The flame retardant mechanism by condensed phase decomposition,condensed phase charring and vapor phase effect gas of isocyanurate ring on polyisocyanurate foam (PIR) was investigated by TG,FT-IR,SEM,cone calorimeter (CONE) and pyrolysis gaseous chromatography mass spectroscopy (Py/GC-MS).The results demonstrate that,firstly it is found that isocyanurate ring can increase the thermal stability of PIR foam,and slow down decomposition of PIR foam during the combustion.Secondly,isocyanurate ring can increase the char yield of PIR foam by 29.9 ％,compared to PU foam,and the char layer of PIR foam is more compact than that of PU foam.The char can provide a barrier of oxygen and heat for internal polymer,and improve the flame retardancy of PIR foam.Thirdly,the results of Py/GC-MS show that the isocyanurate ring reduces the flammable gas emissions of polyol,while increasing the content of the inert gas of carbon dioxide derived from the decomposition of isocyanurate ring.

水下修复技术对水下混凝土建筑物损坏开裂的修补起到极其重要的作用,而修复材料是水下修复技术中至关重要的一环.对水下修复材料的种类、组成和特点进行概述;并对一些修复材料的应用进行介绍.

Shift quality is a part of performance of wheel loader. Based on the study of shift process, the optimized pressure control law of shift is obtained. Matching the parameter of buffering valve for ZLM50 wheel loader, the structure and parameter of buffering valve are inquired into. The experiment proved that the buffering valve improve the shift quality, the shift pressure fit the optimized pressure control law of shift.

Automatic transmission control is the trend of the development of the loader.It can improve the ef- ficient of work and reduce the labor of worker,prolong the life of the loader.Most of the control software mode is front-background mode,author provide a kind of construct of automatic transmission control software,based on the real time operation system.It is more powerful and more easier to maintain.

This paper studies the driver control model in developing of Automatic transmission system of construction vehicle. Base on the neural and fuzzy technology, the driver Control model is founded. The Control model controllability correspond with the control character of real driver better. It's helpful for the simulation of automatic transmission system of construction vehicle.

In this paper,five beam column slab subassemblies are tested under low frequency reversed load.The results are analyzed.It is found that after reinforcement the ultimate strength and aseismatic behavior of joints are greatly enhanced.Almost all the behaviors of strengthened joints exceed the requirement raised by current code.So such technique is a significant one which deserves further investigation.

越来越被广泛应用的自动变速器的换档品质是反应其性能的重要指标,换档品质的控制已成为一个重要的研究课题.本文在分析使用液力自动变速器的车辆换档系统基础上,建立了一个简洁的、可以直接指导换档品质控制的换档过程动力学模型,并且应用模型进行了换档过程的简要分析,获得了一些有益于提高换档品质的结果.

首先对4个十字形混凝土梁板柱节点进行破损加载,模拟中小地震中的损伤,然后进行灌缝修复和粘贴碳纤维加固.加固试件和对比试件的低周反复荷载试验结果表明,采用的加固修复方法非常有效,受损试件加固后的抗震性能要优于对比试件.

首先对一榀单层单跨的无粘结预应力混凝土框架进行了常温下的加载破坏试验,然后通过模拟真实火灾环境,对四榀单层单跨的无粘结预应力混凝土框架进行了不同恒载、不同升温曲线、不同预应力度各工况的火灾试验,并进行了试验分析,从而为无粘结预应力混凝土框架的火灾反应分析提供了可靠的数据.

In this paper,the noise of the cab of the ZLM50B loader was studied with modern signal process technology.The result of the study shows that spectrum analysis and correlation analysis are useful in noise identification and control of construction machinery and equipment.They are of high application value in reducing vibration and noise of construction machinery and equipment.

应用现代信号处理技术,对ZLM50B装载机驾驶室噪声进行了试验研究.试验结果表明,谱分析和相关分析是工程机械噪声识别与控制的有效工具,在工程机械的减振降噪中具有很好的应用价值.