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软岩隧道施工方法数值分析 被引量:13
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作者 李文江 于跃勋 朱永全 《隧道建设》 2010年第2期137-141,共5页
以软岩单线铁路隧道为工程背景,采用三维数值手段对常规台阶法、扩大拱脚台阶法和预留核心土台阶法等典型工法的施工空间效应进行动态模拟。计算结果表明:对于软岩隧道,当采用常规台阶法施工时,加强上台阶围岩支护效果对大变形控制至关... 以软岩单线铁路隧道为工程背景,采用三维数值手段对常规台阶法、扩大拱脚台阶法和预留核心土台阶法等典型工法的施工空间效应进行动态模拟。计算结果表明:对于软岩隧道,当采用常规台阶法施工时,加强上台阶围岩支护效果对大变形控制至关重要;在台阶法开挖过程中掌子面挤出变形明显,掌子面的稳定性不容忽视,而预留核心土在控制掌子面变形、确保掌子面稳定方面有明显的作用;扩大拱脚支护形式与标准断面相比更有利于控制隧道收敛变形和塑性区的发展。综合分析结果认为:兰渝铁路软岩单线隧道采用扩大拱脚支护形式结合预留核心土的台阶法更有利于控制变形和确保洞室稳定。 展开更多
关键词 单线隧道 台阶法 扩大拱脚 预留核心土 数值分析
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提高镀锡铜线质量的初探 被引量:2
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作者 李学俊 《电线电缆》 1997年第4期44-46,共3页
提高镀锡铜线质量的初探江西省德兴铜材线缆厂李学俊主题词镀锡圆铜软单线镀锡质量因素措施镀锡铜线广泛应用于部分橡皮绝缘电线电缆的导电线芯和仪表安装线的导电线芯。前者,为的是防止绝缘橡皮与铜线直接接触后橡皮发粘,铜线芯发黑... 提高镀锡铜线质量的初探江西省德兴铜材线缆厂李学俊主题词镀锡圆铜软单线镀锡质量因素措施镀锡铜线广泛应用于部分橡皮绝缘电线电缆的导电线芯和仪表安装线的导电线芯。前者,为的是防止绝缘橡皮与铜线直接接触后橡皮发粘,铜线芯发黑变脆;后者,为的是提高导电线芯的可... 展开更多
关键词 软单线 镀锡铜线 质量
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锡含量数据在确定电解镀锡铜线其它工艺参数中的应用
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作者 王伯新 《电线电缆》 1997年第1期32-35,共4页
锡含量是电解镀锡铜线的极为重要的基本参数。介绍了锡含量的计算方法与测定方法;进而,应用锡含量来确定锡层厚度、生产时的耗锡量及锡的消耗定额、线坯及成品线各自的线径与锡层厚度、确保成品线电阻率达标下的锡层厚度等。
关键词 镀锡圆铜软单线 锡含量 工艺参数 计算 电线
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高速电镀金属导线的GAT工艺
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作者 A Augustini 赵德湖 《电线电缆》 1992年第4期56-58,共3页
用电子显微镜可以清楚地观察到采用GAT系统和SPS电解液所获得的大小均匀的镀层晶粒。现今生产的电镀导线的常规工艺方法,尚存在某些明显缺点,例如导线的镀层不均,由于锡阳极趋向钝化,而使电解液内金属含量减少,更不用说阳极过早产生沉... 用电子显微镜可以清楚地观察到采用GAT系统和SPS电解液所获得的大小均匀的镀层晶粒。现今生产的电镀导线的常规工艺方法,尚存在某些明显缺点,例如导线的镀层不均,由于锡阳极趋向钝化,而使电解液内金属含量减少,更不用说阳极过早产生沉渣。为了消除这些缺点,开发了GAT工艺方法。 展开更多
关键词 镀锡 圆铜软单线 电镀
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电解镀锡铜线的拉制和退火工艺
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作者 刘英豪 《电线电缆》 1992年第3期61-63,共3页
针对电解镀锡铜线拉制和退火中易出现的锡层太薄和锡耗大的问题,提出了在拉线模、配模、用控制伸长率来调节退火电压及电流等方面应采取的工艺措施。
关键词 电解镀锡 连续退火 圆铜软单线
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A novel finite element model for single-layered wire strand 被引量:2
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作者 周伟 田红旗 《Journal of Central South University》 SCIE EI CAS 2013年第6期1767-1771,共5页
A new finite element model for single-layered strand was investigated for accurate and efficient mechanical behavior analysis.Mathematical model was created by sectional path-nodes sweeping and dynamic node-beam mappi... A new finite element model for single-layered strand was investigated for accurate and efficient mechanical behavior analysis.Mathematical model was created by sectional path-nodes sweeping and dynamic node-beam mapping.Geometric relations between nodes in center core wire and helical wires were deduced in tension and bending incorporating material elasticity theory and deformation geometrical compatibility.Based on Timoshenko beam theory,strand of a pitch length was modeled with specific material,geometric parameters and synthesized constraint equations defined in ANSYS software,and predetermined load cases were performed.The obtained results show that discrepancies between suggested method and Costello theory do not exceed 1.51% in tension and 6.21% in bending,which verifies the correctness and accuracy of the suggested finite element model in predicting mechanical behavior of single-layered wire strand. 展开更多
关键词 wire strand finite element analysis nodal constraint equation geometrical compatibility Timoshenko beam theory
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Shop-Floor Controller Based on RT-Middleware Technology
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作者 Ferenc Tajti Geza Szayer +1 位作者 Bence Kovacs Peter Korondi 《Journal of Mechanics Engineering and Automation》 2013年第11期685-693,共9页
Nowadays the flexible configuration of manufacturing cells becomes to an important requirement especially at small and medium sized companies. This method can make the production fast and effective at small series or ... Nowadays the flexible configuration of manufacturing cells becomes to an important requirement especially at small and medium sized companies. This method can make the production fast and effective at small series or frequent manufacturing changes. The shop-floor control method, presented in this paper, offers a solution for the facing problem of fast and easy reconfiguration. The hardware of the controller designed modular with software components for online configuration. This solution allows sensor integration on different levels for every part of the manufacturing cell. With unified programming language and the machine specific controllers (post-processing) the cells can be defined easily by different types of human-machine interaction. The shop-floor control architecture is implemented and validated on an Adept SCARA (selective compliance assembly robot arm) robot. The robot is driven by standalone, low-level, interchangeable, software and hardware components. 展开更多
关键词 Robot controller RT-middleware CNC (computer numerical control) SCARA.
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A single stage EEHG at SXFEL for narrow-bandwidth soft X-ray generation
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作者 Chao Feng Dazhang Huang +5 位作者 Haixiao Deng Jianhui Chen Dao Xiang Bo Liu DongWang Zhentang Zhao 《Science Bulletin》 SCIE EI CAS CSCD 2016年第15期1202-1212,共11页
The echo-enabled harmonic generation (EEHG) scheme holds promising prospects for efficiently generat- ing intense coherent radiation at very high harmonics of the initial seed laser. In this paper, we study the feas... The echo-enabled harmonic generation (EEHG) scheme holds promising prospects for efficiently generat- ing intense coherent radiation at very high harmonics of the initial seed laser. In this paper, we study the feasibility of operating the Shanghai X-ray free-electron laser test facility with a single stage EEHG setup. With a combina- tion of existing numerical codes, start-to-end simulations considering various three-dimensional effects have been carried out to show the possible performance of the EEHG FEL. Simulation results demonstrate that a single stage EEHG can generate high power soft X-ray radiation pulses with narrow bandwidth directly from UV seed lasers. With the help of the harmonic lasing technique or upgraded linac, we also show the possibility of generating coherent soft X-ray radiation in the "water window" with a single stage EEHG. 展开更多
关键词 X-ray free-electron lasers EEHG Coherent soft X-ray Harmonic lasing Waterwindow
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