大功率交流传动内燃机车发展现状及对开发200km/h客运机车技术问题的探讨

介绍了国内外交流传动内燃机车发展的概况,结合国内出现的开发200km/h大功率客运内燃机车的要求,针对其中的一些技术问题进行了探讨,并提出了建议.     

Forging penetration efficiency of steel H13 stepped shaft radial forging with GFM forging machine

The numerical thermal mechanical simulation of radial forging process of steel H13 stepped shaft with GFM (Gesellschaft fur Fertigungstechnik und Maschinenbau) forging machine was carried out by three-dimensional finite element code DEFORM 3D. According to the effective plastic strain, the mean stress and the mean plastic strain distribution of the radial forging, the forging penetration efficiency (FPE) was studied throughout each operation. The results show that the effective plastic strain in the center of the forging is always greater than zero for the desirable larger axial drawing velocity. The mean stress in the center of the workpiece is proposed to describe hydrostatic pressure in this paper. There is compressive strain layer beneath the surface of the workpiece to be found, while there is tensile strain core in the center of the workpiece. These results could be a valuable reference for designing the similar forging operations.     

红外线阵探测器驱动电路的低噪声设计

论文首先介绍了红外线阵探测器的系统组成和各个组成部分的功能,详细分析了红外探测系统的噪声来源,并结合实际经验,从软件到硬件电路设计,总结了降低噪声的方法,最后通过分析实验数据,得出红外线阵探测系统输出信号的噪声均方差（RMS）等于0．68mV,计算得到中波线阵探测器的NETD等于80ink,长波红外探测器的NETD等于40mK。实验数据显示通过采用本文低噪声的设计,驱动采集电路达到了比较低的噪声值,红外焦平面探测系统总体成像性能达到理想效果。     

中交四航院海岸工程勘察技术的回顾与展望

我国沿岸港口建设日趋饱和,需要在自然条件更加恶劣的沿岸建设大型港口物流枢纽、大型跨海桥梁、海底隧道及清洁能源风电机组等基础设施,海岸工程勘察常遇上浪高、流急、水深、风大等作业条件;另一方面,大型基础建设越来越需要高标准严要求的综合勘察技术以解决复杂多变的地质条件,采用传统单一的海上工程勘察技术越来越难满足大型工程建设的需要,寻求海岸工程勘察技术的革新是必然的要求。以四航院为例,回顾海岸工程勘察技术的发展过程,并展望勘察技术水平提高可增强国际竞争力,为推动我国水运行业的海岸工程勘察技术与国际接轨并参与国际竞争提供参考。     

基于驱动桥减速器轴承的失效分析

对驱动桥台架试验中失效轴承进行了检测及受力分析,运用疲劳强度分析找出了失效原因并进行改进,最终使台架试验顺利达标。提出了轴承挡边是驱动桥减速器设计中的一个薄弱环节,并给出了轴承挡边强度的校核方法和评价指标。     

某汽车驱动桥桥壳有限元分书

以某型汽车后桥为例,应用三维建模软件及有限元分析软件对驱动桥桥壳进行有限元分析,为驱动桥桥壳的设计提供理论设计依据。     

隧道工程大断面深竖井施工安全计算分析

针对隧道工程大断面竖井施工技术复杂、施工难度大、安全隐患集中等难题,文章以甘肃省武罐高速公路麻崖子隧道竖井施工为例,从施工方案的选择,设备提升、钢丝绳选型、校核验算及施工过程的安全监管等方面进行安全监控探讨,确保了施工安全,可为同类工程提供借鉴。     

北京地铁8号线安-安区间明挖盾构始发井快速提供始发条件技术探讨

随着城市轨道交通的迅猛发展,盾构区间隧道被大量采用,如何快速利用盾构井提供盾构始发条件,成为设计及施工人员需要考虑的问题。以北京地铁8号线安华桥站-安德里北街站区间（简称安-安区间）盾构井为研究对象,取消该盾构井地下1层和地下2层结构,并通过理论计算,采用混凝土腰梁代替钢支撑的作用。结果显示,安-安区间盾构井在回筑、盾构机始发吊装及盾构机掘进期间,该盾构井周边地表沉降最大值仅6.42 mm,周边管线沉降不足1 mm。从而证明： 在单个盾构井中,采用混凝土腰梁代替钢支撑可以满足安全、快速提供盾构始发条件的要求。     

Mental flexibility impairment in drivers with early Alzheimer's disease: A simulator-based study

After memory impairment, one of the most common troubles of early Alzheimer's disease (AD) is the impairment of executive functioning. However, it can have major consequences on daily life, notably on the driving activity. The present study focused on one important executive function involved in driving: mental flexibility; and considered how this impairment can affect driving. Ten patients with early AD were matched with 29 healthy older drivers. All participants were given an evaluation of mental flexibility through neuropsychological tests and an experimental test developed on a static driving simulator. The experiment was divided in two conditions; one without mental flexibility and another condition with a mental flexibility demand. AD patients showed impairments in the neuropsychological tests evaluating mental flexibility. These deficits are linked to the deficits they showed in the driving simulator flexibility tests. This study contributes to the understanding of mental flexibility mechanisms and on their role in driving activity. It also confirms that the driving simulator is a suitable tool to explore cognitive disorders and driving ability.     

煤矿斜井TBM施工长距离反坡排水技术

结合TBM法施工煤矿长距离斜井面临埋深达660m、反坡坡度为6°（-10．5％）、地层富水的问题,通过斜井排水管线路设计、排水设备及储水水仓等设计研究,从经济可靠的角度出发,提出TBM斜井分级、分流量梯度反坡排水方案,解决TBM长距离反坡排水施工技术难题。