摘要：In the present work, an alternative numerical methodology is developed for a fast and effective simulation and analysis of the complex flow and energy conversion in Pelton impulse hydro turbines. The algorithm is based on the Lagrangian approach and the unsteady free-surface flow during the jet-bucket interaction is simulated by tracking the trajectories of representative fluid particles at very low computer cost. Modern regression tools are implemented in a new parameterization technique of the inner bucket surface. Key-feature of the model is the introduction of additional terms into the particle motion equations to account for various hydraulic losses and the flow spreading, which are regulated and evaluated with the aid of experimental data in a Laboratory Pelton turbine. The model is applied to study the jet-runner interaction in various operation conditions and then to perform numerical design optimization of the bucket shape, using a stochastic optimizer based on evolutionary algorithms. The obtained optimum runner attains remarkably higher hydraulic efficiency in the entire load range. Finally, a new small Pelton turbine （150 kW） is designed, manufactured and tested in the Laboratory, and its performance and efficiency verify the model predictions.

摘要：In order to improve the test accuracy of CCD,a new type of CCD device is *** columns(rows) of photoelectric diodes(PDs) are combined together,and staggered with the distance of H1=H/N,where H is the space between two adjacent PDs,and N is the number of columns(rows).The photoelectric signals are collected simultaneously by multi-channel A/D,and the accurate measurement result is obtained through appropriate signal *** changing the size or space of PDs,more photographic pixels are arranged in the given direction within a finite *** of three standard poles are measured by a single CCD and two staggered CCDs,respectively with length of 30 mm and diameters of 5 mm,8 mm and 12 mm,*** results show that the accuracy of double staggered CCDs is two times of that of single *** new type of CCDs can avoid the impact of PD space theoretically and higher measurement accuracy can be obtained.

摘要：A novel method was proposed to design the structure of a bone tissue engineering scafold based on triply periodic minimal *** this method,reverse engineering software was used to reconstruct the surface from point cloud *** method overcomes the limitations of commercially available software packages that prevent them from generating models with complex surfaces used for bone tissue engineering ***,the fluid feld of the scafolds was simulated through a numerical method based on fnite volume and the cell proliferation performance was evaluated via an in vitro *** cell proliferation and the mass flow evaluated in a bioreactor further verifed the flow feld simulated using computational fluid *** result of this study illustrates that the pressure value drops rapidly from 0.103 Pa to 0.011 Pa in the y-axis direction and the mass flow is unevenly distributed in the *** mass flow in the side outlets is observed to be approximately 24.3 times higher thanthe ***,although the mean value of wall shear stress is signifcantly more than 0.05 Pa,there is stil a large area with a suitable shear stress below 0.05 Pa where most cells can proliferate *** result shows that th inlet velocity 0.0075 m/s is suitable for cell proliferation in the *** study provides an insight into the design analysis,and in vitro experiment of a bone tissue engineering scafold.

摘要：The magnetic force acting on workpiece to be machined plays a significantly important role in magnetic abrasive polishing *** in a case of polishing nonferrous materials,the strength of magnetic force is very low and it leads lower polishing *** magnesium alloy that has superior mechanical properties for industrial application such as a lightweight and high specific strength is one of the most famous nonferrous *** improving strategy of the magnetic force for the AZ31 magnesium alloy installed with a permanent magnet was proposed and experimental verification was carried *** the proposed strategy,the effect of process parameters on the surface roughness of the AZ31 magnesium alloy was evaluated by a design of experimental method.

摘要：Movement accuracy is the key factor to be considered in designing precision instrument linkage and mini-linkage mechanisms. Although manufacturing errors, elastic deformation, kinematic pair clearance and friction factors all will have synthesis effect on the position accuracy of the mechanical system, the essential factor to guarantee the movement precision remains the kinematic dimensions. Combining the classical theory of mechanical synthesis with the modern error theory and the numerical method, the authors put forward a systematic and complete process and method of computer aided design for the instrument crank-coupler mechanism in which the follower takes the linear displacement approximately within a certain limited domain, with the design result of least transmission ratio error.

摘要：Equipment for deep sea mining has risen from a position of virtual non-existence to a major industrial significance and in deep sea bed mining, the miner is the key equipment of the whole system that charges with the most complex and dangerous *** of trafficability for tracked vehicles for deep sea mining is essential. Rare earth elements(REEs) are used in a wide range of modern applications. These applications are highly specific and substitutes are inferior or unknown. One possible source of the REE could be the poly-metallic nodule, at present explored in the tropical part of the Pacific Ocean. In developing miners of high performance, dynamic behaviour should be investigated under various traveling conditions. The mechanics of tracked vehicles is of continuing interest to organizations and agencies that specify design and operate tracked vehicles. Most works done are on the complete track vehicle system but in this work the research activity is aimed only at the track system with the basic aim of optimizing the track system design so that it can be manufactured by using the minimum resources. Equations and models are developed for the track system of a miner during steering motion. These equations and models could further be used for design optimization of the track system.

摘要：Aimed at the optimal analysis and processing technology of die cavity of special-shaped products extrusion, by numerical analysis of trigonometric interpolation and Conformal Mapping theory, on the non-circle cross-section of special-shaped products, the conformal mapping function can be set up to translate the cross-section region into unit dish region, over numerical finite interpolation points between even and odd. Products extrusion forming can be turned into two-dimension problem, and plastic stream function can be deduced, as well as the mathematical model of the die cavity surface is established based on deferent kinds of vertical curve. By applying Upper-bound Principle, the vertical curves and related parameters of die cavity are optimized. Combining with electrical discharge machining (EDM) process and numerical control (NC) milling machine technology, the optimal processing of die cavity can be realized. Taking ellipse-shaped products as an instance, the optimal analysis and processing of die cavity including extruding experiment are carried out.

摘要：During the product family design, it is necessary to reduce the variety of components and share common components among many products. The major benefits are lessened design efforts and reduced costs. Therefore, this paper presents an approach to standardize components of a product family. Form feature modeling for components is discussed. Based on the similarity analysis, a step by step method to standardize the feature architectures of components is described. The algorithms for standardization are identified as well. A case for standardizing components of an auto-body family is used to demonstrate the validity of this approach.

摘要：To improve the computational efficiency of the reliability-based design optimization(RBDO) of flexible mechanism, particle swarm optimization-advanced extremum response surface method(PSO-AERSM) was proposed by integrating particle swarm optimization(PSO) algorithm and advanced extremum response surface method(AERSM). Firstly, the AERSM was developed and its mathematical model was established based on artificial neural network, and the PSO algorithm was investigated. And then the RBDO model of flexible mechanism was presented based on AERSM and PSO. Finally, regarding cross-sectional area as design variable, the reliability optimization of flexible mechanism was implemented subject to reliability degree and uncertainties based on the proposed approach. The optimization results show that the cross-section sizes obviously reduce by 22.96 mm^2 while keeping reliability degree. Through the comparison of methods, it is demonstrated that the AERSM holds high computational efficiency while keeping computational precision for the RBDO of flexible mechanism, and PSO algorithm minimizes the response of the objective function. The efforts of this work provide a useful sight for the reliability optimization of flexible mechanism, and enrich and develop the reliability theory as well.

摘要：Efective Selective Laser Melting(SLM)molding methods for femur implant design and molding can improve femur implant surgerysucess rates and enhance patients quality of *** this study,an individualized femur implant and individualized biological fixed-typefenur implant were designed using the parametric modeling *** implants were then directly manufactured via SLM moldingtechnology as the forming process was carefuly *** results indicate that the proposed implant allows for favorable conjunctionof the reconstructed implant model with the surrounding bone tissues under the premise of a relatively small amount of *** implant also shows even pore distribution,good overall connectivity,relatively high bearing capacity,favorable overlappingbetween supports,and strong inter-pore *** a small amount of powder adheres onto the surface and can be directly usedafter simple sand blasting and *** comprehensive analyses of fenur implant modeling and molding methods given in this papermay provide a sound foundation for the design and direct manufacture of individualized femur implants in the future.