为了全面提高废口罩纤维(Waste Mask Fiber, WMF)改性沥青的高低温性能,将其与SBR改性剂共同制备WMF-SBR复合改性沥青,基于MSCR流变性能试验,对未老化、FTROT短期老化和PAV长期老化三种状态下的复合改性沥青,测试分析其蠕变恢复率R、不...为了全面提高废口罩纤维(Waste Mask Fiber, WMF)改性沥青的高低温性能,将其与SBR改性剂共同制备WMF-SBR复合改性沥青,基于MSCR流变性能试验,对未老化、FTROT短期老化和PAV长期老化三种状态下的复合改性沥青,测试分析其蠕变恢复率R、不可恢复蠕变柔量Jnr、应力敏感性Jnrdiff、Rdiff等指标的变化规律。结果表明,其软化点较基质沥青提高了14.6%,较WMF改性沥青降低了5%,延度较WMF改性沥青增加了380%;在0.1 kPa、3.2 kPa应力作用下,WMF-SBR复合改性沥青的R值、Rdiff值、Jnr值、Jnrdiff值随老化程度的增加分别呈增大、减小、减小、减小的趋势变化;与基质沥青、SBR改性沥青相比,WMF-SBR复合改性沥青在相同老化阶段和应力水平条件下,R、Rdiff指标均最大,Jnr、Jnrdiff指标均最小。WMF-SBR复合改性沥青显著提高了WMF改性沥青的低温塑性;相比SBR改性沥青,其高温抗车辙变形稳定性更好,弹性变形恢复能力更强,应力敏感性更小,老化后性能更稳定、更耐久。In order to comprehensively improve the high and low temperature performance of waste mask fiber (Waste Mask Fiber, WMF) modified asphalt, the WMF-SBR composite modified asphalt was prepared with SBR modifying agent. Based on the MSCR rheological performance test, the changes in creep recovery rate R, unrecoverable creep compliance Jnr, stress sensitivity Jnrdiff, and Rdiff of composite modified asphalt under three states of unaged, FTROT short-term aging, and PAV long-term aging were tested and analyzed. The results show that, its softening point is 14.6% higher than the matrix asphalt, is 5% lower than the WMF modified bitumen. The extension is 380% higher than that of WMF modified asphalt;under the action of the 0.1 kPa, 3.2 kPa stress, the R value, Rdiff value, Jnr value and Jnrdiff value of WMF-SBR composite modified asphalt respectively increase, decrease, decrease and decrease with the increase of aging degree;compared with matrix asphalt and SBR modified bitumen, WMF-SBR composite modified bitumen under the same aging stage and stress level conditions, the indicators (R, Rdiff) are the largest and the indicators (Jnr, Jnrdiff) are the minimum. WMF-SBR composite modified asphalt significantly improves the low temperature plasticity of WMF modified asphalt;compared with SBR modified asphalt, it has better high temperature rut deformation stability, more resilient elastic deformation recovery, less stress sensitivity, and more stable and durable performance after aging.展开更多
The present study investigated the effects and underlying mechanism of ethylacetate fraction of Ribes fasciculatum （ERF） on the lifespan and stress tolerance using a Caenorhabditis elegans model. The longevity activ...The present study investigated the effects and underlying mechanism of ethylacetate fraction of Ribes fasciculatum （ERF） on the lifespan and stress tolerance using a Caenorhabditis elegans model. The longevity activity of ERF was determined by lifespan assay under normal culture condition. The survival rate of nematodes under various stress conditions was assessed to validate the effects of ERF on the stress tolerance. To determine the antioxidant potential of ERF, the superoxide dismutase （SOD） activities and intracellular reactive oxygen species （ROS） levels were investigated. The ERF-mediated change in SOD-3 expression was examined using GFP-expressing transgenic strain. The effects of ERF on the aging-related factors were investigated by reproduction assay and pharyngeal pumping assay. The intestinal lipofuscin levels of aged nematodes were also measured. The mechanistic studies were performed using selected mutant strains. Our results indicated that ERF showed potent lifespan extension effects on the wild-type nematode under both normal and various stress conditions. The ERF treatment also enhanced the activity and expression of superoxide dismutase （SOD） and attenuated the intracellular ROS levels. Moreover, ERF-fed nematodes showed decreased lipofuscin accumulation, indicating ERF might affect age-associated changes in C. elegans. The results of mechanistic studies indicated that there was no significant lifespan extension in ERF-treated daf-2, age-l, sir-2.1, and daf-16 null mutants, suggesting that they were involved in ERF-mediated lifespan regulation. In conclusion, R. fasciculatum confers increased longevity and stress resistance in C. elegans via SIR-2.1-mediated DAF-16 activation, dependent on the insulin/1GF signaling pathway.展开更多
文摘为了全面提高废口罩纤维(Waste Mask Fiber, WMF)改性沥青的高低温性能,将其与SBR改性剂共同制备WMF-SBR复合改性沥青,基于MSCR流变性能试验,对未老化、FTROT短期老化和PAV长期老化三种状态下的复合改性沥青,测试分析其蠕变恢复率R、不可恢复蠕变柔量Jnr、应力敏感性Jnrdiff、Rdiff等指标的变化规律。结果表明,其软化点较基质沥青提高了14.6%,较WMF改性沥青降低了5%,延度较WMF改性沥青增加了380%;在0.1 kPa、3.2 kPa应力作用下,WMF-SBR复合改性沥青的R值、Rdiff值、Jnr值、Jnrdiff值随老化程度的增加分别呈增大、减小、减小、减小的趋势变化;与基质沥青、SBR改性沥青相比,WMF-SBR复合改性沥青在相同老化阶段和应力水平条件下,R、Rdiff指标均最大,Jnr、Jnrdiff指标均最小。WMF-SBR复合改性沥青显著提高了WMF改性沥青的低温塑性;相比SBR改性沥青,其高温抗车辙变形稳定性更好,弹性变形恢复能力更强,应力敏感性更小,老化后性能更稳定、更耐久。In order to comprehensively improve the high and low temperature performance of waste mask fiber (Waste Mask Fiber, WMF) modified asphalt, the WMF-SBR composite modified asphalt was prepared with SBR modifying agent. Based on the MSCR rheological performance test, the changes in creep recovery rate R, unrecoverable creep compliance Jnr, stress sensitivity Jnrdiff, and Rdiff of composite modified asphalt under three states of unaged, FTROT short-term aging, and PAV long-term aging were tested and analyzed. The results show that, its softening point is 14.6% higher than the matrix asphalt, is 5% lower than the WMF modified bitumen. The extension is 380% higher than that of WMF modified asphalt;under the action of the 0.1 kPa, 3.2 kPa stress, the R value, Rdiff value, Jnr value and Jnrdiff value of WMF-SBR composite modified asphalt respectively increase, decrease, decrease and decrease with the increase of aging degree;compared with matrix asphalt and SBR modified bitumen, WMF-SBR composite modified bitumen under the same aging stage and stress level conditions, the indicators (R, Rdiff) are the largest and the indicators (Jnr, Jnrdiff) are the minimum. WMF-SBR composite modified asphalt significantly improves the low temperature plasticity of WMF modified asphalt;compared with SBR modified asphalt, it has better high temperature rut deformation stability, more resilient elastic deformation recovery, less stress sensitivity, and more stable and durable performance after aging.
基金supported by a grant from Woosuk University(2013)
文摘The present study investigated the effects and underlying mechanism of ethylacetate fraction of Ribes fasciculatum （ERF） on the lifespan and stress tolerance using a Caenorhabditis elegans model. The longevity activity of ERF was determined by lifespan assay under normal culture condition. The survival rate of nematodes under various stress conditions was assessed to validate the effects of ERF on the stress tolerance. To determine the antioxidant potential of ERF, the superoxide dismutase （SOD） activities and intracellular reactive oxygen species （ROS） levels were investigated. The ERF-mediated change in SOD-3 expression was examined using GFP-expressing transgenic strain. The effects of ERF on the aging-related factors were investigated by reproduction assay and pharyngeal pumping assay. The intestinal lipofuscin levels of aged nematodes were also measured. The mechanistic studies were performed using selected mutant strains. Our results indicated that ERF showed potent lifespan extension effects on the wild-type nematode under both normal and various stress conditions. The ERF treatment also enhanced the activity and expression of superoxide dismutase （SOD） and attenuated the intracellular ROS levels. Moreover, ERF-fed nematodes showed decreased lipofuscin accumulation, indicating ERF might affect age-associated changes in C. elegans. The results of mechanistic studies indicated that there was no significant lifespan extension in ERF-treated daf-2, age-l, sir-2.1, and daf-16 null mutants, suggesting that they were involved in ERF-mediated lifespan regulation. In conclusion, R. fasciculatum confers increased longevity and stress resistance in C. elegans via SIR-2.1-mediated DAF-16 activation, dependent on the insulin/1GF signaling pathway.
