problem brought up by role inheriting, it impose s restrictions on whether it can role inherit; At last, ACL store the especial instances’ alteration. When a control is accessed, it will examine the role and department and then judge whether it can role inherit and then judge by combing ACL. So this will attain access control objective. The fulfillment indicates that this model can meet the requirement of real application of military information management system.

Abstract: Several methods of the choice in assembled spectral and color composite in the false color composite of multi-spectral RS images are discussed. The research indicates that using the OIF method to carry on the band choice, unifying the easy and feasible RGB false colored synthesis and carrying on the method of image linear extension can realize the false color composite of multi-spectral RS images effectively, and the obtaining false color image has rich information and distinctive visual effects.

Abstract: Corrugated tubes in a heat exchanger are analyzed by using the FEA methods. And the formula how to compute single wave’s rigidity is obtained. Besides, methods of analyzing the stability of corrugated tubes under internal compressive pressure and external pressure are proposed which include characteristic value analysis and non-linear stability analysis, thus providing theory basis for the stability research of heat exchangers.

Abstract: Fault diagnosis method based on embedded acquisition equipment and SVM is proposed in the paper.The function of the module mainly includes data acquisition, data processing and data storage.SVM is trained by the features and the five states of rolling bearing. The structure of diagnostic model by SVM is defined as 5 input nodes and 5 output nodes,among which 5 input nodes are the features including peak factor,waveform factor,impulse factor,margin factor and kurtosis factor and 5 output nodes are the five states of rolling bearing include normal state, housing washer failure, retainer failure, rolling element failure and inner ring failure.The experimental results show that the diagnostic performance of SVM is effective.

Abstract: A contrast test was done about the service performance of using emulsion I and water miscible rolling lubricant KD1 with polyethylene glycol 2000. The test results were given to have analysed them in lubrication, softening, resistance of putrefy, rust protection and so on. And water miscible rolling lubricant KD1 is notable in lubrication, annealing, resistance of putrefy, rust protection. The results may offer the reference for further optimization on water miscible rolling lubricant.

Abstract: By using three dimensions finite element method, the temperature distribution has been simulated in grinding of titanium alloy with SiC wheel. The effects of wheel speed, workpiece speed and tangential grinding force on the grinding temperature field were investigated. The results show that the grinding temperature decreases with the increasing of the workpiece speed, and increases with the increasing of the grinding depth and wheel speed. The obtained results can provide a theory reference for the design and selective of machining parameters during grinding titanium alloy.

Abstract: A three-dimensional unsteady flow for the pulse converter exhaust manifold of 8-cylinder diesel engine was numerical simulated to get the flow characteristics of the exhaust manifold. Simulation results show that there are strong eddy flows, low pressure closed recirculation flow region in the exhaust manifold. Afterwards the structure optimization of the exhaust manifold with baffle was put forward and then the unsteady flow in the normal exhaust manifold, the exhaust manifold with baffle of 30 degrees and the exhaust manifold of 15 degrees were simulated and analyzed. It is concluded that the exhaust manifold with baffle is better than that without baffle, the recirculation flow region and the pressure loss in the exhaust manifold with baffle of 30 degrees is smaller than in it with baffle of 15 degree and the flow in the former exhaust manifold is much smoother.

Abstract: Silicon etching is an essential process step for the fabrication of micro-electro-mechanical systems (MEMS). However, the rough edge of the silicon etching technology has some resistance to microspheres. This study presents fabrication process of the SU-8 photoresists mold which provides sharp edges and smooth sidewalls of the channel and details the RIE bonding of PDMS and glass substrate to realize the fabrication of microfluidic chips. This paper also investigates the hydrodynamic focusing and microsphere single-pass based on sheath flow with the aid of the plunger piston, which is important to the further combination of the microfluidic chip and the flow cytometry.

Abstract: CO₂ corrosion is more prominent in the petrochemical industry, for different influencing factors of CO₂ corrosion, 1Cr18Ni9Ti, 316L, TA2, Q235, 45 steel materials are selected for the study. Using immersion experiment and electrochemical experiment to study the corrosion behavior of these experimental materials in CO2 environment under different external conditions. We finally obtain the law of influence of the temperature, pH, concentration of chlorine ion and alloy elements on the CO₂ corrosion.

Abstract: Viewing to monitoring the continuous casting process, a nonlinear fault detection method based on kernel principal component analysis (KPCA) was introduced. KPCA can efficiently compute principal components in high-dimensional feature spaces by means of integral operators and nonlinear kernel functions, which is to first map the input space into a feature space via nonlinear mapping and then to compute the principal components in that feature space. Based on T2 and SPE charts in feature space, principal component analysis(PCA)can be used to detect faults.. The simulation results show that the proposed approach effectively captured the nonlinear relationship in the process variables and showed superior process monitoring performance compared to linear PCA.