由火灾角度探讨超瘦高中庭的界定

对世界范围内中庭的分类方法进行汇总,对14栋超高层建筑内的中庭进行特征调研,基于得到的几何特征分布,尝试从火灾烟气发展规律角度探讨如何界定超瘦高中庭。以最不利条件下(即中庭地面中心火源)发生烟气羽流触壁为判别超瘦高中庭的条件,得到超瘦高中庭的判定依据以及呈现明显受约束流动特征的条件。对超瘦高中庭的明确界定,有助于区别于其他类型中庭以及进一步针有对性的开展该类中庭内火灾烟气蔓延、火灾探测、烟气控制等相关研究。

Key factor analysis and model establishment of variation of rock face temperature in a deep open-pit mine

In recent years, with the increase of the depth of open-pit mining, the pollution level has been on the rise due to harmful gases and dust occurring in the process of mining. In order to accelerate the diffusion of these air pollutants, the distributed regularity of the rock face temperature which is directly related to the air ventilation in deep open-pit mines should be studied. Here, we establish the key factors influencing the rock face temperature in a deep open-pit mine. We also present an empirical model of the rock face temperature variation in the deep open-pit mine, of which the performance is interestingly high compared with that of the field test. This study lays a foundation to study the ventilation thermodynamic theory in the deep open-pit mine, which is of great importance for theoretical studies and engineering applications of solving air pollution problem in deep open-pit mines.

电石渣-煤基固废混合胶凝体系制硅酸钙板的试验

为减少制备硅酸钙板对矿物原浆资源的损耗和提高对固体废弃物的协同利用效果,试验以电石渣-煤基固废胶凝体系为原料来研制高强度的纯固废硅酸钙板,并通过热重-差示扫描量热法、X射线衍射测试来分析硅酸钙板中生成的主要矿物成分及不同配比对硅酸钙板的强度变化关系.研究表明:在水灰比为0. 3的条件下,使用电石渣完全替代水泥,将粉煤灰和硅灰按1∶1的质量比互掺调制所得的混合胶凝体系最终制得托贝莫来石型纯固废硅酸钙样板.在硅灰占原料的质量分数为0~10%范围内,样板抗折强度随硅灰添量增加而升高,硅灰添量为10%时样板达到最大抗折强度,不同粒径的原料颗粒相互填充,板内晶体与水化胶凝体相互咬合,最终使得样板力学性能得到大幅提升;样板的抗折强度随着Na OH添量的增加呈现先增后降的趋势,Na OH添加质量分数为4%时样板板面平滑,强度达到最大值11. 8 MPa,该添量为Na OH的最佳添量,通过扫描电镜分析发现加入4%Na OH时对该胶凝体系的水化反应起到最佳激发作用,且样板料坯的微观结构对其最终的力学性能有重要影响,但不起决定性作用,其中决定其最终强度的是板坯内水化胶凝体的数量、形态以及其相互间的联结方式.