强非局域非线性介质中高斯光束的传输特性

从Helmholtz方程出发，讨论了高斯光束在1＋1维强非局域非线性介质中的传输特性及其光束柬宽随位置的演化，即当介质的响应函数为高斯型时，用理论分析和数值模拟的方法，讨论了响应函数的特征宽度wm对光束传输的影响．     

Beauty is the promise of happiness?

We measure the impact of individuals' looks on life satisfaction and happiness. Using six data sets, from Canada, Germany, the United Kingdom, and the United States, we construct beauty measures in a number of different ways. Beauty raises happiness: A one standard-deviation change in beauty generates about 0.08 standard deviations of additional satisfaction/happiness among men, 0.07 among women. The finding is robust to a rare opportunity to measure it using an instrumental variables approach. Accounting for a wide variety of covariates, particularly educational, marital, and labor-market outcomes that might be affected by beauty, the gross effects are roughly halved, with small reductions arising from the impact of beauty on monetary outcomes.     

A Framework for Reconsidering the Lake Wobegon Effect

The Lake Wobegon Effect (LWE) describes the potential measurement-error bias introduced into survey-based analyses of education issues. Although this effect potentially applies to any student-report variable, the systematic overreporting of academic achievements such as grade point average is often of preeminent concern. This concern can be easily circumvented if official records data are available; however, many researchers can only access student-reported data. In this article, the authors examine whether using student-survey data in place of official records data meaningfully biases regression estimates. They motivate their contribution by noting a useful statistical feature of overreporting on bounded variables such as grade point average. Specifically, the misreports will be negatively correlated with the true grade point average, yielding a form of nonclassical measurement error that actually counteracts the bias. The authors connect this observation to reliability ratios used in labor economics, which are simple ways to adjust for attenuation bias, when needed. In two applications, we find that it is unnecessary to correct for the LWE bias because it is so small.     

Time Series Analysis of Repeated Surveys: The State–space Approach

Cross sectional estimates from repeated surveys form a time series { y_t }. These estimates can be viewed as the sum y _t = Y _t + e _t of two processes, { Y _t }, the population process and { e _t }, the survey error process. Serial correlations in the latter series are usually present, mainly due to sample overlap. Other sources of data such as censuses, administrative records and demographic population counts are also available. The state–space modelling approach to the analysis of repeated surveys allows combining information from different sources, incorporating benchmarking constraints in a natural way. Results from these methods seem to compare favourably with those from X-11-ARIMA in filtering out survey errors.     

文化翻译阐释中的文化失误——杨译“Manproposes，Heavendisposes”文化阐释的个案研究

人们大都认为杨宪益所译《红楼梦》中“Manproposes，Heavendisposes”一句谚语忠实传达了源语文化内涵。通过综合分析关键词Heaven在英语中的文化内涵以及英语本族者的语感证实，杨完益和戴乃迭用Heaven一词并没有像众多论者所认为的那样忠实地传达了源语中的文化内涵。     

North–South terms‐of‐trade trends from 1960 to 2006

The composition of exports of developing countries is increasingly dominated by manufactured goods. This has not changed the fact that their major trading partners continue to be the developed countries. In order to properly assess the distribution of gains from trade, there is a pressing need to analyze the movements in the terms of trade of developing countries with respect to the developed ones. A statistical analysis of the North–South terms of trade reveals that the terms of trade have turned against the South since the 1960s. However, the terms‐of‐trade deterioration is neither continuous nor evenly distributed over different country groupings. The existence of a structural break in the mid‐to‐late 1970s together with the greatest adverse terms‐of‐trade movements against the highly indebted and least developed countries attest the discontinuity and unevenness of this process.     

煤质化验中的误差的控制

煤质化验是一项技术性强、环节较多的工作,在采样、制备、化验的过程中,因煤的不均匀性,造成各个工作环节产生偏差。要对煤质常规化验操作化验员存在的突出问题进行分析,以保证煤质化验的测值准确,获得理想可靠的结果。本文主要阐述了煤质化验中采样、制样、干燥、分析等环节的误差控制。     

铁路三线大桥帽梁无支架法施工技术及受力检算

帽梁施工采用无支架法施工相对满堂支架法施工而言,具有施工简便,对地面承载力无要求,节约大量钢管,降低施工成本,缩短工期等优点。文章针对洛湛铁路旺甫1号三线大桥设计出穿心棒无支架法施工帽梁的支撑系统方案,成功地解决了三线大桥因帽梁砼重量大、跨度长而致使常用材料不适合做承托梁的问题,并对支撑系统进行了受力检算。     

津西钢铁异型坯中间包快换

为了节约中间包换包时间,提高连浇生产率,从而提高产量,津西钢铁集团与安徽工业大学共同开发异形坯连铸中间包快换技术,实现三机三流薄腹板异形坯连铸中间包快换的目的,减少铸机停机次数,提高异形坯连铸机的作业率,提高铸机产能。