科创中国

为研究沥青性能对应力吸收层沥青混合料路用性能的影响,通过室内试验测定了齐鲁70#道路石油沥青、复合改性沥青、橡胶沥青这3种沥青的技术指标,对设计的应力吸收层沥青混合料进行了高低温性能、水稳定性和疲劳性能评价,并得到了相应的动态模量主曲线和相位角主曲线.结果表明,复合改性沥青和橡胶沥青用于应力吸收层具有良好的路用性能和力学性能,建议在实际应用中结合经济因素选用.

采用废旧聚乙烯(PE)与硫酸钙晶须为原料,通过熔融挤出共混制得废旧PE/硫酸钙晶须复合材料,比较了经硅烷偶联剂KH-590改性与未改性的硫酸钙晶须用量对废旧PE/硫酸钙晶须复合材料力学性能的影响,分析硫酸钙晶须增强度旧PE的机理和废旧PE/硫酸钙晶须复合材料的微观结构.结果表明:当硫酸钙晶须用量为15%时,未改性硫酸钙晶须使复合材料的拉伸强度、冲击强度提高了23.1%、9.1%;改性硫酸钙晶须使复合材料的拉伸强度、冲击强度、弯曲强度提高了26.7%、15.6%和5 3%,其在废旧PE中分布均匀,能起到明显的增强作用.

In order to find a parameter as the evaluation index that can capture the effect of the interaction between asphalt and aggregate, the rheological properties of asphalt mastics using two kinds of asphalts and four kinds of aggregates under different filler-asphalt ratios were measured by a dynamic shear rheometer (DSR). Moreover, four rheological parameters of K.Ziegel-B, Luis Ibrarra-A, complex shear modulus ΔG*and complex viscosity Δη* for evaluating the interaction ability were studied. Results indicate that all the four parameters can characterize the interaction ability of asphalt and aggregate correctly and feasibly. Through the comparison of sensitivities and physical meanings of the four parameters, K.Ziegel-B with high sensitivity and exact physical meaning is finally selected as the evaluation index for interaction ability of asphalt and aggregate.

基于沥青路面裂纹扩展行为,设计预切口小梁试件的疲劳试验,以模拟其复合裂纹扩展模式;以疲劳寿命指标来评价沥青混合料的抗裂性能,同时进行沥青混合料的低温弯曲试验和J积分试验,试验混合料采用4种低温性能差异显著的沥青胶结料.判别各项评价指标对试验混合料抗裂性能的鉴别程度,并分析沥青低温临界温度指标、低温弯曲试验指标、J积分试验指标与预切口小梁疲劳寿命的相关性.结果表明:以混合料疲劳性能为基准的混合料抗裂性能排序与沥青胶结料临界温度的排序一致,也与沥青混合料低温弯曲试验和J积分试验中能量指标的排序一致.

目的:探讨新生大鼠缺氧缺血性脑损伤(HIBD)后大脑皮质分子伴侣介导的自噬(CMA)活性的变化及参附注射液的干预作用.方法:参照Rice法制备HIBD模型.将新生7日龄SD大鼠随机分为假手术组(S组)、生理盐水对照组(C组)、参附注射液治疗组(SF组),每组按照观察时间依次分为6 h、12 h、1 d、3 d、5 d、7 d六个亚组,每个亚组8只大鼠.采用免疫组化法和Western Blot法检测大鼠大脑皮质溶酶体相关膜蛋白-2A(LAMP-2A)的表达情况.结果:免疫组化法和Western Blot法显示LAMP-2A在S组各时间点表达水平差异无统计学意义(P>0.05);C组和SF组LAMP-2A的表达水平在各时间点较S组明显升高(P<0.05),且在3 d达到高峰,随后其表达水平下降;SF组LAMP-2A的表达水平在6 h、12 h、1 d较C组高(P<0.05),但其3 d时峰值表达水平较C组低(P<0.05).结论:HIBD时存在CMA现象,参附注射液在早期能促进LAMP-2A大量表达,后期则抑制其过度表达,从而对HIBD后的新生大鼠可能具有保护作用.

对外径为Ф10mm碳纤维复合材料管成型工艺及性能进行了研究.结果表明,采用热缩工艺成型的碳纤维复合材料管工艺简单、质量可靠,Ф10mm碳纤维复合材料管件弯曲刚度与不锈钢管相当,弯曲强度为不锈钢的3倍以上,质量仅为不锈钢的50%,尺寸精度满足设计要求.

Eddy current pulsed thermography(ECPT) is an emerging Non-destructive testing and evaluation(NDT & E) technique, which uses hybrid eddy current and thermography NDT & E techniques that enhances the detectability from their compensation. Currently, this technique is limited by the manual selection of proper contrast frames and the issue of improving the efficiency of defect detection of complex structure samples remains a challenge. In order to select a specific frame from transient thermal image sequences to maximize the contrast of thermal variation and defect pattern from complex structure samples, an energy driven approach to compute the coefficient energy of wavelet transform is proposed which has the potential of automatically selecting both optimal transient frame and spatial scale for defect detection using ECPT. According to analysis of the variation of different frequency component and the comparison study of the detection performance of different scale and wavelets, the frame at the end of heating phase is automatically selected as an optimal transient frame for defect detection. In addition, the detection capabilities of the complex structure samples can be enhanced through proper spatial scale and wavelet selection. The proposed method has successfully been applied to low speed impact damage detection of carbon fibre reinforced polymer(CFRP) composite as well as providing the guidance to improve the detectability of ECPT technique.

UV固化不仅可以使复合材料快速固化,而且不需要高温,能避免残余热应力的产生,在应急抢修中比通常的热固化复合材料更具优势.本文采用UV固化的方法实现了损伤金属结构的快速修复,分析了复合材料补片的铺设层数、长度以及损伤结构表面处理对修复效果的影响.

采用不同偶联剂对纳米碳化硅进行表面处理后,制备了聚四氟乙烯/纳米碳化硅复合材料,考察了偶联剂种类和含量随载荷变化对复合材料摩擦磨损性能的影响,并利用扫描电子显微镜观察和分析了复合材料磨损表面形貌及其磨损机理.结果表明,经表面处理的纳米碳化硅填充后的复合材料硬度和摩擦磨损性能均有提高,以钛酸酯偶联剂(NDZ101)处理效果最好;随着偶联剂含量的增大,钛酸酯偶联剂(NDZ101)处理的复合材料的磨损量和摩擦因数均增大,偶联剂最佳含量为填料质量的1%;偶联剂处理后的纳米碳化硅与基体之间形成了良好的界面,复合材料的磨损以黏着磨损和磨粒磨损为主.