浅析几种结构砼裂缝产生原因及控制措施

结合在施工实践中碰到的若干裂缝，根据裂缝原理对裂缝类型、形成原因进行了分析，从材料、设计、施工等方面提出了控制措施，对确保混凝土的外观质量具有实用意义。     

三连件防跳装置在13号上作用式车钩上的实现与仿真

通过对13号上作用式车钩防跳机理的讨论,分析了其失效的原因.由于它存在着结构性缺陷,零件间又存在较大的配合间隙,导致了防跳功能的失效.对其部分零件进行了结构改进,设计出了新型三连件防跳装置,并应用Pro/ENGINEER软件对其防跳性能进行了仿真模拟,所得结果与试验吻合,验证了该防跳装置能够大大提高防止自然分离的能力.在模拟过程中采用了Pro/Mechanism和Pro/Animation相结合的方法,在保证结果可靠的情况下有效地简化了模拟的难度,可作为一种快捷高效的模拟方法推广应用.     

小儿铁缺乏症血清促甲状腺素含量及尿17—酮类固醇排量的研究

作者观察了47名铁缺乏症儿童血清促甲状腺素含量及64名尿17—酮类固醇排量在肌注右旋糖酐铁治疗前后的动态变化,并分别与32名及28名正常对照组者作了比较。结果显示:铁缺乏症各期儿童上述两项指标均值均高于对照组者,治疗后恢复正常,治疗前后数值统计学上有显著差异;各期间改变程度无差异。结果说明,铁缺乏时出现促甲状腺素及肾上腺皮质激素的代谢紊乱,这种紊乱与缺铁本身有关,与因缺铁而引起的贫血无关。     

电气化铁道通信防护设计的问题探讨

重点介绍电气化铁道对通信的电磁影响,分析产生影响的途径、种类和危害,以及两线路间相对位置的特点和计算方法等关键技术问题,对通信防护设计具有积极的指导作用。     

货物列车分离的原因及改进建议

对造成货物列车分离的原因进行了归纳：解钩装置造成的分离；钩尾框断裂及车钩自动分离。对每种分离原因进行具体的分析,并结合现场实际,对每种原因提出了相应的改进建议。     

Real-world gaseous and particle emissions of a Bi-fuel gasoline/CNG Euro 6 passenger car

The objective of the present study is the assessment of the environmental impact of a bivalent (bi-fuel) vehicle, running either on gasoline or compressed natural gas (CNG). To that aim, a Euro 6 passenger car was tested under various real-world driving conditions. In order to cover the full range of conventional powertrains currently in the market, the tests were also repeated on a Euro 6 diesel passenger car. Both cars were driven in two routes, the first complying with the regulation limits and the second going beyond them. Carbon monoxide (CO), nitrogen oxides (NO_x) and particle number (PN) emissions were recorded using a Portable Emissions Measurement System (PEMS). Apart from the aggregated emission levels, in g/km, the exact emission location along the route was also assessed. Natural gas proved beneficial for CO and PN emissions, the level of which always remained below the respective legislation limits. On the other hand, under the dynamic driving conditions with gasoline, the relevant limits were exceeded. Cold start, occurring at the beginning of the urban part, and motorway driving were identified as major contributors to total emissions, especially in gasoline mode. However, the application of natural gas was associated with a penalty in NO_x emissions, which were significantly increased as compared to gasoline. Local peaks within the urban part were identified in CNG mode. In any case, the diesel vehicle was by far the highest NO_x emitter.     

货车车钩分离原因分析及建议措施

文章对运用部门反映的几个导致车钩自动分离的原因,用分析或推演的方法逐一做了甄别,得出提钩链松余量不足应是导致车钩自动分离的主要原因,并据此提出了建议措施。     

校企协同模式下开放性双师型教师队伍建设机制探讨

高等职业教育的发展和改革正在步入深水区,校企协同的深入推进,为"四位一体"的校企合作模式提出了更多实质性的要求,为具有开放性特征的现代职业教育体系建设搭建了平台。本文分析了现代职业教育体系构建背景下对教师队伍建设的新要求和校企协同育人模式的主要内容,探讨了校企协同模式下开放性双师型教师队伍的建设机制。     

13号上作用式车钩防跳锁方案设计

通过对13号上作用式车钩防跳机理的分析,得出其失效的原因;根据三杆机构直立不稳定原理,对车钩防跳锁组件进行了结构改造,设计出三连件防跳装置。     

基于液力偶合器试验曲线的数学模型

在船舶动力装置稳、动态特性研究中,需要知道液力偶合器在任意工况下的力矩特性,但厂家提供的试验特性图只包含数条泵轮转速恒定情况下小滑差范围内输出力矩随涡轮转速变化的特性曲线。本文先根据液力偶合器的物理特性得出力矩外特性的解析式,再利用试验曲线提供的数据求出该解析式的系数,然后利用已知系数的力矩表达式,将泵轮转速恒定时的力矩试验特性曲线扩充到整个涡轮转速变化范围。最后将这些扩充了的力矩特性曲线进行曲面拟合,从而得出液力偶合器在任意输入泵轮转速和任意输出涡轮转速下的力矩特性,进而获得船舶动力装置仿真研究中液力偶合器完整的数学模型。