排序方式: 共有17条查询结果,搜索用时 15 毫秒
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施工技术资料是市政工程建设过程的全面记录和真实反映.是市政设施管理、养护、维修的一个重要技术依据,在市政工程施工、竣工、养护、改建和扩建都起到重要作用。分析了目前存在的常见问题,提出了改进意见和措施。 相似文献
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制备负载无机纳米颗粒的形状规整的微囊 总被引:1,自引:1,他引:0
A facile and efficient method has been developed for microencapsulation of metal oxide nanoparticles in polyurea via interfacial polymerization of toluene-2, 4-diisocyanate and H2O through the atomizing emulsification approach. The resultant microcapsules were well-shaped and uniform sphere with diameter ranging from 2 to 6μm. Thermogravimetry (TG) and differential scanning calorimetry (DSC) curves revealed that the microcapsules showed good thermal stability (no decomposition observed under 245℃). Besides, the microencapsulated TiO2 has been used as an efficient catalyst for photocatalytic degradation of methyl orange. Furthermore, the photocatalysis of immobilized TiO2 could be enhanced by introducing UV absorbing agent to the wall of microcapsules. 相似文献
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一种基于分形修正PID算法的弹上舵机控制器 总被引:3,自引:0,他引:3
针对某型号弹上舵机采用的小型稀土力矩电机与谐波减速器的组合结构方案,设计了一种基于分形几何度量变化率特征的增量比例-积分-微分控制器.该控制器考虑了谐波传动随速度波动和低阻尼特点,以提高舵机系统控制品质为目标,从传动过程在一定的尺度范围内具有参数自相似性的特征出发,利用了线性模型与分形模型所表达的规律性之间存在的固有互补性,用反馈信号短时分形维数估计舵机实际转角与电机驱动力之间的相背离程度,并利用这个估计函数修正比例-积分-微分输出值.实验表明,该舵机系统对25°阶跃响应时常数小于100 ms,20 Hz,±15°振幅条件下的频率响应相位延时小于20°,定位精度优于0.06°,半振荡次数小于两次. 相似文献
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A facile and efficient method has been developed for microencapsulation of metal oxide nanoparticles in polyurea via interfacial polymerization of toluene-2,4-diisocyanate and H20 through the atomizing emulsification approach. The resultant microcapsules were well-shaped and uniform sphere with diameter ranging from 2 to 6 um. Thermogravimetry (TG) and differential scanning calorimetry (DSC) curves revealed that the microcapsules showed good thermal stability (no decomposition observed under 245℃). Besides, the microencapsulated TiC2 has been used as an efficient catalyst for photocatalytic degradation of methyl orange. Furthermore, the photocatalysis of immobilized TiC2 could be enhanced by introducing UV absorbing agent to the wall of microcapsules. 相似文献