排序方式: 共有29条查询结果,搜索用时 31 毫秒
1.
┌────────────────┬───┬────┬──┬───┬────┬───┬───┬───┬────┬────┐│车型 │座位和│发动机缸│功率│车长 │整备质 │车速 │从零加│ 油耗│(L/10( │)km) ││ │车门数│数和工作│(kw)│(mm) │量(kg) │(l‘m │速至 │以90 │以1 20 │卜 ││ │ │ 容积 │ │ │ │/h) │100km │km/h │km/h │ ││ │ │ (ml汀)│ │ │ │ │/h的 │速度在│速度在 │ ││ │ │ │ │ │ │ │时间 │公路行│公路行一│ ││ │ │ │ │ │ │ │ (s) │驶时 │驶时一 │… 相似文献
2.
Piezoelectric resonators are widely used in frequency reference devices, mass sensors, resonant sensors(such as gyros and accelerometers), etc. Piezoelectric resonators usually work in a special resonant mode. Obtaining working resonant mode with high quality is key to improve the performance of piezoelectric resonators. In this paper, the resonance characteristics of a rectangular lead zirconium titanate(PZT) piezoelectric resonator are studied. On the basis of the field-programmable gate array(FPGA) embedded system, direct digital synthesizer(DDS) and automatic gain controller(AGC) are used to generate the driving signals with precisely adjustable frequency and amplitude. The driving signals are used to excite the piezoelectric resonator to the working vibration mode. The influence of the connection of driving electrodes and voltage amplitude on the vibration of the resonator is studied. The quality factor and vibration linearity of the resonator are studied with various driving methods mentioned in this paper. The resonator reaches resonant mode at 330 kHz by different driving methods.The relationship between resonant amplitude and driving signal amplitude is linear. The quality factor reaches over 150 by different driving methods. The results provide a theoretical reference for the efficient excitation of the piezoelectric resonator. 相似文献
3.
柴油机喷油器针阀体座面的磨损是由于针阀对针阀体座面冲击引起的,它会影响燃油喷雾的形态和喷油特性。近年来,在针阀表面采用涂上类金钢石碳(DLC)覆层来防止磨损。介绍了磨损试验,并进行了各种分析研究。利用场致发射扫描电子显微镜(FE-SEM)观察针阀体座面磨损表面,发现在非DLC的常规喷油嘴中能够看到腐蚀磨损痕迹,而DLC喷油嘴中则仍保留着机械磨损痕迹。所以,在磨损区域硬度测量的结果发现其表面以下硬度增加了。腐蚀磨损是非DLC喷油嘴的磨损原因,塑性变形是DLC喷油嘴的主要磨损原因。 相似文献
5.
为更进一步提高绞吸挖泥船施工效率,通过对新海鳄轮挖泥船在曹妃甸三港池施工中的经验进行总结,提出几项建议措施,以达到保证安全施工的前提下提高施工效率、节能、降耗、降本、增效的目的。 相似文献
6.
7.
8.
9.
10.
考虑客户对高铁快运产品的选择行为与高铁快运产品供给的相互关系,设计了基于供需匹配的两阶段高铁快运产品货流分担率计算方法.第1阶段考虑客户对高铁快运产品的选择意愿,构建高铁快运产品效用函数,建立考虑货流类型的高铁快运产品货流分担率计算模型,以刻画客户选择行为的差异和货流结构的差异对货流分担率的影响;第2阶段考虑高铁快运产品的供给特征,设计与客户选择效用值相关的货流转移概率的计算方法,并修正第1阶段的货流分担率计算结果.最后,以哈大高铁通道为例,对本文提出的方法进行验证.研究结果表明,考虑供需关系的高铁快运产品分担率计算方法更符合实际. 相似文献