摘要：Corrosion in complex coupling environments is an important issue in corrosion field, because it is difficult to take into account a large number of environment factors and their interactions. Design of experiment(DOE) can present a methodology to deal with this difficulty, although DOE is not commonly spread in corrosion field. Thus, modeling corrosion of Ni-Cr-Mo-V steel in deep sea environment was performed in order to provide example demonstrating the advantage of DOE. In addition, an artificial neural network mapping using back-propagation method was developed for Ni-Cr-Mo-V steel such that the ANN model can be used to predict polarization curves under different complex sea environments without experimentation. Furthermore, roles of environment factors on corrosion of Ni-Cr-Mo-V steel in deep sea environment were discussed.

摘要：Molten salt pebble bed reactor is one of the sixth-generation Ⅳ reactor types. To investigate the mechanical behavior of the fuel pebbles in the core, a visualization experiment facility of pebble bed(VEFPB) is designed. To obtain a uniform flow field of the core and analyze the influence of the flow field on the structure of the pebble bed, computational fluid dynamics software Fluent is used to simulate the flow field distribution of the core of VEFPB. The simulation results show that the disturbance at the bottom of the pebble bed is proportional to the flow velocity of the inlet pipe, and the flow velocity close to the inlet side is more significant than that in other parts; the design of the cylinder bottom plate with holes of different sizes can effectively reduce the flow velocity and the disturbance at the bottom of the pebble bed. In addition,according to the velocity contours of the core of VEFPB, it is observed that the flow field distribution of the core is considerably uniform except at the bottom of the pebble bed. This ensures the stability of the pebble bed and verifies the rationality of the design of VEFPB. This study provides the technical support and reference for the flow field analysis of the core of molten salt pebble bed reactor.

摘要：The uniform experiment design is an effective way of optimizing technology scheme for refining the grain size during multistage deformation. In this paper, it is adopted to evaluate the effect of each technology parameter on final grain size of AISI H13 hot work tool steel during multistage deformation. It has been verified that the technology scheme for refining the final grain size can be determined rapidly and efficiently with the aid of the uniform design. The results show that the deformation parameters and the intermission time after deformation of the first stage affect the final grain size remarkably. For AISI H13 hot work tool steel, the final grain size can be refined notably when deformation parameters for the first stage are set as follows: a deformation temperature range of 1?025 1?085 ℃; a true strain of above 0.26 and the interpass time between the first and the second stage of deformation less than 10 s.

摘要：In order to introduce gap drainage technology into practice, the design concept and expression format of spatial geometry are proposed for gap drainage impeller with twisted vice blades. First, the profile of vice blade at leading edge and relative position of main blade need to be parameterized. In addition, the influence of these parameters on the performance of a centrifugal pump should be studied. After the above-mentioned work is done, a centrifugal pump with good performance can be designed. On the basis of previous research results, the geometric parameters of twisted blades are determined and the centrifugal pump impellers are designed and manufactured. Through performance tests and cavitation tests, it is verified that the twisted vice blades on centrifugal pumps are effective and practical.

摘要：In recent years, virtual simulation experiments have been widely used in education. However, at present, academic research on virtual simulation experiments mostly focuses on key technologies, and there are few emotional studies on virtual experiments. Based on the three-layer model of emotional design theory, this paper puts forward the method strategy of emotional simulation design in virtual simulation experiment, in order to provide some reference value for the design of virtual simulation experiment.

摘要：This paper presents the findings of an experimental investigation into the effects of cutting speed, feed rate, depth of cut and approach angle in turning of titanium (Grade 5) alloy. A two-level factorial experiment has been used to accomplish the objective of the experimental study. The main cutting force, i.e. tangential force (Fc) and surface roughness (Ra) were the response variables investigated. The experimental results indicate that the proposed mathematical models suggested could adequately describe the performance indicators within the limits of the factors that are being investigated. The feed, cutting speed and depth of cut is the most significant factor that influences the surface roughness and the tangential force. However, there are other factors that provide secondary contributions to the performance indicators.

摘要：The data topology structure of uniform experiment design (UD) is too complex to be reasonable regressed. In this paper, the principle and method of distinguish the training data and testing data were described to make a reasonable regression when uniform experiment design combined with support vector regression (SVR). Two equivalent ways which were the smallest enclosing hypersphere perceptron (SEH) and the enclosing simplex perceptron (ES) were provided to discover the topology relationship of the process parameter datum. To give an application, a series of experiments about laser cladding layer quality were conducted by UD to get the relationship of load, velocity and wearing capacity. Results showed that only the testing datum recommended by the two perceptrons got a good forecasting by SVR. Therefore, the two perceptrons could guide experiments with process parameter data of complex topology structure. Further, the application could be extended over a much wider field of experiments.

摘要：Using the supercavitation phenomenon is necessary to reach high velocities underwater. Supercavitation can be achieved in two ways: natural and artificial. In this article, the simulation of flows around a torpedo was studied naturally and artificially. The validity of simulation using theoretical and practical data in the natural and artificial phases was evaluated. Results showed that the simulations were consistent with the laboratory results. The results in different injection coefficient rates, injection angles, and cavitation numbers were studied. The obtained results showed the importance of cavitation number, injection rate coefficient, and injection angle in cavity shape. At the final level, determining the performance conditions using the Design of experiment (DOE) method was emphasized, and the performance of cavitation number, injection rate coefficient, and injection angle in drag and lift coefficient was studied. The increase in injection angle in the low injection rate coefficient resulted in a diminished drag coefficient and that in the high injection rate coefficient resulted in an enhanced drag coefficient.

摘要：In the modern era of manufacturing, it is important to optimize every design parameter in product development stage to reduce cost, material usage and to achieve the desired efficacy level. There are various models which serve those purposes, for instance, Design of experiment (DoE) is used to check the parameters after adopting optimization tactics which results in reduced cost or saving operating time. In this regard, this research aims to construct a DoE model on a portable workstation to optimize its design parameters. The methodology of DOE would be a 2 level 3 factors full factorial DOE which is conducted to determine the optimal value for three design parameters (factors) which are material density, the length of the table and the length of the table stand in terms of the response which is the required time of fold ability function of the portable workstation. Based upon the evaluated interactions between the parameters, the optimized parameters are chosen for responses. Here, the resultant design parameters are at their lowest level, so the goal of time efficiency in fold ability function is achieved. This similar sort of DoE can be implemented in the furniture and other manufacturing industries who wish to optimize their material usage as well as increase efficiency and reduce cycle time.

摘要：Production of tachyons in, among other things, air showers would be in accordance with predictions of general relativity. Some such tachyons would travel with a precisely determined speed, almost equal to 5c/3 relative to the earth, and would be registered high above the region of creation of air showers, e.g. on board of a satellite. A very simple experiment designed to detect these tachyons is outlined here. Brief justification to search for tachyons is also given.