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This paper analyzed temperature field and temperature stress of cement concrete pavement under periodic variable low temperature using finite element method modeling technique in ABAQUS. And discussed the effect of wind speed, surface thermal conductivity coefficient on temperature field. Cracking and warping at the joint of concrete panel was simulated to analyze pavement deformation and mechanical characteristics. Results show that at lower temperature, concrete face will appear horizontal longitudinal displacement, causing the appearance of cracking; and warping effect will appear at the concrete panel, leading to concrete pavement void. It is revealed that dowel bar has not occurred plastic deformation, that is, bending strength meets the requirements.

With the rapid development of Internet of things, the RFID technology also develops very fast. Because of the RFID system has the advantage of low cost and do not require to contact identification, it has been used in many applications. But when system works, there may be many tags at the same time around the reader and may cause the collision problem. In this paper, we propose a Method of ID - BTS tag recognition based on the QT protocol. This method can effectively solve the problem of tag collision and it has fewer times of tags searching and less traffic.

An unanticipated sideeffect of China’s developing economy was the increase in heavy road trafficvehicles utilizing high pressure tires on both new and old infrastructure.Today the extent of rutting has become one of the main forms of asphalt road surfacebreakage. To improve the robustness and high temperature properties of roadsurfacing asphalt, a new high-modulus material has been developed and used tomodify normal road petroleum asphalt. The results from laboratory experimentsconducted at the Jiangsu Baoli Asphalt Co., LTD and real road trials inPeople's Democratic Republic of Algeria, Shanghai, Shanxi and Jiangsu provincein China, indicate that the high-modulus asphalt performed significantly betterat higher-temperatures when compared to samples of more commonly used asphaltmixtures. The high-modulus additive (No. ZQ-1) was prepared in Jiangsu BaoliAsphalt Co. LTD, and the basic production process, the basic properties as wellas the effection to base bitumen was analysed in the paper. And the DynamicStability was evaluated using an automated rut-depth measuring system. Thewater stability and low temperature properties were also discussed. Themodified asphalt material has comparable storage and usage costs to existingutilized asphalts though with enhanced high-temperature properties.

Studies on active transit signal priority (active TSP) focus primarily on the advantages and parameters of priority strategies within a given cycle time, which is not necessarily the optimal cycle. With consideration for the restrictions resulting from arterial coordination, the effect of three active TSP strategies on vehicle delays at a key intersection on an arterial road was discussed. Using an actual case, the effect of possible real volume variations on optimal cycles under active TSP strategies was analyzed. Results show that under special flow conditions, additional benefits exist when the cycle time is increased from the value generated by the TRRL approach. The extent of increase can rise with the ratio of priority phase flow to nonpriority phase flow. Cycle time can be dynamically established in accordance with the flow conditions in actual operations. The findings also show that the efficacy of red truncation is better than that of green extension.

According to the characteristics of the aluminum conductors, coated-steel reinforced (ACSR), combined the feature that isotropic and continuity of the folded yarns, establish the calculated equation of the Poisson ratio of the discrete and anisotropic wires. After given the calculated equation of stiffness of large cross-section wires, we obtained the calculated equation of elastic modulus, shear modulus and Poisson ratio. These wires stiffness not only reflect the characteristics of the composite material, but also provide guidance and reference for the mechanical calculation of the wires and installation of overhead conductor and ground wires and the following equation also has certain value in mechanics calculation and lines of construction.

Resistance spot welding (RSW) is being taken place by partial lap laser welding for the poor surface quality and bad airtight due to the pressure of electrodes. The shape of partial lap laser welding is similar to the vase. When the penetration of the joint is in a certain range, there is no welding trace on the outer surface. Laser welding temperature field numerical analysis based on Abaqus finite element analysis software is committed to obtain a suitable range of process parameters to improve production efficiency and automation by determining the joint penetration. To master the laser lap welding of stainless steel weld penetration state, the combination of three-dimensional positive cone + three-dimensional inverted cone + half-ellipsoid heat source model was established simulating stainless steel lap laser weld pool shape and forecasting the range of process parameters .

A series of novel liquid crystal polyurethanes containing biphenylnate and imide units were synthesized through the polyaddition reaction of 4,4′-Bis-(2-hydroxyhexoxy)biphenyl (BP2), 2,4-toluenediisocyanate (2,4-TDI) with N,N′-bis(2-hydroxyhexyl)-dicarboxyimide (BHDI) by altering the molar ratio of BP2 and BHDI. The effects of structure difference molar ratio between BP2 and BHDI on the liquid crystalline behavior and thermal stability were studied. Results showed that all of the polyurethane polymers exhibited thermotropic nematic liquid crystalline textures in the range of 160~190°C. The melting temperatures (Tm) and the thermal stability increased with increasing BHDI content.

A new kind of lower-branched liquid crystalline polyester (LLCP) containing polyester mesogenic units was synthesized by p-hydroxybenzoic acid, terephthalyl chloride and trimellitic anhydride (TMA), then was used as collaborative modifier for the epoxy resin (E-51) with γ-azyl polyhedral oligomeric silsesquioxane (POSS). The experimental results showed that the LLCP / POSS could act as an effective toughening modifier for the epoxy resin. The impact strength of the composites modified with LLCP and POSS was 1.1 times higher than that of the unmodified system. The temperature of starting decomposition and maximum decomposition rate improved about 20 oC and 13 oC , respectively.

Liquid crystal polyurethane (LCPBI) containing biphenylnate and imide units was synthesized and characterized and used to modify the conventional epoxy resin (E-51). Experimental results revealed that the impact strength of the epoxy resin modified with LCPBI was 2.5 times higher than that of unmodified epoxy resin, and the tensile strength as well as the bending strength was also improved. The thermal decomposition temperature of modified systems was also 15-20oC higher than that of the unmodified system, and the fracture structures of the blends was investigated by SEM.

Crude alkaloidal extraction from Gelsemium elegans Benth. produces analgesic property. However, its clinical utility has been obstructed by its narrow therapeutic index. Here, we investigated the potential of koumine, a monomer of Gelsemium alkaloids, to reduce both inflammatory and neuropathic pain. Interestingly, allopregnanolone, a neurosteroid, appeared to mediate the reduction of neuropathic pain. The potential anti-inflammatory pain effects of koumine were evaluated by acetic acid-, formalin- and complete Freund's adjuvant (CFA) -induced nociceptive behaviors in mice. Chronic constriction injury (CCI) and L5 spinal nerve ligation (L5 SNL), inducing thermal hyperalgesia and mechanical allodynia in rats, were used to test whether repeated treatment of koumine ameliorated neuropathic pain. Finally, we explored if koumine altered the level of neurosteroids in rat spinal cord of CCI neuropathy using liquid chromatography-tandem mass spectrometry. Koumine dose-dependently reduced the acetic acid-induced writhes and formalin-induced licking/biting time of Phase II in mice. Repeated administrations of koumine also dose-dependently reversed the CFA-, CCI- and L5 SNL-induced thermal hyperalgesia, as well as, CCI- and L5 SNL-induced mechanical allodynia in rats. The level of allopregnanolone, but not pregnenolone, in the L5-6 spinal cord was elevated by repeated treatment of koumine in CCI-induced neuropathic rats. These results demonstrate that koumine has a significant analgesic effect in rodent behavioral models of inflammatory and neuropathic pain, and that the reduction in neuropathic pain may be associated with the upregulation of allopregnanolone in the spinal cord.

A forensic investigation was conducted to determine the underlying cause of a premature pavement failure. The premature pavement failure was occurred in the form of rutting and alligator cracking. Through extensive field and lab testing, it was found that the moisture susceptible base is the primary cause of the premature failure and the porous asphalt concrete (AC) being the secondary cause. It is noted that the base layer was built according to plan and met the current material and field density requirements. As part of the field investigation, ground penetration radar (GPR) was utilized to survey the entire area. AC cores were taken to correlate the dielectric measurements from GPR with the lab measured density to generate the density/air-void map. More than 50 cores were taken to accurately determine the air void content. The results indicate that the air void exceeds 10% and did not meet the specification requirements. Based on the lab results, there are 36% of the cores fall into the category of either penalty or remove and replace. It was concluded that material requirements which are only based on the field density and moisture content are inadequate to control the construction quality, as it was not able to protect against premature failures illustrated in this paper from occurring. Even though it is tedious to conduct the moisture susceptibility tests to determine strengths at different moisture levels, it is a viable tool to minimize the premature pavement failures.

Proceedings of the GeoHunan International Conference II: Emerging Technologies for Design, Construction, Rehabilitation, and Inspection of Transportation Infrastructure, held in Hunan, China, June 9-11, 2011. This Geotechnical Special Publication contains 28 papers addressing contemporary geotechnical topics. These papers focus on testing, modeling, and case studies of geomaterials, pavements, and tunnels. Topics include: nondestructive characterization of geomaterials; nondestructive characterization of pavement layer materials; in situ test methods for site characterization, design, and quality control of earth structures and subgrades; tunneling in soft ground, ground conditioning, and modification; and case histories of special and long tunnels.