用组合气化炉发展现代煤化工的建议

当前发展煤化工碰到的第一个难题就是如何选择适宜、高效、经济实用的大型气化炉。由于煤质的特殊性,至今尚没有各方面都令人满意的煤气化技术。本文中提出采用气流床和固定床组合气化炉的方案:向气流床气化炉出口煤气喷入Lurgi炉出口含有焦油的粗煤气,以降低气流床气化炉的出口温度,并使Lurgi炉出口煤气中的焦油等有机物得以气化和裂解。     

城市异形排涝通道消能防冲新技术

该文针对感潮河段魁岐排涝二站?型复杂流道的不利冲刷问题,通过建立整体水工模型,研究城市异形排涝通道消能防冲新技术,提出导流坎、消力坎和消力墩联合消能防冲技术,探索其在宽幅水位变化、多工程交替运行及通航情况下的适应能力,并给出水力设计方法。研究表明,联合消能工对复杂工况适应良好,能有效解决异形排涝通道的消能防冲问题。     

带柔性天线卫星机动过程动力学分析

基于刚柔耦合动力学模型仿真分析卫星机动过程的动力学特性.模型将天线上的柔性金属网近似成阻尼弹簧模型,将径向肋刚化并等效其柔性为径向肋根部的扭簧转角;利用该简化模型研究了卫星机动过程中径向肋和金属网的柔性对卫星姿态的影响.通过仿真分析天线卫星系统在不同结构参数情况以及不同驱动力作用下的卫星机动过程动力学特性,对比分析得出：提高径向肋的固有频率,增加金属网以及增大径向肋扭簧的阻尼能有效降低刚柔耦合问题对卫星本体姿态的影响.     

马桑皮植鞣剂与铝盐结合鞣制性能及机理

以提取于马桑皮的植物鞣剂为原料，与铝盐进行绵羊酸皮结合鞣制，优化鞣制工艺并建立基于马桑皮鞣剂的植铝结合鞣制方法，对鞣制后皮革性能及鞣制机理进行研究。结果表明，当马桑皮鞣剂用量为酸皮质量的15%、Al3(SO4)2•18H2O用量为酸皮质量的20%、渗透pH为4.0、结合pH为4.5的条件下，皮革收缩温度可达110.5 ℃。皮革表观性能良好，增厚率为82.2%，抗张强度为10.0 MPa，撕裂强度为52.5 N/mm，断裂伸长率为76.8%，优于橡椀植物鞣剂结合鞣制的皮革。鞣制后皮革胶原纤维变粗，形成紧密的网状结构。马桑皮植物鞣剂能充分渗透至皮革胶原纤维中，并与其产生氢键交联。在结合鞣制时，铝盐与皮革胶原纤维中结合的单宁类成分产生络合，使交联作用增强，从而显著提高成革的热稳定性能和机械性能。     

Oxidation and reforming reactions of CH4 on a stepped Pt(5 5 7) single crystal

The oxidation and reforming kinetics of methane by O₂, CO₂ and H₂O were studied on a stepped Pt(5 5 7) single crystal from 623 to 1050 K under methane rich conditions. The rate of carbon deposition was followed by ex-situ Auger electron spectroscopy under non-oxidative conditions. The apparent activation energy for methane decomposition was significantly lower than the apparent barriers measured for both total oxidation, CO₂ and H₂O reforming. Total oxidation of methane to CO₂ and H₂O followed by combined dry and steam reforming (combined combustion-reforming) led to CO production rates which were higher than direct CO₂ or H₂O reforming rates. The enhanced rates are most likely due to the ability of adsorbed oxygen to prevent carbon nucleation and/or scavenge carbon enabling the reforming reaction to turnover on a larger fraction of sites. Comparable amounts of carbon were found by Auger electron spectroscopy measurements after both direct dry or steam reforming, while combined oxidation-reforming had considerable less carbon. During direct dry or steam reforming, CO₂ and H₂O serve only to scavenge adsorbed atomic carbon, while in the presence of oxygen, carbon is removed by both combustion and reforming routes.     

大跨双曲混凝土组合扭壳屋盖施工拆模优化分析

由于混凝土抗拉能力较差,双曲组合扭壳抵抗悬垂线方向的主拉应力控制至关重要.如果拆模顺序不当,可能会使壳体结构产生过大的拉应力.为解决此问题,以华工扭壳为例,对平行四边形底面双曲组合扭壳的满堂脚手架施工拆模顺序进行全面优化分析,并与工程实测进行对比,得出较为合理的拆模方式.     

Binding materials of dehydrated phases of waste hardened cement paste and pozzolanic admixture

Fly ash (FA) and ground granulated blast-furnace slag (GGBFS) were added to improve the performances of regenerated binding materials (RBM) which refer to dehydrated phases with rebinding ability of waste hardened cement paste. Flowability tests, compressive strength tests, SEM, TG-DSC, and non-evaporable water content tests were employed to study the performances of the combined binding materials and the interactions between RBM, FA, and GGBFS. Results show that adding FA or GGBFS can improve the workability of RBM paste, and GGBFS has positive effects on strength of RBM. Pozzolanic reactions happen between RBM, FA, and GGBFS. And the activation effect of RBM to FA and GGBFS is superior to that of P.O grade-32.5 cement, especially at earlier ages, because of the high reactive f-CaO existing in RBM. On the advantages of the synergetic effects of RBM and pozzolanic admixtures such as FA and GGBFS, new combined binding materials can be prepared by blending them together. Funded by the National Science Foundation of China(No. 50508034)     

置换率对刚-柔性桩复合地基的影响

为了研究桩置换率对刚-柔性桩复合地基性能的影响程度,在温州地区进行了多个大型刚-柔性桩复合地基静荷载试验.在静荷载试验中对刚性承压板下压力盒进行同步检测,根据检测成果比较不同置换率下刚-柔性桩复合地基沉降情况,分析置换率对刚-柔性桩复合地基的桩土应力、桩土应力比以及荷载分担比的影响.检测结果表明:复合地基中刚性桩置换率对沉降特性影响较大,增大刚性桩置换率会明显减小沉降.刚-柔性桩复合地基中刚性桩在承载方面发挥重要作用,刚性桩置换率越高作用越明显.复合变形模量随复合地基中桩置换率减小而减小.刚性桩置换率越高,刚性桩承载力发挥度越小,柔性桩承载力发挥度越大,土承载力发挥度越小.     

新型钢铅组合耗能器性能试验及参数优选

为了考察新型钢铅组合耗能器(NCSLD)的力学性能和提高其耗能能力,利用电液伺服压剪试验机对NCSLD耗能器进行力学性能试验,采用ANSYS实体建模的方法对耗能器进行大量的数值分析,并对性能试验和数值分析的结果进行对比,研究耗能器的滞回特征参数与其6个几何参数之间的关系,回归出二者之间的公式.提出评价耗能器性能优劣的标准及其附加条件,并以此标准为依据,利用均匀设计法和遗传算法分别对耗能器的6个几何参数进行优选.结果表明遗传算法的选优效果要好于均匀设计法,同时得到一系列性能良好的NCSLD耗能器.