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71.
72.
Qing-Wen Gui Fan Teng Hao Yang Changping Xun Wen-Jie Huang Zi-Qin Lu Meng-Xue Zhu Wen-Tao Ouyang Wei-Min He 《化学:亚洲杂志》2022,17(1):e202101139
With eco-friendly and sustainable CO2-derived dimethyl carbonate as the sole solvent, the visible-light-induced cascade radical reactions have been established as a green and efficient tool for constructing various CHF2/CClF2/CBrF2-substituted ring-fused quinazolinones. 相似文献
73.
Chemical study of the whole plants of Sarcandra hainanensis yielded two new biflavonoids with a flavan-flavanone skeleton, sarcandrone C (1), D (2) and 6 known compounds (3-8). Structures were elucidated on the basis of NMR spectroscopic methods. 相似文献
74.
A facile way has been developed to provide a series of novel chiral N-(4-(piperidin-1-yl)pyridin-2-yl)amide derivatives as potential stereoselective catalysts. The key intermediate, 2-amino-4-piperidinyl pyridine, was obtained by nucleophilic substitution of 2-amino-4-chloropyridine with piperidine in good yields (up to 96%). The total control of enantioselectivity was obtained for the synthesis of L-proline and (R)-1,1′-bi(2-naphthol) derivatives. 相似文献
75.
76.
Time Rates of Hill's Strain Tensors 总被引:4,自引:0,他引:4
Based on Hill's principal components formulae, two kinds of basis-free time rate formulae for Hill's strain tensors are proposed
in this paper, which are obtained for the cases of distinct stretches, double coalescence and triple coalescence. Furthermore,
relations between the coefficients in the representation for the strain tensor and its time derivative are disclosed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
77.
78.
Yong-Ming Zhao Yu-jin Wang Mei Dong Man-Li Zhang Chang-Hong Huo Yu-Cheng Gu Qing-Wen Shi 《Chemistry of Natural Compounds》2010,46(3):373-376
Two new eudesmanes, 1α-hydroxy-11,13-dihydroisoalantolactone (1), 3α-hydroxy-11,13dihydroalantolactone (2), and one known compound were isolated from the roots of Inula helenium. Their structures were established on the basis of
spectral evidence. 相似文献
79.
80.
In this paper, the Gibbs-Appell' s equations of the nonholonomic controllable mechanical systems with variable mass in terms of quasi-velocities and quasi-accelerations are obtained, and the application of the new equation is illustrated by an example.The project was Supported by the Heilongjiang Natural Science Foundation 相似文献