辐射场的有效源

给出时谐电磁场矢量的积分关系式，探讨了辐射场的有效源，并应用于几个实例的计算.     

高性能自动限电保护器的原理

本文较详细地就一种小型高性能自动限电保护器进行了探讨,并介绍了这种自动限电保护器的电路原理、功能和特点.     

Revisiting Nested Group Testing Procedures: New Results,Comparisons, and Robustness

Group testing has its origin in the identification of syphilis in the U.S. army during World War II. Much of the theoretical framework of group testing was developed starting in the late 1950s, with continued work into the 1990s. Recently, with the advent of new laboratory and genetic technologies, there has been an increasing interest in group testing designs for cost saving purposes. In this article, we compare different nested designs, including Dorfman, Sterrett and an optimal nested procedure obtained through dynamic programming. To elucidate these comparisons, we develop closed-form expressions for the optimal Sterrett procedure and provide a concise review of the prior literature for other commonly used procedures. We consider designs where the prevalence of disease is known as well as investigate the robustness of these procedures, when it is incorrectly assumed. This article provides a technical presentation that will be of interest to researchers as well as from a pedagogical perspective. Supplementary material for this article is available online.     

Adolescents gradually improve at detecting trustworthiness from the facial features of unknown adults

People can (to some extent) detect trustworthiness from the facial features of social partners, and populations which underperform at this task are at a greater risk of abuse. Here we focus on situations in which adolescents make a decision whether to trust an unknown adult. Adolescents aged 13–18 (N = 540) played a trust game, in which they made decisions whether to trust unknown adults based on their picture. We show that trusting decisions become increasingly accurate with age, from a small effect size at age 13 to an effect size 2.5 times larger at age 18. We consider the implications of this result for the development of prosociality and the possible mechanisms underlying the development of trustworthiness detection from faces.     

也评《唯物中文字典》的编码一检索法

本文在肯定《唯物中文字典》所用的部码类汉字编码法的优点的同时对关于它优于同类的汉字编码法及其他编码法一说加以辨析，主要是将之与部码类的《表形码编排汉语字典》及用角码类的四角号码法的一些数据作出统计比较。本文还指出《唯物中文字典》的一些存在问题，并对如何充分发挥其特有的编码法之优势提出具体而微的改进方案。     

Decomposition of Scatter Ratios Used in Monitoring Multivariate Process Variability

Wilks’ ratio statistic can be defined in terms of the ratio of the sample generalized variances of two non-independent estimators of the same covariance matrix. Recently this statistic has been proposed as a control statistic for monitoring changes in the covariance matrix of a multivariate normal process in a Phase II situation, particularly when the dimension is larger than the sample size. In this article we derive a technique for decomposing Wilks’ ratio statistic into the product of independent factors that can be associated with the components of the covariance matrix. With these results, we demonstrate that, when a signal is detected in a control procedure for the Phase II monitoring of process variability using the ratio statistic, the signaling value can be decomposed and the process variables contributing to the signal can be specifically identified.     

A NOTE ON ESTIMATING THE NUMBER OF SUPERIMPOSED EXPONENTIAL SIGNALS BY THE CROSS-VALIDATION APPROACH

In this paper, a procedure based on the delete-1 cross-validation is given for estimating the number of superimposed exponential signals, its limiting behavior is explored and it is shown that the probability of overestimating the true number of signals is greater than a positive constant for sufficiently large samples. Also a general procedure based on the cross-validation is presented when the deletion proceeds according to a collection of subsets of indices. The result is similar to the delete-1 cross-validation if the number of deletions is fixed. The simulation results are provided for the performance of the procedure when the collections of subsets of indices are chosen as those suggested by Shao [1] Shao, J. 1993. Linear model selection by cross-validation. J. Amer. Statist. Assoc., 88: 486–494. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]in a linear model selection problem.     

试论史学界的“炒古”现象——从《华夏探源》说起

史学研究的目的是探究历史的真面目,而不是为了世俗名利。近年来,中华民族的源头问题是史学研究的热门话题,许多学者进行了艰苦的研究,并取得了重大成果。然而,有人盲目信古、复古,发表没有科学根据的言论,再加上媒体盲目的炒作,使史学研究走入歧途。《华夏探源》一书提出了许多令人费解的所谓“新观点”,出现了很多常识性的错误,但还能顺利出版,并得到媒体的大力推荐,这是作为“史学工作者”和新闻工作者缺乏史德、盲目“炒古”的表现。为了制止“炒古”现象,使史学研究走向正轨,需要国家、史学研究者和新闻工作者共同努力承担起各自的责任。     

Adaptive Percolation Using Subjective Likelihoods

A phenomenon that I call “adaptive percolation” commonly arises in biology, business, economics, defense, finance, manufacturing, and the social sciences. Here one wishes to select a handful of entities from a large pool of entities via a process of screening through a hierarchy of sieves. The process is not unlike the percolation of a liquid through a porous medium. The probability model developed here is based on a nested and adaptive Bayesian approach that results in the product of beta-binomial distributions with common parameters. The common parameters happen to be the observed data. I call this the percolated beta-binomial distribution . The model turns out to be a slight generalization of the probabilistic model used in percolation theory. The generalization is a consequence of using a subjectively specified likelihood function to construct a probability model. The notion of using likelihoods for constructing probability models is not a part of the conventional toolkit of applied probabilists. To the best of my knowledge, a use of the product of beta-binomial distributions as a probability model for Bernoulli trials appears to be new. The development of the material of this article is illustrated via data from the 2009 astronaut selection program, which motivated this work.     

《辞源》通假字注释例商

《辞源》（修订本）是今人阅读古代典籍无可替代的权威工具书,但由于历史的局限,它在收词、释义、书证等方面,还存在着不能尽如人意的地方,尤其在通假字解释方面存在着本借字互倒和以通假字术语说解同义词、古今字、假借字以及解说自相矛盾等情况,有进一步补正之必要。