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我们日常办公经常要用到Word97,笔者在使用Word97当中体会到一些能够简化工作、提高速度的方法,现将几点体会与读者共享。1关于Word97中的表格平时,我们经常要用到表格,但是在表格的使用中还是有一些不尽如人意的地方,使得表格不够美观或不能完全达到使用者的要求,下面向大家推荐几种常用的表格处理方法。1.1表格的居中选定表格之后,按“格式”工具栏中的“居中”按钮。但是,最省事的办法是在插入表格之前预先按下此钮。1.2表格内容的居中1.2.1水平居中选定表格内容(或部分表格内容),按“格式”工… 相似文献
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Based on the primitive equations in polar coordinates, supposing that parcel velocity in tropical cyclones is in linear variation and that the distribution of surface pressure agrees with the Fujita formula, a set of equations are derived, which describe the impact of perturbations of central pressure, position of tropical cyclones, direction and velocity of movement of tropical cyclones on the wind field. It is proved that the second order approximation of the kinetic energy of tropical cyclones can be described by the equations under linear approximation. Typhoon Wipha (2007) is selected to verify the above interpretation method, and the results show that the interpretation method of the wind field could give very good results before the landfall of tropical cyclones, while making no apparent improvement after the landfall. The dynamical interpretation method in this paper is applicable to improving the forecasts of the wind field of tropical cyclones close to the coast. 相似文献
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矿体受元古界高黎贡山群下亚群第三层的层间破碎带及大理岩双重控制。大理岩破碎带为良好容矿空间,姚家坪岩体提供矿质。 相似文献
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Ultraviolet (UV) solar radiation has a significant influence on human health, the environment and climate. A series of measurements, including UV radiation (290 400 nm) and global solar radiation (Rs), were continuously recorded from August 2004 at the Lhasa and Haibei sites on the Tibetan Plateau. Both observation sites' altitudes are above 3000 m and have similar meteorological conditions. The data from 2005 2006 was used to identify the varying characteristics of UV radiation. It's relation to the clearness index Ks, the relative optical mass mr, and Rs were established. The annual mean values of total daily UV radiation are 0.92 and 0.67 MJ m^-2 at Lhasa and Haibei, respectively. The UV radiation in Lhasa represented 4.6% of the global solar radiation while in Haibei this percentage was 4.2%. In the case of clear days (Ks 〉 0.8), these percentages ranged between 4.0% and 4.5% in Lhasa and between 5.1% and 5.5% in Haibei. In the case of cloudy days (Ks 〈 0.4), these percentages ranged from 4.4% to 6.8% in Lhasa and from 5.1% to 5.5% in Haibei. The maximum values of UV radiation for each relative optical mass diminished exponentially with mr. Thus, for Lhasa and Haibei, UV=46.25mr-129, and UV=51.76mr-142, respectively. The results of this study can be used to obtain more UV radiation data for the study of UV climate characteristics, the effects of UV on ecological processes and the feedback of the thinning of the stratospheric ozone, from more routine measurements Rs data. 相似文献
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自然过程大都具有非线性非平稳性,一种自适应数据分析方法对于分析这些过程来说是极其必要的。Huang于1998年创立的H ilbert-Huang变换(HHT)就是这样一种自适应性非线性非平稳数据分析方法,该方法由经验模态分解(EMD)和H ilbert变换两部分组成。文中首先详细解释了HHT的思想和基本理论;然后介绍了该方法近期的重要研究进展,列举了其在科研和工程领域的应用;最后,对方法中仍然存在的问题进行了讨论。 相似文献