减少波束指向抖动的捷变频方法

采用裂缝波导阵列天线的雷达在频率捷变时将引起雷达波束指向的抖动，严重时抖动可超出波束宽度范围，影响目标检测，甚至造成目标丢失。本文对此进行了分析，提出了解决方法，并简述为此而设计的一种小型、实用的频率捷变系统。     

湿塑性水泥土增强研究

从水泥在水泥-水-粘土系统中水化的特点出发，阐述了湿塑性水泥土的强度形成过程，主要是依赖于水泥石的强度骨架与粘土之间的结构连接。通过实验，研究了几种外加剂对湿塑性水泥土的增强作用及其增强机理，结果表明，外加剂能改善水泥土的水化介质环境和结构粘接，可改善水泥土的稠度和强度。     

Investigation of rheological properties of TPS modified bitumen

Rheological properties of the virgin bitumen and TPS modified bitumen binders with several percentages of TPS additives were studied.All TPS modified bituminous binders were prepared on a laboratory scale.Dynamic shear rheometer(DSR) strain sweep test was made to measure the linear viscoelasticity areas of various bitumen binders at -20-70 ℃,then temperature sweep test and frequency sweep test were made in the linear viscoelasticity areas.Complex modulus master curves were drawn to analyze and compare various bitumen binders’ rheological properties.Based on the test results,the ideal percentage of TPS additive was brought forward.The results show that TPS modified bitumen binders have more excellent properties at high,medium and low temperatures compared with original bitumen.The dosages of TPS additive are vital to their properties.     

Effect of ageing on fatigue properties of asphalt

The fatigue properties of asphalts were investigated after various laboratory simulation ageing tests and outdoor natural exposure ultraviolet radiation ageing,by dynamic shear rheometer(DSR) time sweep fatigue test in constant strain model and a new type of specimen which was introduced to avoid the problem of adhesion failure between rotor and asphalt binder.The results show that outdoor natural exposure ageing(NEA) causes the decrease of retained fatigue life distinctly,and photodegradation caused by outdoor NEA of 1 250 μm thin films asphalt for three months,is found to be severer than pressure ageing vessel(PAV) with respects to retained fatigue life.The effect of photodegradation increases as the time of outdoor NEA increases.DSR time sweep fatigue test in constant strain indicates that the aged styrene-butadiene-styrene(SBS) modified asphalt still displays better fatigue properties than the corresponding base asphalt after ageing.     

不同组成设计方案的钢渣稳定碎石沥青混合料低温抗裂性能研究

沥青稳定碎石混合料由于可以解决传统半刚性基层容易形成干缩裂缝和温缩裂缝等问题,已成为研究热点之一。针对柔性基层的材料性能特点,本文将重点研究不同组成设计方案的钢渣稳定碎石沥青混合料的低温抗裂性能。实验结果发现钢渣稳定碎石沥青混合料弯拉应变能力较石灰石混合料更强,因而拥有良好的低温抗裂性能。     

优质氧化沥青及其油毡的老化研究

优质氧化沥青及其油毡的老化研究吴少鹏（武汉工业大学）中图分类号ＴＥ６２６．８１导言沥青在贮运、加工、施工及使用过程中，由于长时间地暴露在空气中，在风雨、温度变化等自然条件的作用下，会发生一系列的物理及化学变化，如蒸发、脱氢、缩合、氧化等等。此时，沥青...     

海用雷达升级改造的发展思路

简述了国外海用雷达升级改造的发展历程,针对现代不断提高的反雷达技术水平,提出了对旧型海用雷达进行优化升级改造的发展思路和工作方向。     

4.75mm最大公称粒径沥青马蹄脂碎石混合料

由于在预防性维护项目中有很好的前景 ,4 .75 mm最大公称粒径 (NMAS)热拌沥青混合料在高速公路的工程中越来越受欢迎。基于试验结果与分析 ,可成功的设计出粉尘含量小于 12 %的级配的 4 .75 m m NMAS的 SMA混合料 ,而且只要满足其它各方面的要求 ,可以用 0 .0 75 mm筛的通过率为 9%的级配。用 2 .36 mm网孔的金属网篮进行的析漏试验结果比用 6 .3mm网孔的金属网篮的析漏结果要小。集料通过不同的网孔掉出的量的不同造成了用两种网篮的析漏的试验结果不同     

Effect of fiber types on relevant properties of porous asphalt

The research was conducted to evaluate the effects of cellulose and polyester fibers on the properties of porous asphalt mixes, using the tests of draindown, abrasion, volumetric properties, rutting, and moisture damage. Images of scanning electron microscopy and X-ray computerized tomography were adopted to identify the microstructure of the fiber and inner stone skeleton of porous asphalt. The influence of rutting parameter （G＊/sin δ） of asphalt modified by different fibers on the rutting resistance of the mixes was investigated. Based upon MOHR-COULOMB theory, the cohesion and the angle of internal friction of the mixes were derived from both indirect tension and unconfined compression strength. The experimental results indicate that fibers mainly stabilize asphalt binder and thicken asphalt film around aggregates. Furthermore, they result in the improved mechanical strength of porous asphalt mixes at high temperature slightly. From comparison analysis, cellulose fibers appear to perform better than polyester fibers in porous asphalt mixes.     

高速公路沥青面层设计、施工工艺与质量控制

通过马歇尔设计方法和Superpave设计方法进行沥青混合料设计，应用3种不同的级配合成曲线对配合比进行优选，分剐是级配偏上限、级配中值、级配偏下限，同时吸收Superpave级配设计的优点，对级配禁区进行分析。沥青用量采用马歇尔击实或旋转压实进行优选，同时亦采用二者进行双控，确保沥青路面在高温季节行车荷载的作用下不产生车辙，泛油等病害。通过路面试验段现场研究，提出了沥青面层实际施工的摊铺和碾压施工工艺，建立和完善了路面施工质量控制以及质量保证措施和手段。