维修小技法

防止GY6发动机机油泵小链脱落一法一般情况下,GY6发动机行驶2万公里左右时,容易出现机油泵小链神长脱落现象,造成抱缸、抱轴等,加重了用户在修理时的经济负担。笔者认为,GY6机以小链带动机油泵工作的设计方式不太科学,如果能改成以齿轮带动机油泵工作,故障率可能会低一些。本人在日常维修中摸索出以下方法,可防止机油泵小链脱落,即将机油泵小链左侧一个与中箱相连的螺栓更换成较原螺栓约长10mm的螺栓,将五羊WY125车的张紧条截去三分之二后,固定在长螺栓处,压住机油泵小链,起到导向和张紧作用。本人用此法维修过三辆GY6机,效果很好。     

构建现代企业组织文化建设战略

企业的组织文化对企业的竞争、生存和发展具有重大影响。本文分析了组织文化构成四要件,提出了构建现代企业组织文化建设战略方案,指出了战略方案实施的途径,并提出了推进现代企业组织文化建设过程中还应注意的三个方面的问题。     

深水刚性跨接管安装过程中关键因素分析

结合中国南海1500m水深海况,使用非线性时域分析软件Orcaflex建立“M”型深水刚性跨接管有限元模型。分析跨接管在波浪及海流作用下,三种典型安装工况：提升工况,通过飞溅区工况以及着陆工况中,不同浪向和绞车下放速度对跨接管强度的影响。并根据API RP 2RD规范校核不同安装工况中的牵引力和结构应力响应是否满足要求。结果表明：提升过程中,绞车需要控制适宜的提升速度以避免发生支撑框架结构碰撞;通过飞溅区过程中, 45°浪向角时跨接管的应力响应最小,为理想施工浪向角;着陆过程中,绞车牵引力达到最大值,数值仿真可以预报安装施工船所需的基本起重能力。分析结果对南海深水跨接管安装具有一定参考意义。     

Mammalin cochlear supporting cells transdifferentiation into outer hair cells

Objective To study the recovery of the outer hair cells in the bat cochlea after gentamicin exposure.Methods Bats were injected with a daily dose of gentamicin for 15 consecutive days and bromodeoxyuridine (BrdU)was given from day 16 to day 40 of this recovery phase. Hearing was assessed by overt acoustic behavior and auditory brainstem responses analysis, which was performed one day prior to the first injection and a day after the last injection (day 16). On day 40 animals were sacrificed for detection of cells that could take up BrdU. Results After 15 days of gentamicin treatment, all of the animals were proved to be deafened with significant increases of ABR thresholds,compared with control group. The findings in immunocytochemical stained samples and scanning electron microscopy revealed that BrdU labeled nuclei were observed in the cochlea in all of the deafened animals most commonly in the regions of the first-row and second-row Deiter's cells (DCs) and occasionally in the regions of the third-ruw DCs.Conclusion We suggest that, under sufficient drug and enough time, the bat cochlear supporting cells can directly transdifferentiate into the outer hair cells after aminoglycoside exposure. This transdifferentation process is essential for repair of outer hair cells and recovery of normal function after gentamicin exposure.     

一种用于弹性转子防撞护栏的废旧橡胶改性ABS材料研究

针对现有弹性转子防撞护栏存在的问题,使用NBR胶粒改性ABS,期望得到一种新型转子成型材料.结果显示,NBR改性后的ABS冲击强度有大幅提升,但拉伸强渡、弯曲强度有所下降,材料可加工性变差;使用CPE增容后,复合材料各项性能均有所提升,流动性无影响.最终确定配方为ABS:NBR:CPE为100:30:15,所得复合材料拉伸强度、弯曲强度保持不变,冲击强度大幅增长,可用作弹性转子材料.     

发动智慧科技 彰显自主魅力

<正>对于整车企业来说,核心竞争力的第一要素是拥有自己的动力总成,东风商用车有限公司把动力总成战略视为攸关企业存亡的根本性问题。如今,dCi 1 1和4H发动机良好的成长性表明,东风商用车有限公司励精图治多年的动力总成战略已然破局。近期,随着新产品X7的即将投产,东风商用车将拥有全功率段动力澎湃的"心脏"。     

公路桥梁设计及防水措施

公路桥梁上部结构构造设计中应当注意的问题 公路桥梁的上部结构构造基本包括主梁、伸缩缝、搭板等结构．这些结构的设计质量直接的影响着桥梁设计的成功与否。从施工的施工难度角度来看,在进行桥梁主梁的设计施工时,     

图像分块下的隧道裂缝识别方法

针对隧道衬砌表面不均匀光照、渗水和噪声等强视觉干扰,设计了基于图像分块的隧道衬砌裂缝检测算法;根据中国西部地区的地理特征和隧道衬砌的外观病害,研制开发出一种快速、自动化的非接触式智能隧道结构物外观检测系统; 以非均匀光照下隧道图像数据集为研究对象,在图像分块的基础上提出一种适用于隧道裂缝特征提取的图像识别算法;研究了电子元件产生的噪声,并分析和总结了隧道衬砌的灾害特征;根据裂缝特征和分辨率将图像矩阵划分为适当数量的区域块,根据区域块的灰度特征将原始图像划分为目标背景区、目标病害区、病害背景区和其他区域,通过最大类间方差法和局部阈值法分割得到了隧道裂缝的粗图像,在此基础上进行了粗图像裂缝特征提取;对原始图像的每个区域块进行了对比度受限的自适应直方图均衡操作和局部阈值分割,得到了细节图像;将细节图像和粗图像的重叠区域设为理想裂缝二值化图像;结合隧道结构物外观检测系统对不同方向的裂缝图像进行了二值化试验,并通过隧道裂缝定位和投影法得到了隧道衬砌图像中裂缝的位置信息和方向。研究结果表明:提出的算法对隧道裂缝识别的准确值、召回率和F值可分别达90.34%、98.78%和94.37%,既可以保证隧道裂缝的完整性,也可以在非均匀光照下最大程度地保留目标裂缝的细节,可用于处理一般灰度图像的二值化问题。      

Receiver autonomous integrity monitoring availability and fault detection capability comparison between BeiDou and GPS

This paper used the statistical methods of quality control to assess receiver autonomous integrity monitoring （RAIM） availability and fault detection （FD） capability of BeiDou14 （Phase II with 14 satellites）, BeiDou （Phase III with 35 satellites） and GPS （with 31 satellites） for the first time. The three constellations are simulated and their RAIM performances are quantified by the global, Asia-Pacific region and temporal variations respectively. RAIM availability must be determined before RAIM detection. It is proposed that RAIM availability performances from satellites and constellation geometry configuration are evaluated by the number of visible satellites （NVS, NVS 〉 5） and geometric dilution of precision （GDOP, GDOP 〈 6） together. The minimal detectable bias （MDB） and minimal detectable effect （MDE） are considered as a measure of the minimum FD capability of RAIM in the measurement level and navigation position level respectively. The analyses of simulation results testify that the average global RAIM performances for BeiDou are better than that for GPS except global RAIM holes proportion. Moreover, the Asia-Pacific RAIM performances for BeiDou are much better than that for GPS in all indexes. RAIM availability from constellation geometry configuration and RAIM minimum FD capability for BeiDou14 are better than that for GPS in Asia-Pacific region in all cases, but the BeiDou14 RAIM availability from satellites are worse than GPS＇s. The methods and conclusions can be used for RAIM prediction and real-time assessment of all kinds of Global Navigation Satellite Systems （GNSS） constellation.     

高家花园大桥挠度快速监测系统研究

通过设计、安装重庆嘉陵江高家花园大桥快速挠度监测系统,并分析了该桥火灾后的监测数据,结果对指导桥梁状态评估起到较好作用。在桥梁受火灾后很短时间内该系统就可以开始观察、监测桥梁后期挠度变化情况,因此相关数据对研究桥梁火灾后结构变化具有一定指导意义。