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某产品法兰端框快速换产工艺研究
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作者 李臣达 崔志宏 +3 位作者 于淼 秦书勤 吴春德 张伟伟 《机械工程与自动化》 2023年第2期130-132,共3页
某法兰端框以往生产选用大型设备加工,为提高生产效率、降低大设备使用等待浪费时间,基于130数控铣镗床设备展开了一系列工艺攻关,通过工艺装备的设计、刀具的选用及工艺流程的优化展开探索试验。多次生产试验结果表明,130数控铣镗床的... 某法兰端框以往生产选用大型设备加工,为提高生产效率、降低大设备使用等待浪费时间,基于130数控铣镗床设备展开了一系列工艺攻关,通过工艺装备的设计、刀具的选用及工艺流程的优化展开探索试验。多次生产试验结果表明,130数控铣镗床的加工能力满足法兰端框的加工要求,为后续设备的改良设计打下扎实基础。 展开更多
关键词 快速换产 工艺装备 刀具选用 法兰端框
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Isolation, Crystal Structure and Cytotoxic Activity of Natural Maistemonine and Comparison with the Synthetic Compound
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作者 WU Yia YE qing-Mei +1 位作者 qin shu-qin JIANG Ren-Wang 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2020年第7期1277-1282,共6页
The title compound maistemonine(1)was isolated from the total alkaloid fraction of the 95%ethanol extract of the roots of Stemona japonica,followed by preparative HPLC and recrystallization from a mixture of n-hexane ... The title compound maistemonine(1)was isolated from the total alkaloid fraction of the 95%ethanol extract of the roots of Stemona japonica,followed by preparative HPLC and recrystallization from a mixture of n-hexane and ethyl acetate.The crystal structure of 1,C23H29NO)6,was determined by single-crystal X-ray diffraction analysis.The crystal belongs to orthorhombic system,space group P212121 with a=8.5698(6),b=14.0460(11),c=17.8815(17)?,V=2152.4(3)?3,Z=4,Mr=415.47,Dc=1.282 g/cm3,λ=0.71079?,μ=0.092 cm^–1,F(000)=888,S=0.995,R=0.0535 and wR=0.1067.A total of 5136 unique reflections were collected,of which 3523 were observed(Ⅰ>2σ(Ⅰ)).The absolute configuration of 1 could be assigned by referring to the conserved configuration of the methyl groups at C(2).Compound 1 shows mild cytotoxic activity against the prostate cancer cells LNCaP and PC3 with the IC50 values of 29.4±2.3 and 46.6±3.1 mM,respectively.It is noteworthy that the natural maistemonine(1)is different from the synthetic compound which was a racemic with the triclinic space group P1.The lactone rings E from the natural and synthetic 1 are almost perpendicular to each other when overlapping the remaining parts of the molecules. 展开更多
关键词 maistemonine ISOLATION crystal structure CYTOTOXIC COMPARISON synthesis
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