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21.
1 IntroductionThe only finite dimensional aIternative di.ili.,1 algebras over R are ffeal algebra R, Com-plex algebra C, Quaternion algebra H, Octonidn algebra O with the embedding relations:R G C C H g O. R and C are commutative and associative, H is associative but notcomlnutative, while O is neither commutative nor a.s..i.ti.e[1].Much earlier the great Swiss mathematician FUeter (a student of Hilbert) and hi8 studentsdeveloped Quaternion analysis up to l950.[2'3] and it was a great… 相似文献
22.
跨音压气机转子叶尖间隙复杂流动观测 总被引:8,自引:1,他引:7
本文利用高频响动态压力传感器,在文献[1]的基础上,对WP11压气机转子叶尖间隙 流场进行了流场测量。测试包括三个转速多个节流条件下的间隙流场。测试结果表明:激波总体位 置随节流加深而向上游移动,但吸力面最小压力点基本维持在40%或20%弦长处不变。当激波位 置在该点之后时,二次漏流直接冲击激波结构;当激波位置在该点之前时,激波结构基本只受前缘 漏流的影响。 相似文献
23.
介绍螺桨转子系统颤振涡动的一种算法。本算法考察桨叶的振动变形,桨轴-支承系统的振动特性,以及螺转子的不平衡力。利用本算法对一模型螺桨转子和一实际螺桨转子进行了分析计算,对螺桨转子轴头动刚度、浆叶弹性变形、桨盘不平衡度等因素对螺桨转子系统颤振涡动的影响进行了分析,表明螺桨转子轴头动刚度下降时,螺浆发生颤振涡动的极限飞行速度下降。模型螺桨转子的计算结果与风洞试验结果相当吻合,证明本算法是正确的。 相似文献
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Grazing Bifurcation in the Response of Cracked Jeffcott Rotor 总被引:2,自引:1,他引:2
A cracked rotor is modeled by a piecewise linear system due to thebreath of crack in a rotating shaft. The differential equations ofmotion for the nonsmooth system are derived and solved with thenumerical integration method. From the simulation results, it isobserved that a grazing bifurcation exists in the response. Thegrazing bifurcation can give rise to jumps between periodic motions,quasi-periodic motions from the periodic ones, chaos, and intermittentchaos. 相似文献
27.
We show that the Dirac operator ${D = \sum_{0}^{7} e_k \frac{\partial}{\partial _{{x}_k}}}$ is orthogonal invariant. As an application, we give a new proof of the theorem in [7]. 相似文献
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合成了一种新螯合物,Cd(PMBP)_2(HPMBP),并进行了元素分析,IR,~1HNMR,TGA和DSC研究. 相似文献
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Li Cui Li Xu Hongxia Yu Qixiang Feng Huijiao Yan Shahid Aziz Qixu Chen Jibo Ren Xingmin Gao Daijie Wang 《Journal of separation science》2023,46(9):2300046
As a famous health food, roots of Panax quinquefolium L. possessed immune regulation and enhancement of the central nervous system, in which ginsenosides are the main active component with different numbers and positions of sugars, causing different chemical polarities with a challenge for the separation and isolation. In this study, a fast and effective bilinear gradient counter-current chromatography was proposed for preparative isolation ginsenosides with a broad partition coefficient range from roots of Panax quinquefolium L. In terms of the established method, the mobile phases comprising n-butanol and ethyl acetate were achieved by adjusting the proportion. Coupled with the preparative HPLC, eleven main ginsenosides were successfully separated, including ginsenoside Rg1 ( 1 ), Re ( 2 ), acetyl ginsenoside Rg1 ( 3 ), Rb1 ( 4 ), Rc ( 5 ), Rg2 ( 6 ), Rb3 ( 7 ), quinquefolium R1 ( 8 ), Rd ( 9 ), gypenoside X VII ( 10 ) and notoginsenoside Fd ( 11 ), with purities exceeding 95% according to the HPLC results. Tandem mass spectrometry and electrospray ionization mass spectrometry were adopted for recognizing the isolated compound architectures. Our study suggests that linear gradient counter-current chromatography effectively separates the broad partition coefficient range of ginsenosides compounds from the roots of Panax quinquefolium L. In addition, it can apply to active compound isolation from other complicated natural products. 相似文献