某轮式起重机后悬架板簧销的强度校核

本文对某轮式起重机后悬架的推力杆以及板簧销的受力进行了详尽的分析以及计算,为轮式起重机后悬架系统各总成的设计提供理论依据。     

基于J2EE的通信资源网络管理设计

根据目前各军兵种所控制的本级管控的专用长途光纤传输系统存在的问题,设计了基于J2EE技术,系统采用五层的结构模式,同时结合SSH架构进行开发,实现了通信资源的系统设置、资源管理、业务管理和 FTP文件管理等功能,为通信资源能够准确、灵活、可靠地按照业务流程进行信道资源统一管理和调度,并实现对所有相关数据的查询、检索、更新、导入导出、打印等功能。     

夏利轿车液力减振器簧片的变形分析

应用有限元法对夏利轿车液力减振器簧片的变形特性进行了分析，对不同厚度的组合簧片计算表明，重叠放置的簧片变形不等于一个簧片的变形。中所采取的分析方法及论点，对夏利轿车液力减振器及类似 减振器的设计，生产具有一定的参考意义。     

Low cost carrier competition and route entry in an emerging but regulated aviation market – The case of China

Although China lags behind other liberalized aviation markets in low cost carrier (LCC) development, its largest LCC, Spring Airlines, has achieved rapid growth in traffic volume and revenue, as well as consistent profitability, since its inauguration in 2005. Our empirical study on the Chinese domestic market suggests that Spring adopts a “cream skimming” strategy to enter high-priced routes, allowing the carrier to achieve both a very high load factor and considerable profitability. Spring’s capacity and market share on individual routes are constrained to low levels, likely due to government regulation and/or a “puppy dog” strategy adopted by the carrier. As a result, Spring is able to achieve fast growth without triggering price wars. To incumbent full service carriers, high speed rail (HSR) services impose much more significant competitive pressure than low cost carriers. Similar to LCCs in developed markets, Spring prefers to serve markets with high traffic volumes out of its operational base in Shanghai. Overall, Spring’s entry decision is not significantly affected by competition, either from full service airlines or HSR services. Our investigation suggests that LCCs have potential to introduce more competition but are yet to be a “game changer” in China. Further deregulation of the domestic market is needed.     

商用车板簧支架的轻量化设计

板簧支架的作用是将车架与钢板弹簧连接在一起,并传递二者之间的相对运动和作用力。为了保证整车的重量、成本和可靠性能,对支架的应力和重量都有一定的要求,本文基于Hyperworks平台,采用变密度法进行板簧支架的优化设计,成功改进一种性能优异而重量成本又低的支架,为后期的整车性能提升打下基础。     

后背门气弹簧设计探析

本文首先论述了压缩式气弹簧的结构以及工作原理。以后背门气弹簧布置为例,详细阐述了气弹簧的布置型式;安装点的位置和最大开启角度的确定;有效行程和最小支撑力的计算。     

春节期间货运组织工作的难点与对策

针对铁路春运期间存在的货源下降、运输方向受限等货运组织工作的难点进行分析,提出了强化路企合作,组织有效货源;动态优化方案,细化日历装车计划;改善产品结构,灵活调度指挥等对策,促进春节期间的增运增收,实现客货运输双赢。     

Large-scale physical controls on phytoplankton growth in the Irminger Sea Part I: Hydrographic zones, mixing and stratification

Hydrographic surveys in three consecutive seasons in the Irminger Sea in 2001/2002 have revealed six physical regimes (zones) in which different surface mixing and spring re-stratification processes dominate. They are the South Irminger Current, the North Irminger Current, the Central Irminger Sea, the Polar-origin East Greenland Current, the Atlantic-origin East Greenland Current and the Reykjanes Ridge. The variations in restratification processes in particular have significant implications for the timing of shallow spring mixed layer development and therefore the timing and strength of the spring bloom. The relative roles of heat and freshwater in controlling re-stratification are examined for each hydrographic zone, and it is shown that the simplest concept of solar warming generating spring stratification is appropriate for the Irminger Current and the central Irminger Sea. However in the East Greenland Current and the Reykjanes Ridge zones, the springtime arrival of fresh or saline water at the surface dominates re-stratification and generates the earliest and strongest spring blooms of the region. In the cool fresh centre of the Irminger Sea the relatively low chlorophyll-a throughout the year cannot be wholly explained by stratification or nutrient concentrations. Details of the annual cycle in temperature, salinity, chlorophyll-a and nutrients are presented for each hydrographic zone.     

某款125发动机气门弹簧的选择计算

气门弹簧是四冲程发动机配气系统的关键部件，其参数设计不仅影响发动机的动力性，更重要的是影响发动机能否在高转速下正常运行。通过对某款125mL摩托车发动机配气参数及现有气门弹簧参数的计算，确定了新机型气门弹簧的选型，通过校核计算表明，甲机型的气门弹簧应用于新机型，可以保证使用可靠性和稳定性。     

基于Web的货车检修工序监测系统的研制

介绍了铁路货车检修工序进展监控与管理软件的设计.系统通过Web服务器的串口所连接的无线通信模块与现场的无线手持机通信.主机通过轮询方式查询手持机发送的作业进展信息,利用多线程协调完成通信信息的获取与分析.同时,系统采用B/S模式在浏览器页面能对检修工序进展进行实时监视.在Web服务器端,利用Spring任务定时实现每天工作的启停,以及用Spring编写REST风格的Web服务.在浏览器端,利用AJAX技术实现对Web服务的访问,以及将显示结果在页面上动态显示.Web服务通过Json变换向浏览器传递对象消息.