新型微带交叉耦合环微波带通滤波器

设计了一种新型交叉耦合结构带通滤波器,采用了凹槽环形式谐振器,使得获得同样的耦合系数新型结构相邻两环间的距离明显减小,因此这种滤波器具有小型化的优点。通过在传输函数中引入了两个传输零点,使得此种结构的滤波器具有更高的品质因数。利用电磁软件CST的分析给出了此种结构的耦合系数的结构参数,设计了一个工作在X波段的该结构带通滤波器,尺寸为5.9mm×5.9mm,带外抑制为25dB以上,带内插损为3.2dB,最后的实验结果与仿真曲线一致性较好。     

唐宋禅宗文献“自X”类词的历史形成

唐宋禅宗语言里“自后”、“自外”、“自余”一类词可以追溯到中古汉语。“自后”是由上古汉语以来的介词“自”组成的时间短语“自Y后(已后,而后)”在一定句法环境里省缩词化的结果;“自外”、“自余”缺乏相应的“自”字短语词化的历史语言基础,大约是受“自后”形成的类化影响而产生。     

就“3+X”谈高校教学改革的方向

从当今世界科技发展最新趋势的观点出发 ,结合发达国家基础科学的教学现状 ,发表了对当前我国高校教学改革方向的看法 ,并提出了一些建议 ,供教育决策部门参考     

元认知策略培养在“3＋1＋X”的大学英语教学模式中的作用

＂3＋1＋X＂的大学英语教学模式是一种基于课堂教学和网络学习相结合的新模式。元认知就是对认知的认知,元认知不是一个由准备、计划向评估过渡的线性过程,在一种外语学习中,有时可以同时应用到不止一种元认知策略。对学生进行元认知策略的培养可以更好地促进他们在这种新教学模式下进行自主学习、改善学习效果。     

现代汉语“好（你/一）个X”构式分析

汉语口语存在一个典型构式“好（你/一）个X”。在结构语义上该构式可以分化为三个小类：好（你）个＋消极性词语NP;好（你）个＋表人名词或短语NP;好（一）个＋NP/VP。构式“好（你/一）个X”的构式义是“结构赋义”的结果,三个小类在语境适切性、定指与不定指、焦点结构及主观性等方面各有其独特的语用特点。基于真实文本语料分析了构式的外部结构关系,“好（你）个X”通常前置,而“好一个X”倾向于陈述维度,可前置也可后置。最后分析讨论了构式形成的几个可能动因,如类推、非常规语序、反向认知、叠加强化和去范畴化等。     

论政府经济行为悖论——中国经济改革速度缓慢的原因之三

关于中国经济改革的大部分理论问题 ,经过近 2 0年的讨论 ,已基本论证清楚 ,剩下的问题则是政府如何做。政府经济行为的成败将取决于中国经济改革的成败与速度。本文讨论政府经济行为悖论的表现、原因、具体问题的解决办法 ,意在总结经验和减少失误出现的可能性     

Estimation in noncentral distributions

This paper investigates alternatives to MIU estimators in noncentral X ² and F distributions. Two directions are pursued. In the first, a general approach for uniformly improving on MVU estimators is described and illustrated. In the second, Bayesian, procedures are characterized and illustrated as well. This effort extends earlier work of Perlman and Rasmussen and of Neff and Strawderman.     

敦煌写本《古贤集》典出《史记》考

《古贤集》现存九个抄本,是敦煌遗书中一部重要的民间文学作品,也是唐五代民间流行的有关历史知识的蒙书之一。该作品的特点是大量运用典故,其中疑似出自《史记》者约15处。本文对这15处典故作了考论,求证了其实际情况。     

On the property of multivariate generalized hyperbolic distribution and the Stein-type inequality

This note consists of two parts . In the first part, we provide a pedagogic review on the multivariate generalized hyperbolic (MGH) distribution. We show that this probability family is close under margining, conditioning, and linear transforms; however, such property does not hold for its subclasses. In the second part, we obtain the Stein-type inequality in the context of MGH distribution. Moreover, we apply the Stein-type inequality to prove a lower bound for Var[h(X)]. Particularly, we present examples when X belongs to some well-known subclasses in MGH family.     

Distribution-free tests in randomized blocks

Classes of distribution-free tests are proposed for testing homogeneity against order restricted as well as unrestricted alternatives in randomized block designs with multiple observations per cell. Allowing for different interblock scoring schemes, these tests are constructed based on the method of within block rankings. Asymptotic distributions (cell sizes tending to infinity) of these tests are derived under the assumption of homogeneity. The Pitman asymptotic relative efficiencies relative to the least squares statistics are studied. It is shown that when blocks are governed by different distributions, adaptive choice of scores within each block results in asymptotically more efficient tests as compared with methods that ignore such information. Monte Carlo simulations of selected designs indicate that the method of within block rankings is more power robust with respect to differing block distributions.