汽车轮胎非正常损坏的原因及预防措施

轮胎非正常损坏的原因①轮胎气压异常。每款轮胎都有其特定的充气压力,而且其充气压力随着外界温度、路况和载荷的变化还需要进行一定的调整。在车辆的日常保养中,多数情况都是凭经验和感觉检查胎压,很少用气压表仔细检查轮胎气压．这样就造成了胎压过高或过低的情况,从而影响了轮胎的使用寿命。适当提高轮胎的充气量,可以减少轮胎的滚动阻力,节约燃油。但充气量过大时,不但影响胎冠的减振性能,     

夏季汽车应进行换季保养

在炎热的夏季,汽车发动机容易过热,充气系数降低,易产生爆震,使功率下降;润滑条件变差,容易产生气阻等。为了使汽车适应高温酷暑的运行条件,除了正常的维护作业之外,还应及时进行换季保养,其主要检查和调整的项目如下:     

汽缸压力、充气系数与节油的关系

一、汽缸压力发动机在使用过程中汽缸压力不足,可使油耗增约4%～6%。汽缸压力不足有以下原因:①活塞环磨损过甚,或活塞环黏结卡住。②汽缸磨损严重或变形。③气门与气门座结合不严密,密封     

四连杆铰链气弹簧助力式开启机构的设计

四连杆铰链气弹簧助力式开启机构是目前高档汽车特别是轿车上经常采用的一种结构。以行李箱盖为例，详细介绍了该开启机构的设计过程。四连杆机构铰链设计必须保证开启机构灵活可靠；通过选择合适的气弹簧，可使开启机构运动平缓，人手助力轻松。     

该延安SX2190型汽车驻车制动储气筒充气时间过长析因

故障现象：一辆延安SX2190型汽车,发动机启动后,主制动储气筒充气正常,但在主制动气压警告灯熄灭后,驻车制动气压警告灯迟迟不能熄灭,出现驻车制动储气筒充气时间过长现象。     

Experimental study on cyclosporine A drug delivery system in prevention of posterior capsule opacification after intraocular lens implantation in rabbits

Objective To study the effect of cyclosporine A drug delivery system (CsA-DDS) on the prevention of posterior capsule opacification (PCO) after experimental intraocular lens implantation in rabbit eyes. Methods Twenty healthy New Zealand white rabbits, whose left eyes and right eyes were used respectively as experiment eyes and controls, were subjected to extracapsular lens extraction and artificial lens implantation. During the operation, CsA-DDS with poly (lactideco-glycolide) as carriers or empty DDS was implanted in the capsular bag for the experimental eyes and controls respectively. After the operation, anterior chamber reaction, intraocular pressure (IOP) and CsA concentration were monitored and twelve weeks after the operation, the eyes were extracted for histopathological and morphological examinations. Results There were no differences between the two groups in conjunctival congestion,IOP change and anterior chamber reaction. PCO was less severe in the experimental eyes than in the controls. Light microscopy revealed that posterior capsular membrane in the experimental eyes was slick, with no obvious proliferation,whereas in the controls, there were lens epithelial cell proliferation and cortex regeneration of different degrees.Morphological examination with electron microscope showed that in the experimental eyes, lens epithelial cells did not function actively and apoptosis occurred, whereas in the controls, epithelial cells presented active function. No marked ultrastructural changes were found in either group. Conclusion Cs-DDS can inhibit PCO after intraocular lens implantation in rabbit eyes and does not have toxic effects on the surrounding ocular tissues. Therefore, it has a good potential for clinical use in prevention of PCO.