混凝土砂基透水路面砖制备及物理性能测试

推广砂基透水砖是实现沙漠沙资源化的有效途径.以烘干砂为主要骨料、高标号水泥为粘结剂并采用静压成型工艺,研制出一种预制透水孔的混凝土砂基透水路面砖,并对所研制的透水砖进行了物理性能测试和造价分析.结果表明:(1)所研制的混凝土砂基透水砖抗压强度超出我国建筑材料行业标准Cc60透水砖的要求,抗压强度可达100 MPa.(2)预设的透水孔使混凝土透水砖的透水性超过行业标准,而且透水孔上小下大,不易堵塞,不影响人行步道的舒适性.(3)根据透水砖的抗压强度、透水性、保水性、造价等方面综合考虑,选取细砂率70%、水灰比0.34、孔隙率2%、添加水性氯丁胶(AN)的第20组作为高强透水砖优选方案,选取细砂率85%、水灰比0.30、孔隙率1%、无添加剂的第22组作为常用广场透水砖优选方案,用于后续产业化开发研究.(4)增加粗骨料可显著提高透水砖的抗压强度,透水砖的细砂率可控制在70%~85%.(5)添加合适类型和剂量的添加剂可提高透水砖的抗压强度.(6)除了第7、11、12、19组造价偏高以外,其余组次造价都在60~100元/m2,与常规无砂混凝土透水砖价格接近,远小于市场上已有同类砂基透水砖的价格.     

复吹转炉氧枪喷吹石灰石颗粒的物理模拟

建立了氧枪喷吹石灰石粉的冷态模型,用水模拟钢水,用浸盐空心三氧化二铝模拟石灰石粉,用真空泵油模拟炉渣,研究了熔池的均混时间、粉剂分布和粉剂穿透比.考察了底气流量和枪位对均混时间的影响,同时在优化的工艺条件下,测定了熔池的粉剂穿透比和粉剂分布,确定了实验室条件下最佳操作工艺.结果表明,顶吹喷粉条件下氧枪枪位应略微下降,枪位为258mm,底气流量为20m3/h;粉剂穿透比随固气比和粉剂粒度的增加而增加,确定了实验条件下最佳粉剂粒度为0212~0380mm.     

具有波纹形貌的聚苯胺微纳米管的制备及表征

以富勒烯C60微纳米纤维（fullerenemicro／nano fibers,FM／NFs）作为可容易移除模板,利用直接超声混合法,成功地制备了具有波纹形貌的聚苯胺微纳米管。光学显微镜观察表明,聚苯胺呈纤维状,其长度分布在2～5μm之间。扫描电镜和透射电镜观察结果表明,聚苯胺微纳米纤维形貌类似于波纹管,波纹周期约为100nm,外径在0．5～1μm之间,为空心管状结构。     

Entrainment-mixing parameterization in shallow cumuli and effects of secondary mixing events

Parameterization of entrainment-mixing pro- cesses in cumulus clouds is critical to improve cloud parameterization in models, but is still at its infancy. For this purpose, we have lately developed a formulation to represent a microphysical measure defined as homoge- neous mixing degree in terms of a dynamical measure defined as transition scale numbers, and demonstrated the formulation with measurements from stratocumulus clouds. Here, we extend the previous work by examining data from observed cumulus clouds and find positive cor- relations between the homogeneous mixing degree and transition scale numbers. These results are similar to those in the stratocumulus clouds, but proved valid for the first time in observed cumulus clouds. The empiricalrelationships can be used to parameterize entrainment- mixing processes in two-moment microphysical schemes. Further examined are the effects of secondary mixing events on the relationships between homogeneous mixing degree and transition scale numbers with the explicit mixing parcel model. The secondary mixing events are found to be at least partially responsible for the larger scatter in the above positive correlations based on obser- vations than that in the previous results based on numerical simulations without considering secondary mixing events.     

210 tRH精炼过程的混匀特性

以某钢厂210tRH真空精炼装置为原型,根据相似原理建立1﹕4水模型,研究了吹气量、浸入深度、真空度以及气孔堵塞对混匀时间的影响。结果表明,RH混匀时间随着吹气量的增加而呈现减小的趋势;随着浸入深度的增加先减小后增大,并存在最佳浸入深度480 mm;随真空室压力的减小而减小;随着吹气孔堵塞个数的增加先减小后增加。利用粒子成像测速技术( particle image velocimetry,PIV)测量了RH精炼过程钢包内二维流场,与数值模拟结果对比,发现钢包内的流体运动主要是从下降管到上升管的循环流动以及下降管周围的回流运动,不活跃区主要集中在渣-钢界面以下浸渍管浸入深度范围内。     

软土地基处理过程中搅拌桩下沉的机理和判别方法

针对江苏某高速公路软土地基处理过程中的水泥搅拌桩下沉现象,通过现场测量桩周土中的超静孔隙水压力、土压力和剪切强度等,分析搅拌桩下沉机理,提出搅拌桩下沉的判别方法。超静孔隙水压力和土压力的现场测试结果表明,在搅拌桩下沉处,桩周土中的超静孔隙水压力大于土压力,桩周土出现了类似于液化的现象,可以以此作为搅拌桩下沉的判别方法。     

粉煤灰粉喷桩加固软土地基机理及计算

探讨了利用工业废渣粉煤炭加固软土的机理,认为利用粉煤灰粉喷桩加固软土地基可以获得很强的水稳性和一定强度的桩体,其加固效果是可靠的.同时依据现场试验对粉煤灰粉喷桩的特性及设计计算进行了初步研究,得出粉煤灰粉喷桩侧摩阻力平均值和粉煤灰粉喷桩复合地基承载力桩间土强度折减系数.     

热混合层中温度脉动的多重分形特性

运用广义计盒维数方法,对测量热混合层所得到的温度脉动时间序列信号进行了详细研究,发现等温截面的时间点集在一定尺度范围内表现出多重分形几何特性,并计算了截面阀值的绝对值范围为０～１．５ 时的等温截面的多重分形的广义计盒维数Ｄｑ,当ｑ ３,Ｄｑ 随截面阀值Ｈ以及测量点位置Ｙ的变化不大,热混合层温度脉动时间序列具有统一的多重分形维数;但当ｑ ＞ ３,Ｄｑ 受湍流流场本身的影响很大．     

Harmonic mixing of Bi2Sr2CaCu2O8+x intrinsic junction at millimeter waveband

Using intrinsic Josephson junctions in Ba₂Sr₂CaCu₂O_8+x single crystal, harmonic frequency mixing at 8 and 3 mm wavebands was successfully demonstrated at liquid nitrogen temperatures with harmonic numbers up to 68 and 50 respectively. The dependences of intermediate frequency output on the local oscillator power and dc bias were carefully studied.     

Influence of the Structure Parameters on the Characteristics of Dynamic Mixer with Striped Channels

The influence of the structure parameters on the characteristics of dynamic mixer with striped channels is studied. As results indicate that, given the proper structure parameters, the output of the extruder can be increased with low energy consumption and stable temperature. Furthermore, the mixing effect will be improved up to or even above that of spherical cavity mixer.