工业缝纫机针杆的气浮轴承性能数值计算与分析

为了对气浮针杆的小孔节流型轴承的支承性能进行研究,文章在建立数学模型的基础上,运用有限差分法对控 制方程进行数值有限差分的推导,利用MATLAB对针杆在低速和高速的情况下的压力分布进行了数值求解。结果表 明：气浮轴承能够较好地实现工业缝纫机的低速和高速情况下的气浮支承;双排节流小孔的压力分布承载效果比单排节 流小孔好;随着气浮针杆运动速度的变化双排节流小孔的气浮轴承的稳定性较好。对进一步深入对工业缝纫机针杆的 气浮支承研究具有指导意义。     

Expanding Boundaries of Whiteness? A Look at the Marital Patterns of Part‐White Multiracial Groups

Using a boundary perspective (Alba and Nee 2003 ), I examine the marital behavior of three self‐identified multiracial groups: black/whites, American Indian/whites, Asian/whites. With a focus on marriage with whites, I assess whether the boundaries of whiteness are expanding to include these part‐white multiracial groups. Marrying whites at a large scale may signify that part‐white multiracial Americans are in the process of being accepted as “white.” At the same time, due to differences in the racial identity experiences of multiracial groups, marital patterns may differ by racial combination. Based on analysis of 2008–2012 American Community Survey data, I find that the majority of all three groups are married to whites, suggesting that most members in these groups are on the path to whiteness. On the other hand, multinomial logistic regression analysis demonstrates that American Indian/whites and Asian/whites are more likely than black/whites to have a white spouse, relative to spouses of another race/ethnicity. Moreover, separate regression analyses by multiracial group reveal gender differences in their likelihood of marrying whites for black/whites and Asian/whites. These results indicate racial stratification in the marriage market among part‐white multiracial Americans, with further stratification by gender for some groups.     

‘Keeping the story alive’: is ethnic and racial dilution inevitable for multiracial people and their children?

This paper explores how multiracial parents with White partners articulate narratives of ethnic and racial ‘dilution’ and cultural loss in relation to the socialization of their children. In our broader study of how multiracial parents raise their children, we found that parents commonly spoke of concerns around dilution and generational change in relation to four key themes: the loss of cultural knowledge and diminishing practices that connected parents and their children to a minority ancestry; the embodiment of White‐appearing children and the implications of this for family relationships; the use of biological or genetic discourses in relation to reduced blood quantum; and concerns amongst Black/White participants about whitening and the loss of racial consciousness. Parental understandings of dilution varied greatly; some expressed sadness at ‘inevitable’ loss; others were more philosophical about generational change; and others still proactively countered loss through strategies to connect their children to their minority heritages. We show that despite growing awareness of the social constructedness of race and an emergent cosmopolitanism among these parents, discourses of genetics, cultural lineage, and the ‘naturalness’ of race continue to hold sway amongst many multiracial parents.     

我国相对资源承载力区域差异分析

相对资源承载力是将理想状态区域作为参考标准,将研究区与参照区进行对比,得到相对意义上的资源在某区域内可承载的适度人口数量。以全国为参照区,依此计算我国东、中、西部相对资源承载力,结果表明东部地区相对经济资源承载力富余较多,而中部和西部地区经济资源承载力均处于超载;东部地区相对自然资源承载力严重超载,而中部和西部地区相对自然资源承载力均处于富余状态。通过对资源承载力现状及相对资源承载力计算比较的综合分析,反映出我国东、中、西部区域存在明显差异。     

试论农村社会的灾变承载能力

长期以来,我国农村社会结构及政府对农村社会经济的管理体制存在诸多弊端。这次SARS流行则暴露出农村社会的灾变承载能力严重不足。政府为控制SARS在农村蔓延,付出了高昂的代价。从理论角度考察,它反映的也是一个社会公正问题。要提高农村社会抵御灾变的能力,惟有中央政府加快制度创新,推动行政制度、土地制度、户籍制度等一系列改革。     

环首都城市群资源环境承载力综合评价及政策建议

基于资源环境承载力的内涵,构建了环首都城市群资源环境承载力的指标体系,并运用层次分析法对环首都城市群11个城市资源环境承载力的空间差异进行了比较研究。最后结合低碳经济的发展理念,就如何提高环首都城市群的资源环境承载力提出了相应的对策建议。     

道家寓言与"夸父逐日"神话

寓言是中国古代神话形成的一个重要途径。战国时期形成的"夸父逐日"神话是由道家寓言故事演化而来的,寓意在于讥讽夸父式违背天道不自量力的愚者行为。用进化论和自然神话论解释而来的原始社会父权制确立的反映和自然现象的反映等结论不能成立。摈弃西方进化论神话理论,采用文化要素分析法,用中国文化来解释中国神话是21世纪中国神话学研究的理想选择。     

城市农民工社会保障问题的思考

城市化是有着丰富涵义的社会变迁过程。城市农民工作为我国城市化进程中的一个特定部分,由于体制、环境以及自身素质等方面因素,使得他们对于城市知觉处于一种普遍的焦虑之中。他们的社会保障由于缺乏应有的制度安排,而成为城市中的弱势族群。关注城市农民工的生存状况,妥善解决农民工的社会保障是解决当前中国农民工问题的关键所在。     

简论壮族五大文化遗产

南方稻作民族人文始祖洛甲及布洛陀、洪水育人神话盘古兄妹、左江花山崖壁画、歌圩的女儿、歌仙刘三姐、全国篇幅最长的民间抒情长诗《嘹歌》,及壮族原生态民歌,是广西壮族五大文化遗产。文化遗产是建设先进文化的民族根基,抢救文化遗产与建设首府先进文化密切相关。