基于微型惯性测量单元的姿态测量系统

采用国产微机械石英陀螺仪和挠性加速度计,研制出微型惯性测量单元,利用外部速度和航向信息,构成微型惯性测量单元的姿态测量系统,用它来测量关心区域的局部水平姿态,经模拟台和跑车试验,该姿态测量系统的水平姿态测量精度小于0.2°.     

Simulation of unsteady free-surface flow around a ship hull using a fully coupled multi-phase flow method

An accurate, efficient algorithm for solving free surface flows around ship hulls is described. Accuracy is achieved using a compressive advection discretization which maintains a sharp free surface interface representation without relying on a small time step. Efficiency is obtained using a solution algorithm which implicitly couples velocity, pressure, and volume fractions. The algorithm has been implemented in a computational fluid dynamics code called CFX and is validated by means of a comparisonwith experimental data of benchmark cases in both steady and transient conditions.     

公交精神

5·12这天的网络上,赫然惊见中国精神四个字,让我久久为之震撼。平日里,很多时候我们淡忘了这种精神,在和平的环境下,会为一些鸡毛蒜皮的琐事斤斤计较,会为一些名利金钱伤了和气,然而面对大灾,很多平凡的人所做出的让人荡气回肠的事迹,让我们不由感到自惭形秽,感到自己的渺小,感到平日里的相互抱怨是那么不屑那么     

简码扩充输入法原理及其应用

计算机处理的文本中重复出现的词组定义为简码，这有利于减少输入工作量，但一种编码法已定义了一定量的简码汉字，在一个编译系统里就无法再重定义。现考虑了一种ＷＰＳ与原有汉字输入法不矛盾的简码扩充输入法，可实时以简码形式定义词组，并有相应的译码软件翻译成汉字，方便了使用。     

南京港集装箱运输发展战略分析

介绍了南京港集装箱运输的现状,分析了南京港集装箱运输发展的优势、劣势、面临的机遇和威胁。对南京港“十一五”期间集装箱运输发展提出了对策及建议。     

A comparative analysis of the European and North-American approaches to dealing with major oil spills

Background  

The question of what should be the right level of preparedness to react to a major oil spill (i.e. the EXXON VALDEZ spill, the ERIKA spill, and the PRESTIGE spill) is highly debated, especially in the aftermath of such spills. Little research, however, has been conducted with the aim to identify and compare governments’ best practices not only to fund preparedness measures but also to assess the countries’ ability to respond effectively to catastrophic oil spills. It is the author’s belief that important lessons can be learnt from a comparative analysis of countries’ best practices.     

浅谈基坑计算方面的一些经验和体会

水利工作者在从事和接触水利工程的设计和概预算工作中,常涉及到的工程主要有泵闸、水闸、箱涵、桥梁、河道整治,以及防汛论证等。这些水利工程中,较多地涉及到基坑工程。该文就基坑工程的计算与复核工作阐述一些经验与体会,可供同行参考。     

Numerical analysis of crack under compression by 3D displacement discontinuity method

A 3D displacement discontinuity method is applied to solve the fracture mechanics problems of the mixed mode crack under compression. Friction between the surface of the closed crack is considered by establishing a simple and efficient iterative algorithm based on method of contact resistance mitigation. On the surfaces of the closed crack, the Mohr-coulomb rule is satisfied by iteration when the crack is in condition of sliding. The stress intensity factors are obtained using displacement fitting method. It is shown that the numerical results agree with the experimental results well and that friction plays an important role in resisting crack propagation.     

Experimental study on the liquid slug of cryogenic slug flow in inclined tubes

An experimental study was carried out to understand the phenomena of the boiling flow of liquid nitrogen in inclined tubes with closed bottom by using a high speed motion analyzer.The experimental tubes are 0.018 and 0.014 m inner diameter(ID) and 1.0 m in length.The range of the inclination angle is 45°-90° from the horizontal.The experimental observation on the liquid slug was carried out along the tubes.Statistical method was employed to analyze the experimental data.The experiment analyzed the influences of the inclination angle and the tube diameter on the liquid slug length and velocity.The results show the liquid slug propagation velocity increases with the decrease of inclination angle θ.For all cases,the maximum values of the mean liquid slug lengths were obtained at θ = 60°.The mean liquid slug lengths were greater for large tube at higher tube position.These conclusions provide a basis for further study liquid slug of cryogenic two-phase undeveloped slug flow.     

“Turn on the radio,bust out a song”: the experience of driving to work

Though driving to and from work has become a prevalent experience in the lives of individuals in every metropolitan region in the US, much remains to be learned about the activity from the perspective of the drivers. To increase our understanding of the motivation for certain travel behaviors, we must first know something about what those drivers experience. The existing literature explains much, but the application of new methodologies could improve our ability to explain the willingness of individuals to choose to drive through increasingly congested road networks. The results of this study of oral histories of 12 women commuters underscore the idea that commute should be seen as a set of subjective behaviors that contradict some existing assumptions about why individuals commute.