Papers by Keyword: MA

Abstract: Cu - SiC composite powders were discussed in this paper the microstructure after ball mill, through to the ball mill after Cu-SiC composite powder particle size and lattice constant analysis, confirmed the high-energy ball mill to Cu-SiC micro structure of the binary alloy. The experimental results show that the ball mill after 20 h, Cu particle size has a larger extent reduce after high-energy ball mill and SiC lattice constant increase.

Abstract: Diamond is a kind of ultra-hard and difficult-to-machine material. By means of the graphitization of diamond, dynamic friction polishing (DFP) technology is used to achieve a high-efficiency material removal of diamond. The polishing plate of DFP plays a key role in the process of polishing, and catalytic metal with unpaired d electrons is considered as ideal polishing material. To discuss and verify the feasibility that amorphous alloy can be used to polish CVD diamond film by DFP, Fe based amorphous alloy was prepared by mechanical alloying method and spark plasma sintering technology. The results showed that diamond film got a higher removal and a better polishing effect. This work provided a new selection for the polishing plate used for DFP of diamond.

Abstract: Diamond is widely used in the fields of precise and ultraprecise machining because of its superlative characters. Due to high hardness and great brittleness of diamond, the grinding of diamond needs a kind of high effective and stable polishing method. Dynamic friction polishing (DFP) is deemed to be an innovative method by means of a synergistic reaction of mechanical effect and chemical change. The condition of high pressure and high temperature puts forward a high requirement for mechanical property of the grinding wheel in DFP, other than that, the graphitization of diamond catalyzed by catalytic metal is also a focus of research. In this paper, the transition metals with unpaired d electrons were selected as polishing materials, and powder metallurgy technique was used to prepare alloy grinding wheel for polishing diamond by dynamic friction polishing.

Abstract: Ith the method of empirical analysis, based on the huge amounts of real data opened by securities market, through testing the expert system of securities trading software MTM, MACD and MA, with odds, annual returns and net profit margin as management goals, statistical theory as research basis, comparatively analyzed the advantages and disadvantages of the three systems. Except for annual transaction times of number, MA expert system is slightly better than the MACD expert system; while MA expert system, no matter in odds, net profit margin or in annual returns, trading opportunities, is better than that of MTM expert system in all-round way.

Abstract: With the clear emission reduction target of China for 2020, the refining industry as a large emission source inevitably plays a significant role. The paper confirmed and assessed three commercially available CO₂ separation technologies for refineries, vacuum swing adsorption (VSA), monoethanolamine (MEA) and membrane absorption (MA). The economic results indicate that the capital cost of constructing a CO₂ capture unit is 35.996 M¥, 34.418 M¥, 37.502 M¥, respectively. And the corresponding cost of avoided is 379.8 ¥/tCO₂, 249.6 ¥/tCO₂ and 376.5 ¥/tCO₂. Sensitivity analyses are also performed examining the effect of CO₂ price on economic feasibility, as well as improvements of regeneration energy demand and CO₂ capture system on the CO₂ avoided cost. The regeneration energy demand impacts the avoided cost significantly, whereas CO₂ capture system demonstrates insensitivity. Though the CO₂ avoided cost for MEA case is highest, MEA has been commercially the most available processe so far for existing refineries. However, MA will be the most promising alternative to chemical absorption in the future, provided that membrane performance is further improved. In addition, the CO₂ avoided cost of VSA is close to that of MEA, but other economic indicators are optimal due to a large amount of H₂ recovered. Currently, without any incentive and a major technological break-through, CO₂ capture from the source of hydrogen production units at Chinese refineries is the most attractive opportunity.

Abstract: Based on the public and actual massive data of securities market, through testing the MA and RSI expert system of securities trading software by simulation experiment method, with the winning percentage, the annual rate of return, and the net profit margin as the management objectives, and with the theory of mathematical statistics as the research basis, the article carried out the comparative analysis of strength and weakness of these two systems. Except the annual transaction number, RSI expert system is comprehensively superior to MA expert system.

Abstract: This paper discusses Fe50Cu50 composite powder mechanical alloying of morphology and solution condition, through to the mechanical alloying Fe50Cu50 after composite powder on scanning electron microscopy and distribution analysis has determined its morphology and Fe -Cu the solution conditions. The experimental results show that the ball mill 50 h, Fe50Cu50 composite powder particle size basically stable, size in a few microns or so, and Fe and Cu has fully fuses in together to form the uniform solid solution.

Abstract: Coal and gas outburst is one of the most important natural disasters in our country. Thus pre-warning has the great significance to production safety for coal mine. In view of the facts of current pre-warning technologies, such as single pre-warning indicators, poor performance under interference and low real-time capability, some new pre-warning models are presented. The models include G line, moving average line and so on. Based on data mining theory, the pre-warning system works on the time series of gas emission concentration (which is called G series), and the pre-warning system for outburst is designed as well. 4.19 coal and gas outburst in Dashu Village Coal Mine of Hebei Fengfeng Coal Mining Group is studied based on pre-warning system. And the result is in accord with accident investigation. The analysis shows that the pre-warning system can mine the outburst developing process information of coal-rock dynamical system from the time series of gas concentration and realize outburst accidents pre-warning.

Abstract: According to the characteristic of abounding use of digital information in the domain of maintenance of equipment, design a sort of PMA system which is high efficient, low dissipative and convenient to operate. The system is consisted of free scale i.MX51 embedded microprocessor, that its core is the newest ARM Cortex-A8 chip, and Windows CE operating system. Therefore, it achieved various functions, such as interactive query of IETM, sampling video and audio information, analysis fault, downloading and examining the maintained tasks and records

Abstract: In this paper, Mobile Agent (MA) and a number of intrusion detection system described. Considering the shortcoming of the current intrusion detection system, a new system called the intrusion detection system based on MA was described. Using the autonomy of MA, Intrusion Detection System based on MA avoids single-point failure, and robusts the system. As a result, the security of network has been increased.