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41.
Proton and carbon-13 chemical shifts of para-substituted stilbenes have been measured. 1H-1H, 1H-13C COSY spectra were obtained to analyze unambiguously the chemical shifts of protons and carbons. A long range coupling between 2-H and α-H was observed in a 1H-1H COSY spectrum. The observed chemical shifts have been correlated with Hammett substituent parameters. Among ethenyl protons and carbons, all but the chemical shifts of α-H show good correlation with both dual substituent parameters and single substituent parameters. In addition to this finding, the excellent linear correlations of C-l, and 4′-H of 4-substituted trans-stilbenes are also reported. Besides the correlations of chemical shifts with Hammett parameters, a good correlation between the chemical shifts and the calculated charges of position C-4′ are reported. 相似文献
42.
色彩是生活中必不可少的元素,由于中国传统文化与西方文化有极大的差异,人们对颜色有着不同的理解和审美取向。掌握颜色词在不同文化中的不同含义有助于促进跨文化交际的顺利进行。 相似文献
43.
刘芳 《南阳理工学院学报》2010,2(5):121-125
意象是诗歌的灵魂和生命,是诗人主观情思的载体。汉英民族有着各自不同的文化背景和审美情趣,因此,汉英诗歌爱情意象词语的选取和解读必然受到汉英民族不同文化的制约。 相似文献
44.
明末传教士的汉语罗马字注音方案是研究明末官话的重要材料。要利用这些材料研究明末官话,首要的工作是考察各个方案所依据的源语言。杨福绵先生提出罗氏方案是“根据十六世纪意大利语及葡萄牙语字母的拼音”。而学界对利、金二人方案所依据的源语言尚未有定论。文章首次提出利、金方案乃依据当时葡萄牙语拼音,为金氏一字符母分“甚、次、中”找到依据,澄清前说,并为构拟明代官话音值提供参考。 相似文献
45.
John Noonan 《Journal of Difference Equations and Applications》2013,19(4-5):355-377
Th powerful (and so far under-utilized) Goulden—Jackson Cluster method for finding the generating function for the number of words avoiding, as factors, the members of a prescribed set of ‘dirty words’, is tutorialized and extended in various directions. The authors' Maple implementations, contained in several Maple packages available from this paper's website www.math.temple.edu/zeilberg/gj.html, ar described and explained. 相似文献
46.
通过对《岁月无悔》的文本分析,解读作为改革者和启蒙者的李增文,阐释了他的改革理想和启蒙理念;从官方话语的积极性和推动性的角度诠释了官方话语对李增文的正面意义和必要的存在;在《岁月无悔》的叙事中,谭践进行了多样化的艺术探索。《岁月无悔》是当代报告文学发展的一个风向标。 相似文献
47.
Generally, text proofreading consists of two procedures, finding the wrongly used words and then presenting the correct forms. At present, most of the Chinese text proofreading focuses on finding the wrongly used words, but pays less attention to correcting these errors. In this paper, the Chinese text features are interpreted first and then a Chinese text proofreading method and its algorithm are introduced. In this algorithm, text features, including text statistical feature and language structure feature, are properly used. Here, correcting errors goes on at the same time with finding errors. Experimental results show that this method has a performance of detecting 75% of wrongly used Chinese words and correcting about 60% of them with the first candidates. 相似文献
48.
层状三元材料LiNi0.8Co0.15Al0.05O2(NCA)具有高能量密度和高比容量,在电动汽车领域占据重要地位.但是较差的容量保持率和热安全问题限制了其应用. 本文研究了18650型NCA/graphite(2.4 Ah)锂电池分区间循环容量衰退机理和热行为. 所考虑的荷电状态(state of charge,SOC)区间有0% ~ 20%(低)、20% ~ 70%(中)、70% ~ 100%(高)及0% ~ 100%(全)四个区间. 为了获得电池在不同SOC区间循环后衰减状况,以100个循环为一个周期,每个循环周期结束后,在25 oC下测试四个电池的基础特性,包括容量、容量增量(incremental capacity,IC)、电阻及电化学阻抗谱(electrochemical impedance spectroscopy, EIS),同时监测电池放电时的温度来讨论电池不同区间循环后的热行为. 测试结果表明,电池在全区间循环会降低电池寿命,而在非全区间循环的电池都能一定程度上减缓电池衰老的速度. 另外,全区间循环热特性最差而中端循环则表现出较好的热性能,对容量增量曲线分析发现,在高中低区间的性能衰退的主要原因是活性锂离子的损失,而在全区间还包括活性材料的损失和反应内阻的增大. 相似文献
49.
王希恩 《广西民族大学学报》2007,(3)
少数民族城市化进程中发生的各类矛盾和纠纷其实都可归结为两个方面的问题:一是现有的城市环境不利于少数民族的融入;二是少数民族自身对于既有城市环境的不适应。前者涉及城市建设的模式或目标设计问题,后者涉及少数民族城市化中的素质准备问题。解决好这两个问题是推进少数民族城市化进程的两大基本环节。 相似文献
50.