可降解地膜残留碎片对小油菜生长和土壤性状的影响

采用盆栽试验的方法研究了3种可降解地膜残留碎片对小油菜生长和土壤性状的影响。结果表明:当土壤中可降解地膜残留碎片含量较高时其对小油菜产量和叶片叶绿素含量产生了一定的抑制作用,降低了土壤中碱解氮和有效磷的含量,提高了土壤含水量和速效钾的含量;各地膜处理对小油菜叶片数、土壤p H值和有机质含量无显著影响;可降解地膜与普通地膜相比,其残留碎片对小油菜生长和土壤环境的影响降低。

Beyond Public Spaces： Shared Spaces in the Contemporary City

The text aims to investigate the relevance of the concept of＂public space＂ and the continuous variations which have changed its meaning. Going beyond the concept of public space, the author can understand the semantic boundaries of this definition： Today, relational spaces and shared spaces are the forms with which people can express the concept of public space. The gradual spread of new forms of communication has transformed the static view of public space in a more dynamic condition, the distinction between square, street, garden has lost its meaning leaving space to fragments and residues. Contemporary public spaces are defined, as the residual places that come from the abandonment of industries. The large mono-functional voids, which originate from industrial dismantlement, should be strategically reconsidered as new shared public spaces, where the integration between different functions leads to reactivate new forms of re-using of built space.

肾结石的超声波推进技术

超声推进是一种新型的技术,它利用短时间的聚焦超声脉冲在肾脏收集系统和输尿管上重新定位结石。本综述的目的是探讨效能与安全性的初步测试、技术的改进方向及临床应用的观点。临床前的研究已经证明了超声推进的可行性和一致性,并为特定的应用程序提供了更多的输出和改进。初步的可行性研究显示了其在临床方面的适用性,包括促进输尿管镜下残留碎片的通道,或冲击波碎石术,在肾盂输尿管连接部移动大结石从而减轻痛苦,把大结石与一堆小碎片区别开来。作为一种基于办公室内系统,超声推进显示了其良好的前景,可以将肾结石重新定位。潜在的应用包括:在输尿管镜检查或冲击波碎石后促进清除残留碎片,在治疗前重新定位结石,并重新定位从肾盂输尿管连接部进入肾脏的结石,以减轻急性肾绞痛。