Advanced Materials Research Vols. 490-495

Abstract: The viscosity of DO(dissolved oxygen) in high density aquiculture is affected by many factors, and its characters have nonlinearity, hysteresis and big-inertial. Normal PID control is difficult to achieve perfect purpose. According to the variety of DO’s viscosity, a fuzzy algorithm was advanced to make system output relevant voltage/frequency to be master of transducer. It can control the electric machine’s rev to ensure the steady DO’s viscosity, at the same time it can also save energy and prolong equipment’s useful time

Abstract: To study motion range changes with wave condition and motion relationship between cages, physical model experiments were carried out. The authors designed 2 models of composite-type sea cages. Experimental data obtained by the CCD data acquisition system. The experiment results showed that 1.in the same period, horizontal motion range,vertical motion range and inclination changes of float collar increase with wave height; 2.In the same wave height, horizontal motion range of the float collar increases with period; 3.The laws between vertical motion and period are not obvious 4.The laws between inclination changes and period are not obvious 5.Motion range of the first cage along the direction of waves is less than other cages.

Abstract: In the long journey of the western aesthetics development, science and aesthetics especially the mathematics and the aesthetics relationship is more intimate. In the ancient Greece civilization, there is a very prominent characteristic, which is a kind of unparalleled thick interesting to question closely to the nature. As they don’t satisfied only stay in the imagination of the world picture view of the poetic in the mythology, and try to use the reason to guide the heaven sent human being’s imagination, they try eagerly to explain the nature order, evolution and movement. When the ancient Greece natural philosophers do the nature science research, they also do the aesthetic research. Pythagoras, as a mathematician and physicist and a astronomer, who with most of the disciples used the nature science view to see the aesthetics problems once at the beginning, which created the second to none of the method of quantitative research of the things.

Abstract: This paper introduces a new standard reflecting plate’s manufacture, which is used to calibrate the measurement system for radar absorbing materials in 3 mm band. The new standard plate is designed and employed with two reflecting surface, one is a plane, the other one is curve, and metal with high permittivity. It has the nominal reflectivity of -15dB, -10dB, -5dB and has the advantages of high stability, easy manufacture and convenient usage

Abstract: The effect on diffusion layer depth and copper content of the variation of various parameters in copper-infiltrated process on stainless steel surface by double glow plasma technology were researched. The process parameters contain Ar2 pressure, source voltage, heat insulation temperature and heat insulation time. The best process parameters are as follows: gas pressure:20Pa, source voltage:1000V, heat insulation temperature:950°C and heat insulation time:3h. Nowadays, the main methods of copper-infiltrated on stainless steel surface include: solid-infiltration method, paste-infiltration method, particle beam injection etc[1~4]. The strength of diffusion layer treated by the plasma metal infiltration technique is comparable to metallurgical bonding strength, and the process is low cost and less pollution.The paper systematically studied the plasma copper-infiltrated process on 304 Stainless Steel. The initial copper-infiltrated process parameters on 304 Stainless Steel were as follows[5]: Ar2 pressure: 20 Pa; source voltage: 1000 V; heat insulation temperature: 950°C; heat insulation time: 3 hours. The optimum seeking method is based on the initial process parameters, varying the value of one parameter each time. Four values of one parameter is a group contrasting experiments. Testing diffusion layer depth and copper content on surface of each experiment to be standerds of evaluation every value. The values of each parameter to be seleted were as follows: Ar2+ pressure: 10 Pa, 15 Pa, 20 Pa, 25 Pa; source voltage: 800V, 900V, 1000V, 1100V; heat insulation temperature: 800°C, 900°C, 950°C, 1000°C; heat insulation time: 2.5 h, 3 h, 3.5 h, 4 h.

Abstract: The hot deformation characteristics of TC18 titanium alloy were studied in the temperature range 750-850°C and strain rate range 0.001-1 s-1 by using hot compression tests. Processing maps for hot working are developed on the basis of the variations of efficiency of power dissipation with temperature and strain rate. The results reveal that the flow stress of TC18 is sensitive to strain rate. Processing map at stain of 0.6 reveals two domains: one is centered at 750°C and 0.001s-1; another is centered at 850°C and 0.001s-1. The maximum efficiency is more than 60%. According to the maps, the zone with the temperature range of 750-850°C and strain rate range of 0.01-0.001s-1 may be suitable for hot working

Abstract: In vibration control field magneto-rheological (MR) fluid dampers are semi-active control devices that have recently begun to receive more attention. This paper presents a new type of MR fluid damper with external coil. The new structure of the damper was optimized and analyzed based on a static magnetic analysis with the help of electromagnetic finite element analysis (FEA) using the software of ANSYS. The damping characteristics of the damper were theoretically researched. Research results show that the designed MR fluid damper with external coil has wider scope of damping adjustment and strong energy-dissipating ability. The study method in this paper and the obtained results will help designers to create more efficient and reliable MR fluid dampers.

Abstract: A gradient high magnetic field effected significantly the morphology and distribution of the primary silicon grains in Al-18Si alloy. Experimental studies shew that in the gradient high magnetic field the primary silicon phase grains, which are large plate-like or five-star-like in the case of solidification without magnetic field, are accumulated on the top of the specimen and refined remarkably with the morphology of polygonal or nodular shapes when the alloy solidifies from the semisolid state. In the segregated layer of the silicon, the distribution of the silicon grains is homogeneous. The size of the primary silicon grains decreases and the grain number density rises with the increase of the magnetic strength maintaining the magnetization force unchangeable. It seems that the high magnetic field influences the diffusion of silicon. Theoretical models have been proposed to explain the refining and the distribution of the silicon grains.

Abstract: Mesoporous TiO₂ thin films have been prepared with so1-ge1 method by using tetrabutyl titanate(TBT) as precursor and PEG (Molecular weight 3000)as template．The XRD spectrum of the samples of the thin films indicated that the sample crystallized into anatase phase under the 500°C．And the photocatalytic degradation study of dioxins from MSW ash had been carried out. The result showed that the Mesoporous TiO₂ thin films with anatase phase had high photocatalytic efficiency and was in favor of the regeneration and reuse.

Abstract: Based on the requirements of load test technique on existing long-span concrete bridge, a deck arch bridge of large-span reinforced concrete was taken as the engineering background and the emulation analysis was done by building the bridge model using the finite element software Midas/Civil. The values of stress and deflection were measured and calculated. The results of the test show that the static working performance of the arch bridge is fine, the stiffness and load capacity meet the requirements of the design and the construction quality is good. It can provide references for the bridge design of the same type, learning about the actual working condition of the bridge and evaluating the working performance and load capacity of the bridge structure in the serviceability limit states.