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High-precision method of detecting motion straightness based on plane mirror interference
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作者 邓勇军 张之敬 +2 位作者 金鑫 许志尧 孙宏昌 《Journal of Beijing Institute of Technology》 EI CAS 2015年第4期466-470,共5页
A high-precision method of detecting motion straightness was proposed based on the prin- ciple of plane mirror interference after analyzing the motion straightness error of a linear stage. De- tection experiments were... A high-precision method of detecting motion straightness was proposed based on the prin- ciple of plane mirror interference after analyzing the motion straightness error of a linear stage. De- tection experiments were carried out and the motion straightness errors were separated by the linear regression method. Finally, linear measurement uncertainty of the detection method was estimated. The results showed that this detection method was simple and accurate, and was especially suitable for precision detection of motion straightness error in the small travel movement of ultra-precision machining. 展开更多
关键词 motion straightness plane mirror interference UNCERTAINTY HIGH-PRECISION
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Structural and Spectral Studies of Some Geometric Isomers of N-Pivaloyl-Nˊ-dichlorophenyl Thiourea
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作者 Muhammad Khawar Rauf Masahiro Ebihara +1 位作者 Sarwat Sultana Amin Badshah 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第3期349-356,共8页
N-pivaloyl-Nˊ-(3,4-dichlorophenyl)thiourea (1): monoclinic, P21/a, a=11.57(1), b=9.278(8), c=13.51(1), β=103.85(1)°, V=1408(2)3 , Z=4, μ=0.598 mm-1 ; N-pivaloyl-N'-(3,5- dichlorophenyl)thiour... N-pivaloyl-Nˊ-(3,4-dichlorophenyl)thiourea (1): monoclinic, P21/a, a=11.57(1), b=9.278(8), c=13.51(1), β=103.85(1)°, V=1408(2)3 , Z=4, μ=0.598 mm-1 ; N-pivaloyl-N'-(3,5- dichlorophenyl)thiourea (2): monoclinic, P21/a, a=7.176(2), b=16.441(4), c=11.923(2), β=92.48(1)°, V=1405.3(6)3 , Z=4, μ=0.600 mm-1 ; N-pivaloyl-Nˊ-(2,6-dichlorophenyl)thiourea (3): orthorhombic, Pnma, a=26.79(1), b=8.780(4), c=5.955(3), V=1400.7(11)3 , Z=4, μ=0.601 mm-1 . All three complexes have an intramolecular hydrogen bond between NˊH and the carbonyl oxygen. Solution 1H NMR studies (CDCl3) show the NH resonance considerable downfield for each thiourea and their positions, as well as that of NH, is affected by substituents on the phenyl ring. 展开更多
关键词 pivaloyl thioureas single-crystal XRD-studies hydrogen bonds spectral studies mirror plane
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Optimization of Magnetic Field for CR Dipole Magnet 被引量:3
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作者 姚庆高 马力祯 +5 位作者 何源 李青 吴巍 卞文龙 袁平 詹文龙 《Chinese Physics C》 SCIE CAS CSCD 北大核心 2008年第z1期19-21,共3页
High homogeneity of the CR (collector ring) dipole magnet for FAIR (Facility for Antiproton and Ion Research) project at GSI is essential.The two optimized and analysis methods are introduced in detail,In order to obt... High homogeneity of the CR (collector ring) dipole magnet for FAIR (Facility for Antiproton and Ion Research) project at GSI is essential.The two optimized and analysis methods are introduced in detail,In order to obtain an ideal integral magnetic field distribution,the complicated end chamfer has been designed.By chamfering the removable pole,the distribution tolerance of high magnetic field is optimized to±2×10^(-4).The method of adding a mirror plane is suitable for the high magnetic field and it doesn't fit the low one.The OPERA is used to optimize the dipole magnetic field. 展开更多
关键词 removable pole CHAMFER mirror plane OPTIMIZATION
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