Based on comprehensively analyzing the whole structure and its working performance of RT-Flex marine intelligence diesel engine and entirely mastering this kind of engine fuel common rail injection system’s composition, working principle, taking 7RT-Flex60C as simulation object, the mathematical models of this system’s composing part are designed, by using Matlab/Simulink simulation tool, fuel common rail injection system simulation model is set up, then comparing with the simulation data with rack test data, the accuracy and effectiveness of the model are test and verified. The built up model provides a convenient and practical method for design, optimizing and simulation of fuel common rail injection system.

Nanosized tungsten carbide (nanoWC) has been widely studied and applied in many industries as hard materials since it has good combination of high hardness and strength. Thermal mechanical alloying method consisting of high-energy ball milling and subsequent carbonization is a common synthetic approach to prepare nanoWC. In this paper, a special milling process has been reviewed, in which the dielectric barrier discharge plasma (DBDP) is introduced, for the preparation of nanoWC. The DBDP milling renders the W+C powders with specific flake-like structure possible owing to the cooperative effect of DBDP and mechanical milling. The obtained W+C powders are activated significantly within shortened milling period. Furthermore, pure nanoWC powders can be synthesized after subsequent carbonization at a significantly lowered temperature. DBDP milling is demonstrated to be an efficient way to synthesize nanoWC.

Drag suction hopper dredger is dredg the hard compacted soil,dreghead teeth intensity will lead to an undersized cutting depth and a large cutting resistance, it raise failure probability. In this paper, investigate the relation between dredging depth，width,resistance and draghead teeth reliability influenced under different conditions,including various teeth,loads,navigating speeds and high-pressure jets.Discussed their effects on cutting depth,width and resistance.At last this paper obtain the reliability index and failure probability of the draghead teeth through the calculation numerical example.In this example,the method improvements efficiency for Draghead Teeth based on analysis on reliability.