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略论工程“双重双螺旋”及其演化机制 被引量:4
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作者 李伯聪 王晓松 《自然辩证法研究》 CSSCI 北大核心 2011年第4期54-60,共7页
本文把工程演化过程理解为一种"双重双螺旋"过程,即由"技术链"和"非技术链"("经济-社会链")共同构成的"双螺旋"。演化过程则由"技术发明-工程创新-产业扩散"三个环节组成... 本文把工程演化过程理解为一种"双重双螺旋"过程,即由"技术链"和"非技术链"("经济-社会链")共同构成的"双螺旋"。演化过程则由"技术发明-工程创新-产业扩散"三个环节组成。其中,工程"双重双螺旋"中"技术链"的演化,其基本内容是"技术硬件(机器)和技术软件(知识和制度)双螺旋"的演化。"选择与建构"机制是工程演化过程中的一个重要机制。选择机制使得在技术-经济进化过程中,技术创新成果经过市场的选优汰劣,保证了工程活动和市场经济的健康演进。建构机制则体现为技术链与经济-社会链的"双重双螺旋"变革,形成新类型的"双重双螺旋"等形式。 展开更多
关键词 工程 双重双螺旋 演化 机制
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Tooth surface error correction of hypoid gears machined by duplex helical method 被引量:5
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作者 WU Shun-xing YAN Hong-zhi +3 位作者 WANG Zhi-yong BI Ren-gui CHEN Zhi ZHU Peng-fei 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第5期1402-1411,共10页
In this work,synchronous cutting of concave and convex surfaces was achieved using the duplex helical method for the hypoid gear,and the problem of tooth surface error correction was studied.First,the mathematical mod... In this work,synchronous cutting of concave and convex surfaces was achieved using the duplex helical method for the hypoid gear,and the problem of tooth surface error correction was studied.First,the mathematical model of the hypoid gears machined by the duplex helical method was established.Second,the coordinates of discrete points on the tooth surface were obtained by measurement center,and the normal errors of the discrete points were calculated.Third,a tooth surface error correction model is established,and the tooth surface error was corrected using the Levenberg-Marquard algorithm with trust region strategy and least square method.Finally,grinding experiments were carried out on the machining parameters obtained by Levenberg-Marquard algorithm with trust region strategy,which had a better effect on tooth surface error correction than the least square method.After the tooth surface error is corrected,the maximum absolute error is reduced from 30.9μm before correction to 6.8μm,the root mean square of the concave error is reduced from 15.1 to 2.1μm,the root mean square of the convex error is reduced from 10.8 to 1.8μm,and the sum of squared errors of the concave and convex surfaces was reduced from 15471 to 358μm^(2).It is verified that the Levenberg-Marquard algorithm with trust region strategy has a good accuracy for the tooth surface error correction of hypoid gear machined by duplex helical method. 展开更多
关键词 duplex helical method hypoid gear error measurement Levenberg–Marquard algorithm with trust region strategy correction of tooth surface error
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