负载型纳米非晶合金NiB/MCM-41催化松香加氢反应性能研究

将采用化学还原沉积法制备的负载型非晶合金NiB/MCM-41中孔分子筛催化剂用于松香的氢化反应,表现出很高的加氢催化活性。研究确定在Ni负载量为13%～15%、反应温度180～190℃、反应压力7～9MPa条件下加氢反应5h,去氢枞酸(DEHAA)、枞酸(AA)在加氢产物中的含量分别小于2.5%和0.5%,且在催化剂重复使用过程中加氢产物分布基本保持稳定。分别采用XRD、TEM、EDAX、ICP和比表面测定等手段对催化剂进行了表征。研究表明:NiB活性组分具有非晶结构特征、催化剂具有典型的中孔结构和较大的比表面积。     

简支变连续小箱梁裸梁静载试验研究

简支转连续箱梁桥是现今公路与城市道路桥梁中一种常用的桥梁结构形式。在结构体系转换前单根小箱梁裸梁是处于简支状态。本文提出一种确定简支转连续小箱梁裸梁静荷载试验加载内力的计算方法,并采用加载块等效的方法对小箱梁裸梁进行静力荷载试验加载,对裸梁承载能力进行了评定测试与评估,结果表明,计算方法与试验满足评估要求。     

复合材料简支梁的模态分析

利用ABAQUS软件建立复合材料简支梁的有限元模型,并进行模态分析。分析复合材料简支梁的前6阶振型,研究铺层方式、铺层角度和铺层数目对复合材料简支梁固有频率的影响。结果显示:采用不同的铺层方式,简支梁1~10阶的固有频率都是单调递增的;简支梁1~10阶的固有频率随铺层角度的增加,从总体来看呈下降趋势;而随着铺层数目的增加,简支梁1~10阶的固有频率都呈现上升趋势,且铺层数目对复合材料简支梁固有频率的影响最大。     

槽模圈梁在多层砖混结构房屋中的应用

作者着重的对设计中采用的槽模圈梁在施工中的复杂性提出了简便易行的施工工艺,是一项较好的新技术,本文由浅入深的论述了一些实际应用的效果。     

植物叶片弹性模量的测量

现代农业要求对植物叶片进行高精度测量,为了确定最佳的测量力就要对植物的弹性模量进行精确测量。本文针对这一问题提出了两种测量方法,即胡克定律法和悬臂梁法。针对这两种方法分别设计了测量装置,并用这两种测量装置对同种植物进行测量,对实验数据进行误差分析。通过对这两种方法进行研究比较,筛选出一种比较准确的测量方法,本研究对植物叶片测量仪器的设计参数选择具有重要价值。     

教学楼结构的综合加固

某教学楼钢筋混凝土现浇梁板、承重墙体严重开裂,梁板挠度大幅度超过规范允许值、刚度严 重不足,致使建筑物不能正常使用。教学楼的承重墙体及梁板的裂缝采用环氧树脂浆液压力灌浆补强,而梁 板的刚度不足则是通过增设组合钢梁的方法进行了加固,本文就其加固方法作了详细叙述。     

Dynamic Behavior of Geogrid Reinforced Pile Supported Embankments under Moving Load

In order to investigate the dynamic behavior of geogrid reinforced pile supported embankments (GRPS) under moving load, a three dimensional coupled mechanical and hydraulic model was built by FLAC 3D. The results from two cases including unreinforced and no pile embankments, and geogrid reinforced pile supported embankments were presented. The behaviors of vertical displacement, pile soil stress ratio, excess pore water pressure, and vertical acceleration under two cases were compared and discussed. Additionally, studies on the effect of speed and weight of the moving load were performed. It is indicated that the value of vertical displacement, pile soil stress ratio, excess pore water pressure, and vertical acceleration of GRPS decrease evidently compared with those of unreinforced and no pile embankment, which is caused by the soil arching effect and the reinforcement effect. It is also shown that the greater the axle load value is, the less the beneficial effect of GRPS on the vertical displacement. With the increase of the moving speed of the load, the vertical displacement increases.     

Sensitivity Analysis of Cantilever Box Beam Temperature Effects Based on the Prestressed Concrete Parameter Changes

On the construction of large-span prestressed box beam Cantilever, the parameter frequent changes in concrete modulus E, coefficient of thermal expansion α.In a certain temperature case, the change of concrete parameters will cause the changes on internal stress and strain of the bridge and the difference of the changes will affect the bridge safety. Accordingly,based on a bridge cross-section of a temperature field and combined with the actual bridge construction, give concrete Cantilever bridge parameters change, calculated and analyzed the sphere of influence of parameters on the stress and strain fields of bridge, asked the law of sensitivity on stress changes. Summarize the sensitivity factors of temperature stress which is used to improve bridge safety.     

变截面钢箱梁曲线形底板单元制造工艺

崇启大桥主桥钢箱粱为二次抛物线变截面高度钢筋梁，其底板单元纵向为曲线形。文章介绍了该曲线形底板单元制作过程中的线形控制技术，经实践证明该方法可靠实用，可为同类型桥梁制造提供参考。     

关于底部大空间结构中墙梁的计算方法初探

作者根据设计经验详细论述了底部大空间结构中的墙梁的具体计算方法和设计原则。对从事该专业的技术人员具有一定的参考价值。