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Rail transportation experimental system is the urgent need of modern railway signal professional teaching equipment in the university. This equipment can deepen students' understanding of theoretical knowledge and improve their ability of practical operation. In this paper, the hardware design of rail power supply circuit in the testing system was completed. Using ICL8038 as a signal generator of the power output board, the design met the functional requirements in practical test.

Recently, an efficient homotopy method termed the nonlinear homotopy method (NLH) has been proposed for finding DC operating points of MOS transistor circuits. This method is not only efficient but also globally convergent. However, the programming of sophisticated homotopy methods is often difficult for non-experts or beginners. In this paper, an effective method for implementing the MOS NLH method on SPICE is proposed. By this method, we can implement the MOS NLH method from a good initial solution with various efficient techniques and without programming.

In order to study the stress of box-girder web under prestressing, and confirming the internal stress distribution of the web, analyzing of vertical prestressed box girder, curved beam prestressed sensitivity under the webs. Establishing finite element model of the box-girder webs vertical prestressing effect is analyzed, results show that the principal tensile stress of the web is sensitive to the vertical prestress, applying the vertical prestress can effectively reduce the principal tensile stress of the web; with the decrease of the effective vertical prestress, the neutral axis above the principal compressive stress decreases rapidly, while below the neutral axis decreases relatively slow; Under the same vertical preloading stress level, the roots of cross section of the compressive stress of web reserves than L/4 section of the web.

Rail transportation experimental system is the urgent need of modern railway signal professional colleges and universities teaching equipment. This equipment can deepen students' understanding of theoretical knowledge and improve their ability of practical operation. In this article the design schemes of track circuit for high-frequency test system are simulated. Through the result of simulation the design meet the functional requirement.

Coal rock boundary recognition is one of the core techniques to realize the automation of the fully mechanized coal face, however, this kind of technique has not been effectively resolved. We put forward a kind of coal-rock boundary recognition method based on the modal analysis, and through the theory analysis, we put forward the key parameters and recognition method for the coal rock boundary recognition. By using this method weve analyzed the vibration data from underground working face. The analyzing result indicates that this method could efficiently recognize the coal-rock boundary, which has provided a new and easily realizable method for coal-rock boundary recognition problem.

PC often uses HostLink protocol to communicate with Omron PLC through serial port. In Labview, HostLink protocol implementation using DLL method has some disadvantages: messy interfaces and consideration of compatibility between different programming languages. This paper introduces the HostLink communication protocol, describes the native implementation of HostLink in LabVIEW in detail which overcomes the above shortcomings.

This paper summarizes the design of reinforced concrete structure and its enclosure for a subaqueous tunnel used to cross a river in urban highway line. The tunnel mainly consists of open-cut section on river bank and cut-cover section under river bed. Their structure and enclosure are both illustrated in the paper according to site geology and general layout of urban highway line. The use of rotary bored pile and soil mixing wall to preserve the stability of open-cut foundation pit are summarized in the paper.

In China, water disaster often occurred in coal mines in recent years. According to official statistics on coal mine water accidents occurred in recent twelve years in China, major characteristics of the water disaster have been illustrated. The result shows that the number of both water accidents and corresponding fatalities decreased from 2001 to 2012. And apparently, the accidents occurred in township-owned coal mines and triggered by gob area water accounted for a higher proportion, respectively.

RFID technology has many advantages and plays an important part in eliminating the inaccuracy of inventory information. This paper analyzed how manufacturers decided the raw material ordering quantity to maximize their profit when the price of raw materials was given through newsvendor model. Combined with the impact of putting raw materials wrongly and lost of raw materials, we compare the profits of not adopting RFID technology and that of adopting it. Then we obtain the biggest cost that manufacturer could undertake when adopting RFID, and the results can provide the foundation for the decision maker of manufacturing enterprise.

This article discusses a series of technologies of comprehensive utilization of coal resources,and puts forward countermeasures of comprehensive utilization of coal resources.These are benefical for comprehensive utilization of coal resources and maximize economic and social interests of coal resources.

Detection and characterization of defects in metal parts in industrial and commercial settings has typically been carried out by nondestructive ultrasonic inspection systems. The aim of present work is to propose a kind of non-contact nondestructive testing system based on the laser and electro-magnetic acoustic transducer (EMAT) techniques, which is suitable to inspect the defects in metal material. The maximum lift-off value (LOV) of the system is 10 mm. Wavelet threshold method (WTM) is employed to improve the signal to noise ratio (SNR), and the values of SNR increase to 67.42 dB and 64.66 dB for the case of LOV=0 mm and LOV=10 mm, respectively.

Based on a great deal of geological data, we analyzed the geological tectonic features of Zhaoguan mine field. On the basis of the analytical method of traditional geology, the paper revealed the general development mechanism of geological structures of this research area. Combined with the fractal theory, and taking the calculation chart of reserve in coal seam as the foundation drawing, the faults and folds can be deeply studied to obtain their fractal characteristics with geological structure complexity in this area quantificationally evaluated.

At the beginning,we used the ABAQUS to establish a two-dimensional finite element model of typical asphalt pavement, and analysised the changing axiom of road surface shearing stress under the half sine wave load. Also, we studied on the impact of damping ratio and the driving speed on shearing stress. Finally, by using SPSS13.0 software to compare the impact of speed, the surface layer material damping ratio, lower modulus ratio, the thickness of the surface layer and the thickness of the subbase. The results show that, to reduce the cracking damage caused by oversized shearing stress in asphalt pavement, we should first consider the damping ratio of surface layer material, and the most effective method is to use the road-building material of high damping ratio to prevent cracks, at the same time we should raise the driving speed.