双输出轴式手动变速器匹配噪声问题分析与解决

分析了盘式减振器和双质量飞轮两种减振结构的优势和局限性.分析了双输出轴式六速手动变速器匹配过程中噪声问题产生的原因和类型,并从变速器本体、减振系统匹配两个方面对变速器噪声进行了研究,提出了对变速器、离合器进行优化且同时采用双质量飞轮的噪音解决方案.试验测试结果表明,该方案解决了变速器匹配噪声问题.     

Evidence of double diffusion in the East China Sea

Double diffusion is an important phenomenon induced by the difference between the thermal conducting coefficient of the molecule and haline diffusive coefficient. Warm, salty water overlying cold, fresh water induces salt finger. On the contrary, when cold, fresh water overlies warm, salty water, diffusive convection occurs. In the East China Sea, double diffusion was observed during a cruise in September 2003. In order to describe the phenomenon precisely, Turner (TU) angle values are calculated station by station at Section YT. TU angle is a practical tool to indicate the water states. Different TU angle values represent salt finger, diffusive convection and stable stratification respectively. We map the distributions of the two forms of double diffusion at Section YT, and determine that the physical mechanism of the phenomenon is the mixing of water masses. The Changjiang Diluted Water (CDW) has great effect on the mixing of water masses, and the Kuroshio Water System dominates on the continental slope. Temperature and salinity varied in a manner consistent with double diffusion.     

增大截面法加固双曲拱桥

双曲拱桥是我国上世纪60～80年代大量采用的一种桥梁结构形式,因其具有节省钢材,可无支架施工等特点而倍受推崇,但由于受当时经济、技术等多方条件限制,设计荷载普遍较低.目前普遍面临加固提载的问题,以国道G101线的敖汉桥为例,介绍对双曲拱桥进行了加固提载的实例.     

液体黏滞阻尼器与双曲面球形减隔震支座联合应用研究

以某城际铁路105 m简支系杆拱桥为工程依托,采用液体黏滞阻尼器与双曲面球形减隔震支座联合作用方式,对结构进行罕遇地震下的抗震设计,以了解二者联合应用于减隔震设计时的特性。利用Midas/Civil软件,采用非线性时程分析方法,对液体黏滞阻尼器与双曲面球形减隔震支座分别应用于结构的减震效果,以及二者联合应用时的减震特性分别进行了分析。分析结果显示,液体黏滞阻尼器的减震效果要优于双曲面球形减隔震支座。在给定的减震目标下二者联合应用时,液体黏滞阻尼器的吨位及结构墩顶水平力均较单独使用有所降低,对阻尼器的布置及结构的抗震设计是有利的;双曲面球形减隔震支座对地震能量耗散小,支座的摩阻系数提高时虽然增大了地震能量消耗比,但增大了结构墩顶水平力与震后残余位移,对结构抗震是不利的;二者联合应用时,应结合设防结构自身特点与减隔震设计目标,选取合适的设计参数。     

渝怀铁路信号控制方案研究

铁路提速需要配套的信号控制系统.阐述"进站双接近区段 点式查询应答器 主体化机车信号"与列车运行监控装置相结合信号控制方案,介绍渝怀铁路信号控制方案实施情况,并时工程建设及运用维护提出建议.     

真空预压法加固软土地基的几点新认识

通过近20年的推广应用，真空预压法已形成一种成熟的软土地基加固法，加固软土地基达1000万平方米。本文通过室内试验和工程实例分析了真空预压法膜上覆盖水的作用、有效加固深度、密封帷幕技术以及下卧强透水层的影响．供有关工程参考。     

自然垄断行业实现普遍服务目标政策分析

要实现在具有自然垄断性质的网络行业中引入竞争、提高效率和履行普遍服务义务的双重目标,政策制定者有必要引入一些竞争中性的规制措施.介绍了统一定价、价格上限和范围限制等几项措施及措施组合的内容,通过一个实证性模型,分析了各种情况下在位者和进入者均衡价格和均衡服务范围的决定.结论：在没有明确其他措施的内容时,单一措施的福利评价是不可能的,必须将同时发挥作用的各项措施结合起来进行综合评价.并且,政策制定者在制定各项措施时,必须在提供更大的服务范围、提高接受服务的消费者福利、提高垄断地区消费者福利和提高竞争地区消费者福利之间做出权衡.     

箱形拱加固方法在大房身桥维修中的应用

结合工程实路,介绍了箱形拱加固方法在双曲拱桥维修中的应用。     

A multi-objective analysis of a rural road network problem in the hilly regions of Nepal

This paper considers the rural road network upgrading problem, using a multi-objective optimization model, to support decision-makers in the choice of roads to upgrade in the hilly regions of Nepal. The model considers two objectives: minimization of user operation costs and maximization of population covered. The problem was solved for a real-world rural road network in the Gorkha district of Nepal. For this case, all non-dominated solutions were obtained and the ones providing more interesting trade-offs were analysed. The model was found suitable for the case under study, and possibly, easily extendable to rural areas of other developing countries.     

转向驱动桥双联式万向传动轴运动学分析

转向驱动桥在整个转向过程中,对双联式万向传动轴运动做了理论分析,主要通过数值方法模拟了其不等速的变化趋势,给出传动轴在给定转角范围内,合理设计内部参数的过程,为双联式万向传动轴设计及评价提供理论参考.