立井强化冻结施工理论分析

本文以谢桥主井为例,从冻结壁强度、变形、工作面底鼓和超前位移及冻胀压力等几方面.分析了深厚表土立井强化冻结施工对防止冻结管断裂和外层井壁破坏的机理.给出了强化冻结施工适用条件.并提出了按井帮温度进行强化冻结设计的方法.     

Ti-Pd形状记忆合金马氏体相变温度

采用DTA和STA测定了TiPd系合金的相变温度 .结果表明 ,可以通过改变TiPd合金的成分和采用合金化的方法来调整TiPd系合金的相变温度 .合金化元素Fe ,W ,Cr等替代Ti50 Pd50 合金中的部分Pd均降低合金的相变温度 ,但程度有所不同     

小区暖气失调原因调查和改造方案的实施

通过对镇苑小区采暖情况的跟踪调查及数据采集，找出了供暖系统不热的原因，据此对系统进行了针对性的改造，取得了良好的改造效果。     

两样本对称统计量的Berry-Esseen定理

在适当的矩条件下。证明了两样本对称统计量的Berry—ESseen定理．作为该定理的推论。还得到了广义U-统计量正态逼近的速度．     

疫苗冷藏温度自动监测系统的研究

利用微机芯片８０３１为主体部件设计测温系统，输入信号采用三线式桥路输入方法。实现了温度自动监测和记录打印。     

Analysis of Pyrolysates for Phenol Formaldehyde Resin by Py-GC/MS

Pyrolysis of phenol formaldehyde resin has been investigated by Pyrolysis Gas Chromatography-Mass Spectroscopy at the different temperatures from 500℃ to 750℃. Its composition of pyrclysates has been analyzed. Several compounds, especially benzene, toluene, p-xylene could only be formed above 500-550℃. Howerver, peak intensities for some pbend derivatives were decreased at the higher temperature. During pyrolysis, for thermo-setting phenol formaldehyde resins, polymeric chain scissions take place as a successive removal of the monomer units from the polymeric chain. The chain scissions are followed by secondary reactions, which leads to a variety of compounds. Addition reactions can also take place among the double-bond compounds during pyrolysis.