Abstract:The quality and safety of agricultural products are closely related to the health of consumers. The tra- ditional analysis methods for the quality and safety indexes of agricultural products have complex operational procedures and high analytical costs. With the rapid development of spectroscopy and imaging technology, near- infrared spectroscopy, Raman spectroscopy, and hyperspectral imaging technology have been widely used in the rapid non-destructive detection of agricultural product quality and safety. In the paper, the recent advances were summarized for rapid analysis of quality and safety indexes of agricultural products by using spectroscopy and imaging technology. Three aspects of the study were selective analyzed including the application of near-infrared spectroscopy in the internal and external quality and safety detection for fruits, eggs and pepper, Raman spec- troscopy in the detection of pesticide residues, and the application of hyperspectral imaging technology in the determination of nutrient contents of fruit trees.

Abstract:Masonry lining is very important in railway line, and it is influenced by many factors in operating pro- cess. Lining diseases may often have negative effects on running safety. Based on masonry lining disease infor- mation of Chengdu Bureau, by analyzing the distribution of masonry lining diseases, this paper established ma- sonry lining tunnel safety evaluation system according to AHP, introduced relative difference function to identify indicators for each membership level of security and obtained the value of the safety evaluation masonry lining of the tunnel through a variable recognition model. The evaluation of typical tunnel shows that using relative differ- ence function masonry lining tunnel safety evaluation is feasible, and the evaluation results are more reasonable, which can provide the basis for the maintenance of masonry lining of the tunnel.

Abstract:Based on the experimental result of eight concrete columns (including one unreinforced specimen and seven strengthened specimens with prestressed high strength steel wire mesh) under low cyclic loading, this pa- per, by calculating the hysteretic curve, skeleton curve and ductility change of specimens in terms of different factors, analyzed the effects of such factors as steel strand space, prestressing level and axial compression ratio on the seismic behavior of the strengthened columns. The research results show that within the prestressing level range of 0~60%, with the increase of prestressing level, the yield load, ultimate load, displacement ductility co- efficient of the reinforced concrete columns increased by 4.4%~30.6%, 16.4%~60.4% and 8.2%~49.8%. The yield load, ultimate load ductility coefficient and displacement ductility coefficient of the reinforced specimens with strand spacing of 30mm were 7.0%~10.9%, 17.0%~25.1% and 15.1%~35.2% greater than those of the re- inforced specimens with strand spacing of 60mm respectively.

Abstract:The natural asphalt has a stable physical and chemical properties, good anti-aging performance and temperature sensitivity thanks to the influence of natural environment for long time. The commonly used 90# base asphalt and two kinds of natural asphalts were selected to prepare the modified asphalt by melt blending method, then the technical properties of natural asphalt modified asphalt were studied. The effects of natural as- phalt on the pavement performance and mechanical properties of the asphalt mixture were studied based on the AC-13 asphalt mixture. The research results show that after adding TLA and rock asphalt, the penetration and ductility of the 90# base asphalt decrease, and the softening point and the viscosity increase. The dynamic sta- bility, the RMS and TSR of asphalt mixture increase, the compressive strength and modulus of resilience of as- phalt mixture increase, which show that the TLA and rock asphalt can improve the anti-rutting performance, wa- ter stability and structural bearing capacity of the asphalt mixture, and with the increase of dosage of the TLA and rock asphalt, the improvement effect is more significant. The results of low temperature bending test show that the low temperature cracking resistance performance of asphalt mixture is decreased after adding TLA and rock asphalt. However, the modified asphalt mixture with 4%, 8% and 12% rock asphalt, and the modified as- phalt mixture with 20% and 30% TLA asphalt are still in accordance with the requirements of the winter cold zone level (greater than 2 300 με).

Abstract:The phenomenon of highway tunnel disease is inevitable during daily operation. Traditional detection methods mainly relying on manual detection are characterized by low detection efficiency and obvious subjectivi- ty in test results. At the same time, it is difficult to guarantee the safety of the detector. With the rapid develop- ment of highway in our country, traditional detection methods can no longer meet the needs of highway operation and maintenance, then the rapid non-destructive detection was introduced at the right moment. At present, a va- riety of highway tunnel inspection vehicles have been developed to detect tunnel diseases efficiently and accu- rately and can automatically process data with supporting software. Highway tunnel inspection has such advan- tages as high degree of automation, rapid detection speed, high accuracy, objective results, full coverage and so on . This paper summarizes the highway tunnel detection technology to explore the development of highway tun- nel disease inspection vehicles in China.

Abstract:To study the bond-slip performance of recycled aggregate concrete steel pipe column, eight large- scale aggregate concrete columns were designed and push tests were also carried out, which mainly studied the relationship between replacement rate as well as bond interface length and initial bond strength as well as ulti- mate bond strength. Then, the corresponding bond slip curve was obtained. The research results show that the stress-slip curve of the reinforced aggregate concrete column has three stages, namely, non-slipping stage, rising stage and descending stage. The stress-slip curves of the whole loading end, the middle and the free end share similarities. While the replacement rate is at a certain range (0~40%), the ultimate bond strength increases with the increase of replacement rate and reaches the maximum when the replacement rate is at 40%; the initial bond strength increases with the replacement rate, but the increase rate is not large. The optimal replacement rate of obtained large aggregates is about 40%. While the bonding interface length is at a certain range (400~700 mm), the initial slip bond strength increases with the bonding interface length, but the increase rate is not large, about 0.001 Mpa, but the ultimate bond strength decreases with the increase of bond interface length.

Abstract:High-speed railway strategy is China's national strategy, many provinces and cities step into the high- speed railway era with the opening of high-speed railway. What is the impact of high-speed railway on the quality of urban economic development in China? This paper takes Jiangxi Province as an example and analyzes the impact of high-speed railway on the economic development quality of every district in Jiangxi Province by using difference in difference model (DID) based on the data of 11 districts in Jiangxi Province from 2010 to 2016. The research shows that high-speed railway has a significant positive impact on the proportion of tertiary industry along the city,implying that high-speed rail is a very important factor to optimize the quality of urban economic development. In addition, the urbanization level of an area, investment structure, import and export structure and employment structure significantly affect the quality of urban economic development.

Abstract:To obtain the optimal luminaire-distribution parameters (LDPs) of highway tunnel threshold and tran- sition zone lighting system with symmetrical luminaire-distribution-style (LDS), a parameter optimization model (POM) of SLDS for tunnel threshold and transition zone was established, by taking illuminance of road surface meeting lighting requirement as constraint conditions, and taking minimum total power consumption of the light- ing system as the objective function. In this paper, Yanlieshan tunnel of Jiujing highway was taken as an exam- ple for the optimization. The optimal LDPs and the corresponding total power of the lighting system were ob- tained by the POM, and a comparison analysis between the optimization results and that of the real tunnel light- ing system was performed. The research results show that the total power of the LED lighting system installed according to the optimized LDPs was less 69.59% than the total power of the transformed lighting system in- stalled with electromagnetic induction?lamps. A simulation experiment of the optimized LDPs of Yanlieshan tun- nel lighting system was carried out by using Dialux software and the simulation results verified the correctness of the POM. The comparison between the optimized brightness adaptation curve and the theoretical brightness adaptation curve of the highway tunnel indicates that the optimized LDS can meet the visual adaptation require- ment preferably.

Abstract:This paper investigated the actual parking situation along the rail transit Line No.1, rail transit travel of citizens, and vehicle speed at central and suburb areas. Besides, it adopted the method of qualitative and quantitative analysis to identify the feasibility of park and ride (P&R)by drawing on experience of both domestic and foreign urban construction. The research results show that Nanchang city would have basic P&R construction condition when the network is formed with two or three rail lines in the near future. Based on a case study in Changbei suburban area, this paper proposes that the method of disaggregate Logit model to predict the parking demand is practical and feasible. P&R construction land should be well reserved or controlled during the period of rail transit construction. Some concrete construction suggestions on P&R are put forward accordingly.

Abstract:Scientific and rational evaluation on the coordination degree of comprehensive transportation and eco- nomic and social development is of great significance for the governments’ planning and decision-making. First- ly, this paper established the evaluation index system and main indicators were obtained by using PCA method. Then, effective value calculation and diachronic evaluation and analysis for comprehensive transportation and e- conomic and social development of Jiangxi Province in recent years were carried out by DEA. Finally, from the perspective of how to promote development, this paper provided some suggestions for the medium-and long-term development of comprehensive transportation system in Jiangxi Province.

Abstract:The maximum aggregate number of high-speed rail terminal is the main basis for designing the termi- nal scale of the high-speed rail terminal. With the continuous development of high-speed railway, the travel pattern of passengers has undergone great changes and the passenger gathering rules of high-speed rail terminal are also changing. Based on the research results of the maximum aggregate number of existing railway terminals, this paper studied the calculation method of the maximum aggregate number of high-speed railway terminal, im- proved and modified the original probability calculation method. At the same time, by considering the effects of train frequency and the number of ticket-tipping on the aggregate number of high-speed rail terminal, it finds out that the distribution of waiting time for high-speed railway passengers conforms to the lognormal distribution. Then, it established the maximum aggregate number forecasting model of high-speed railway passenger terminal, and verified the above conclusion through case calculation.

Abstract:The upper and lower approximation sets of rough sets derived from approximate space are the core foundation of the rough set theory and its applied research. However， this description only gives a range of rough sets. To depict the target concept and promote rough set application more accurately， this paper， according to the computation problem of the optimal approximate set of rough sets， proposed a calculation method based on matrixes. Then， some concepts such as Boolean matrix， relation matrix， set matrix and similarity degree matrix were introduced. By discussing the similarity degree between the target concept and its approximate set， some relevant rules were obtained. A new judgment and algorithm of optimal approximate set based on matrix for rough set was eventually established. Finally， a practical example was given to further illustrate results above.

Abstract:Window interpolation algorithm based on Fast Fourier transform (FFT) was adopted to analyze the har- monics. The current harmonic detection system has many bottlenecks, such as large amount of operation, long calculation time and poor real-time performance. Then, a scheme that takes ZYNQ which integrates Field-Pro- grammable Gate Array's (FPGA) high speed data processing capability and ARM efficient digital information management capability as the main control chip was proposed. The FPGA technology was used to realize the window interpolation FFT algorithm. The harmonic analysis system was also established in the Vivado platform. The frequency, amplitude and phase of 50 harmonics were calculated by the ZedBoard development board e- quipped with ZYNQ chip, and the results are compared with that of Matlab simulation. The research results show that harmonic analysis by using this system has high accuracy.

Abstract:Due to the chromatic dispersion of the traveling wave in the transmission line, it is difficult to calcu- late the wave velocity accurately by use of the traveling wave fault location device. And the accuracy of the lo- cation would be affected too. The chromatic dispersion of the traveling wave is mainly caused by the frequency dependent character of the line impedance. Different from other guide lines, the steel rail in the traction network has its specificity. In this paper, the magnetic characteristic of the steel rail was tested by using the ballistic method from magnetic property detection of soft magnetic materials. The accurate magnetic characteristic data were obtained, including P60 steel rail fundamental magnetization curve, hysteresis loop and coercivity, etc. With the help of these data, the finite element simulation software was adopted to calculate the accurate frequency- dependent parameters of the impedance. On this basis, the traction network impedance and the frequency-de- pendent parameter matrix of the admittance were calculated by the parallel multi-conductor transmission line theory, while the special ferromagnetic characteristic of the steel rail was well-considered. It provides calculation scheme and the data foundation of the line impedance for the study of the traveling wave fault location of trac- tion network.

Abstract:The function of the circuit breaker module provided in the Simulink simulation platform is simple and cannot meet the needs of building distribution simulation. The main functional units of low-voltage AC circuit breakers for line protection are short-delay release and long-delay release. By analyzing the functions of the two trip units, two types of release models were built in Simulink and were verified in the AC distribution system, The simulation results show that the two new releases meet the requirements of protection functions, and are suitable for building distribution simulation.

Abstract:In this paper, an arbitrary signal generator was designed based on Xilinx IP core. Sine wave, triangle wave, square wave, sawtooth wave and other signals can be generated at any frequency, amplitude and phase. It can be conveniently used in simulation design in engineering design. First of all, through the DDS IP core con- figuration design, it has different amplitude sine wave by adding multiplier IP core, and different frequency and phase sine wave by adding multiple DDS IP core to set the cosine signal frequency and phase control word width and initial phase. However, the DDS IP core can only generate sine and cosine signals by means of the sine and cosine sampling look-up table. Then the data can be imported through the adding of ROM IP. By changing the frequency control word, addressing address and setting the initial value of the ROM address, the signal generator of arbitrary signal amplitude, frequency and phase can be realized. The simulation results show that different frequency and phase of sine wave, triangle wave, square wave, sawtooth wave and other signals can be output. The overall design scheme of this method is feasible, and it is easy to adjust the design of parameters, which can achieve the desired results, and has certain application value in engineering.

Abstract:The use of ultra-thin salinity from the snow melting asphalt as a road cover can not only effectively remove the road snow and reduce road maintenance costs, but also effectively extend the use of asphalt pavement life. Based on current researches in China and abroad, the mechanism of snow melting by TSSAM was explained in this paper, and the effects of mechanism of porosity, temperature, water and salt substitution and other factors on the snowmelt performance of TSSAM were analyzed. Then, the key factors influencing the snow melting per- formance and snow melting life were obtained by using the gray correlation entropy analysis. Finally, the regres- sion equation was used to obtain the prediction equation of snow melting performance and snow melting life. This paper provides reference for the research of salinized snow surface.

Abstract:GAMIT/GLOBK software was adopted to complete the batch processing for IGS station data. Combined with the baseline solution for the site control network data obtained from some tracking station of the Interna- tional Geomechanical Service Organization (IGS)， this paper obtained GPS baseline vector, station coordinates and station speed and the reliability analysis was also carried out. The research results show that the error in the coordinate component of each baseline does not exceed 1cm and the median error of the baseline length is not more than 3mm. The coordinate of the plane coordinate is in millimeter precision, which can meet the basic re- quirements of base-line computing with high accuracy.

Abstract:Based on current researches at home and abroad, the rheological properties of nano-graphene modified asphalt were studied through Brinell viscosity, dynamic shear rheological test (DSRs) and low temperature bend- ing beam rheological test (BBR). The research results show that graphene can obviously increase the viscosity of asphalt and improve its resistance to permanent deformation at high temperature, but it may have a negative ef- fect on the performance at low temperature.

Abstract:The asphalt mixtures with self-repairing function were developed by utilizing shape memory effect of shape memory alloys. The phase transformation behavior and shape recovery properties of the shape memory al- loy wires were characterized by differential scanning calorimeter (DSC) and mechanical tester. The deformation recovery experiments were carried out on wheel track samples to verify the self-healing performance of the bitu- men pavement material. The research results show that the shape memory alloy wires presents two-stage B2-R- B19 martensitic transformation and a recovered strain of 7.8% with 10% pre-strain. These shape memory alloy wires can improve the shape recovery rates of the wheel tracking samples significantly. The paving mode of the shape memory alloy wires also plays an important role in the shape recovery rate of the asphalt mixtures. Finally, the wheel tracking samples paved with bidirection and double -layer shape memory alloy wires show higher shape recovery rate than that of samples paved with one-direction and one layer shape memory alloy wires.