旧水泥混凝土路面上沥青薄层罩面力学响应分析

为了研究旧水泥混凝土路面上沥青薄层罩面的力学行为,运用BISAR程序对荷载作用下旧水泥混凝土路面上沥青薄层罩层层内及层间力学的响应规律做了分析,通过定义最不利值探讨了材料和荷载参数变化对罩面层结构应力的影响。结果显示:超载对罩面层的影响比罩面层厚度和模量的增加对罩面层的影响要大;当荷载、罩面层模量、罩面层厚度同时增加50%时,罩面层模量对减小εmax、γmax最有利,增大模量可以减小剪切变形,增强路面的抗滑移能力;从减小最大剪应力γmax的效果来看,增大罩面层模量比增加罩面层厚度更合理。     

基于预报误差的船舶遭遇台风概率预报

在航船做避台决策时,首先要判断该系统预报的恶劣天气对本船未来航线是否有影响。考虑到台风运动的不确定性及台风预报存在误差,根据概率预报的思想,提出了船舶遭遇台风概率的概念,将大范围、不确定的航区天气预报具体到本船航线上。首先针对航行条件下接收的航区的气象预报信息的特点,提出了计算台风预报误差的概率密度的方法;然后提出了以船舶遭遇台风安全距离为依据的预报航线上船舶遭遇台风概率的方法。该方法综合考虑了台风运动与预报的不确定性并将这种不确定性定量化,船长可以此概率预报为基础,结合具体情况确定概率评价值,从而为作出避台决策提供了依据。     

浅议我国城市轨道交通可持续发展对策

本文分析了我国城市轨道交通发展存在的主要问题,通过构建可持续发展模式,在经济、社会、技术和内部发展四方面提出了13条对策,运用层次分析法计算指标权重确定广义函数总值。最后对城市轨道交通可持续发展程度进行量化分级,指导城市轨道交通可持续发展。     

Effects of systemic domestic recombinant human erythropoietin on HIF-1α expression in the retina in a rabbit model of acute high intraocular pressure

Objective To observe the expression of hypoxia inducible faetor-1α (HIF-1α) in the retina of rabbits with acute high intraocular pressure and to investigate the mechanism of systemic domestic recombinant human erythropoietin (rhEPO) protecting the retina from ischemia-reperfusion injury. Methods First, control group and model group were established in rabbit eyes. The acute high intraocular pressure model was established by saline perfusion into anterior chamber, and then hypodermic injection of domestic rhEPO was made. HIF-1α protein in the retina was observed by immunohistochemical staining method on days 1, 3, 7 and 14 after retinal ischemla-reperfusion, respectively. Results No cells with HIF-la positive expression were observed in the retina of the control group. Ceils with HIF-1α positive expression in the model group outnumbered those in the control group (P < 0. 01). The resemblance pattern occurred in EPO group but its degree was slightly greater than that in the model group from day 3 after ischemia-reperfusion (P<0.05). Conclusion Domestic rhEPO can down-regulate the expression of HIF-1α in the retina with acute high intraocular pressure, which may be one of the mechanisms that rhEPO protects the retina from ischemia-reperfusion injury.     

汽车轮胎噪声及其欧洲认证标准

为了使国内汽车轮胎厂家积极应对欧洲即将强制执行的轮胎噪声法规,文章阐述了轮胎噪声研究的重要性、轮胎噪声机理及常规测试方法,并结合具体产品详细介绍了欧洲ECE R117轮胎噪声标准,并对试验过程中应注意的问题及我国轮胎产品的噪声现状进行了标准分析。结果表明,我国轮胎产品噪声控制远低于ECE R117标准,但为了适应不断加严的国际标准,我国应加速发展低噪声轮胎。     

贝雷梁挂篮设计与应用

挂篮是构造箱粱施工的主要设备之一,种类繁多,造价也各不相同,在施工过程中,需根据实际情况选用。以楠木渡战备大桥为例,对由贝雷梁组拼的简易挂篮在连续刚构中的设计及应用作一介绍．对于挂篮的合理选用具有一定的现实意义。     

城市轨道交通可持续发展对策分析

从上海城市轨道交通现状出发,以城市轨道交通可持续发展理论为基础,借鉴国内外经验,指出我国城市轨道交通发展存在的主要问题。研究城市轨道交通可持续发展的必要性和发展模式,着眼于交通运输系统内部和外部效应,提出14务实现城市轨道交通可持续发展的对策。对我国城市轨道交通可持续发展有一定的指导作用。     

基于LS-DYNA的岸桥门腿受冲屈曲仿真分析

利用LS-DYNA软件,通过实体建模对岸桥门腿受冲进行仿真,讨论岸桥因倾斜跌落而使门腿发生冲击屈曲的原理,并针对起重机实例求出导致门腿动态失稳的临界高度,以便进一步探寻岸桥发生风灾事故的原因和防范措施。     

三维数控船台小车控制系统设计

本文介绍了一套应用于大型船厂焊接生产线上的三维数控船台小车控制系统的设计概要,简要描述了该控制系统的用途、软硬件配置及控制系统的一些主要控制策略。     

Theoretical,Simulation and Experimental Analysis of Microfluidic Droplet Generation and Recovering Process with Applications in Frying Oil Assessments

The research on microfluidic droplet size prediction has been extensive and fruitful, while the droplet deforming process has been seldom studied. In this paper, a frying-oil-assessing microfluidic device was designed to study the droplet deforming and recovering processes, which were dominated by channel geometry, flow rates, sheath flow viscosity and interfacial tension of the two phases. Theoretical expressions of the deforming process and its extreme value were obtained for the first time, supported by simulation and experiments. Theoretical, simulation and experimental results indicated that the steady-state droplet length could be a useful parameter for frying oil assessment.