Advanced Materials Research Vols. 156-157

Abstract: Magnetic fluid was invested in 20thcn 60s, and nowadays, it is used as an effective way for mechanical seal. This paper follows the seal requirements of stirred reactor rotating axis, analyzes the applicability for its seal condition. Meanwhile, in this paper the magnetic field is calculated by numerical simulation, the free boundary of magnetic fluid is analyzed in conditions of static seal and dynamic seal. The boundary analysis for magnetic fluid seal can directly show its position, when the boundary of magnetic fluid moves to the lower extreme of pole teeth, it can be considered the seal is invalid. This is a simple way to supervise the magnetic fluid seal.

Abstract: ZnSe is a kind of important semiconductor photo-electricity materials, which has received common attentions. The preparation and photoelectric property of high quality ZnSe single crystal have become the focus on current research fields. In this paper, the preparation methods were discussed emphatically and optical and electrical properties were analyzed on these bases. Furthermore, the application prospective was discussed. Therefore, this paper provided research basis for preparation and application of ZnSe.

Abstract: The Sugarcane field excitation has notable influence on the sugarcane cutting quality, but its mechanism has seldom been studied. Based on the dynamic model analysis, this paper measure, analysis and test how the field excitation impacts the vibration of the cutter. After building up 3D model of the vehicle and field system, virtual simulation analysis on it is carried out, deducing that the frequency of field unevenness has notable influence on the vibration of the cutter. In physical experiment, it compares and analyzes the vibration of the cutter and cutting quality under different frequencies of field unevenness. The result shows that, the frequency of field unevenness has magnificent influence on the vibration of the cutter, and the higher the frequency the more deteriorated the sugarcane cutting quality.

Abstract: Three repellent coated PE film were development for avoiding storage insects and microorganisms. In this work, the microbiological and physiological properties of tetramethrin, cymperator and capsaicin-coated PE packing for rice grain were investigated. The results showed that the capsaicin-coated PE film was the optimal packaging material to preserve rice grain fresh. After three months storage of rice grain, capsaicin-coated PE inhibited the growth of bacteria and fungi than blank-coated PE, and had the similarly inhibiting roles than potent synthetic insecticide-coated PE packing. Especially, free fatty acid content increasing was decreased in storage of capsaicin-coated PE film, the flavor changes in slow.

Abstract: Evaluated with the yield of litsea cubeba essential oil, water extraction technology of essential oil from the seed of Litsea Cubeba (Lour.) Pers. assisted by microwave and ultrasonic is studied for the first time in this paper. The optimal water extraction technology of litsea cubeba essential oil assisted by pure microwave is as follows: extracting time 40 minutes, microwave power 650 W, solid-liquid ratio 1:4 (g/mL). Average yield of litsea cubeba essential oil is up to 10.287% (g/g) under the above optimal technology. The optimal water extraction technology of litsea cubeba essential oil assisted by microwave together with ultrasonic is as follows: extracting time 8 minutes, microwave power 600 W, solid-liquid ratio 1:7 (g/mL), extracting temperature 85 . Average yield of litsea cubeba essential oil is up to 14.188% under the above optimal technology. Microwave and ultrasonic can effectively enhance the extraction process of litsea cubeba essential oil.

Abstract: Based on the concept of independent dehumidification, a system which can test the dehydration property of both the adsorbent bed and the adsorbent has been designed. As the adsorbent, the activated alumina and the 4A molecular sieve are used to test the dehydration property of the whole adsorbent bed with two kinds of adsorbent. Finally, three new evaluation indexes about the dehumidification efficiency based on the experimental data are proposed in this paper.

Abstract: A new passive vibration control strategy has been put forward and applied to a cantilever beam in this paper. For the beam under principal resonant harmonic excitations, a steel ball was inlaid in its interior closed cavity without any restricts, constructing an impact system. For the system, a spring-damping impact model was employed to simulate impacts between the beam and the steel ball, and dynamic governing equations ware derived. Numerical simulations show that the amplitude of the beam vibration response is significantly reduced by the impact damping of the steel ball, and moreover, the vibration response isn’t periodic but quasi-periodic due to impacts. The self-adaptive characteristic of the steel ball is fully demonstrated by assuming that the ball impacts the beam on a virtual location instead of the actual location observed in experiments. In general, all numerical results agree with those of experiments.

Abstract: A new index U* which represents load paths in structures was applied to a truck cab under collision. After obtaining the deformed body by a dynamic crash simulation, U* for the extracted deformed body was statically calculated. The distributions of U* were compared with the values of U** obtained in our previous report. The U* and U** distributions show almost the same pattern. However, the absolute value of U* is larger than U** by about 1.6 times. The difference is inevitable because of the difference in their definitions. The concepts of U*sum and its histogram were used to express the effectiveness of the load transfer. Using these expressions, it was shown that the main member of this cab transfers the loading effectively.

Abstract: Expandable cased-hole liners is to solve the sealing problem of level six multilateral wells. It is a trigeminal expandable tube which is usually prefabricated on the ground and re-expanded when placed in the proper position. In this paper, the trigeminal expandable tubular compression molding process of the pre-forming stage is mainly studied. In this compression process, both sides of the branch pipe should be compressed to a certain shape in order to successfully enter the main borehole; meanwhile, we want to make sure that failures such as rupture do not occur in the subsequent expansion process. According to the theory about sheet metal bending forming process, three different shapes of the mold are designed to control the cross-section shape of the compressed trigeminal expandable tube so that it meets the application requirements. Rack-shaped cross-section is finally selected as a reference of the best through simulation of compression process and comparative analysis of simulation results. At last, field tests show that this cross-section shape is compatible with the theoretical and simulation results.

Abstract: Mg76Ti12Ni12-xCrx(x=0,3,6,9) alloys were synthesized by mechanical alloying(MA) approach and hydrogen storage properties of the alloys were investigated by X-ray diffraction, thermal analysis and pressure-composition isotherm measurement. It is found that Ti2Ni phase and Mg2Ni phase exist as the main phases in Mg76Ti12Ni12-xCrx(x=0,3,6,9) alloys. The Mg76Ti12Ni12-xCrx(x=0,3,6,9) alloys exhibit the hydrogen storage capacity of 4.61,4.30,4.21 and 4.12wt%, and the decomposition enthalpies of the alloy hydrides are 928.4, 898.3, 831.2 and 851.4J/g H2, respectively. Mg76Ti12Ni6Cr6 alloy shows small hysteresis and fast hydrogen absorption rate. Proper Cr content can improve the performance of the Mg76Ti12Ni12-xCrx(x =0,3,6,9) alloys.