Zonal disintegration phenomenon in enclosing rock mass surrounding deep tunnels -- Elasto-plastic analysis of stress field of enclosing rock mass

The zonal disintegration phenomenon (ZDP) is a typical phenomenon in deep block rock masses. In order to investigate the mechanism of ZDP, an improved non-linear Hock-Brown strength criterion and a bi-linear constitutive model of rock mass were used to analyze the elasto-plastic stress field of the enclosing rock mass around a deep round tunnel. The radius of the plastic region and stress of the enclosing rock mass were obtained by introducing dimensionless parameters of radial distance. The results show that tunneling in deep rock mass causes a maximum stress zone to appear in the vicinity of the boundary of the elastic and the plas-tic zone in the surrounding rock mass. Under the compression of a large tangential force and a small radial force, the rock mass in the maximum stress zone was in an approximate uniaxial loading state, which could lead to a split failure in the rock mass.     

Analytical solution of electromagnetic field generated by induction logging tool in a fan-ring slot of drill collar while drilling

Based on the structural characteristic of metal drill collar for induction logging while drilling, we have given the analytical formulae of lengthways fields E _z and H _z when the tool is located in a fan-ring shaped slot of drill collar by the boundary conditions of electromagnetic field, and derived the other components of electromagnetic field in and out the fan-ring slot from E _z and H _z . In the other intervals of formation, where the drill collar is a solid cylinder, the analytical formulae of field are educed through the method of variable coefficient. The total analytical solutions of field in whole space have been obtained. With the help of the analytical formulae, we have also given numerical examples and analyzed the distributive characteristic of electromagnetic field. From the computational results we find that the secondary scattering field H _z is in a linear relation with the conductivity of stratum. The characteristic of field is very useful for induction logging while drilling, which can be used to measure and analyze the logging responses of the stratum conductivity. This paper sets up a theoretical foundation for us to study the distrbutions of field and to direct the design of logging instruments. Supported by the National Natural Science Foundation of China (Grant No. 10705049), the Beijing Natural Science Foundation (Grant No.1083011) and Funding Project for Academic Human Resources Development in Institutions of Higher Learning [PHR(IHLB)]     

从管道检测的角度,分析涂层失效的原因

本文首先阐明涂层对管道保护的重要作用，综述了目前长输管道涂层现状及常用涂层材料的特点，通过近几年来对数千公里管道的不同类型涂层检测、评价，总结出涂层失效的主要形式，从管道周围介质的腐蚀性、环境及涂层施工等方面，分析了外界条件与涂层失效的关系，以及导致涂层失效的主要原因。目前长输管道涂层失效的形式主要有：涂层的剥离、龟裂、破损及变形等。     

贴身穿竹毛混纺针织物开发及性能测试

采用80S丝光羊毛纤维和3D毛型竹浆纤维混纺纱,混纺比例竹浆/丝光羊毛分别为30/70、50/50、70/30,进行针织物开发及舒适性探究。通过对混纺纱的强力、伸长率、耐磨性及毛羽进行测试,得出:实验结果均满足上机织造标准。以纬平针组织为例,织造出三种混纺比针织物,并对其透气性、透湿性和热导率进行了测试分析,实验结果表明:织物透气性、热导率随丝光羊毛含量的增加而降低,透湿量随之增加。     

吸湿发热纤维混纺针织物耐磨性和悬垂性研究

研究吸湿发热纤维混纺针织物的力学性能,就其耐磨性和悬垂性与纯棉织物、涤棉混纺织物做了对比,实验结果显示,吸湿发热纤维混纺针织物的耐磨性、悬垂性均优于纯棉,与涤棉混纺织物相比略差。通过对吸湿发热纤维混纺针织物力学性能的测试分析,为后续针织物的研究奠定基础。     

无溶剂法合成水性聚氨酯在针织物抗起毛起球的应用

选择新型亲水扩链剂DMBA,采用无溶剂法合成抗起毛起球整理剂WPU,优化制备工艺,并将其应用在纯棉针织物和涤毛混纺针织物上。结果表明,针织物抗起毛起球等级提高了4级,织物手感和白度与原织物等级相当。红外光谱表征,异氰酸根已全部参与反应。扫描电镜(SEM)表明,经整理后的织物,纤维尾端被黏附在纱线的表面,织物表现出抗起毛起球的特征。     

不同缝纫工艺下缝纫阻力的测试与分析

本文采用LM缝纫性测试仪对不同缝纫工艺下的针织物和机织物缝纫阻力进行了测试.测试了织物层数、织物正反面以及缝纫方向不同时,面料缝纫阻力的大小;测试了不同缝针、缝纫线时的缝纫阻力.实验结果表明:织物的缝纫阻力随织物的层数增加而成倍数以上的增大;机织物在45°角左右缝纫时,缝纫阻力最大;针织物在接近纵行和横列方向,缝纫阻力出现最大值;穿引缝纫线会增大缝纫阻力,但缝纫线对缝纫阻力的增大作用较缝针的作用微弱.同时,实验过程中还发现,针织物的缝纫阻力比机织物的不匀率高,缝针刺到纱线上的概率高,因此针织物不易于缝纫.本论文的研究,希望对服装加工给予帮助,以提高服装质量和服装加工效率.     

纯棉针织物果胶酶精练工艺优化及效果分析

利用KDN果胶酶,采用田口实验设计的方法,控制酶浓度、温度、pH值和时间,分别处理纯棉纬编针织物,通过测试处理后织物的白度、毛细效应、顶破强力、质量损失等性能,分析果胶酶处理织物的效果.结果表明纯棉纬编钟织物经果胶酶处理后毛细效应得到很大改善,白度增加,但织物顶破强力下降,质量减轻.综合各项指标,通过统计分析得出KDN果胶酶最优处理工艺如下：酶质量浓度1.5 g/L,温度50℃,pH值为6,时间40 min.与碱精练相比,毛细效应变好,白度稍差,织物强力及质量损失小.     

环口套管加强型T型圆钢管节点的滞回性能研究

为了提高桁架管节点的承载力及抗震性能,采用环口套管加强方式对管节点进行加强.基于有限元分析环口套管加强型管节点在承受轴向循环荷载作用下的滞回性能.通过分析发现:环口套管加强模型滞回曲线包围的面积显著大于未加固模型滞回曲线所包围的面积.同时,由于环口套管提高了节点相贯部位的主管刚度,使得破坏部位于相贯处的焊趾处转移到了套管两端边缘部位的主管表面.此外,基于有限元计算结果,分析了模型的延性比和能量耗散等抗震性能参数.结果表明:加强型节点的延性比和能量耗散值均有大幅度提高.     

稀土强化Pt-Pd-Rh合金针织催化网在硝酸生产常压炉中的应用研究

在H厂生产硝酸的2套机组4台氨氧化常压炉中用Pt-Rh或Pt-Pd-Rh针织催化网作实验,并将稀土强化Pt-Pd-Rh针织催化网与该2种催化网进行了应用比较.用化学分析、光谱定量、光电子能谱、扫描电镜等方法分析了样品的组成及状态.结果表明,优化配套的稀土强化Pt-Pd-Rh针织催化网转化效率高、吨酸铂耗低、使用寿命长,合金中Pt高温氧化轻微,Rh的表面氧化及富集减弱,催化效果明显.提出了氨氧化常压炉用铂合金针织催化网的配套措施.