压力大，动力更大

要更深层次了解增压发动机，我们最好先从原理入手，那么所有的问题就都能迎刃而解了。之所以叫增压发动机，其实从字面上就很容易理解其与自然吸气发动机的区别。对于自然吸气发动机来说。空气是在活塞向下运动时被动地吸进气缸当中去的。这就好比我们用注射器抽血一样。由于活塞向下运动产生了一个真空度，那么在大气压力的作用下，空气被挤进了气缸。所以理论上讲，无论活塞与气缸壁的密封性能有多好，进气时产生的压力差永远不可能高于1个大气压。     

薄壁曲线箱梁剪力滞效用的有限元解法与实验研究

解释了箱梁的剪力滞效应并对其常用解法的优缺点进行了比较,介绍了有限元解法,利用SHELL63 单元,运用ANSYS有限元分析方法对一具体箱梁进行分析,得出计算值与实验值吻合良好,可见利用ANSYS对薄壁箱梁剪力滞进行求解简单且可靠.     

莱姆推出新型HO6／10／25-P系列电流传感器

日前，全球领先的电流传感器制造商莱姆电子为HO系列的PCB直插式电流传感器增加了三个新产品，带原边（8×8）mm的穿孔，可测量6A、10A、25A的DC、AC、脉冲信号，基于开环霍尔效应ASIC技术，满足低成本、高性能需求。     

船企“白名单”效应

随着《船舶行业规范条件》企业名单（第一批）的正式公示，其潜在的连锁效应，也正逐渐显现。近年来，国内造船业集中度低，一直被业界诟病。船市繁荣之时，航运和造船业都赚得钵满盆满，少有人留意此问题。     

30th International Workshop on Water Waves and Floating Bodies

About the Workshop...
The International Workshop on Water Waves and Floating Bodies is an annual meeting of mathematicians and engineers with a particular interest in water waves and their effects on floating and submerged marine structures. The IWWWFB was initiated by Professor D.V. Evans （University of Bristol） and Professor J.N. Newman （MIT） following informal meetings between their research groups in 1984. First intended to promote communications between workers in the UK and the USA, the interest and participation quickly spread to include researchers from many other countries around the world. The workshop places particular emphasis on the participation of younger researchers, on the stimulation of discussions between engineers and scientists, and to the presentation of preliminary basic scientific work before its publication elsewhere. The workshop is an important reference point for organizing and spreading knowledge in this area. In particular, the workshop proceedings are freely accessible through the dedicated internet address www.iwwwfb.org where all contributions from 1986 on can be found.     

城市轨交网络化规划与建设的几点思考

结合上海轨交网络化规划的实例分析,提出轨交进入网络化时代,应创新规划设计理念,适度超前规划,构建集约化、多层次的轨交体系,并加强与城市规划互动和用地控制。倡导以车站为核心的轨交综合体,实现网络化发展阶段车站可持续发展的创新设计。概括总结了以上海为代表的软土地区轨交工程修建技术、枢纽工程的修建方法和对城市环境的保护技术及措施,对轨交工程修建新技术提出应用展望。