The density of social networks moderates effects of intergroup contact

This study tests how the density of the social network in which intergroup contact takes place might affect the extent to which contact improves intergroup attitudes. Having contact with more outgroup members in dense social networks, in which everybody knows each other, may reinforce contact's positive effect. In this case, outgroup contact is shared with ingroup members, which suggests positive ingroup norms toward the outgroup. Alternatively, more contact in denser networks may improve intergroup attitudes less because density may increase subtyping or reduce the salience of ethnic group memberships. These competing hypotheses are tested among white American adults in a nonprobability online sample (N = 305) and in a representative national sample (N = 1270). In both studies, contact is associated with more positive attitudes toward racial outgroups but the positive contact effect is weakened if that contact takes place in a denser social network.     

提高切削加工表面质量方法的探讨

机械零件加工表面质量的好坏,对零件的使用性能有很大的影响。本文主要探讨已加工表面的形成过程,已加工表面质量的影响因素以及提高切削加工表面质量的一些方法。     

论强国富民离不开美育

美育有助于提高生产力.从社会的发展趋势来看,美育和科学技术愈来愈紧密地融合.美育和科学技术融合有深厚的理论基础.培养人才离不开美育,美育和创造性人才有内在的心理联系.将美育真正融入学校、家庭、社会,全面提升学生素质是切实可行的.     

EXCEL在角度转换中存在的问题及解决的方法

EXCEL在工程领域应用广泛,但它在角度不同单位间的转换过程中,当以度分秒为单位的角度值的秒位数为零转换成以度为单位的数值时,会出现较大的误差,甚至达 38″或-61″。对于严密工程如精密机器安装定位、公路铁路等地下隧洞控制测量及贯通等,这个误差的影响会造成比较严重的后果。提出了角度不同单位间的转换公式,同时也分析了出错的原因和解决的办法。     

Helical angle measurement of worm by a coordinate measuring machine and its uncertainty evaluation

The purpose of the study concerns the measurement of worm’s helical angle by a coordinate measurement machine in the ambient industrial environment. The novel measurement method and sampling strategy were described firstly. This method used the coordinate measurement machine to measure both of the worm gear’s left and right surfaces. The worm surface was reconstructed based on the measured data of all the sampling points. Then a middle cylinder was established to truncate the fitted worm surfaces, and the truncated spiral lines were straightened to calculate the helical angle. The measurement uncertainty of worm’s helical angle was evaluated by taking the difference of calculated helical angles along the truncated spiral lines on both the left and right side surfaces of the worm. Twenty-four measurement experiments show that the maximum measurement error of the proposed method is 0.105, and the measurement error ratios are all less than 3.5?. The result means that the measurement method can realize the precision measurement of worm’s helical angle and can be employed in the generally industrial application.     

说话者指称第三者时的视点选择研究

说话者指称第三者时有三个视点可供选择,即第一人称视点、第二人称视点和第三人称视点。通过研究具体言语行为中指称第三者时人称视点的选择情况,我们发现,视点的选择主要受到三条语用原则的支配：亲疏原则、地位原则和目的性原则。     

Simulation of Fragment Impact on Multi-Layer Targets Using Contact Method

Cased explosives generate highly energetic fragments as their casing breaks up. Due to the complexity of casing fragment related behavior such as embedment, perforation and ricochet, it may be insufficient to use equivalent triangular pressure loading in fragment impact simulations. This simplified method may over- or under-predict the target response. Recently, a procedure using contact techniques has been proposed to overcome such difficulties. It has been shown that the new method has the inherent capability in modeling the multi-piece and multi-hit fragment impact problems in a more realistic way. To investigate the applicability of the proposed method to simulations involving multi-layer penetration, the selected problems of fragment impact on multi-layer targets are described in this paper. It is demonstrated that this method is capable of predicting the complicated multi-layer structural response caused by fragment impact and penetration. Modeling procedures and some technical issues are also discussed.     

C语言计算X射线Bragg's角的探讨

X射线衍射Bragg's角计算,公式比较复杂,难以准确地得出Bragg's角.利用X射线衍射图形与晶体结构关系,使用C语言设计程序,不仅能节约时间,而且能够简单明了而又准确地得出结论.     

好氧生物处理实验的研究

介绍了具有代表性的好氧生物处理的两个典型实验的方法,讨论了作为研究生阶段开设这两个实验的具体的实验内容以及最佳运行方案。     

保险合同中违反告知义务的构成要件分析

保险合同中违反如实告知义务的构成要件是：违反如实告知义务的主体是投保人或被保险人；违反告知义务的范围仅限于保险人询问的范围；过失违反告知义务的事实应当是重要事实；投保人、被保险人违反告知义务是出于主观上的故意或过失。