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571.
针对以往基于质点速度波形测量使用拉格朗日分析法反推材料动态力学性能时,需作某种简化假定或者必须同时实测应力边界,而在实验过程中的边界应力数据在某些情况下测不到或测不准的状况.因此基于路径线法和零初始条件,提出了一种改进的拉格朗日分析法,新方法可不涉及边界应力,直接反推出材料高应变率下的动态应力应变曲线.并且运用该方法对有机玻璃材料的动态性能进行了数值模拟研究分析,其结果与运用特征线法求得到的数据非常吻合,从而证实了该方法的可靠性和有效性. 相似文献
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利用UG自带的STEP运动仿真函数可控制模型驱动的运动时间段,从而获得从动件在不同时间段运动变化规律的特点,分析了UG仿真模块中的运动控制函数,提出一种将运动函数模型转化为UG仿真模块内的STEP运动控制函数,以方便设计者更好地掌握机构的运动仿真变化规律.还阐述了在UG仿真模块中,如何使用STEP运动函数来控制曲柄摇杆机构运动时间以及对双摇杆机构在运动极限范围内的运动仿真. 相似文献
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Chang Sheng JIANG You Gui LI Chen JIANG Fang WANG Tian Pa YOU* Department of Chemistry Universtity of Science & Technology of China Hefei 《中国化学快报》2002,13(12)
Catalytic asymmetric cyclopropanation of diazoacetates with olefins has attracted much attention. Those catalysts containing various metals and optically active ligands have been employed for this reaction1,2. The first catalytic asymmetric cyclopropanation reaction was reported in 1966 by Nozaki et al.3. The author used the copper(II) complex 1 bearing a salicyladimine ligand as catalyst though with a low e.e. value of 6%. Aratani and his coworkers designed the copper-(Schiff-base) comp… 相似文献
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YE YANQIAN * 《数学年刊B辑(英文版)》1997,(3)
LIMITCYCLESANDBIFURCATIONCURVESFORTHEQUADRATICDIFFERENTIALSYSTEM(II)m=0HAVINGTHREEANTISADDLES(I)YEYANQIANAbstractAsaconti... 相似文献
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Jin Cui Ming Jie Zhang~* Xiang Qian Wang Nai Jing Cui School of Science Tianjin University Tianjin China 《中国化学快报》2008,(3)
By the addition of rice wine koji,enhancement of the reactivity was observed for the baker's yeast reduction ofβ-keto esters into (S)-β-hydroxy esters with high enantiomeric purity (73-98%). 相似文献
579.
Jian She Zhang Jiu Gao Yu~* Ying Wu Xiao Fei Ma School of Science Tianjin University Tianjin PR China 《中国化学快报》2008,19(4):395-398
In this paper,aliphatic amidediol was synthesized and mixed with glycerol used as a plasticizer for preparing thermoplastic starch(AGPTPS).The yield of aliphatic amidediol was 91%.FF-IR expressed that the mixture of aliphatic amidediol and glycerol formed stronger and stable hydrogen bond with starch molecules compared to the native cornstarch.By scanning electron microscope(SEM)native cornstarch granules were proved to transfer to a homogeneous continuous system.After being stored for a period time at room temperature,the mechanical properties of AGPTPS were also studied.As a mixed plasticizer,aliphatic amidediol and glycerol would be practical to extend TPS application scopes. 相似文献
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Hui Tang You Jun Zhou~* Yao Wu Li Jia Guo Lv Can Hui Zheng Jun Chen Ju Zhu~* Department of Medicinal Chemistry School of Pharmacy Second Military Medical University Shanghai China 《中国化学快报》2008,19(3):264-268
Novel chiral tetralin compounds were designed and synthesized, and their antifungal activities in vitro were tested. The results showed that all of target compounds had potent antifungal activities, and were stronger than that of control compounds tetrahydroisoquinolines. The binding model of lead molecules in the active site of CYP51 of Candida albicans showed that lead compound specifically interacted with the amino acids residues in the active site, without binding with the heme of CYP51, which was different from azole antifungal drugs. The present study might afford a novel lead molecule to develop non-azole CYP51 inhihitars of fungi. 相似文献