Energy‐Efficient Train Speed Profile Generator Combining Partial Energy‐Oriented Driving Approaches

One way of reducing the energy consumption of trains is to drive them in an energy‐efficient manner. There can be various driving patterns between two adjacent stops, or various speed profiles, because there is a gap called the running time supplement between the planned running time set in a timetable and the shortest possible running time of the train. Previous studies have proposed using up the supplement by changing the driving operation from powering to coasting at optimal points in terms of energy consumption. Others have shown that full use of regenerative braking helps save energy. In this study, we developed an energy‐efficient speed profile generator by combining these partial energy‐oriented driving approaches when the planned running time is given. We added this generator to existing shortest running time calculation software, so that it works for various vehicle and train route data. Numerical experiments showed that our profile provided superior performance compared to manually created ones for artificial and real data.     

Computation of extreme eigenvalues in higher dimensions using block tensor train format

We consider approximate computation of several minimal eigenpairs of large Hermitian matrices which come from high-dimensional problems. We use the tensor train (TT) format for vectors and matrices to overcome the curse of dimensionality and make storage and computational cost feasible. We approximate several low-lying eigenvectors simultaneously in the block version of the TT format. The computation is done by the alternating minimization of the block Rayleigh quotient sequentially for all TT cores. The proposed method combines the advances of the density matrix renormalization group (DMRG) and the variational numerical renormalization group (vNRG) methods. We compare the performance of the proposed method with several versions of the DMRG codes, and show that it may be preferable for systems with large dimension and/or mode size, or when a large number of eigenstates is sought.     

无机化学实验中学生良好习惯的培养

针对来源于边远贫困地区的学生实际，在实验教学中，从实验前的预习、实验台的合理安排、观察记录实验现象、规范操作与仪表等六个方面，分析了无机化学实验中学生的常见问题，并从上述六个方面人手，尝试培养学生的良好实验习惯，收到了积极的效果。     

High-Speed Trains Automatic Operation with Protection Constraints: A Resilient Nonlinear Gain-based Feedback Control Approach

This paper addresses the control design for automatic train operation of high-speed trains with protection constraints. A new resilient nonlinear gain-based feedback control approach is proposed, which is capable of guaranteeing, under some proper non-restrictive initial conditions, the protection constraints control raised by the distance-to-go (moving authority) curve and automatic train protection in practice. A new hyperbolic tangent function-based model is presented to mimic the whole operation process of high-speed trains. The proposed feedback control methods are easily implementable and computationally inexpensive because the presence of only two feedback gains guarantee satisfactory tracking performance and closed-loop stability, no adaptations of unknown parameters, function approximation of unknown nonlinearities, and attenuation of external disturbances in the proposed control strategies. Finally, rigorous proofs and comparative simulation results are given to demonstrate the effectiveness of the proposed approaches.      

复合材料磁悬浮列车车体结构数值模拟(Ⅱ)——车体结构性能数值模拟试验

以参数化磁悬浮列车车体有限元模型为基础，在各种载荷和边界条件下开展数值模拟试验，研究各种运营环境中车体结构的静力学和动力学性能。在Siemens NX中完成车体在各种典型载荷工况下的结构静力学和动力学性能模拟试验，包括车体结构载荷变形、车体主要连接部件结构力学性能、车体频率及振型、车体结构线性屈曲性能，以及车体动力响应性能等。数值模拟结果认为给定的复合材料磁悬浮列车车体设计可行，同时验证参数化车体有限元模型的有效性。     

岳西县小水电开发思路与具体做法

文章介绍了岳西县小水电开发思路与具体做法。主要是认真编制规划、股份合作融资、优化设计方案、工程公开发包、实行目标管理等。     

Psychological work characteristics,psychological workload and associated psychological and cognitive requirements of train drivers

This study aimed to assess the psychological work characteristics and psychological workload of train drivers and to define the psychological and cognitive requirements of their work. A systematic literature search was performed, and expert interviews were conducted. The following work demands were specific to train drivers: high emotional and mental demands, small amount of autonomy and skill discretion. No evidence of a high emotional workload, a high mental workload or short-term stress reactivity was found. In general, the drivers' fatigue complaints and recovery needs after work were comparable to that of other workers. However, severe sleepiness and high need for recovery did affect a substantial proportion of train drivers. The ability to stay aware, to anticipate, to remain attentive and to cope with fatigue are psychological and cognitive skills that are required to adequately and safely perform the train drivers' job. Including these requirements in periodic assessments of train drivers is recommended.     

Passenger comfort on high-speed trains: effect of tunnel noise on the subjective assessment of pressure variations

When passing through a tunnel, aerodynamic effects on high-speed trains may impair passenger comfort. These variations in atmospheric pressure are accompanied by transient increases in sound pressure level. To date, it is unclear whether the latter influences the perceived discomfort associated with the variations in atmospheric pressure. In a pressure chamber of the DLR-Institute of Aerospace Medicine, 71 participants (M = 28.3 years ± 8.1 SD) rated randomised pressure changes during two conditions according to a crossover design. The pressure changes were presented together with tunnel noise such that the sound pressure level was transiently elevated by either +6 dB (low noise condition) or +12 dB (high noise condition) above background noise level (65 dB(A)). Data were combined with those of a recent study, in which identical pressure changes were presented without tunnel noise (Schwanitz et al., 2013, ‘Pressure Variations on a Train – Where is the Threshold to Railway Passenger Discomfort?’ Applied Ergonomics 44 (2): 200-209). Exposure-response relationships for the combined data set comprising all three noise conditions show that pressure discomfort increases with the magnitude and speed of the pressure changes but decreases with increasing tunnel noise.

Practitioner Summary: In a pressure chamber, we systematically examined how pressure discomfort, as it may be experienced by railway passengers, is affected by the presence of tunnel noise during pressure changes. It is shown that across three conditions (no noise, low noise (+6 dB), high noise (+12 dB)) pressure discomfort decreases with increasing tunnel noise.     

客车水栓压力在线监控系统的应用及推广

针对铁路客车上水栓的现状及特点,设计出一套客车水栓压力在线监测及故障自动切除系统,并分析了使用该系统的必要性,介绍了该系统可实现的功能,对该系统的关键技术及监控组态软件设计作了详细论述,以促进其推广应用。     

Investigation of solar hybrid system with concentrating Fresnel lens,photovoltaic and thermoelectric generators

An experimental model of a solar hybrid system including photovoltaic (PV) module, concentrating Fresnel lens, thermoelectric generator (TEG), and running water heat extracting unit was created and studied. The PV module used was of c‐Si and TEG of Bi₂Te₃; the Fresnel lens (solar concentrator) and TEG share an optical train, whereas PV module was illuminated separately with non‐concentrated light. Heat extracting unit operated in thermo siphon mode. In climatic conditions of Mexico (Queretaro, 20^o of North latitude, summer time), the Fresnel lens accepted 120 W of solar radiation power, and the system generated 7.0 W of electric power and 30 W of thermal one. The discussion is made of the possible characteristics of a hypothetical hybrid system where all its elements share the same optical train. Copyright © 2016 John Wiley & Sons, Ltd.