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The microstructure and tensile properties at room temperature of as-cast, solution-treated and aged samples of a Mg-5Sn-4Al (wt%) alloy are investigated. The microstructure of the as-cast sample consists of a-Mg primary, Mg2Sn and Mg₁₇Al₁₂ divorced eutectic, secondary precipitations Mg₁₇Al₁₂ and Mg₂Sn. After solution treatment, all the Mg₁₇Al₁₂ particles and the majority of Mg2Sn phases are dissolved into the matrix and the tensile strength and the elongation of the alloy increase obviously. During aging process many fine particles of Mg₂Sn precipitate which result in the improvement of the yield strength.

A quantitative analysis of input-output status and sustainable development status of agro-ecosystem in Fuyang City was conducted by using the method of ecological emergy analysis in this paper. The results showed that the ESI of agro-ecosystem in Fuyang city was 5.31 in 2010, comparing with its neighboring provinces and cities, the sustainable development ability of agricultural ecology of Fuyang City was in a middle level.

The Cu0.81Ni0.19 has been synthesized directly from elemental powder of nickel and copper by mechanical alloying. The alloyed Cu0.81Ni0.19 alloy powders are prepared by milling of 8h. The grain size calculated by Scherrer equation of the NiCu alloy decreased with the increasing of milling time. The end-product was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM)

Single-grain grinding test plays an important part in studying the high speed grinding mechanism of materials. In this paper, a new experimental system for high speed grinding test with single diamond grain is presented. The differences of surface topography and chip morphology of Inconel 718 machined by single diamond grain and single CBN grain were evaluated. The grinding forces and corresponding maximum undeformed chip thickness were measured under different grinding speeds. The chips, characterized by crack and segment band feature like the cutting segmented chips, were collected to study the high speed grinding mechanism of nickel-based superalloy. The results show that the grinding speed has an important effect on the forces and chip formation, partly due to the temperature variation. As the speed increases, the groove surface becomes smoother.

The characteristics in microstructure, surface morphology, chemical composition, hardness and wear resistance of the three protective iron-based compound coatings prepared by Supersonic Arc Spraying (HVAS), were investigated by X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Energy disperse spectroscopy (EDS) and Rockwell apparatus in this paper. It is indicated that the three coatings are typical layer and compact structures. The coatings are composed of Fe (s.s) phase and various kinds of ferric oxides, chrome carbides and/or intermetallic phase distributing along the interface of lamellar layers. More Cr and Ti, Al elements in the cored wires can degrease the diameter and alternate the morphologies of the holes in the coating, resulting from the formation of oxides, carbides and intermetallic phase during depositing the coating. The results indicate the SXTiAlC coating shows the most excellent wear performance among the three coatings. The wear behavior and mechanism are discussed.

Heavy machinery processing industry has its own disadvantages, that is, the large size and heavy weight of workpieces. Some of them may even weigh hundreds of tons. When processing horizontal lathe, the turning diameter of it can be as long as six meters and the vertical lathe can reach ten meters. Heavy duty cutting mainly concerns about how to improve the processing efficiency, enhance the equipment utilization and to reduce energy consumption. Therefore, this proposes a higher requirement to heavy cutting tool, especially the design of the blade is of great importance. Based on the analysis of heavy cutting blade’s structure, this dissertation uses the method of parametric design which is suitable for Solidworks, with the combination of OLE and COM technology. It also utilizes Visual Basic on the Solidworks platform for secondary development and design, and develops the fast digital modeling software design. The software can not only realize the rapid modeling of heavy cutting blade, but also shorten the design cycle and improve the efficiency of the cutting tool which benefited from the convenient design of the heavy blade, which has a significantly practical application value.

The EG scheme also had some shortcomings: the node could not resist attack effectively, and only one routing path was used during the communication. To solve these problems, this scheme proposed to use the multi-path routing to replace the one routing, and the pairwise key was established after the hash function. The connectivity of the system was improved by the multi-path routing, if one routing path was broken, there were also some other alternative paths. Due to the hash function, the attackers could not get any useful information. So the proposed scheme can not only develop the connectivity of the WSNs, but also improve the security of the system.

To achieve engineering application of pulse motor as soon as possible,designed a soft pulse separation device(PSD), numerical simulated its process of bearing pressure and turning on,used the XFEM to simulate its failure form,got strain and stress distribution,found the bearing capability and failure form of the structure of soft PSD was reliable;Designed a few of verification monomial tests,verified the accuracy of simulation,proved that its bearing capability and failure form satisfied with design requirements,could be applied to pulse motor.The simulation technique,test method and conclusion are useful for designing pulse solid rocket motor configuration.

The transparent ZnO films were deposited on the indium tin oxide (ITO) coated glass substrates by using the square wave potential deposition method. The conductive graphite plate is used for counter electrode, electrolyte consist of zinc nitrate and additive of electrochemistry, which is made up CTAB and potassium nitrate. Crystallinities of the films were examined by X-ray diffractometer. The morphologies of zinc oxide films were observed with atomic force microscope. Optical characteristics of zinc oxide layers were measured with UV–vis spectrophotometer. The optimal conditions for preparation of zinc oxide thin films with the square wave potential method were as follows: the deposition time was 6 min, concentration of zinc nitrate was 0.05mol/L, deposition temperature was 80 °C, and the annealing temperature was 500 º C. The average optical transmittance of the ZnO films is higher than 85% in the visible range. Moreover, the films have flat surface and small grain size.

Axial turning is a method to cut the cylindrical work piece along its axis, using the kinetic energy of high-speed rotation annularity tool, the abrasives in tool tip (or toes) as the main cutting edge to remove materials and the abrasives in the inner surface of tool as a minor cutting edge to sharpen the processed surface. The cutting thickness and feed rate could be more than 3~5mm and 30mm/min respectively in a cutting, and realized high-efficient, low-cost processing of engineering ceramics. Processing mechanism analyses showed that both median/radial cracks and lateral cracks occurred in the part to be removed, and the intensity of the processed part had little destroyed, only needing adjust the axial force to control the length of transverse cracks.