The viscosity-time curve of a single-component polyurethane(PU)was examined to determine the mixing and compacting temperatures of its mixture and investigate the curing and mechanical properties of single-component P...The viscosity-time curve of a single-component polyurethane(PU)was examined to determine the mixing and compacting temperatures of its mixture and investigate the curing and mechanical properties of single-component PU porous elastic mixture(PPEM).The curing properties of the single-component PU and PPEM were studied with Fourier transform infrared spectroscopy(FTIR)and Marshall test.The mechanical properties of PPEM were explored via the following tests:rutting test,3-point bending test,soaked Marshall stability test,freeze-thaw splitting test,and Cantabro test.The effects of a water bath on the stability of aggregate-PU/asphalt mortar-aggregate systems were evaluated through a pull-out test and a shear test.The results show that the recommended mixing temperatures of toluene diisocyanate and methylene diphenyl diisocyanate range from 75 to 80℃and from 64 to 68℃,respectively.Room temperature(25℃)can be adopted as the compacting temperature of PPEM.PPEM can be fully cured in 4 d.Nevertheless,the water sprinkle method can obviously shorten the full curing time of PPEM.PPEM exhibites good resistance to rutting,brittle cracking,and raveling.The adhesive and shear strength of aggregate-PU/asphalt mortar-aggregate systems are negatively related to water bath duration.展开更多
The impact of online social networks and the necessity to sustain their rapid growth emphasize the importance to unravel the laws governing their evolution.With online data crawled from"Sina micro-blog",we d...The impact of online social networks and the necessity to sustain their rapid growth emphasize the importance to unravel the laws governing their evolution.With online data crawled from"Sina micro-blog",we divide the entire users into opinion leaders and ordinary microbloggers without verification.This allows us to illustrate a quantitative two-layer model to reproduce the evolution of the online social networks from the birth of it,which is a visual framework for micro-blog users'behaviors.The empirical study of the model shows that the different influence between ordinary users and opinion leaders and the viral spreading mechanism and mass media influence govern the evolution of online social networks.At the end we verify the accuracy of our model with real"Sina micro-blog"dataset.Furthermore,considering the complexity of microbloggers,we can develop the information dissemination to show the mutual impact of various social values.展开更多
基金The Fundamental Research Funds for the Central Research Institute (No. 2020-9054)。
文摘The viscosity-time curve of a single-component polyurethane(PU)was examined to determine the mixing and compacting temperatures of its mixture and investigate the curing and mechanical properties of single-component PU porous elastic mixture(PPEM).The curing properties of the single-component PU and PPEM were studied with Fourier transform infrared spectroscopy(FTIR)and Marshall test.The mechanical properties of PPEM were explored via the following tests:rutting test,3-point bending test,soaked Marshall stability test,freeze-thaw splitting test,and Cantabro test.The effects of a water bath on the stability of aggregate-PU/asphalt mortar-aggregate systems were evaluated through a pull-out test and a shear test.The results show that the recommended mixing temperatures of toluene diisocyanate and methylene diphenyl diisocyanate range from 75 to 80℃and from 64 to 68℃,respectively.Room temperature(25℃)can be adopted as the compacting temperature of PPEM.PPEM can be fully cured in 4 d.Nevertheless,the water sprinkle method can obviously shorten the full curing time of PPEM.PPEM exhibites good resistance to rutting,brittle cracking,and raveling.The adhesive and shear strength of aggregate-PU/asphalt mortar-aggregate systems are negatively related to water bath duration.
文摘The impact of online social networks and the necessity to sustain their rapid growth emphasize the importance to unravel the laws governing their evolution.With online data crawled from"Sina micro-blog",we divide the entire users into opinion leaders and ordinary microbloggers without verification.This allows us to illustrate a quantitative two-layer model to reproduce the evolution of the online social networks from the birth of it,which is a visual framework for micro-blog users'behaviors.The empirical study of the model shows that the different influence between ordinary users and opinion leaders and the viral spreading mechanism and mass media influence govern the evolution of online social networks.At the end we verify the accuracy of our model with real"Sina micro-blog"dataset.Furthermore,considering the complexity of microbloggers,we can develop the information dissemination to show the mutual impact of various social values.
