锅炉飞灰磨损特性的试验研究

本文在对五种煤灰试验结果的基础上,利用确定的飞灰磨损数学模型,建立了可以作为烟气安全流速计算基础的相对磨损量的计算公式。作者对试验结果及影响飞灰磨损的主要因素,如粒子速度、灰的磨损性能、粒度等进行了讨论。分析了飞灰磨损性能系数a与飞灰物理化学特性之间的关系;认为a值可以作为判断飞灰磨损能力的一个重要指标。     

化学镀Ni-P合金性能的影响因素研究

本文从镀液配方、施镀温度以及镀层的后处理温度等方面考虑,研究它们在一定范围内的取值,及对镀层的硬度、摩擦磨损性能、耐蚀性的影响.试验结果证实影响甚微.这样,由于这些工艺条件的适当放宽,将会降低生产成本并给实际工作提供了方便.     

“镜像”映照下女性的“自我”构建——电影《嘉年华》的女性主义阐释

电影《嘉年华》以女童性侵案为视点,将几位女性的命运融入其中,描绘了当下女性的生存状态,具有浓厚的女性主义意识。本文以《嘉年华》中三位女主人公小米、小文、新新为对象,以拉康的镜像理论切入,具体分析当下男权社会女性被无意识"凝视"的关系,以及女性如何在被"凝视"的关系中构建"自我"。该电影显示了导演的匠心,这为女性主义电影与电影未来发展提供了有益的理论启示。     

可加工陶瓷切削中钻头磨损特性的研究

以硬质合金和高速钢钻头对微晶玻璃可加工陶瓷进行钻削加工,测试主后刀面的磨损宽度,考察刀具磨损特性,通过单因素试验法考察刀具材料、冷却条件、刀具角度等参数对刀具磨损的影响。试验结果表明,刀具材料和冷却方式是影响刀具磨损的主要因素,高速钢刀具不适于微晶玻璃陶瓷的钻削加工,冷却条件对硬质合金刀具磨损的影响较为显著。钻头顶角对刀具磨损率的影响较小。     

防磨涂料耐冲蚀磨损性能的试验研究

本文对４种防涂料及２０＃碳钢进行厂耐冲蚀磨损性能的试验研究．根据理论研究及分析，确定了计算相对磨损量的数学模型．通过试验数据的回归处理，分别获得其重量相对磨损率与体积相对磨损率的计算公式．由４种涂料的耐磨性能分析及与２０＃碳钢的相对比较，发现其中一种涂料的耐磨性能明显高于２０＃碳钢，而且便于制造与维护，具有较高的实用价值．对燃用高灰分燃料的电站锅炉（或其他行业）具有良好的应用前景．     

网络政治中农民抗争的转型及治理

在网络政治的范式中，农民的网络抗争可谓随处可见，他们利用网络工具进行利益表达。通过案例法和关键词研究法获得研究数据，并对此进行分析，发现农民抗争发生了三个转变：线上抗争增多；问责机制更为强烈；情感诉求更为丰富，对问题被解决的期盼性更强。而要解决这类问题，就需按照依法治村的要求，从线下而不是线上入手，对农民反映的问题进行根治，从而减少农民在网络上的抗争内容与烈度。在依法治村的框架内，村民或村干部“踩线不越线”的行为如何根治，基层政府没及时回应村民诉求的问题如何根治，村民在表达利益时策略性地造谣基层干部如何根治等，都是十九大报告所提出的加强基层建设的重要内容。     

Trampling tolerance of understorey vegetation in different hemiboreal urban forest site types in Finland

The effects of trampling on the understorey vegetation were studied in boreal urban forests of different fertility in the greater Helsinki area, Finland. The three studied forest types in decreasing order of fertility were: 1) herb-rich heath forest, 2) mesic heath forest, and 3) sub-xeric heath forest. We inventoried the cover percentages of understorey vegetation in 40 herb-rich, 75 mesic and 40 sub-xeric biotopes located in 51 urban forests varying in size (0.6–502 ha). Cover percentages were compared to those of untrampled reference areas. In our study, trampling tolerance increased with increasing fertility of the forest type. Wear of understorey vegetation correlated positively with the number of residents (i.e. recreational pressure) around the forest patch. In general, understorey vegetation cover in all three forest types was lower than in the same forest types in untrampled reference areas. Ground layer cover in urban forests was less than half of that in reference areas. Mosses, lichens, and dwarf shrubs, especially Vaccinium vitis-idaea, proved to be sensitive to trampling and consequently decreased in cover. The cover of tree saplings, mainly Sorbus aucuparia, and some resilient herbs increased.     

基于切削温度分析的刀具磨损状态研究

为了解刀具在切削时的实际状况,课题组提出了基于切削温度的刀具状态实时监测的方案。[JP2]采用仿真与试验相结合相验证的方法,对刀具在新刀、早期磨损、严重磨损以及失效4种状态下的切削温度进行分析。通过试验采集刀具磨损及失效的温度信号数据,建立了基于最小模糊度的隶属度函数优化模型,用于诊断刀具加工过程中的磨损及失效状态。应用结果表明,该方法可以实现对刀具磨损及失效状态的实时监测,对提高机床的加工效率及加工精度具有重要意义。     

Effects of fragmentation and trampling on carabid beetle assemblages in urban woodlands in Helsinki, Finland

We studied the effects of fragmentation (edge effects and patch size) and trampling (path cover) on carabid beetle assemblages in urban woodland patches in Helsinki, Finland. We expected that (1) open habitat and generalist species would benefit and forest species would suffer from increased woodland fragmentation, and (2) most carabid species would respond negatively to increased levels of trampling. A total of 2088 carabid individuals representing 37 species were collected. A cluster analysis distinguished sites in the interior of large woodland patches, with low or moderate path cover, from the other sites. The other sites did not cluster meaningfully, suggesting increased variation in the carabid fauna with increasing human impact. All species and ecological species-groups decreased with increasing distance from the edge toward the woodland interior and with increasing patch size. This pattern is in accordance with our expectation for open habitat and generalist species but opposite to what we expected for forest species. The reason for these surprising results may be that (1) the species we collected are not true forest interior species, (2) urban woodland edges are optimal habitats for many forest carabids, or (3) edges are actually sub-optimal, and high catches simply reflect increased activity of beetles moving away from the edge. Trampling did not have an overall negative effect on carabids as hypothesized. Species associated with moist forest habitat responded as predicted: they decreased in abundance with increasing path cover. Furthermore, open habitat species decreased with increasing path cover but more straightforward than we had predicted. Model elaboration, by dropping the highly trampled sites from the analyses, suggested that our data of high trampling may be too scarce: the results without these sites were more in accordance with our predictions than with the full dataset.