青川天然沥青的组成及其沥青质结构参数研究

利用化学分析、X射线衍射分析、红外光谱等方法对四川青川天然沥青的组成及其沥青质晶体结构进行研究。结果表明,该天然沥青样品富含沥青质,矿物质含量较高,属于沥青矿中的脆沥青类;其沥青质X射线衍射图谱中重叠的γ、(002)峰可以用Gauss、Lorentz两种分峰方式进行有效分离,得到的沥青质结构参数与石油沥青质有较大差别,主要体现在芳碳率较小,芳香层堆积平均高度较低,有效芳香层数要比石油沥青质小得多,约为2层左右。     

60N钢轨18号无砟道岔的运用研究

60N钢轨18号无砟道岔在京沈客运专线喀左站进行了试铺,通过预打磨试验、联调联试道岔动力学性能测试及开通后服役性能分析,验证其在高速条件下的适应性。结果表明:60N钢轨道岔可实现与区间60N钢轨的匹配,与60 kg/m钢轨18号无砟道岔预打磨相比减少打磨工作量60%以上,打磨质量更容易保证;综合检测列车以不同速度通过60N钢轨18号无砟道岔时,安全性、平稳性、舒适性和道岔结构动力学等指标均满足列车运行要求。与60 kg/m钢轨18号无砟道岔列车动力学性能测试结果对比表明,构架脱轨系数和轮轨横向力峰值有所降低,其他动力学指标基本相当;60N钢轨18号无砟道岔服役性能试验结果表明,钢轨服役性能良好,无明显磨耗及伤损情况产生。     

Experimental validation of connected automated vehicle design among human-driven vehicles

In this paper, we present results regarding the experimental validation of connected automated vehicle design. In order for a connected automated vehicle to integrate well with human-dominated traffic, we propose a class of connected cruise control algorithms with feedback structure originated from human driving behavior. We test the connected cruise controllers using real vehicles under several driving scenarios while utilizing beyond-line-of-sight motion information obtained from neighboring human-driven vehicles via vehicle-to-everything (V2X) communication. We experimentally show that the design is robust against variations in human behavior as well as changes in the topology of the communication network. We demonstrate that both safety and energy efficiency can be significantly improved for the connected automated vehicle as well as for the neighboring human-driven vehicles and that the connected automated vehicle may bring additional societal benefits by mitigating traffic waves.     

Stability analysis on a dynamical model of route choice in a connected vehicle environment

Research on connected vehicle environment has been growing rapidly to investigate the effects of real-time exchange of kinetic information between vehicles and road condition information from the infrastructure through radio communication technologies. A fully connected vehicle environment can substantially reduce the latency in response caused by human perception-reaction time with the prospect of improving both safety and comfort. This study presents a dynamical model of route choice under a connected vehicle environment. We analyze the stability of headways by perturbing various factors in the microscopic traffic flow model and traffic flow dynamics in the car-following model and dynamical model of route choice. The advantage of this approach is that it complements the macroscopic traffic assignment model of route choice with microscopic elements that represent the important features of connected vehicles. The gaps between cars can be decreased and stabilized even in the presence of perturbations caused by incidents. The reduction in gaps will be helpful to optimize the traffic flow dynamics more easily with safe and stable conditions. The results show that the dynamics under the connected vehicle environment have equilibria. The approach presented in this study will be helpful to identify the important properties of a connected vehicle environment and to evaluate its benefits.     

皮层下缺血性脑血管病CT表现与血管性痴呆的相关研究

目的　探讨皮层下缺血性脑血管病CT表现与血管性痴呆之间的关系。方法　对比分析 6 0例皮层下多发脑梗死痴呆者和 6 8例皮层下多发梗死无痴呆者CT表现。结果　痴呆组中额叶皮层下、内囊前肢、尾状核、半卵圆中心前部、侧脑室体旁前部白质及丘脑梗死发生率、平均梗死灶数目及平均梗死体积均大于对照组 (P <0 .0 5 ) ;3级、4级脑白质疏松出现率显著高于对照组 (P <0 .0 5 ) ;脑萎缩指数测量值明显大于对照组 (P <0 .0 5 )。非条件Logistic回归分析额叶皮层下及丘脑梗死灶数目、侧脑室体旁前部白质梗死灶体积、脑白质疏松以及脑皮层萎缩的程度与血管性痴呆的发生显著相关。结论　皮层下多发脑梗死性痴呆与梗死灶的部位、数目、体积和脑白质疏松及脑皮质萎缩的程度密切相关     

Ni60自熔性合金高频感应熔涂组织分析

研究分析了Ni60自熔性合金高频感应熔涂组织。结果表明:高频感应熔涂Ni基涂层与基体形成了良好的冶金结合,涂层与基体之间存在明显的扩散转移带,涂层组织中存在明显的柱状晶。高频感应熔涂涂层中有丰富的增强耐磨性的杂质相,能显著提高基体表面硬度。     

基于Intel PXA26X处理器的BootLoader的设计与实现

介绍了基于PXA26X处理器构造的高端手持嵌入式产品的BootLoader的设计与实现．简要介绍了PXA26X处理器的芯片结构,给出了一种基本手持设备的硬件结构框．说明了BootLoader的整体框架结构,给出流程图,并详细讲解了调试硬件遇到的关键问题和与操作系统配合的方法．     

基于ARM的嵌入式虚拟示波器系统的设计

基于ARM技术，以S3C44BOX为CPU，在uClinux基础上，通过USB设备来连接装有Labview的PC机，设计了一种嵌入式虚拟示波器系统．uClinux是一种运行于没有MMU的嵌入式微处理器的Linux衍生操作系统，实现了多任务运行．介绍了虚拟示波器的概念及Labview的特点和工作过程．     

谈基于CDMA1X的海事虚拟拨号专网(VPDN)的实现

现代信息技术正在以前所未有的速度蓬勃发展，它正在从根本上改变人们的传统理念和思维方式。现代信息技术的发展给海事事业在管理方面带来了机遇和挑战，如何利用好信息化技术实现海事工作的跨越式发展，是每个海事员工应积极思考的问题。交通部海事局提出：“对辖区海事各项业务进行数字化综合管理”，实现海事业务管理向信息化、数字化和现代化的转变。因此，利用计算机网络技术、无线通讯技术、流媒体技术实现数字移动办公在海事工作中是极其重要的。通过联通无限CDMA1X高速无线上网与海事内部专用网络建立虚拟拨号专网（VPDN）连接是实现数字移动办公的一个比较理想的选择。     

V／X接线与Scott接线牵引变压器的工程应用比较

通过对采用V/X接线110/2×27.5kV牵引变压器与采用AT方式Scott接线110/55kV牵引变压器的牵引变电所在占地面积、投资、负序影响、节能等方面进行比较,并结合朔黄电气化铁道增建的AT方式龙宫牵引变电所选择采用V/X接线牵引变压器的工程实例,说明了V/X接线牵引变压器在工程应用上的合理性,还结合国家政策分析了这种接线牵引变压器的应用前景。