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A series of air knife flow rate were conducted by a hot dipping process simulator in laboratory to study its effect on coating weight and thickness. The research results show that, when the experimental steel were immersed for 3.5s in a Zn-0.24%Al zinc bath, with atmosphere of N2-10%H2 and dew point-60°C in the whole simulation, air knife flow rate (FR) was a key factor for coating surface quality. When FR was precisely controlled by the simulator from 200~500 l/min, the coating weight and thickness decreased significantly from 159.68 to 56.19 g/m2 and 17.45 to 7.84 μm. In which the decreasing line was more obvious when FR increased from 300 to 400 l/min, that the coating thickness had a dramatic decreasing from 18.08 to 11.07μm.

An investigation has been made into the machining feasibility when wire electro-discharge machining with an extremely high travelling speed of wire electrode (WEDM-HS) has been employed to process particle-reinforced 6061 Al matrix composites with 20-vol% Al2O3 (20ALO). And in this study, for the water based emulsion is used as working liquid, there exists an electrochemical effect. And thus, the EDM spark can operate under a relatively large spark gap size condition, and this would be helpful for the removal of the loosen particles and the machined debris. In this study, the material removal rate (MRR) has been examined. Since there are many factors that can influence the MRR during the wire electro-discharge machining process, in order to determine which factor has the most significant effect on the MRR and to obtain the optimal machining parameters, the relative importance of the various machining parameters on material removal rate was analysed by employing an orthogonal design. The results of the orthogonal analysis show that to obtain a high MRR for WEDM-HS machining of 20ALO materials, the duty cycle has the most significant effect on the MRR among current, pulse duration and duty cycle. And the impact of significance for the different factors follows the sequence of duty cycle > current > pulse duration. And under the experiment condition of this study, a duty cycle of 1:4, a current of 5A and a pulse duration of 32μs is the best arrangement for the MRR.

The assembly of printed circuit boards is conducted by the sophisticated PCB placement machines. The cycle time for a machine to complete an assembly job is determined by solving two machine optimization problems, i.e., the feeder arrangement and placement sequencing.Rapid and accurate estimation of these cycle times is important for solving the higher level planning problems including the line balancing problem. In this paper, a regression-based estimator was established to estimate the cycle time. Statistical results on 100 PCB samples showed that the proposed estimator could estimate the cycle times accurately. At the same time, the computationally efficiency makes it suitableto be used in solving higher level planning problems.

Availability of Mercator projection in polar regions mainly suffers from gross scale error and only can be improved by control of scale error; methods of scale error control such as properly adjusting of standard parallels, appropriately defining and relaxing acceptable scale error thresholds together with adopting appropriate chart scales and sheet specifications are presented; appropriate acceptable scale error thresholds are discussed by referring to domestic and abroad chart compilation specifications and existing Russian polar nautical charts; availability of Mercator projection in latitudes of 75°~85°is analyzed on charts with various standard parallels, scale error thresholds and latitude ranges, the result indicates that Mecator projection still satisfies compiling requirements of nautical charts with commonly used scales and sheet specifications in latitudes between 75°and 85°.

Image halftoning is the core technique of digital image output, which determines the quality of the color and tonal gradation reproduction. In this paper, the existing halftoning techniques were analyzed and evaluated, such as FM halftoning and AM halftoning, etc. And a new halftoning mode, frequency conversion amplitude modulation (FCAM), was proposed. This method is still based on AM halftoning, but it uses the different screen frequency for halftoning image of the different color version, so as to avoid moiré fringes on the smaller superposition angle. The use of new halftoning model can achieve halftoning image output which is more than 4 colors (such as 6 colors or 7 colors) without visual moirè pattern when overprinting. By the new technique, high-fidelity printing is achieved, and the color gamut of the output image is expanded, and we can get more vivid realistic effect of image transmission. We tested color gamut expansion of 6 colors and 7 colors high-fidelity printing, and obtained the expected conclusion by quantitative analysis.

We proposed overall design of the visualization browsing map data in network environment in this paper. And we developed map data flow according to the data structure and attributes of map data base. We programmed one map display control, MapCtrl.ocx, with GUI in the specific implementation. It could browse the map by utilizing map data base and self-designed map symbol base. Furthermore, we detailed the specific process of programming the control and the related techniques, such as component technique, data exchange technique and display technique. We developed a prototype of map data visualization browsing system based on ActiveX in network environment, which could achieve several functions such as browsing vector graphics of map data on internet, operation and simple query and analysis.

There are some common problems, such as low sampling efficiency and large amount of calculation, in mobile localization algorithm based on Monte Carlo localization (MCL) in wireless sensor networks. To improve these issues, an enhanced MCL algorithm is proposed. The algorithm uses the continuity of the nodes movement to predict the area where the unknown node may reach, constructs high posteriori density distribution area, adds the corresponding weights to the sample points which fall in different areas, and filters the sample points again by using the position relations between the unknown node and its one-hop neighbors which include anchor nodes and ordinary nodes. Simulation results show that the localization accuracy of the algorithm is superior to the traditional localization algorithm. Especially when the anchor node density is lower or the unknown nodes speed is higher, the algorithm has higher location accuracy.

In order to meet the designed demands of military seabed sediment thematic map, this paper researches the designed methods of sediment symbols on military seabed sediment thematic map. Combined with analyzing the characteristics of sediment elements, this paper studies the restrictive factors and designed principles of seabed sediment symbols on general charts. For the sake of the requirements of marine military affairs, this paper discusses the designed principles and implemented methods of sediment symbols on military seabed sediment thematic map.

There are three working conditions namely drilling a guide hole, expanding the guide hole and pulling back pipeline in trenchless directional drilling. The position of drill string in the wellbore and loads exerted on the drill string varied in different working conditions. The models of buckling analysis of drill strings under compression, mechanical analysis of drill string under axial compression near drill bit in inclined straight section, mechanical analysis of drill string with multi-centralizers under axial compression near drill bit in inclined straight section, mechanical analysis of drill string near drill bit under axial compression in horizontal section, mechanical analysis of drill string near drill bit under axial tension in horizontal section, mechanical analysis of drill strings near drill bit under axial tension in inclined straight section and mechanical analysis of drill string in failed well are established based on the characteristic of loads and trajectories in each section. The establishment of sectionalized mechanical model of drilling tool is the fundament of further study of force analysis, deformation analysis and stress analysis.

The first component of the Polyurethane adhesive was prepared with polyester polyol, polyether polyol ,castor oil and isophorone diisocyanate. And this component was mixed with the castor oil and its modified production to prepare a two-component solvent-free aliphatic polyurethane laminating adhesive. In this study, the influences of the copolymerization ratio of polyester/ether on viscosity, heat resistance, adhesion strength and boiling resistance were studied, as well as influences of castor oil and its modified production on curing speed and adhesion strength. The results showed that when proportion of polyether diol was 25% and castor oil was 50% of the total hydroxyl content of first component, the PU adhesive with lower viscosity, better reactivity and enhanced boiling resistance would be achieved. And with an appropriate amount of derivatives castor oil in second component, the curing speed and adhesion strength of the PU adhesive were significantly improved.

Due to collapses of tubings during well testing and completing in HPHT wells, it is required by Petrochina officially to calculate and analysis the collapse strength of down hole tubings with axial forces and corresponding bending moment being taken into considerations. Based on the 4th strength theorem, formulas were derived and method was present to analyze the collapse strength of down hole tubings loaded by compressive axial forces and bending moment to fulfill the official requirements, which could not be accomplished according to published standards and references. And, influences of axial tensile forces, compressive forces and bending loads on the collapse strengths of down hole tubings were studied. It is found that the collapse strength of down hole tubing loaded by compressive axial force is smaller with compressive axial force and buckling bending moment taking into considerations. The bigger the compressive axial forces, the smaller the collapse strengths.

Single pulse experiments were conducted to study electrochemical discharge machining (ECDM) of particulate reinforced metal matrix composites (MMCs) which are widely used in the packaging industry. This article reports the first phase of this study with an emphasis on the effects of pulse current on crater volume. The results showed that all the ECDM craters have a circular shape surrounded by a rim of re-solidified material. This indicates that ECDM craters were created by arc effect. The craters produced by both electrical discharge machining (EDM) and ECDM increased in volume with increasing peak current. However, within the range of currents studied, the craters formed by ECDM were always smaller than those produced by EDM alone under the same current. Moreover, the crater volume difference between EDM and ECDM did not change considerably with increasing current. This is considered to be due to an increase in ECDM current mainly enhances the arc energy and has little effect on the ECM action. Furthermore, the experiment results showed that the efficiency of the arc action in ECDM is reduced when the percent of reinforcement phase is increased.