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Fuel economy is an important indicator to evaluate vehicle performance as it is directly associated with fuel costs. This paper introduces a method to evaluate the fuel economy of fuel cell vehicles (FCVs). A fuel cell truck (FCT) was tested under a 40 km/h constant speed and a China heavy-duty commercial vehicle test cycle-heavy truck (CHTC-HT) driving cycle scenarios to determine the FCV energy consumption, driving range, and hydrogen emissions in different driving cycles and analyze the influences of these driving cycles on fuel economy evaluation. The test results demonstrated that compared with its performance under the 40 km/h constant speed scenario, when the FCT was tested under the CHTC-HT scenario, the electricity consumption per 100 km and the hydrogen consumption per 100 km were increased by 60.35% and 52.02%, respectively; the driving range was reduced by 43.49%; the hydrogen emission per 100 km rose by 171.17%, and the hydrogen emission rate grew by 26.96%.

With the increase of fatigue rolling cycles between the wheel and rail, it’s easy to generate small angle microcracks on the surface or shallow surface of the rail, which is located in the blind spot of ultrasonic detection. Therefore, pulsed eddy current thermography (ECPT) is selected for detection. In this paper, the finite element software was used to simulate the thermal characteristics of microcracks, and the data was extracted for simulation data analysis. Then principal component analysis(PCA), tensor CANDECOMP/PARAFAC de- composition(CP), and Tucker decomposition were compared horizontally, and the signal-to-noise ratios (SNR) of the three algorithms were obtained by experimental data. Experimental analysis shows that the characteristics of microcracks are very weak, the optimal extraction time is in the beginning of the heating stage, and the tensor algorithm can improve the SNR ratio of the microcrack effectively.

Oblique crack is one of the common defects in industrial ultrasonic testing. The angle probe can detect oblique defects more efficiently. The path of the ultrasonic wave in the multi-layer medium can be calculated by the ray tracing technique. Then it can be used in synthetic aperture imaging algorithm for improving ultrasonic imaging resolution. In this paper, the new forward interpretation algorithm is used to image the internal oblique crack. The better result is shown in comparing with the traditional SAFT algorithm for straight probe.

In the running process of locomotive, many tiny cracks emerge on the wheel tread due to the rolling contact between wheel and rail. On account of being exposed to complex environment, the crack flank will be corroded and filled with a third medium such as corrosion, then contact with each other under cyclic tensile or compressive stress, leading to local closure of the crack region, which affects the physical properties of the crack, showing low electrical conductivity for example. This is a new phenomenon that conventional electromagnetic detection method might not be capable of detecting such defects effectively. This paper aims to detect crack with corrosion on the basis of eddy current pulsed thermography (ECPT), establish a composite crack model to explore the performance of ECPT over low conductivity crack, and the influence of varying electromagnetic properties to ECPT will be studied as well. Crack detection principle was introduced first, and numerical simulations were conducted to detect crack with corrosion, transient and spatial temperature distribution characteristics were extracted during heating and cooling stage, experiments were designed and conducted to verify the accuracy and consistency.

In order to process real-time phased array ultrasound imaging, to improve imaging resolution, and achieve on-line defect detection, total focusing method (TFM) imaging algorithm is used for the complete data, thrust reversers the focus and algorithm in different positions, the computational problems of large data can be solved by the FPGA parallel algorithms. After that, the total focusing method imaging algorithm can be realized in the real-time detection.

This article is based on the correlation of FFT(Fast Fourier Transform) to study the ultrasonic TOFD(Time Of Flight Diffraction) image registration algorithm and according to the principle of template matching algorithm, the process is simple and the registration locations are accurate, so that the detected images are clear and defected features are obvious. The subsequent sub-pixel image registration algorithm of TOFD will improve registration accuracy to sub-pixel level, to further perfect the TOFD image registration algorithms, more conducive to subsequent image processing.

Total focusing method (TFM) is a post-processing algorithm for ultrasonic imaging, usually used for processing linear array data. In this paper, TFM is extended to obtain three-dimensional (3D) image based on two-dimensional array data. However, it takes a long time to get 3D information from large amount of 2D array data by TFM. So Sub-aperture matrix capture (SMC) and sparse array are taken into account to solve this issue. The experimental results prove that TFM precisely reconstruct 3D information of defects through the optimized method. In a small angle imaging range, SMC can reach the same image quality and the same array performance indicator (API) as full matrix capture (FMC). In addition, it won't take more than one quarter of the time token by FMC for ultrasonic imaging. Although the spurious image is enhanced with the reducing sparseness, the processing time is reduced. Considering both image quality and real-time imaging, the imaging efficiency might be improved by 50 times through the combination of the two methods. The paper provides an optional approach to achieve real-time imaging system.

Single amplitude apodization technology applied in ultrasound imaging system can obtain better imaging resolution only within a certain distance, outside of this range the resolution is significantly lower, while using segment dynamic apodization technique can make up for this shortfall. Therefore, we make an analysis and research on the basis of the beams about the 3 dB equivalent distribution with a variety of single amplitude apodization functions, and observe to come to the best imaging resolution range for each function, then calculate the dynamic weighting value by establishing a linear phased array sound field simulation model, thus find a way to achieve segment dynamic amplitude apodization, and draw the 3 dB contour and the distribution of sound field to prove the feasibility of this technique.

As one of the core contents of the company's financial management, dividend policy receives universal attention in the theoretical circles. This paper selects the IT industry as research object, firstly analyzes the status quo of dividend distribution about past six years, and then selects the financial data of 2011 to build a multiple linear regression model to verify the influence factors in the cash dividend. The analysis results show that a company's cash dividend level is positively related to company's profitability, the amount of wealth, solvency, company size, but is not directly related to the relationship with the company's growth and cash flow. It can play a guiding role for the IT industry's dividend allocation through analyzing the influence factors of the cash dividend.

Ultrasonic transducer is the ultrasonic transmitting and receiving component for ultrasonic equipment. The performance of its driving circuit plays an important role in the whole system. This paper presents a driving circuit for ultrasonic transducer based on transducer's operating principle. The circuit uses the capacitor to generate the high voltage pulse with the help of MOSFET The experimental results show that the circuit has achieved the ultrasonic transmitting. It is simple, adjustable, and easy to be modularized

Currently, ball grid array (BGA) is the mainstream technology of semiconductor package. The alignment accuracy of BGA ball mounting processing has a great impact on the rate of finished products. In order to reduce the accuracy requirement for mechanism and increase the automation level, visual servo technology is introduced to BGA ball mounting processing in tins paper. Coaxial lighting is adopted to emphasize the characteristics of positioning hole, and parallel processing flow is designed for image capture. Image smoothing and histogram equalization technology are used in image preprocessing to clear up image noise and increase image contrast. Template matching technology is used to identify the positioning hole and calculate the coordinates of positioning hole. And the difference between the coordinates of header and substrate is used as the driving signal to achieve the automatic alignment. Double-closed-loop feedback is adopted in servo system to improve positioning accuracy. And S-shape acceleration curve reduces the impact in the movement. Based on the research on the above technology, an effective scheme for automatic orientation of BGA ball mounting processing is put forward, and it will provide the great support to the development of BGA ball mounting machine.