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In this paper the physical and chemical grain refining of the Mg-10Sm alloy was investigated. Physical grain refinement was achieved by strongly shearing the melt above the liquidus temperature using a twin-screw string device and then cast at the near liquidus temperature. Chemical grain refiner was added into Zr master alloy in the melt. Casting the Mg-10Sm alloy at 730°C produced an extremely coarse microstructure consisting of huge dendritic grains. The physical grain refinement greatly refined the dendritic grains to smaller rosette grains, being reduced from several millimeters to about 200μm. Chemical grain refinement produced fine and equiaxed grain structure with size of approximated 111μm. Combination of the physical and chemical grain refinement creates more significant refining effect than either of the two methods.

Aiming to shorten the inkjet printing mechanism single printing time based on the existing digital printing machine,the plan of wide-format digital inkjet printer with double-carriage was proposed to improve the printing speed.Referencing these ordinary printing machine products, the double-carriage reasonable motion parameters were given and the equations of the motion were established.After simulating the real printing process,the phenomenon of collision and printing deficiency was avoided by the way“carriage will give the way".PID control algorithm was adopted to control the carriages’ displacement and solve the coupling problem of mechanical systems.The ADAMS/Simulink combined simulation control systems ensures the displacement fluctuations within the permissible range.

Proposed general distribution power flow algorithm based on the current network equation. The power flow equations of the algorithm based on the node current balance, and the Jacobian matrix is a constant coefficient matrix compared to the conventional Newton method. It has the characteristics of easy programming, and the method has universality at the same time. It can be used for radial distribution network and systems with loops. The example shows that the method is superior to conventional Newton method on speed and convergence.

Micro stereovision technology has been widely used in the small scale micro objects which are not convenient observed for human eyes, through micromanipulation and other ways to do image reconstruction for the object surface and show them out in the computer, but during the operation, the precision problem of the position control system and the microgripper system relation to the precision of micro stereovision system. This paper built the camera projection model based on the micro stereovision system and have done lots of displacement experiments of the mobile platform and the gripper reconstruction experiments of microgripper system, through statistical analyzed these experiment data to show the accuracy of the microgripper system.

Oxidation of organic phosphorus pesticides wastewater (OPPs-MW) was studied in a batch-reactor under the supercritical oxidizing water condition. The temperature, pressure and coefficient of oxidation were investigated as influence factor for COD removal efficiency by response surface methodology. Temperature is the most significant factor in treatment OPPs-MW and a good fitting polynomial equation obtained. Organic acid would generate under incomplete decomposition condition and NH3-N could hardly decompose effectively when temperature below 600°C

Intermittent fault is the main factor for the raise of false alarm during the process of the detection in built-in test (BIT). Two-state Markov model and three-state Markov model for test is built for system fault diagnosis with BIT. According to the application of BIT in some complex system, a comparison of the false alarm rate between two-state Markov model and three-state Markov model is present, which shows we can reduce the false alarm rate (FAR) and improve fault detection rate by using three-state Markov model in BIT.

Insulator contamination threatens grid safety. And insulator pollution detection can prevent accident occurrence. An invented insulator pollution detector based on microwave radiation is introduced in the paper. The result of testing on-site high-voltage insulator pollution with the detector compared with ESDD and NSDD. And the comparison results indicate the insulator pollution detector can test high-voltage insulator pollution.

Applying Toda and Yamamoto’s approach within a multivariate framework, this paper investigates the causal relationship between nuclear power consumption and real output. The results suggest suggest that there is presence of a positive significant Granger causality running from real output to nuclear power consumption, but there is no presence of a significant Granger causality running from nuclear power consumption to real output. The finding implies that nuclear power consumption doesn’t affect real output and policies assisting expansion of nuclear power consumption may not hinder real output, while policies promoting real output may boost nuclear power consumption.

According to the characteristic of out-water movement of submarine-launched missile, a mathematical model was developed. Then a simulation model was established in Matlab/simulink environment based on the mathematical model, and the simulation was made. The result of the simulation shows that the simulation model can describe the submarine missile out-water movement perfectly, and the study may provide powerful base to the submarine missile trajectory design.

Silica fillers are well known to improve the mechanical properties of elastomers.Nevertheless, the silica filler particles tend to aggregate and affect the properties of the elastomer. In the present study, the silica filler was modified by silane coupling agent (A-151) in order to improve the dispersion of the filler in silicone rubber. The composites samples added with surface treated silica filler was characterized by FT-IR, bound rubber, and fluorescent microscope with that reinforced by the unmodified filler as a comparison. FT-IR results evidences the successful surface modified by silane coupling agent. Bound rubber contents of the origin silica filler are much lower than that of the silica filler with the silane coupling agent treatment. The modified silica-filled shows a better dispersion than that of the origin silica filler and the agglomeration of filler occurs in the unmodified silica-filler compounds.

In order to overcome the inefficiency shortcoming of traditional step-based searching method for extremum seeking in two-dimensional fractional Fourier domain, some typical intelligent optimization methods such as genetic algorithms, continuous ant colony algorithm, particle swarm optimization and chaos optimization method are introduced and applied successfully in fractional Fourier transform. The performances of the global optimization methods are compared with step-based method based on simulation. Results show that the COA optimization algorithm is much more preferable considering computation efficiency, precision and resolution in all the above mentioned optimization methods

To satisfy the demand of inlet pressure for air powered engine, it is necessarily to design control valve. The design idea of control valve was proposed, and the models for simulation design were established. These models are air bottle state model, open area model of control valve, spool dynamic model and shape calculation model of characteristic vent. Based on these models, the joint simulation and the experiment test have been done. The result shows that the designed control valve can provide required inlet pressure for air powered engine and satisfy the work demand well. The result of the experiment verifies the rationality and validity of the simulation design, and the method can be used in the design of the congener valve.

Parallel computation is an effective approach to real-time simulation and transient stability online assessment of large-scale power systems. In this paper, the s-stage 2s-order symplectic Runge-Kutta-Nyström method is adopted for transient stability simulation of power system using classic model. Using Butcher transformation, a new parallel algorithm has been derived. The proposed algorithm has the convergence characteristic of a Newton type method and is of fully parallel-in-time. Through numerical simulation where the IEEE 145-bus power system is used, the proposed algorithm has been tested and compared with the conventional parallel-in-time Newton approach using implicit trapezoidal rule.

Piston of cam engines for torpedo works in terrible condition and always be caused fatigue breakdown by thermal load. In this paper, the thermal boundary condition of different piston parts are ascertained, such as the crown surface of piston and high-temp gas, the side of piston and cooling water, and the skirt of piston and cooling oil. Then the piston’s temperature field is obtained by using the finite element analysis software. This result provides the practical reference for further improving the structure and optimizing the design of the piston. Keywords: cam engine; piston; heat-transfer coefficient; temperature field.

The symplectic algorithm is a kind of new numerical integration methods. This paper proposes the application of the explicit and symplectic Runge-Kutta-Nyström method to solve the differential equations encountered in the power system transient stability simulation. The proposed method achieves significant improvement both in speed and in calculation precision as compared to the conventional Runge-Kutta method which is widely used for power system transient stability simulation. The proposed method is applied to the IEEE 145-bus system and the results are reported.

In order to solve centralized installation and cooling problems of airborne electronic equipment with big power and high heat flow density in aircraft, the paper put forward an innovative closed-loop forced ventilation cooling system, expatiated system compositions and operation principles, and also took a cabinet system for example to introduce new cooling system design method and simulation results.

It is well-known that, the identification of the single-phase to ground faulted line in neutral non-grounded distribution systems is a difficult problem, due to its very small faulted current. This paper proposes a new method for the solution of this problem. The principle of the proposed method is to convert the neutral non-grounded system into a neutral grounded system temporarily by using a triggered vacuum switch based controllable short-circuit equipment. By time-domain numerical simulation, the proposed method is evaluated, and the simulation results have shown the effectiveness of the proposed method.

430 stainless steel is used as raw material and pickling in HCl-based electrolytes is adopted, and the effect of oxidation agent on removal behavior of the oxide layer on stainless steel is systematically studied; study found that the oxide layer of stainless steel after heat treatment in the lab is composed of iron oxide and chromium oxide, and outer oxide layer has dense structure while inner layer has multihole structure; with the increasing oxidation agent addition, corrosion potential of stainless steel after heat treatment increased; under 1.0% oxidation agent addtion condition, only few inner oxide remained and removal tendency of oxide layer is obvious when pickled for 200s; oxide on surface totally got removed, and a smooth surface obtained after pickled for 400s.

Both total potential energy and buckling equation of two-span continuous beam with lateral elastic brace under uniform load are deduced, based on energy variation method and the principle of minimum potential energy. Buckling of H-beams is simulated by ANSYS software, then compared to theoretical value, validated its rationality. High precision buckling moment formula is regressed using 1stOpt which is a famous mathematical optimization analysis software in China. The relationship between lateral brace stiffness and buckling moment is obtained. Results: with lateral brace stiffness increases, critical bending moment of beam increases within up-limit, e.g. when lateral brace stiffness increases to certain extent, buckling moment no longer increases.