板柱与梁板结构受力性能对比研究

以某工程为算例,分别选取合理板柱与梁板结构计算模型,按照相关规范进行大型广场在平时工况与战时工况顶板各构件承载力计算,并对其两种结构型式的受力性能分析对比,以总结出地下人防结构顶板的适用原则,为实际工程设计提供参考依据。     

带约束拉杆L形方钢管混凝土组合异形柱的受力研究

为研究对拉约束拉杆对组合柱性能的影响,针对L形组合异形柱设置不同类型的约束拉杆、不同强度材料等进行数值模拟,对比该类型下的相应试验结果,分析验证了对拉约束拉杆对L形组合异形柱的性能改善作用,得到了对拉约束在柱延性及承载力方面的积极影响效果。最后基于线性回归分析的理论计算方法表现出了和数值结果较高的一致性,建立了具有较高参考价值的带约束拉杆的组合异形柱承载力计算公式。     

气相色谱法测定3-氯-1-丙醇

以填充柱气相色谱对 3 氯 1 丙醇进行了分析研究 ,方法变异系数 0 .5 % ,回收率99.5 0 %～ 10 0 .6 7%     

Vapour- and liquid-side volumetric mass transfer coefficients measured in distillation column. Comparison with data calculated from absorption correlations

Volumetric mass transfer coefficients in liquid and vapour phases in distillation column were measured by the method consisting of a fitting of the concentration profile of liquid phase along the column obtained by the integration of a differential model to the experimental one. The mathematical model of distillation process includes mass and energy balances and the heat and mass transfer equations. The film model flux expressions with the convective transport contributions have been considered in the transfer equations. Vapour and liquid phases are supposed to be at their saturated temperatures along the column. Effect of changes of phase flows and physical properties of phases on the mass transfer coefficients along the column and non-ideal thermodynamic behaviour of the liquid phase have been taken into account. The concentration profiles of liquid phase are measured in the binary distillation of the ethanol-water and methanol-ethanol systems at total reflux on metal Pall Rings and Intalox saddles 25 mm in the column with diameter of 150 mm. The distillation mass transfer coefficients obtained by the fitting procedure are compared with those calculated from absorption data using Onda's, Billet's and Linek's correlations. The distillation heat transfer coefficients calculated from the model assuming saturated temperatures in both phases are compared with those calculated from the Chilton-Colburn and penetration model analogy between mass and heat transfer. The results have confirmed an agreement neither between distillation and from absorption correlations calculated mass transfer coefficients nor between analogy and from enthalpy balance calculated heat transfer coefficients. Also the concentration profiles obtained by the integration of the differential model of the distillation column using the coefficients from absorption correlation have differed from the experimental profiles considerably.     

新型螺旋式浓硝酸漂白塔及其应用

针对传统的帽罩式浓硝酸漂白塔存在的缺点和不足，找出原因并予以改进，开发研制出螺旋式浓硝酸漂白塔，改进了工艺状况，减少了维修工作量，达到了节能降耗的目的，确保了直接法浓硝酸装置的长周期运行。     

Flow regime, hydrodynamics, floc size distribution and sludge properties in activated sludge bubble column, air-lift and aerated stirred reactors

This paper presents a comparative study how reactor configuration, sludge loading and air flowrate affect flow regimes, hydrodynamics, floc size distribution and sludge solids-liquid separation properties. Three reactor configurations were studied in bench scale activated sludge bubble column reactor (BCR), air-lift reactor (ALR) and aerated stirred reactor (ASR). The ASR demonstrated the highest capacity of gas holdup and resistance, and homogeneity in flow regimes and shearing forces, resulting in producing large numbers of small and compact flocs. The fluid dynamics in the ALR created regularly directed recirculation forces to enhance the gas holdup and sludge flocculation. The BCR distributed a high turbulent flow regime and non-homogeneity in gas holdup and mixing, and generated large numbers of larger and looser flocs. The sludge size distributions, compressibility and settleability were significantly influenced by the reactor configurations associated with the flow regimes and hydrodynamics.     

影响丁二烯抽提装置第二萃取塔运行周期的因素探讨及优化

DMF法丁二烯抽提装置第二萃取塔的结焦堵挂问题一直是制约装置长周期运行的主要因素，胶状聚合物的生成、焦油状物质的析出等都会造成第二萃取塔堵挂，影响装置的长周期稳定运行，本文从生产实际出发，对导致第二萃取塔堵挂的因素进行剖析，并提出相应的解决措施。     

Transport of Gellan Gum Microbeads in Soil Columns of Various Grain Size Distributions

The transport of gellan gum microbeads as potential cell carriers was investigated in horizontal columns packed with different grain size classes of gravel (2–16 mm) and sand (0.25–2 mm). A suspension of microbeads was pulsed into each column for 6 h, followed by injection of water for 42 h. In general, the total amount of microbeads travelling across a given section of the column increased with injection time but decreased towards the column outlet, varying as a direct function of grain size. The results of this study demonstrate the feasibility of the transport of gellan gum microbeads through medium sand to medium gravel across distances up to 110 cm.     

影响蜂窝状钢骨混凝土L形柱性能的参数分析

针对钢骨混凝土L形柱,提出了一种新型的钢骨形式.为了掌握该构件的受力特性,通过ANSYS软件,对腹板开洞率、配钢率、加载角、偏心距等影响因素进行理论分析.结果表明,在相对偏心距较大的情况下构件承载力会急剧下降,而且存在不利荷载角的问题;腹板开洞能有效地减少钢骨与混凝土之间的滑移,但对承载力的削弱有限,并就该构件的最佳配钢率提出建议.     

Modelling Gas Holdup in Flotation Column Froths

A one‐dimensional steady‐state model is developed for the prediction of axial variation of the gas holdup in flotation column froths. Froth is considered as an inverse fluidized bed of bubbles and hence the frictional pressure gradient is obtained based on the energy balance. Pressure gradient can also be obtained from the Ergun equation with adjustable constants. The model correctly captures the effect of superficial gas velocity, superficial liquid velocity and bubble diameter on the variation of the gas holdup along the froth height. The predictions of the model are in agreement with the experimental data from the literature.