排序方式: 共有11条查询结果,搜索用时 15 毫秒
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在讨论了含水率对路用土质量的影响因素后,通过对不同种类测试器的分析,确定了较为适用的微波传感器,并给出了微波传感器的输出电压与集料含水率之间的关系式,进而对测试准确度进行计算。 相似文献
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针对船舶交管系统中数字微波通信子系统应用方案进行探讨,通过理论分析和计算,并联系VTS系统实际情况,在数字微波通信子系统工程设计和设备选择方面提出一些建议及参考标准。 相似文献
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结合铁通通信城域网建设的实际情况,提出了数字微波通信技术在城域网建设中应用的方案.对今后铁通通信网络建设及通信市场的发展有一定的参考价值. 相似文献
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微波溶样/原子吸收法测定铁路危货站固体废弃物中的重金属 总被引:1,自引:0,他引:1
参照美国EPASW846规定的标准方法,采用Q-45型微波溶样系统消解样品,原子吸收法测定铁路桃浦危险品货站固体废渣原样、浸滤渣样、浸提液样中的重金属Be、Cd、Cr、Cu、Ni、Pb、Zn。研究了样品的消解条件、分析的最佳条件。各元素精密度实验的相对标准偏差在0.54%~12.8%,标准土样的测定回收率在76.49%~103.33%。并报告了对上海铁路局桃浦危货站现场样品的测定结果。 相似文献
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This study investigates the effect of traffic volume and speed data on the simulation of vehicle emissions and hotspot analysis. Data from a microwave radar and video cameras were first used directly for emission modelling. They were then used as input to a traffic simulation model whereby vehicle drive cycles were extracted to estimate emissions. To reach this objective, hourly traffic data were collected from three periods including morning peak (6–9 am), midday (11–2 pm), and afternoon peak (3–6 pm) on a weekday (June 23, 2016) along a high-volume corridor in Toronto, Canada. Traffic volumes were detected by a single radar and two video cameras operated by the Southern Ontario Centre for Atmospheric Aerosol Research. Traffic volume and composition derived from the radar had lower accuracy than the video camera data and the radar performance varied by lane exhibiting poorer performance in the remote lanes. Radar speeds collected at a single point on the corridor had higher variability than simulated traffic speeds, and average speeds were closer after model calibration. Traffic emissions of nitrogen oxides (NOx) and particulate matter (PM10 and PM2.5) were estimated using radar data as well as using simulated traffic based on various speed aggregation methods. Our results illustrate the range of emission estimates (NOx: 4.0–27.0 g; PM10: 0.3–4.8 g; PM2.5: 0.2–1.3 g) for the corridor. The estimates based on radar speeds were at least three times lower than emissions derived from simulated vehicle trajectories. Finally, the PM10 and PM2.5 near-road concentrations derived from emissions based on simulated speeds were two or three times higher than concentrations based on emissions derived using radar data. Our findings are relevant for project-level emission inventories and PM hot-spot analysis; caution must be exercised when using raw radar data for emission modeling purposes. 相似文献
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用硫酸亚铁为原料,加NH_3·H_2O得到的氢氧化亚铁作前驱物经干燥后,在有CO_3~(2-)存在下热解可得γ-Fe_2O_3。实验结果显示:前驱物经微波干燥得到的产物分散性比真空干燥法好且粒径减小;而前驱物在无CO_3~(2-)存在时热解产物却为α-Fe_2O_3。并采用XRD、TEM等方法对产物进行了表征。 相似文献
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Novolacs were successfully synthesized using oxalic acid as the catalyst in a self-designed device based on a domestic microwave oven, The fundamental characteristics of the synthesis of novolacs under microwave irradiation (MI) were investigated, and the properties of the resins polymerized and dehydrated under microwave irradiation and conventional heating (CH) were analyzed comparatively, The results show that MI reduced the polymerization and dehydration time greatly; and that the resins polymedzed and dehydrated under MI presented longer flow distances ( i. e., higher flowability) and shorter cure time than those obtained under CH. 相似文献
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对广东三家微波炉厂的生产场所及15种型号的成品微波炉漏能进行了监测。结果显示:6名检测岗位工人距离微波炉(未上外壳)40cm处,微波辐射的功率密度平均为17μW/cm2(4μW/cm2~60μW/cm2),仅一个点超标;6种型号(未上外壳)微波炉5cm处,微波辐射的功率密度平均为194μW/cm2(1μW/cm2~1002μW/cm2),只有一种型号超标;在15种型号的成品微波炉5cm处,微波辐射的功率密度平均为126μW/cm2(1μW/cm2~860μW/cm2),均未超标。微波炉的不同部位微波泄漏主要是视屏窗、门缝的位置。 相似文献
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