I、II型架桥机在香港西铁高架桥中的施工

香港西铁高架桥施工场地狭小,主梁整体预制可能性较小,在设计中采用组合拼装主梁方案.在施工中采用工厂预制混凝土梁节、桥位拼装成梁施工,本文分别介绍了在香港西铁CC213合同段采用I型架桥机拼装高架桥箱梁和II型架桥机拼装主梁的施工工艺.     

基于PC的NSP可视电话系统的实现

介绍了基于PC的多层分布式可视电话系统的实现。论述了一系列技术难点的实现策略和取得的主要性能指标。     

基于SNMP/Web双协议的嵌入式网络管理研究与实现

介绍SNMP网络管理协议的管理方式和基于Web的管理方式，然后给出嵌入式设备上将二者相结合的SNMP／Web实现框架，其中重点提出如何构造设备上的嵌入式Web服务器等关键技术，使设备支持基于SNMP和HTTP两种协议的网络管理，并提出新的对设备生成嵌入式SNMP代理的设计构想．     

Performance Design of an Exhaust Superheater for Waste Heat Recovery of Construction Equipment

Although fuel cost has been the largest portion of annual operating costs of construction equipment, it is possible to save the energy and reduce cost using fuel economy enhancement technology. In this study, an organic Rankine cycle is applied to an excavator in order to recover waste heat, reproduce it into electrical energy, and consequently reduce the fuel consumption by 10 %. A design process was carried out to develop an exhaust gas superheater that recovers the waste heat from exhaust gas through a composite-dimensional thermal flow analysis. A one-dimensional code was developed to perform a size design for the exhaust gas superheater. The ranges for the major design parameters were determined to satisfy the target of the heat recovery, as well as the pressure drop at both fluid sides. Performance analysis was done through onedimensional design code results, which were compared with three-dimensional CFD analysis. By utilizing a 3D commercial code, the arrangement of the tubes was selected and the working fluid pressure drop was reduced through a detailed layout design. The design procedure was verified by a performance evaluation of the prototype, which yielded only a 7 % tolerance in heat recovery.     

Research on the coefficient of sound absorption in turbid water

China’s coastal waters are turbid and the properties of the seabed are complex. This negatively impacts the performance of underwater detection equipment. The properties of sound absorption in turbid water are not well understood. In this paper, the coefficient of sound absorption in turbid water was measured by the reverberation technique. All work was done in a reverberation barrel made of seamless aluminum. First, pure water was poured into the reverberation barrel and its reverberation time measured. Next, various concentrations of turbid water were poured into the barrel and their reverberation time measured. After all data had been gathered, the coefficient of sound absorption in turbid water of different concentrations was calculated. From this we determined a law of sound absorption in turbid water as summarized in the paper.     

温福铁路琯头岭隧道下穿公路隧道施工技术

温福铁路琯头岭隧道在DK280＋950-DK281＋100段下穿同三高速公路琯头岭隧道，在将数值模拟结论作为施工方案制定依据的基础上，通过计算确定分部开挖几何形状及钻爆方案，并将监控量测数据作为施工过程控制的第一手资料，确保铁路隧道下穿公路隧道顺利完成。     

How remote is remote pilotage?

“Today, the idea of allowing aircraft pilots to operate as they see fit, without any control from the land, is unthinkable. Will the same things apply to ships in twenty to thirty years’ time?”Current maritime pilotage regimes are clearly seen in some quarters as too restrictive and old fashioned. Change is “in the air” and VTS, pilotage, and the relationship between them cannot be immune to it. Subject to the attainment of the appropriate standards by both ships and their crews there is no practical reason why more flexible Vessel Traffic Management cannot be introduced. The required technology is largely available and, with the introduction of AIS, the required dynamic data can be available. Technical problems foreseen are believed capable of solution. The more significant obstacles to implementation are, therefore, largely political, commercial, organisational, and cultural. These issues are discussed in this paper taking into account the viewpoints of major stakeholders.     

PS30水翼客船推进轴系校中若干动态因素的考虑

根据在PS30水翼船上采用理论分析及定量计算方法进行推进轴系校中时首次尝试考虑各动态因素的情况，介绍了其推进轴系的交形特点、校中的原则、变形量的计算与处理、预报的轴系校中预偏置量和实际安装值，以及在实船试航与营运中取得的令人满意的结果。     

S型、卵型曲线设计与计算

介绍在高等级公路线形设计中，应用“曲线法”进行S型、卵型曲线设计与计算的基本方法。并以此     

Link choice proportions from trip distribution and assignment models: An overview and comparison

A number of estimation procedures have been suggested for the situation where a prior estimate of an origin-destination matrix is to be updated on the basis of recently-acquired traffic counts. These procedures assume that both the link flows and the proportionate usage of each link made by each origin-destination flow (referred to collectively as the link choice proportions) are known. This paper examines the possibility and methods for estimating the link choice proportions. Three methods are presented: (1) using ad hoc iteration between trip distribution and traffic assignment; (2) combining trip distribution and assignment in one step; (3) solving a new optimization problem in which the path flows are directly considered as variables and its optimal solution is governed by a logit type formula. The algorithms, covergencies and computational efficiencies of these methods are investigated. Results of testing the three methods on example networks are discussed.