光纤码分多址技术在城域接入网中的应用

分析了光纤码分多址技术O -CDMA在城域接入网中的应用。回顾了O -CDMA技术的发展历史 ,详细地介绍了O -CDMA技术的特点 ,其具有的公平性、灵活性、网络控制管理、对服务区处理能力以及高的安全性使O -CDMA技术成为较好的城域接入网技术。阐述了目前在应用中O -CDMA存在的一些技术方面的问题     

滚子加工工艺分析及改进

对圆锥、圆柱滚子加工工序繁多的原因进行了深入的分析,并在此基础上,从多方面压缩了工艺留量。     

嵌入式系统在数控零编程滚齿机中的应用

该课题首次将嵌入式技术与数控零编程思想相结合，以μCOS-Ⅱ实时操作系统为核心，建立了一套具有友好人机界面的零编程数控系统。该系统不仅突破了传统的手工编写数控程序的方法，实现了NC程序的自动生成；而且通过USB接口将系统巧妙的设计成了一个可移动的存储器，间接的扩大了数控系统的存储容量；通过RS232串口，系统还能与滚齿机床实现NC程序的上传和下载，是一个集NC程序自动生成、存储和传输的集成化系统。     

航显系统中LED显示软件应用

现代机场的航显系统中大量应用LED显示屏，包括值机、进出港、行李提取、登机等业务中，如何将大量的数据及时、准确的发送到数量众多的LED屏上是航显系统的关键任务。本文以实际项目为基础介绍航显系统中的LED显示软件是如何安全、可靠的提供服务的。     

土钉加锚杆联合支护基坑的失稳分析及处理

根据具体工程实例,介绍了在基坑开挖时采用土钉加锚杆的联合支护方式后在施工过程中出现坍塌裂缝的现象,针对这一现象,分析了施工条件与环境,得出了事故发生的原因,并结合实际情况提出了处理措施.     

带传动摆架式自动张紧装置的张紧力计算

基于带传动在稳定工作时的受力平衡，从理论上导出了摆架式自动张紧装置所产生的张紧力的计算公式。结果表明：只要合理选择计算安装参数，其张紧力总能满足张紧条件的要求，以对张紧装置进行设计计算；并指出该装置产生的张紧力，具有随外载荷变化而自动调节的性能，使传力零件部分卸载。     

曲柄摇杆机构的三圆图解设计法

这里探讨了对给定行程速比系数K，摇杆摆角ψ，另外再给定摇杆长度l3(机架长度l4)、曲柄长度l1(连杆长度l2)等，找出如何运用辅助圆图解设计曲柄摇杆机构的方法。     

Accumulation and Mixing of Oils in Jinghu Sag of Subei Basin： Constraints from Thermal Maturity Parameters

Oils in Jinghu sag are abundant with high content of polar compounds and have a low ratio of saturate to aromatic hydrocarbons and a high ratio of resin to asphaltene. The gross composition of oils in the Jinghu sag suggests typical immature to low mature characteristics. Some compounds with low thermal stability were identified. Light hydrocarbons, a carbon preference index, an odd even index, n-alkane and hopane maturity parameters show mature features and little differences in the maturity level among oils. Sterane isomerization parameters indicate an immature to low mature status of oil. Transfer of the sedimentary center during sedimentation has led to different thermal histories among subsags and thus generated oils with different maturities. On the basis of source analyses, four migration and accumulation patterns with different maturity can be classified. Combined with available information on mergers of source, reservoir and long distance oil lateral migration, mixing conditions were present in the Jinghu sag. Experimental results indicate that maturity variations are caused by mixtures of hydrocarbons with different maturity.     

Investigation on the Recrystallization Behaviour of Cold Deformed MP159 Alloy

The recrystallization behaviour of cold drawn MP159 alloy was investigated by optical and TEM examinations. It is found that the platelet ε phase in the MP alloy inhibits the recrystallization,and this effect makes the MP159 alloy with high recrystallization temperature of about 920℃.This inhibition mainly comes from the increasing of the interfacial energy, which results from the change of the coherent interfaces of (0001)hcp//(111)fcc into the incoherent interfaces when the recrystallizing grain fronts bypass the platelet ε martensite. The increasing of the interfacial energy also causes the dissolution of a few segments on the ε martensite platelets, which decreases the strength of the MP alloy