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991.
随着计算机技术的快速发展,数控加工技术凭借精确和高效的优势,已经成为机械制造中的主流技术。主要分析了数控技术的发展现状和特点,并分析了数控技术在机械制造中的应用优势,以促进机械制造业的快速发展。 相似文献
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994.
The effects of potassium on the catalytic behavior in CO hydrogenation over K-promoted Fe/carbon catalysts having low K/Fe
ratios were investigated. Even though the doses of potassium were low the promotional effects were pronounced, especially
on the olefin-to-paraffin ratio, and theC
3
toC
4
olefin selectivities of the K-promoted catalysts were as high as 51 to 66 mol%. Over the catalysts having no or low potassium
content the olefin-to-paraffin ratio and the ratio of the CO2 formation rate to the rate of CO conversion to hydrocarbons remained roughly the same regardless of temperature, while over
the K-promoted catalysts having higher potassium content they increased with temperature. Formation of significant amounts
of filamentous carbon was observed in the K-promoted catalysts; however, the carbon deposition did not appear to affect the
inherent activity and selectivity of the K-promoted catalysts. 相似文献
995.
Adsorption of benzoic acid by CTAB exchanged montmorillonite 总被引:1,自引:1,他引:1
Liang-Guo Yan Jin Wang Hai-Qin Yu Qin Wei Bin Du Xiao-Quan Shan 《Applied Clay Science》2007,37(3-4):226-230
This paper reports the adsorption of benzoic acid from water on cetyl trimethylammonium exchanged montmorillonite (CTAB-montmorillonite). Important factors are the adsorbent concentration, ionic strength, equilibrium time and pH. The largest adsorption is at pH 9. The adsorption kinetics data fitted the pseudo-second-order equation. The adsorption isotherms at different pH were linear indicating a partition mechanism. Up to about 61% of the dissolved benzoic acid was adsorbed by CTAB-montmorillonite. These results indicate that CTAB-montmorillonite is a potential adsorbent for benzoic acid. 相似文献
996.
世界草甘膦的主要供应商是美国的孟山都公司 ,孟山都公司 2 0 0 0年的生产能力超过了 10万t/a。国内草甘膦原药生产企业有 2 3家 ,制剂生产企业有 2 4家 ,至 2 0 0 3年 10月我国草甘膦生产企业出口总量已达 4 135万t/a(10 0 % ) ,中国草甘膦生产企业的壮大引来了国外厂家不断地反倾销诉讼 ,同时高含量草甘膦原药生产技术也制约着中国生产企业的发展。 相似文献
997.
An Yong Lee Jongguk Yim Youngjin Choi 《International Journal of Control, Automation and Systems》2014,12(5):1102-1109
This paper presents a scaled Jacobian transpose based control method for robotic manipulators as a modification of a conventional Jacobian transpose based method. The proposed method has several advantages such as it shows faster convergence and better tracking performance than the conventional method, furthermore, it does not have any singularity problem similar to the conventional method. The scaled Jacobian transpose is obtained by collecting each pseudoinverse of the column vector of the Jacobian matrix. The proposed method performs a given task well under singular configurations while minimizing the task error. Finally, a few comparative studies with the conventional method are provided to show the effectiveness of the proposed method through simulations. 相似文献
998.
Mai Ba Loc Hyeung-Sik Choi Jung-Min Seo Se-Hoon Baek Joon-Young Kim 《International Journal of Control, Automation and Systems》2014,12(4):886-894
This paper presents an architecture of a newly developed autonomous underwater vehicle (AUV) platform, named KAUV-1, which is designed as a torpedo with very light weight and small size, suitable for use in marine exploration and monitoring. The KAUV-1 has a unique ducted propeller located at the aft end with yawing actuation acting as a rudder. For depth motion, the KAUV-1 is designed to have a mass shifter mechanism inside to change the vehicle center of gravity and to control its pitch angle and depth motion. The paper also presents an analysis on the equations of motion of the KAUV-1 with mass shifter mechanism and a new depth control strategy for the KAUV-1. The feasibility of the proposed control strategy is validated through simulation and experiment of performance of the vehicle. 相似文献
999.
Min Jeong Kim Mina Choi Yong Bum Kim Fengyi Liu Hyungpil Moon Ja Choon Koo Hyouk Ryeol Choi 《International Journal of Control, Automation and Systems》2014,12(2):406-414
This paper proposes a method of exploring the local shape of an unknown object using the force and torque information obtained from active touch. In the first, we present a method to estimate an unknown curvature, using rolling and sliding motion with a force/torque sensor attached to the fingertip of the hand. Then, the normal curvature equation from 2D curvatures is obtained. Finally we present a reconstruction algorithm of local geometry by using a normal curvature equation, which is composed of principal curvatures and principal directions. The method is tested by using a hand-arm system consisting of an industrial robot arm and an anthropomorphic robot hand with 6-axis force/torque sensor. The feasibility of the proposed method is experimentally validated for objects with simple geometries such as cylinder, spheres etc. 相似文献
1000.
Chang-Hyun Park Jun-Hee Lee Jae-Hyuk Jeong Dong-Hoon Choi 《Structural and Multidisciplinary Optimization》2014,49(1):131-145
When a cleaning blade in a laser printer is excessively deformed, immoderate permanent set can result, leading to weaker nip pressure between the cleaning blade and OPC drum that worsens its cleaning performance and printing quality. In this study, the correlation of the permanent set with stress and strain was investigated through tensile tests with rubber test specimens. Based on the experimental results, the maximum von-Mises stress value was used to quantify the permanent set. A design optimization problem was formulated to minimize the maximum von-Mises stress while satisfying the design constraints for maintaining appropriate contact between the cleaning blade and the OPC drum. We employed metamodel-based design optimization using design of experiments, metamodeling and an optimization algorithm to circumvent the difficulty of structural analyses at some design points. Using the proposed design approach, the optimal maximum von-Mises stress was reduced by 40.2 % compared to the initial stress value while all the design constraints were satisfied. In order to verify the validity of our design optimization result, we manufactured the cleaning blades according to the optimum design solution and performed permanent set and printer tests. The test results clearly showed the validity of our design optimization result. 相似文献