超柔浓染仿HOY 83 dtex/144 f涤纶全拉伸丝的生产工艺

为生产超柔浓染仿高取向丝(HOY)工艺的83 dtex/144 f涤纶全拉伸丝(FDY),讨论了底部加热器温度、无风区高度、集束高度、预网络压力以及GR_(1)辊壳材质对涤纶FDY的生产及物理性能的影响。结果表明:底部加热器温度为305℃,无风区高度为69.5 mm,集束高度为510 mm,预网络压力为0.025 MPa,GR_(1)辊壳材质选择镀陶瓷时,生产的83 dtex/144 f涤纶FDY具有较好的柔软度和吸色性。

Traffic Calming in Historic District Conservation

The Historic Conservation District(HCD) is an important target for urban heritage protection in China. The spatial characteristics of its road system,formed before the appearance of automobile,do not adapt to the car traffic. In the context of very rapid motorization in Chinese cities,the increase in car traffic brings an inevitable trouble for the protection of HCDs. Road widening and pedestrianization are two popular solutions to this problem in current practices; however,both of them may lead to negative consequences. Inspired by the development of Zone 30 in European cities,this paper firstly cleared up first some misunderstandings of the concept of traffic calming,then taking the inner city of Paris as an example,explained how traffic calming measures can be implemented in HCDs and what effects will be generated. Finally,it discussed the possible application of traffic calming measures in HCDs projects in China and pointed out the specific situations of Chinese cities to which the planners should pay more attention.

南北地震带北段6级以上地震前M_L≥3.0地震活动特征

对1970年以来南北地震带北段6级以上地震前的M_L≥3.0地震活动特征进行了分析,讨论了平静或增强现象的特征,并结合主震震源机制解和区域活动性差异,对6级以上地震的平静现象进行较为深入的分析。结果表明,主震前震中区M_L≥3.0地震活动主要存在平静异常,各个区域的平静特征和时间有差异,震中区M_L≥3.0地震平静持续时间的长短与其主震前活动水平密切相关。