新车使用的几点建议

当你辛苦奋斗多年，终于把爱车购为己有时，肯定是无比激动，急切地想驾着你的爱车去驰骋，去翱翔，享受爱车带给你的便利和飞一般的感觉。那么，且慢，朋友，为了你的爱车和你的健康和安全，新车使用前有必要了解一些知识，相信会对你有所帮助。     

车架涂装前处理工艺的改进

为避免铆接车架涂装后漆膜表面出现白色粉斑、弹簧垫圈易断裂、铆钉松动且强度下降等问题，采取了几项有针对性的措施，取消了原来的整体车架酸洗工序；加大了对外协件生产厂家的管理力度；严格了外协件进厂检验和库存制度；对存放过程中生锈的零部件先除锈再防锈，然后上线铆焊，确保车架涂装前表面无锈。经过述改进后，大大提高了车架涂装质量、降低了车架制造成本，还避免了酸液排放对环境造成的污染。     

浅谈大跨预应力混凝土斜拉桥综合施工技术

随着我国经济的飞速发展,桥梁施工技术也在不断发展,施工机械设备也在不断更新,大跨度斜拉桥施工技术因其结构新颖美观、跨越能力大而在工程实践中得到越来越多的应用。以永宁黄河大桥采用预应力混凝土斜拉桥施工为例,针对主要施工技术及施工创新和大跨度斜拉主梁冬季施工技术等方面对其整个施工过程进行了分析和讨论,解决了施工中的难点问题,实现了良好的结果并被推广应用,可供同类的公铁路桥梁建设项目参考借鉴。     

客车左前轮转向节断裂分析

采用金相检验、扫描电镜等分析手段，对客车左前轮转向节断裂进行了分析。结果表明，转向节采用了存在粗大魏氏组织的30号钢制造，该转向节未经调质热处理，断裂起源于加工刀沟的缺陷处，在过载冲击载荷作用下，裂纹逐渐扩展，导致转向节早期疲劳断裂。     

轿车前梁有限元分析

利用轿车前梁的CATIA模型建立其有限元模型。通过前悬架的ADAMS模型确定前梁的受力。应用这些方法将CAD、CAE有机的结合在一起，提高了有限元分析的效率和准确性。为了检验模型的精确程度，对前梁进行了静态加载试验。结果表明计算和试验结果有很好的一致性。     

现代汽车车轮定位参数调整方法(上)

本文归纳了国内常见几十种车型车轮定位参数的调整部位及方法,并配以图解说明,有助于广大汽车维修人员在实际操作中了解各种不同的悬架结构,准确地掌握其车轮定位参数的调整方法,很有实用价值。     

THE EXPRESSION OF BCL-2, BAX AND CASPASE-3 IN NEURON OF THE SPINAL CORD ANTERIOR HORN AFTER CAUDA EQUINA ACUTE COMPRESSION

Objective To explore the influence of the acute cauda equina compression on the iumbosacral spinal cord; To clarify the pathologic change of the motor neuron after acute cauda equina compression. Methods 27 canis familiaris were randomly divided into 9 groups （3 in each） ： one for normal group, one for control group, and seven for compression groups. The control group and compressed groups was given operation and the sac made of silica gel was placed under the lamina of L5-6. Water was injected into the sac until their posterior legs paralysis in compressed groups, the animals had been compressed for 4, 8, 12, 24, 48, 72, 168 hours. The control group were not injected water. Cells apoptosis was investigated with the technology of TdT-mediated biotin dUTP nick end-labeling （TUNEL） staining. The Bcl-2 Bax and Caspase-3 protein was investigated by immunohistochemical method. Results TUNEL staining cells in anterior horn presented after compressed 8-12 hours, and at 72 hours the number of positive cells got to maximum, it decreased subsequently after 168 hours. The protein of Bax, Bcl-2 expressed a little in normal motor neuron. The caspase-3 protein didn＇t express in normal ceil. They all reached the peak at 72 hours after compression. Conclusion The apoptosis of motor neuron occurred earlier after eauda equina acute compression. Bax protein restrained Bcl-2 protein then active caspase-3 and conduced apoptosis of motor neuron.