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21.
随着路内碱性蓄电池用量的增加,由此而来的环境污染问题也日渐突出。除了根据蓄电池特性合理延长使用时间,减少报废外;采用电渗析、超滤组合工艺回收并重复利用废电解液是一种既简便又实用的新技术,能够获得很好的环境、经济、社会效益。  相似文献   
22.
This study aims at presenting a new approach in calibrating standard two-peak design spectra for specific regions in absence of wind data. The main principle in these kinds of fitting for a new area is to minimize the least square error between measured and fitted spectra and there has been less attention to double-peak spectra individual characteristic as co-existence of wind-sea and swell parts in one spectrum. Here, separation frequency, approximately dividing such parts, is implemented to virtually extract wind-sea and swell components of a measured spectrum considering their intrinsic overlap near the separation frequency. Then, they have been easily utilized to calibrate two parts of standard double-peak spectrum in a revisory manner. To verify benefits of this new methodology, it has been applied on Ochi-Hubble as well as Torsethaugen spectra regarding field measurements in a coastal region at Gulf of Oman, Chabahar bay. Results obviously show a better adjustment of formula to field spectrum using this simple approach when compared with output of calibration on integrated field spectrum irrespective of its main characteristic such as availability of two-wave systems.  相似文献   
23.
针对城轨列车跨越多个无线接入点AP高速运行时存在切换延迟的问题,在对城轨列车无线视频监控系统研究的基础上,提出一种RFCS(RF channel switched)机制,在这种机制下,无线接入点AP按照预定的顺序周期性的改变RF信道来防止相邻AP信道的重叠,从而减小了切换延迟,增大了网络吞吐量,最终实现无缝切换.并用NS2仿真软件对该方案进行仿真,与传统的切换过程相比,该方案明显减小了切换时延,保证了城轨列车无线视频监控系统的实时性.  相似文献   
24.
一种基于模式识别的可控整流电路故障诊断方法   总被引:2,自引:0,他引:2  
以双桥串联可控整流电路为例,介绍了大功率可控整流装置的工作原理.在对各种故障进行分类的基础上提出根据整流电压的脉波数将输出波形分段,通过实时监测各波段电压采样均值和标准差,对各段电压波形进行分类,从而将故障波形用模式向量表示.通过对模式向量二进制编码后进行循环移位实现对故障的在线诊断和精确定位.  相似文献   
25.
本文设计了一种采用单片机控制的恒压给水系统,阐述了其工作原理和主要特点,此系统可用于改造或取代水塔供水及含大型气压罐管道直接加压供水等传统供水方式。  相似文献   
26.
Motorised vehicle conditions have been evaluated by many researchers. In contrast, there are very limited studies on vulnerable and non-motorised users, such as cyclists and pedestrians, specifically children, the elderly and the disabled. Thus, this paper reviews prominent studies on street evaluations to identify effective indicators for non-motorised trips. The street condition for these trips is measured by the bicycle level of service (BLOS) and the pedestrian level of service (PLOS). In previous studies, different methods have been introduced for PLOS and BLOS. However, these methods have several major shortcomings. First, pedestrians and cyclists are assumed to be users who can share street facilities with motorised vehicles and thus are considered equivalent to cars. Second, the majority of these methods are complicated and time-consuming, and it is difficult to connect them to a design process. Furthermore, these methods support only a limited number of walking and cycling facilities; therefore, they may not be valid for a wide range of pedestrians and cyclists with a diverse variety of abilities and ages. This study discusses the challenges in the BLOS and PLOS research and attempts to introduce new objectives for further studies in this field to eliminate the aforementioned shortcomings.  相似文献   
27.
Effect of System Nonlinearities on Locomotive Bogie Hunting Stability   总被引:1,自引:0,他引:1  
This paper presents the effect of system parameters on hunting of a rail vehicle with nonlinear yaw dampers and wheel-rail interface. This study is intended to complement earlier studies by True et al. where they investigated the effect of nonlinearities stemming from creep-creep force saturation and wheel/rail contact forces. The rail vehicle is represented by a two-axle truck (bogie) that includes the dynamics of the wheelsets and the truck frame. The numerical simulation results show that yaw damping can have a mixed effect on the hunting critical speed. In some ranges, increasing damping can actually lower the critical speed, unlike the results commonly obtained from a linear model. Flange contact nonlinearities can also have a significant effect on the hunting behavior. Large lateral stiffness of the rail can increase lateral force to vertical force (L/V) ratio during hunting. Increasing the gauge clearance, however, can have an opposite effect. The effect of a variety of other parameters, such as the primary suspension yaw and lateral stiffness, primary suspension lateral damping, wheelset mass, and truck frame mass, are summarized in a table.  相似文献   
28.
在E/N为100~900Td(1Td=1017Vcm2)的场强范围内,对甲烷气体中的电子崩发展进行了仿真研究.采用蒙特卡罗模拟法对其电子崩参数诸如有效电离系数、电子漂移速度、纵向扩散系数等进行了求解计算,计算结果与实验数据相一致.仿真结果表明:随着E/N值的增大,即电离作用的增强,电子的各漂移速度也呈现出差异.  相似文献   
29.
自动导轨交通系统的发展现状   总被引:2,自引:1,他引:1  
介绍了近年来欧美、日本等一些国家正在研究开发的一类新型城市轨道交通系统(AGT)。这类系统成本低、运行灵活可靠,对环境影响小,可以部分取代私人轿车的功能,是有发展前景的城市轨道交通工具。  相似文献   
30.
Applying man-machine-environment system engineering(MMESE)in vessels is a method to improve the effectiveness of the interaction between equipment, environment, and humans for the purpose of advancing operating efficiency, performance, safety, and habitability of a vessel and its subsystems. In the following research, the life cycle of vessels was divided into 9 phases, and 15 research subjects were also identified from among these phases. The 15 subjects were systemized, and then the man-machine-environmen...  相似文献   
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