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Abstract: Several β-aromaticamino ketones,which were designed according to some hypothetical models of the cyclooxygenase and 5-lipoxygenase active sites,were synthesized by an amino exchange reaction.The structures of the eight new compounds were confirm
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文摘:根据环氧化酶、5-脂氧化酶活性中心结构模型设计了一组β-芳胺酮类化合物，并用胺交换反应合成了这些化合物.经红外光谱、核磁共振氢谱及元素分析证实了8个未见文献报道的化合物的结构.药理实验结果显示.部分受试化合物在巴豆油诱发小鼠足趾肿胀模型中表现出一定的抗炎活性. |
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Abstract: Shear force is interrelating with width and thickness of plate and obliquity of knife-edge.
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文摘:斜刃剪切时，剪切力的大小与板料的宽度、厚度及斜刃倾角有关。 |
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Abstract: Shuangzengji was sprayed upon indica rice Shanyou 63 and wheat variety 8504 at the beginning of rice heading and full-earing stag e of wheat respectively,to study the biological effects on rice and wheat.Water was used as control.The results ind
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文摘:以水稻品种汕优63、小麦品种8504为材料，在水稻抽穗始期、小麦齐穗期喷施增粒增重剂(简称双增剂)，清水做对照，研究其对稻麦的生物学效应，试验结果表明：双增剂能明显提高籽粒充实度、结实率和千粒重。 |
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Abstract: Si-based photodetectors are the most promising devices for photoelectronics which can be integrated with microelectronics.
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文摘:硅基长波长光电探测器是最有希望与微电子集成的一种用于光通信的光电器件。 |
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Abstract: Simulated annealing and multigroup parallel evolution are two helpful methods which can improve the performance of genetic algorithm.These two ideas are well combined in this paper,and a new algorithm is derived,that is the multigroup parallel g
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文摘:模拟退火和多种群并行遗传进化是两种较好的改进遗传算法性能的方法.将这两种思想有机地结合起来,提出了一种基于模拟退火机制的多种群并行遗传算法.仿真结果表明,该算法不仅能增强算法的全局收敛性,还能加快遗传进化速度,得到满意的全局最优值. |
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Abstract: Since 1996, In ZF Friedrichshafen AG, Environmental management system based on the international standard ISO14001 have been installed.
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文摘:自1996年起，在ZF，建立在ISO14001基础上的环境管理系统已经完成。 |
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Abstract: Since commercial function is a mainstay of modern urban development, the overall conception of commerce reconstruction should be outlined through the characteristics and trend of urban development, then seeking the countermeasure on the basis of
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摘要：商业功能是现代都市发展中的一个重要支撑因素，为此，就需要从都市发展的特征与趋势中去勾勒商业功能再造的整体构想，并在商业功能再造条件的基础上去探寻对策路径。 |
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Abstract: Since lake eutrophication was first taken into consideration, scientists had managed to simulate the appearance of lake eutrophication, predict the response of lakes to different management through mathematical models, thereby determining the pr
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文摘:自从湖泊富营养化引起人类注意以来，科学家们就设法通过使用数学模型来模拟湖泊富营养化的发生，预测湖泊对不同管理措施的响应，以便找出合理的治理措施。 |
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Abstract: Since piezoelectric resonant filter can not effectively prohibit higher-frequency harmonic,the mechanism of this problem has been discussed by means of a specific example which shows that there exists lots of undesirable resonant frequencies of
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文摘:提出压电谐振滤波器不能很好地滤除高频谐波的问题,结合一个具体例子理论推导了压电谐振滤波器存在许多干扰谐振频率,从而不能有效滤除一些特定频率的干扰信号.为了解决这个问题,提出一种改进型的静电激励谐振滤波器.为了说明其可行性,具体分析了改进型双端固支微梁静电激励谐振滤波器,理论推导证实基于双端固支微梁的各阶振型正交的原理,通过适当调整激振电容的间距,双端固支微梁的高阶振动模态受到很好的抑制,因此这种谐振滤波器可以有效阻止滤波器中心频率的高频谐波的通过. |
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Abstract: Since the 20th century, a great progress has been made in research on infiltration and runoff yield.
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文摘:20世纪以来，入渗与产流研究取得了长足进展。 |
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Abstract: Six compounds were isolated from the whole herb of Phyllanthus urinaria L..On the basis of physical and chemical properties and spectra data,they were identified as ethyl brevifolincarboxylate(1),brevifolin(2)，corilagin(3)，protocatechuic acid(4)
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文摘:从叶下珠中分离得到6个化合物，根据理化数据和光谱方法鉴定为短叶苏木酚酸乙酯(1)、短叶苏木酚(2)、柯里拉京(3)、原儿茶酸(4)、没食子酸(5)和鞣花酸(6).其中(1)、(3)、(4)为本种植物中首次分离.根据2D-NMR修正了文献中化合物(1)和(2)的部分碳信号归属错误，归属了化合物(3)的碳氢谱数据. |
