Prismatic Metropolis: Race and Residential Segregation in the City of the Angels

Most major urban areas remain segregated by race, especially in terms of black segregation from whites. We replicate and extend the innovative approach developed by Farley and colleagues for understanding processes of racial residential segregation with data collected in Los Angeles. Using a large (N = 4025) multiracial sample of adults, we examine (1) actual and perceived differences in economic status, (2) mutual preference for same race neighbors, and (3) racial prejudice and discrimination as hypotheses for the persistence of residential segregation. With a systematic experimental design we gauge respondent openness to living in areas with varying proportions of black, white, Latino, or Asian neighbors. We find no support for actual or perceived cost of housing as a barrier to integration. Although all groups exhibit some degree of ethnocentric preference for same race neighbors, this tendency is strongest among whites rather than blacks and plays only a small role in perpetuating segregation. Blacks face the greatest hostility in the search for housing and are consensually recognized as most likely to face discrimination in the housing market. Racial minorities are more open to sharing residential space with whites than with other minorities. We find generally higher rates of openness to integration than Farley and colleagues found in their recent Detroit survey.     

Racism, conservatism, Affirmative Action, and intellectual sophistication: A matter of principled conservatism or group dominance?

Using data from 3 different samples, the authors found that: (a) the relationships between political conservatism and racism generally increases as a function of educational sophistication; however, the relationship between political conservatism and anti-Black affect did not increase with educational sophistication. (b) The correlation between political conservatism and racism could be entirely accounted for by their mutual relationship with social dominance orientation. (c) Generally, the net effect of political conservatism, racism, and social dominance orientation on opposition to affirmative action increased with increasing education. These findings contradict much of the case for the principled conservatism hypothesis, which maintains that political values that are largely devoid of racism, especially among highly educated people, are the major source of White's opposition to affirmative action. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

科普服务发展与新模式研究

近年来,欧美国家的科普场馆已经在探索面向学校、面向家庭、面向社区和面向社会的科普服务新模式,它们更加强调受众群体的“亲历”和“参与”,并提出了“体验型”的科学传播方式。本文是对国外科普场馆的科普服务新模式研究的阶段性研究成果介绍,以期为我国科普教育场馆服务内容的拓展与创新提供借鉴。     

地下建筑火灾烟气的特点及防排烟措施

通过对地下建筑火灾烟气的特点及危险性分析,指出控制烟气流扩散是地下建筑防火的重点问题。从重视火灾的预防与扑救初期火灾角度出发,提出在地下建筑中应实施合理的防烟、排烟措施,以达到地下建筑防火、防烟和安全使用的目的。     

多因素影响下红陶制品脆值的研究与应用

为了探究结构因素对红陶制品脆值的影响并精确化红陶制品脆值,提出一种通过离散红陶制品为陶片单元来估算其脆值的方法。以红陶片为研究对象,通过单因素试验和L27(313)正交交互试验探究质量、宽厚比和曲率及其交互作用对脆值的影响规律,利用Ansys仿真与试验得到不同陶片脆值。单因素试验结果表明,质量与脆值呈负相关,宽厚比与脆值呈正相关,随着曲率的增加,脆值先增大后减小,在24 m-1有最大值。由正交交互试验得出,各因素及其交互作用对脆值的影响次序由大到小依次为：质量、宽厚比、曲率、质量×曲率、质量×宽厚比、宽厚比×曲率。单个因素对陶片的影响更显著,故在精确陶制品脆值时,应优先考虑单个因素的影响。对8组试样的试验结果与仿真结果进行对比,得到二者最大误差为5.1%,证明了仿真的可靠性。     

基于STM32的频率和功率可调非接触供电超声电源设计

为解决接触式供电中漏电、磨损、电能传输不良以及超声电源在加工中谐振频率漂移、跟踪速度慢、输出功率不稳定等问题,文章以STM32单片机作为主控系统,设计了一种频率和功率可调的非接触供电超声电源。根据采样反馈电路采集的电压电流相位差和有效值信号,采用锁相环和模糊比例积分(Proportional Integral, PI)控制相结合的方法对频率进行跟踪,并用传统 PI 控制法控制输出功率。在 Matlab 软件中搭建电源仿真模型,利用附加电阻、附加电感和附加电容模拟加工过程中负载参数的突变,对有频率调节和功率控制子系统以及没有子系统的电源模型分别进行仿真。仿真结果表明,电源输出功率稳定在 248 W。当负载参数发生改变时,电源的谐振频率发生漂移,经过频率自动跟踪子系统的调节后,电源在 0.01 s 后重新回到谐振状态。此控制算法实现了频率快速跟踪和功率控制。     

轧制与退火对T9S钛合金板材组织与性能的影响

研究了轧制变形量及退火温度对T9S钛合金板材显微组织和室温力学性能的影响。结果表明:增加成品轧制变形量,板材组织破碎更充分,退火后形成等轴α相、拉长α相和晶间β相组织形貌,变形流线比较明显,板材室温强度和硬度升高,伸长率降低,弹性模量增加。随着退火温度升高,板材室温强度和硬度逐渐降低,伸长率逐渐提高,横向弹性模量逐渐减小,纵向弹性模量先增加后减小。经(750~790) ℃×45 min空冷退火处理后的板材可以获得较好的强度和塑性的匹配。     

用好任务栏的锁定功能

正从Windows 7开始,任务栏功能有所增强。而我们印象最深的可能就是任务栏锁定程序图标的功能。其实,除了锁定程序图标外,任务栏锁定功能还有不少值得推介的用法。任务栏锁定的几个内在用途除了程序安装后会自动锁定图标到任务栏,以及用户自行拖动程序到任务栏锁定外,任务栏锁定还有其他的用法。以下均以Windows 8.1为例说明。     

倾斜耦合的光栅耦合器研究进展

近年来,片上光子集成技术备受关注并飞速发展,但在光纤与芯片、芯片与芯片上实现高效、高可靠性的光耦合仍是难题。光栅因其制作简单,位置灵活,对准容差大及可实现片上测试等一系列优点而备受研究者的关注。目前在绝缘体上硅(SOI)平台和绝缘体上铌酸锂(LNOI)平台上已开发出大量的光栅耦合器件,并获得较高的耦合效率和大带宽。该文主要介绍光栅耦合器的工作原理和主要性能指标,阐述了均匀光栅、倾斜光栅、闪耀光栅和切趾光栅耦合的特点及现阶段进展,并对具有代表性的一维光栅性能指标进行了比较。结果表明,分布式布喇格反射镜和金属反射镜可有效地提升光栅耦合效率。此外,该文还介绍了基于LNOI平台的几种光栅耦合器,其可帮助研究者们梳理光栅耦合器的发展历程、研究现状及各耦合器的特点,为未来研究提供一定的参考。