SBR改性沥青混合料紫外光照老化分析

介绍了在室内使用紫外线高压汞灯在散铺情况下对热拌沥青混合料进行光照老化对比实验,用此模拟热拌沥青混合料在西藏地区室外光照下老化情况.试验中利用不同时照的紫外线老化,SBR改性沥青混和料与基质沥青混合料的劈裂强度变化,反映出沥青混合料随时间变化的规律.试验中改性沥青混合料表现出更好的抗紫外线老化性.说明在西藏地区使用改性沥青具有更好的路用性能.     

NOVEL SPLICING MUTATION OF COL1A1 GENE CAUSING OSTEOGENESIS IMPERFECTA TYPE I IN CHINESE PEDIGREE

Objective To detect the peculiar mutation in a Chinese family with osteogenesis imperfecta,COL1A1 and COL1A2 being analysed. Methods A genome screen was undertaken covering COL1A1 at 17q21-22 and COL1A2 at 7q22.1. The Linkage ( Version 5.1 ) was used for 2-point analysis. DNA sequencing was used to screen and identify the mutation. Results A linkage to the markers on chromosome 17q21-22 was observed. Sequence analysis of COL1A1 revealed a splicing mutation ( IVS8-2A ＞ G) that converted the 3' end of intron 8 from AG to GG. Conclusion This mutation ( IVS 8-2A ＞ G) is novel, and has not yet been registered in the Human Type Ⅰ and Type Ⅲ Collagen Mutations Database.     

PRELIMINARY STUDY OF OMENTUM TRANSPOSITION TO BRAIN FOR TREATMENT OF ALZHEIMER'S DISEASE

Objective To learn the effect of omemtum transposition to the brain of patients with Alzheimer's disease. Methods Ten consecutive patients, aged 58 - 81 years old, underwent graft of their elongated pedicled omentum onto their left frontal-temperal-parietal cerebral cortex. Those patients, who had more than five years of dementia with low mini mental-state examination (MMSE) scores of 2 -15, were diagnosed by a neurologist. All subjects underwent single photon evoked computer tomography (SPECT) pre- and post-operatively.SPECT results were analyzed semi-quantitatively by calculation of the left/right radioactivity counts symmetry index (Si). The patients were followed up to one year. The outcome was evaluated by the neurologist with a modified scale of activities of daily living (mADL) as well as the MMSE. Results Three months following the surgery,the Si of SPECT increased from ( 98. 7 ± 1.9) % to ( 103. 9 ± 2.3 ) % ( P = 0. 0307). The neurological and neuropsychological testing scores increased insignificantly during the follow-up period. By the one year, the MMSE score rose from 8. 7 ± 1.4 to 10. 7 ± 1.8 ( P ＞ 0. 05 ), while the mADL from 13.3 ± 1.8 to 16. 9 ± 2. 0 ( P ＞ 0. 05 ). One of the patients suffered a heart attack, two had epileptic episodes postoperatively. Conclusion We believe that omental transposition to the brain augments cerebral blood flow, which might be helpful to decelerate the processing of Alzheimer's disease. However, it is still a potentially risky procedure for the elderly.     

Study on Distributed Motion of Self-Reconfigurable Robot Based on Local Rules

The eigenvector of a module with six adjacent module's state was constructed according to self-reconfigurable robot M-Cubes and the configuration of system was expressed with the eigenvectors of all modules.According to the configuration and motion characteristics of the modules,a 3-dimension motion rule set was provided.The rule sets of each module was run according to eigenvector of the module after the motion direction of system decided and motion rules were selected.At last,the rapid and effective motion and metamorphosis were realized in system.The rule sets are operated on three systems and the distributed motion of system is fully realized.The result of simulation shows that the 3-dimension motion rule sets has perfect applicability and extensibility.The motion steps and communication load of the modules increase with the module number in linear.     

Wind Generator Stabilization with Doubly-Fed Asynchronous Machine

This paper investigates the function of doubly-fed asynchronous machine(DASM)with emphasis placed on its ability to the stabilization of the power system including wind generators.P(active power)and Q(reactive power)compensation from DASM can be regulated independently through secondary-excitation controlling.Simulation results by power system computer aided design(PSCAD)show that DASM can restore the wind-generator system to a normal operating condition rapidly even following severe transmission-line failures.Comparison studies have also been performed between wind turbine pitch control and proposed method.     

SNS柔性防护网在公路边坡中的应用

结合工程实际,介绍了SNS柔性防护网的特点和GAR2+SS2型SNS主动防护网在公路边坡中的应用及其施工工艺和方法。     

基于长间隔大规模数据的地图匹配算法研究

随着GPS定位技术应用的日益推广,GPS技术被大量应用于公交车辆及出租车辆的定位与预测.公共交通调度中心的数据量和处理负荷将变得非常巨大,而且租用电信无线网络的费用也很高.如何使用尽可能少的数据得到比较好的定位信息和节约计算资源就成为我们面对的一个重要课题.针对杭州交通调度中心的出租车和公交车的大间隔定位信息,本文提出了一种将基于权值,道路拓扑和最优路径选择相结合的综合地图匹配算法,并应用于实际,取得了很好的效果.     

土基模量对水泥混凝土路面轮载疲劳开裂损伤的影响

基于有限元软件KENSLABS, 构建了水泥混凝土路面轮载损伤计算模型, 引入地基季节调整系数与零养护疲劳准则, 分析了土基模量整体削弱对路面疲劳开裂指数的影响, 探讨了当量轴载系数与多轴通过一次的计算次数对土基模量的依赖性, 研究了不同土基模量下板厚、水泥混凝土抗弯拉强度、单轴轴重、单轴每日重复作用次数等核心路面设计参数与路面开裂指数的关系。研究结果表明: 水泥混凝土路面疲劳开裂指数随着地基季节调整系数的减小而增大, 增大速度随地基季节调整系数的减小而加快, 当地基季节调整系数从1.0减小为0.8和从0.4减小为0.2时, 在单轴、双轴和三轴荷载作用下, 路面开裂指数分别增大了2.8、2.9、1.5倍和49.8、269.0、1 351.4倍; 当量轴载系数与多轴通过一次的重复计算次数受到板厚与土基模量的影响, 在土基模量为60 MPa, 板厚为15cm或35cm时, 单轴荷载比双轴荷载更易产生损伤, 双轴荷载比三轴荷载更易产生损伤, 在土基模量为20MPa, 板厚为15cm时也是如此, 但在土基模量为20MPa, 板厚为35cm时, 结论则与前相反; 水泥混凝土路面疲劳开裂指数随着面板厚度、水泥混凝土抗弯拉强度、单轴轴重、单轴每日重复作用次数而改变的幅度与土基模量直接相关, 当土基模量为20、60 MPa时, 面板厚度从21cm增加到25cm, 疲劳开裂指数分别减小1.18×10、1.18×10^-2, 当混凝土抗弯拉强度从4.0 MPa增大到4.4 MPa, 疲劳开裂指数分别减小1.28、2.20×10^-3, 当单轴轴重从80kN增大到160kN时, 疲劳开裂指数分别增大5.48、7.36×10^-3, 当单轴荷载每日重复作用次数从50增加到90时, 疲劳开裂指数分别增大2.05×10 -1、5.07×10^-4; 增设厚度为15cm的水泥稳定基层后, 设定工况下的路面疲劳开裂设计寿命增加3.42年; 在提高土基模量的同时, 宜优先考虑适当增加板厚, 严禁超载, 设置水泥稳定基层等措施, 可以控制水泥混凝土路面受轮载作用的疲劳开裂破坏。     

发动机正时齿带故障的检修

1正时齿带故障特征目前,一般轿车和轻型汽车发动机的正时齿轮采用齿形皮带传动,其特点是结构简单、噪声小、运转平稳、传动速比不变、传动可靠及精度高等。但此     

稀浆封层路面成型机理与压实工艺

通过对稀浆封层施工工艺分析,简要阐述了稀浆封层路面的成型机理,提出了选用合理的压实工艺是一种提高稀浆封层施工质量与效率的重要方法。并且主要从碾压方式的选择、专用压实设备的选择与使用这2个方面,对稀浆封层路面的压实工艺进行了探讨。