中心回线瞬变电磁测深一维Occam反演

将Occam反演技术应用到中心回线瞬变电磁测深数据的反演中,为中心回线瞬变电磁测深数据的自动、快速解释奠定基础,解决Occam反演技术中的正则化参数选择、迭代步长的控制、模型约束的影响等关键问题。利用Occam反演技术可以较为准确地获得地电断面的电阻率分布,一般5次迭代目标函数就可以收敛到5×10-2。相对视电阻率的定性或者半定量解释技术,Occam反演的结果更准确。     

浅谈光纤接入网中光纤配线技术

光纤配线主要完成光缆的固定、分纤缓冲、环绕预留、夹持定位、接地保护，以及光纤的分配、组合等。常见的配线产品有光纤配线架、光缆交接箱、光缆分线箱等。光纤配线架用于外线光缆与光通信设备的连接，光缆交接箱是主干光缆与配线光缆节点处的接口设备，光缆分线箱是光纤环路终端的配线分线设备。     

船舶废气排放控制技术的探讨

从IMO对船舶废气排放规定出发,在总结排出物SOX、NOX的生成机理和影响因素的基础上,介绍了当前降低SOX、NOX排放污染物的技术措施,并讨论和分析了各种措施的可行性、优点、适用范围,从而提出了综合应用各种控制技术来满足降低SOX,NOX排放的要求。     

组合式活塞的装配间隙和预紧扭矩的计算方法

在内燃机中组合式活塞结构应用广泛,例如钢顶铝裙活塞、内外组合活塞等。但由于对组合活塞的零件配合间隙(过盈)值选择不当而引起的活塞损坏事故也时有发生。本文给出一种组合活塞配合间隙(过盈)值的计算方法,可以替代以往单凭经验估算的传统方法。 本文还介绍了计算组合活塞螺纹预紧扭矩的新方法,并获得了预紧扭矩与活塞应力的关系曲线,可以对组合活塞的螺纹预紧扭矩进行选择。 作者使用上述两项计算方法对K48E150ZC柴油机活塞进行了计算分析,探明了该活塞长期存在的问题,指出了在配合间隙和预紧扭矩方面的改进措施,为该柴油机顺利通过耐久考核试验和技术鉴定作出贡献。     

燃气轮机叶片造型的混合约束条件三次B样条设计法

本文提出了构造燃气轮机叶型的圆弧和三次Ｂ样条曲线成型方法，并用引入混合约束条件的三Ｂ样条法设计了一整套构造、拟合、修改燃气轮机叶型的计算机辅助设计软件包，为叶片设计及加工提供了依据。     

SBS改性沥青在某军用机场跑道改造工程中的应用

某军用机场跑道应用SBS改性沥青进行加层铺筑，结果表明改性沥青混凝土具有优良的性能，使用效果良好，可以延长跑道寿命。     

轴箱布置方式对地铁直线电机车辆动力学性能的影响

基于车辆系统动力学理论,建立了两种不同轴箱布置方式的地铁车辆动力学模型,在实际线路条件下,分析对比了轴箱内置与外置两种转向架,因为簧下质量以及悬挂系统横向跨距变化而造成轮轨接触以及车辆平稳性改变。研究结果表明,两种轴箱布置方式对车体平稳性影响较小;但轴箱内置车辆为达到理想的稳定性,需要加大一系径向刚度并加装抗蛇行减振器;轴箱内置能够降低轮对摇头角刚度,提高车辆适应线路扭曲不平顺的能力,同时降低轮对踏面磨耗功率,改善小半径曲线上轮轨磨耗。     

结构MTMD振动控制参数优化研究

研究了结构ＳＤＯＦ－ＭＴＭＤ系统在随机激励下的响应,应用谱分析方法优化了ＭＴ－ＭＤ参数,从工程应用实际出给出了其设计方法,数值分析表明,在相同质量比下ＭＴＭＤ的减效果优于单个ＴＭＤ。     

Generalized F distribution model with random parameters for estimating property damage cost in maritime accidents

ABSTRACT

This study develops a generalized F distribution model with random parameters to estimate the ship property damage cost in maritime traffic accidents with 10 years’ shipping accident data in the Fujian waters. Model results show that sinking and capsizing can incur the largest property damage cost, followed by collisions, contact, grounding and fire/explosion. There is a smaller ship property damage cost when the ship is moored or docked. The poor visibility has the least impact on the increment of ship property damage cost. Results reveal that the bigger property damage cost is associated with maritime accidents occurring in the Straits/sea areas and under the strong wind/wave condition and nighttime periods. It is also found that the lookout failure exhibits a bigger effect than the operation error. These results are helpful for policy makers to make efficient strategies for reducing property damage cost in maritime accidents. The developed model is useful for insurance companies in determining the appropriate ship insurance rates.     

Development of a backflow simulation program for automotive body assemblies

Most car body parts are manufactured using thin plates to reduce their weight, and completed assemblies typically have numerous spaces. Because cars are not designed to be completely watertight, rain or wash water may leak into the interior spaces of the assembly through gaps or inlets. When water enters a space and is not drained sufficiently, it can fill the space and overflow into unexpected channels, causing severe problems such as part corrosion and electric shock. In our research, based on a decomposition model representation, we have developed a program to graphically simulate all possible flows within the interior spaces between car parts. Our program can simulate the locations of outlets and overflow channels into unexpected regions, and thus help designers verify the effectiveness of their designs before manufacturing, which can therefore reduce the development time and costs. In particular, since the program can simulate overflow when a car in both horizontal and inclined positions, it can prevent possible design errors by engineers who are accustomed to designing cars only in a horizontal orientation. Our developed method can also be applied to aircraft and ship designs.