The interlayer contact condition of asphalt pavement has a significant impact on stress transfer and energy dissipation with adjacent layers,so a model considering the bonding condition of adjacent layers is introduce...The interlayer contact condition of asphalt pavement has a significant impact on stress transfer and energy dissipation with adjacent layers,so a model considering the bonding condition of adjacent layers is introduced for evaluating the structural response of asphalt pavement.The pavement structure,the material characterization with temperature,the interlayer contact bonding model,the types of bond failure,and the prediction method of pavement life are described in detail.Results show that the transversely tensile strains at the top of asphalt pavement under the condition of high temperature were easy to cause the top-down cracking outside the edge of the dual tire.The bonding failure has a significant influence on strains at the bottom of the surface course with the condition of high temperature,especially,the longitudinally tensile strains would increase obviously as the disengaging area between the surface course of asphalt pavement and the base layer increases.Finally,it is proved that the surface course is vulnerable to form deformations and cause damage under the combined action of low speed and high temperature.展开更多
In areas with large temperature differences,the uneven distribution of temperatures in the CRTS III ballastless track slab due to daytime sunlight can cause warpage deformation,leading to periodic rail irregularities ...In areas with large temperature differences,the uneven distribution of temperatures in the CRTS III ballastless track slab due to daytime sunlight can cause warpage deformation,leading to periodic rail irregularities that increase the wheel-rail impact of high-speed vehicles and accelerate track structure damage.Therefore,it is necessary to study the dynamic contact relationship between the composite slab and the base plate during vehicle running.The results of the study show that:1)Under the influence of temperature gradients,the composite slab tends to deform elliptically.With a positive temperature gradient,the middle part of the track slab bulges upward,causing the slab to be supported by its four corners.Conversely,with a negative temperature gradient,the four corners of the track slab bulge upward,resulting in the slab being supported by its center.2)Temperature gradients can lead to separation between the composite slab and the base plate,reducing the contact area between layers.During vehicle running,the contact area between layers gradually increases,but the separation cannot be completely closed.3)The temperature gradient significantly affects the vertical displacement of the track.The vertical displacement in the middle of the slab increases with a positive temperature gradient.In contrast,the vertical displacement at the ends of the slab increases with a negative temperature gradient.4)The stress of self-compacting concrete at the side position significantly increases under a positive temperature gradient,with the vertical stress increasing by 2.7 times when the temperature gradient increases from 0 to 90℃·m^(-1).展开更多
We report an effective method to improve the formation of nickel stanogermanide（Ni Ge Sn） by the incorporation of a platinum（Pt） interlayer. After the Ni/Pt/Ge Sn samples are annealed we obtain uniform Ni Ge Sn th...We report an effective method to improve the formation of nickel stanogermanide（Ni Ge Sn） by the incorporation of a platinum（Pt） interlayer. After the Ni/Pt/Ge Sn samples are annealed we obtain uniform Ni Ge Sn thin films,which are characterized by means of sheet resistance, atomic force microscopy, scanning electron microscopy,cross-section transmission electron microscopy, and energy dispersive x-ray spectroscopy. These results show that the presence of Pt increases the smoothness and uniform morphology of Ni Ge Sn films.展开更多
基金supported by the Scientific Research Program Funded by Shaanxi Provincial Education Department(Program No.21JK0830)Shaanxi Provincial Natural Science Foundation Research Project(Program No.2022JM-166).
文摘The interlayer contact condition of asphalt pavement has a significant impact on stress transfer and energy dissipation with adjacent layers,so a model considering the bonding condition of adjacent layers is introduced for evaluating the structural response of asphalt pavement.The pavement structure,the material characterization with temperature,the interlayer contact bonding model,the types of bond failure,and the prediction method of pavement life are described in detail.Results show that the transversely tensile strains at the top of asphalt pavement under the condition of high temperature were easy to cause the top-down cracking outside the edge of the dual tire.The bonding failure has a significant influence on strains at the bottom of the surface course with the condition of high temperature,especially,the longitudinally tensile strains would increase obviously as the disengaging area between the surface course of asphalt pavement and the base layer increases.Finally,it is proved that the surface course is vulnerable to form deformations and cause damage under the combined action of low speed and high temperature.
基金supported by the National Natural Science Foundation of China(Grant No.52278466)the Project of China Academy of Railway Sciences Co.,Ltd(Grant No.2023YJ194).The useful contribution and discussions from project partners are also acknowledged.
文摘In areas with large temperature differences,the uneven distribution of temperatures in the CRTS III ballastless track slab due to daytime sunlight can cause warpage deformation,leading to periodic rail irregularities that increase the wheel-rail impact of high-speed vehicles and accelerate track structure damage.Therefore,it is necessary to study the dynamic contact relationship between the composite slab and the base plate during vehicle running.The results of the study show that:1)Under the influence of temperature gradients,the composite slab tends to deform elliptically.With a positive temperature gradient,the middle part of the track slab bulges upward,causing the slab to be supported by its four corners.Conversely,with a negative temperature gradient,the four corners of the track slab bulge upward,resulting in the slab being supported by its center.2)Temperature gradients can lead to separation between the composite slab and the base plate,reducing the contact area between layers.During vehicle running,the contact area between layers gradually increases,but the separation cannot be completely closed.3)The temperature gradient significantly affects the vertical displacement of the track.The vertical displacement in the middle of the slab increases with a positive temperature gradient.In contrast,the vertical displacement at the ends of the slab increases with a negative temperature gradient.4)The stress of self-compacting concrete at the side position significantly increases under a positive temperature gradient,with the vertical stress increasing by 2.7 times when the temperature gradient increases from 0 to 90℃·m^(-1).
基金Supported by the National Natural Science Foundation of China under Grant Nos 51672171 and 61604094the Natural Science Foundation of Shanghai under Grant No 14ZR1418300+2 种基金the National Key Basic Research Program of China under Grant No 2015CB921600the Eastern Scholar Program from the Shanghai Municipal Education Commissionthe Fok Ying Tung Education Foundation
文摘We report an effective method to improve the formation of nickel stanogermanide（Ni Ge Sn） by the incorporation of a platinum（Pt） interlayer. After the Ni/Pt/Ge Sn samples are annealed we obtain uniform Ni Ge Sn thin films,which are characterized by means of sheet resistance, atomic force microscopy, scanning electron microscopy,cross-section transmission electron microscopy, and energy dispersive x-ray spectroscopy. These results show that the presence of Pt increases the smoothness and uniform morphology of Ni Ge Sn films.
