三维涡流场基于有限元法的电磁位对

介绍了用有限元法解决三维涡流场问题时电磁位对的优选问题,分析了其适应情况和优缺点.对目前基于有限元法的三维涡流场数值分析方法的国内外现状作了综合评述.     

识字教学:建构科学的发展之路

汉字是一种“复脑文字”，是音形义的结合体，识字教学是小学阶段语文教学的重点和难点，但对识字教学我们缺少一些科学的研究和实践。教学中一些识字方法，虽然对科学识字进行了积极的探索，但这些识字方法又存在一定的不足。只有建构起科学的识字教学体系，从汉字本身的识记规律出发，从儿童的认知、发展规律出发。对识字量、字种、字序上做出科学的定位，才能提高识字教学的效率。     

论加强和改进大学生教育与管理工作

从四个方面阐述了如何加强和改进大学生教育与管理工作,其中大学生教育与管理的机构设置是前提、队伍建设是保证、工作原则是方向、工作方法是关键。在大学生教育与管理工作中,必须解放思想、实事求是、与时俱进,不断探索和解决大学生教育与管理新的课题。     

Automatic selection of the proper family for simultaneous confidence intervals

Statisticians often employ simultaneous confidence intervals to reduce the likelihood of their drawing false conclusions when they must make a number of comparisons. To do this properly, it is necessary to consider the family of comparisons over which simultaneous confidence must be assured. Sometimes it is not clear what family of comparisons is appropriate. We describe how computer software can monitor the types of contrasts a user examines, and select the smallest family of contrasts that is likely to be of interest. We also describe how to calculate simultaneous confidence intervals for these families using a hybrid of the Bonferroni and Scheffé methods. Our method is especially suitable for problems with discrete and continuous predictors.     

大熊猫主食竹种微量元素研究

用原子吸收分光光度法测定了卧龙自然保护区大熊猫主食竹种——冷箭竹(Bashania fangiana)、拐棍竹(Fargesia robusta)、华西箭竹(Fargesia nit-ida)、峨眉玉山竹(Yushaia chungii)的叶、笋——幼竹、一年杆、二年杆兵208例中的 Cu、Zn、Mn、Fe、Ca、Mg、K 等七种元素含量.找到了微量元素含量与竹类、竹龄、竹株部位、竹的生长环境(海拔高度、季节)以及与大熊猫食性等的关系。     

蓝宝石微带色散特性研究

本文将谱域导纳法推广应用于各向异性介质基片微带,通过详细的理论分析,导出了各向异性等效传输线的特性导纳公式,并考虑了导带厚度的影响,建立了各向异性介质基片平面传输线传播常数色散特性的计算机程序。用本文推导的结果进行数值计算,在2-18GHz内求得的蓝宝石微带色散曲线与文献[1]的结果吻合得很好。此外,本方法直接、简明、且计算量小、适用于各类微波平面传输线的分析。因而,其具有较大的工程实用价值。     

选择价值工程改进对象的动态排序模型

从一个复杂系统中,合理地选择重点改进对象,是有效开展价值工程活动的基础。本文在分析最合适区域法存在的问题的基础上,提出选择价值工程改进对象的动态排序模型。     

STEIN'S METHOD AND THE BERRY-ESSÉEN THEOREM

Stein's method is used to prove the Lindeberg-Feller theorem and a generalization of the Berry-Esséen theorem. The arguments involve only manipulation of probability inequalities, and form an attractive alternative to the less direct Fourier-analytic methods which are traditionally employed.     

Long-range correlation analysis of the Wichmann-Hill random number generator

The distribution of points (r _n,r _n+s), n = 0, 1, 2,...whose coordinates are terms at distance s of the pseudorandom sequence generated by the Wichmann and Hill method is studied. It is known that for many congruential generators critical values of the distance s exist such that these points, far from being uniformly distributed, are concentrated on very few lines. An algorithm is described for computing the critical distances within the Wichmann-Hill sequence and the results obtained are compared with those of other linear congruential generators.     

The strong uniform convergence of multivariate variable kernel estimates

We show that sup, completely as, where f is a uniformly continuous density on are independent random vectors with common density f, and f_n is the variable kernel estimate Here H_ni is the distance between X_i and its kth nearest neighbour, K is a given density satisfying some regularity conditions, and k is a sequence of integers with the property that log asn