工程机械液压传动系统故障分析及维护

现代工程机械广泛采用液压、液力技术,对加强液压系统维护保养提出了更高要求。归纳了液压传动系统常见故障及排除措施,总结了液压传动系统故障诊断方法,从故障成因出发,提出液压系统维护与保养方法。     

45Cr2MoVNiSi锤锻模整体堆焊修复工艺探讨

锤锻模工作环境恶劣,使用寿命短。模具失效后的进一步修复成为延长锤锻模使用寿命的重要措施。目前常用的局部焊修和整体下落的修复方法都存在着不同的缺陷,针对两种方法的不足,就45Cr2MoVNiSi锤锻模提出用整体堆焊修复工艺,可以大幅提高模具的综合机械性能,最终提高使用寿命。     

液压系统清洁度的目标管理

本介绍了污染物颗粒对液压系统影响，液压系统目标清洁度的提出、实现及监测办法。     

钢卷运输车机构改造的设计与研究

钢卷运输车是一种重要的轧钢辅助设备。本文主要是对钢卷运输车的行走装置进行设计改造即将其原有的液压行走机构改造成电动行走机构。总体设计方案向着高效、简单、节能化发展。要求设计既要安全、可靠有利于车体设备的检修和维护,也要实用,适合不同的生产要求。     

IPD-80桩机液压油温异常的故障诊断与排除

本文根据IPD-80桩机液压异常的故障,从液压回路及阀的结构原理进行了多方面的分析,并进行了拆检和故障排除,对实际生产中类似的故障排除提供了相关的参考.     

液压系统管路泄漏原因及改进措施

某车辆产品液压系统管路泄漏频发,影响了产品的性能及质量。以通用扣压式管接头为例,对液压系统管路泄漏的原因进行了分析。通过对液压元件中扣压式管接头及液压系统管路的安装工艺技术的改进,以及对液压管路系统加工及装配质量的控制,解决了车辆液压管路装配后产生的泄漏问题。     

Microtextural and microchemical studies of hydraulic ancient mortars: Two analytical approaches to understand pre-industrial technology processes

Two different analytical approaches have been taken into account to investigate the role of Si-rich phases in enhance hydraulic reactions of bedding mortar mixtures from San Lorenzo Church in Milan (Northern Italy) and from the Medicean Aqueduct in Pisa (Central Italy). In the first case, mortars show clear hydraulic type reactions in the form of coronal layers between the reacting additive and the binder mass. In the second one, the hydraulic reactions do not develop visible mineral phases and processes have been inferred from chemical, mineralogical analyses and mass balance calculation. The microstructural studies not always are sufficient to understand the complex dynamics of reaction attained during pre-industrial manufacturing processing of mortars and related binders. In fact, if the reacting raw materials are fine-grained and/or have remarkable chemical reactivity, no relicts are preserved by mortar microtextures.     

试析力量训练对链球运动员运动成绩的重要性

掷是田径运动中的投掷项目之一,在田径项目中它要求的技术含量非常高,身体素质水平要求也相当全面,尤其对力量素质要求极高,在高速度的旋转中维持身体平衡的能力也相当关键。其影响大小依次为：专项投掷力量,速度力量,基础力量。     

Numerical model application for the restoration of the Racconigi Royal Park (CN, Italy)

After years of neglect and an almost complete lack of maintenance, the Racconigi Royal Park was in an inevitable and widespread state of decay. This decay also involved the waterways that were designed in the nineteenth-century by Xavier Kurten (1811–1840). The seasonal lack of water and the agricultural needs of the farms around the Park made it necessary, during the planning stage of the restoration project, to consider the practicability and the effectiveness of some measures that were conceived to optimize the operation of the restored waterways, without altering the historical structure of the system. The realization of a hydraulic numerical model of the system, which is briefly illustrated in the first part of this case study, resulted to be the most suitable tool to study different possible solutions of the problem. The model simulations in fact helped the restorers put into effect the right remedies to favour the correct flow of the water, to make the whole historical system more efficient and to make its future maintenance easier.     

链球运动员身体素质与专项成绩相关关系的神经网络模型

利用人工神经网络强大的函数映射能力，提出了反映链球运动员身体素质与专项成绩相关关系的神经网络模型。该模型克服了多元回归模型和灰色模型的缺点，在不需要事先确定模型数学表达形式的条件下，更为准确地映射出运动员素质训练水平与专项成绩之间的函数关系、并且运用建立起的神经网络模型，绘制了素质训练水平与专项成绩之间的关系曲线。从而为运动员进行科学训练提供了理论依据。