引领行业发展 填补国内空白 我国环保型发泡剂成功用于生产

1目前面临的环境问题 众所周知，大气臭氧层的损耗是当前世界上普遍关注的全球性大气环境问题，它直接关系到生物圈的安危和人类的生存。     

加大基础投入 提高运输能力

为适应市场对运能增长的需求，大准铁路不断地进行大规模扩能改造，实现线路无缝化，运输能力明显提高，初步具备开行万吨列车的条件。在不断加大基础建设的投入力度，特别是开行万吨列车后，运输能力明显提高的同时，加强安全管理，确保大秦线和大准线周边发电厂对煤炭的需求．     

基于下一代网络的轨道交通综合通信网

NGN(Next Generation Network,意"下一代网络")是目前通信业界关注和探讨的一个热点话题,介绍了轨道交通通信网的现状及NGN技术.对基于NGN的轨道交通综合通信网的特点进行了分析,并与现存网络进行比较.NGN具有更高速率,支持更多的业务,以更综合的方式支持多种业务,运行、维护、管理更简单、经济.     

半刚接钢框架系统的强刚度耦合可靠性分析

将结构系统强刚度耦合失效模式用并联系统模拟,采用逐步等效线性化方法,基于强度主要失效模式计算在单元截面相继失效历程中的强度和刚度失效模式之间的相关性及其交集失效概率.通过算例对比分析半刚接与刚接钢框架同一失效历程的失效概率,结果表明半刚性连接相对增大了结构系统强刚度耦合失效概率,使其成为主要失效模式.因此半刚接钢框架考虑强刚度失效模式更符合实际情况.     

基于工控机和PLC的船舶电力系统故障报警装置设计

为了提高船舶电力系统安全性与稳定性,文中设计了一套基于施耐德M340 PLC和ACP-4000工控机的船舶电力系统故障报警装置。装置硬件方面,运用PM800电力参数测量仪和NI数据采集仪对电力系统现场级数据进行采集,运用ACP-4000工控机对采集数据进行分析并将数据在matlab中实时显示,运用施耐德M340 PLC对所发生的故障做出相应的故障判断、分类与报警。装置通信方面,运用3条网络通讯回路实现ACP-4000工控机、触摸屏、施耐德M340 PLC、PM800电力参数测量仪之间的数据传递与共享。装置实时数据在GUI界面上进行显示,并以.mat文件储存于电脑中供用户查看与使用。实验表明,其功能可以满足船舶电力电力系统监控的要求。     

船舶柴油机超低温排烟余热锅炉的设计

余热锅炉是船舶主机余热利用系统中的重要设备。为了综合利用船舶主机余热,文章结合船舶主机的特点以及传统余热锅炉的设计方法,以哈尔滨工程大学船舶柴油机余热利用系统中应用的三压式超低温排烟余热锅炉为例,给出一种新型船舶柴油机超低温排烟余热锅炉的设计方法和特点。定量分析比较了采用大小管径对锅炉整体质量尺寸的影响,结果显示,小管径在质量、尺寸上表现优越,适合在船舶动力系统中使用。此外,还推导出余热锅炉受热面采用螺旋翅片管时换热面积及烟道流通面积的计算公式,并提出受热面管束6种错列布置方式,可供相关行业参考。     

客船自动应急抗倾覆装置研究

针对客轮倾覆事件,以船舶原理、力学等学科知识为理论基础,采用姿态传感器、气囊及其发生装置等部件设计一种客船抗倾覆应急安全气囊装置。该气囊装置能在船舶发生倾斜、严重撞击等恶劣情况下,及时启动并提供抗倾力矩,减缓或阻止船体的倾覆。本文详细阐述了该装置的组成、作用、工作原理及自动控制系统。该装置属船舶特种辅助机械,当船舶出现倾覆危险时,它能自动迅速地投入工作,在紧急情况下保证船舶安全,使船舶具有抗倾覆性。该装置具有结构简单、灵敏度高、安装使用方便、气囊叠放不占舱容和不影响适航性等特点。     

Structural Design and Performance Analysis of a Deep-Water Ball Joint Seal

To overcome the current difficulties of high-precision machining and the high manufacturing and maintenance costs of spherical seals for deep-water drilling ball joints, a new spherical seal technique is proposed in this paper. The spherical seal is mainly composed of silicone rubber and polytetrafluoroethylene (PTFE). Rational structural design makes the seal independent from the ball and other components, making it easy to replace if leakage occurs at its surface. PTFE can elastically deform over a certain deformation range, which guarantees that two sealing surfaces fit tightly together. O-Ring and PTFE elasticity makes up for any lack of accuracy during spherical machining and decreases the machining precision requirements for spherical surfaces. Using a finite element technique and nonlinear theory, the performance of the spherical seal under the influence of various factors is determined. The results show that the spherical seal designed in this paper exhibits excellent sealing performance under low-temperature and high-pressure conditions. The spherical seal, a combination of an O-ring and PTFE, has the advantages of cheap manufacturing and maintenance costs and excellent sealing performance.     

深水球形接头密封的结构设计和性能分析（英文）

To overcome the current difficulties of high-precision machining and the high manufacturing and maintenance costs of spherical seals for deep-water drilling ball joints, a new spherical seal technique is proposed in this paper. The spherical seal is mainly composed of silicone rubber and polytetrafluoroethylene(PTFE). Rational structural design makes the seal independent from the ball and other components, making it easy to replace if leakage occurs at its surface. PTFE can elastically deform over a certain deformation range, which guarantees that two sealing surfaces fit tightly together. O-Ring and PTFE elasticity makes up for any lack of accuracy during spherical machining and decreases the machining precision requirements for spherical surfaces. Using a finite element technique and nonlinear theory, the performance of the spherical seal under the influence of various factors is determined. The results show that the spherical seal designed in this paper exhibits excellent sealing performance under lowtemperature and high-pressure conditions. The spherical seal, a combination of an O-ring and PTFE, has the advantages of cheap manufacturing and maintenance costs and excellent sealing performance.     

Sensitivity Analysis of the Influence of External Wall Insertion Ratio on Deformation of Pit-in-Pit北大核心CSCD

Adopting Hardening-Soil finite element model based on soil unloading conditions, the influence of external wall insertion ratio on deformation of retaining structure and soil was studied taking the foundation pit of a metro transfer station of Suzhou metro line 1 as background. The results show that the maximum lateral displace- ment of external wall decreases with an increase of insertion ratio within the range of 30-35 mm, and the lateral de- formation at the foot of wall increases significantly in a linear form; the lateral deformation at the top of internal wall obviously increases linearly, while the maximum of lateral wall deformation of wall body increases slowly and there is almost no change at the bottom of wall; the uplift at the internal pit bottom is more than 90 mm and it is slightly effected by the insertion ration of external wall while the uplift at the external pit bottom is more than 70 mm and it increases with an decrease of the distance away from the external wall; soil mass settlement at the back of the exter- nal pit is obvious and it decreases with an increases of insertion ratio of external wall within the range 14 m away from the external wall, and the settlement reaches the maximum when the insertion ratio of external wall is 0.25 while the tendency of settlement develops reversely when the distance from the external wall is beyond 14 m. To en- sure the safety and reduce environmental impact, it is significant to determine a reasonable insertion ratio of exter- nal wall regarding the pit-in-pit excavation. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.